argniest

There is a metal sliding portion inside the dashpot that still moves in and out when I pushed it up, then it just came back down on its own. Although it seems to be positioned so it doesnt effect the throttle/linkage at all. Im hopefully going to see a mechanic friend of mine this weekend. He was one of the people who was talking about something like the dashpot, although he called it something else. So we will take a look at it, and find out if its really working or not. he knows about them, and what to do. He was describing something that helps keep the throttle from slamming shut, I think. Or maybe to hold it open....ahhh heck I cant remember. The reason I am bringing it up, is even though my engine sounds good, the AFR's are looking good, no more lag/surge in higher rpm's, the drivibility is great, and my mpgs are 18 to 25 mpg from town to highway.......I have developed a backfire(at least I think that is what it is), when shifting gears. Now depending on how I shift, can make the backfire happen or not. And I am pretty sure it does it, even when the engine is just warming up but not hot I guess my friend was saying if this dashpot wasnt doing its job, it could be causing my backfire...or I could be running too lean. But I mean, I dont know if that can be possible. I am getting 13.9 to 14.3 range on the AFR's when crusing around in several gears, and even at 65/70 mph I was getting those numbers. That doesnt seem to lean to me. But maybe there is some effect when shifiting, that is causing a quick lean condition... ohhhhhhh well, its a small complaint and I hope he can help me figure it out, and maybe this dashpot is part of the problem or solution. I was told to look for leaks in exhaust system, I hooked up fog machine and didnt see anything coming out anywhere from exhaust. But I am going to stop by another friend who has a real smoke machine at his garage, and see if that shows any leaks in exhaust system. I guess the thinking is, that if I had a leaky exhaust it could be causing this popping when shifting in certain ways. It never did this until I hooked up the TVS, and if I disconnect TVS is doesnt do it, and never did it before that I ever heard. Just another mystery to solve But maybe the dashpot will fix it. We shaaaaaaaaalll see.

can you post of picture of your dashpot, especially if its from a 78 (or any z that would have simlar one to a 78). Im curious about this device, because a mechanic friend of mine was describing something like this dashpot. I didnt know until later, that what he was talking about was the dashpot ;-) And now here ya all are talking about it. I believe I know where my dashpot is at, and it actually seems in OK shape. If there is supposed to be a vacuum line connected to the white nipple, well there isnt on my z car. I have beeen told by a z mechanic to take if off and throw it away. Im not ready to give up on it yet.

Those darn water temp sensors!!! I wonder what your gas milage will be now?

I made a word document of all thing things I have done now. Its over two pages long. And that is a bullet listing in Word. I cant believe how many things I have done. It has definately made me want to dig into another car now. And do other more scary stuff. I had what I considered level 1,2,3,4,and 5 issues to work on the Z car. I am now officially past level 1,2 and 3. And into level 4. Which are issues I consider more of a PITA than safety or drivibility issues. Like my side marker lights not working, or lately one of them is working. And several other similar small electrical issues. At some point I will be taking the dash off, to replace all my lights with brighter ones, but the main reason is that my heater is not blowing very warm, and I need to remove/inspect everything that has to do with the heater system. My A/C works, just not heater. But I dont drive it in the winter, so the fact the heater was only 72degrees doesnt bother me that much. And I might put it off....so I still have a list with quite a few things on it, but at least they are minor issues, as compared to everything else. The neat thing about all of this, is I could do all this on another Z and it would be easy for me. Oh yeah I meant to mention this too, my spark plugs are all reading the same now, and according to what I know, pictures in books, and local mechanic friends, they all agree my plugs are looking fine now. That is just more proof I have it dialed in as good as I can expect it to be

That is awesome! Glad you are working on it! You wont regret it! They are so much fun! I cannot believe how many people wave at me, honk their horns, kids yelling COOL CAR MAN! Adults doing the same, perfect strangers coming up and talking to me about it, people telling me stories about their Z car in the 70's or 80's, lots of people want to race me, it just goes on and on. Talk about a head turner!!! Living in the midwest also, there were not as many Z's here I figure. And I have only seen 1 other 280 Z in 3 years now. I never expected this much attention....but it is fun! I had an aftermarket fuel pump, and my gas tank as I found out (after opening the inspection plate in the back of my 1978), I saw an inch or two deep of rust INSIDE THE GAS TANK!!!!! You might be dealing with that problem too. But my first step, I decided to remove the fuel filter, and cut it open, and omg! it was filled with rust. Thats when I figured i better just look inside the tank with flashlight. Once I saw that, I knew I needed to remove the gas tank and have it professionally cleaned and sealed up. Now it will probably be rust free inside for a few hundred years Be careful messing with gasoline! I was scared to death messing with the gas tank, was very careful. And it led to many other things being replaced, that are well documented on this forum.

Im back...for a moment in time. I have only good news and more good news since my last postings. I have increased the gas mileage from 7 to 8, to 14, to 18, and now 25 mpg on the highway going 65 to 70 mph. That was just a few days ago. The car is purring I swear!....Besides the MASSIVE intake leak that was inside the intake system and almost impossible to know about (even for people who have worked on these cars for 30 years and didnt remember this problem could actually happen, but then later remember oooooh crap thats right the inside of the EGR housing can actually be eaten away by the corrosive exhaust, causing the massive air intake leak which completely screwed up everything!!!! with the engine and sent me on a long wild goose chase, but taught me so much and I ended up replacing everything from the gas tank to the fuel injectors and everything in between. And I was a person who had never touched a car before. It has been such a pleasure getting to learn how to work on cars, and have it be a Z car) Oh well, I have been working on many little things on the car, and some other important things like the TVS switch and the AFM. My TVS switch was bad and misconfigured. I had a spare one I bought, so I was comparing the two. Well once I got it adjusted, my gas mileage got somewhat better. But all along, I had been testing it with an Innovate AFR computer exhaust sniffer. And learning and watching the AFR's. Now I know a LOT more about how all these things are linked together. And then I turned my attention to the AFM. I took the black plastic cover off, and adjusted it clockwise about 5 teeth the first time, and then two more teeth CW. And that is how it is now. And The car is driving better than ever!!! Its sounds good, it feels great, its getting 25 mpg on interstate...and I can GO FAST as I want. It gets 18 to 20 mpg in town depending on how its being driven. I could write a lot more....but I just wanted to follow up with this great news. It took me a while to learn all this stuff, and how they were all related, and make little by little changes to the idle screw, AFM bypass screw, the TVS switch and the AFM wheel/potentiometer/spring. I am very very happy about how the car drives now. I can take it up to 5500 rpms in any gear (wellllllllllllllll I havent done that in 5th gear until I get on a race track). After fixing the massive intake leak in the EGR housing, all these other things needed to be dealt with one by one. Many other things were checked/dbl checked...but those things I mentioned are what needed the adjustment. Brand new the 78 was supposed to get 28 mpg and 18 mpg in town (I am just going by the original gas mileage sticker, because I got all original paperwork with my car). So for an engine that has 187,000+ miles on it now, my performance and drivibility, and mpg, and air to fuel ratio's are telling me that my engine is about as good as its gonna get!!!!!!!!!! I am very happy with it, drive it every day, and many long trips crusing at night, even on a 300+ mile trip a few weeks ago to see an old friend. Was beautiful trip beautiful vblue sky day! Also, I meant to mention, that one of the drivibility problems was that the engine was surging/stalling in the higher rpms. At first maybe around 3500, then 4000, then 4500, etc But, as I adjusted all these things as best as I could, those drivibility problems went away. They are history now as best as I can tell. Now I can just barely step on the gas and the car wants to go!!! And when I shift into higher gears, I feel it wanting to immediately go faster. It was NEVER like that before. So yeah, dialing all those things in transformed the car. Powering up hills is no problem in 1,2, and 3rd. I love going up huge hills in second gear now. I can feel the torque of the engine pushing and pushing, and plenty more to give...... Now I want another, that is in worse shape and needs a lot of work, that is cheapo, that I can take my time and just restore it from ground up. Doesnt matter how long it takes...because I have my blue baby to drive anyway. I could have never ever done what I did, without all the kind words, and patience, and help from people here, and many others in my life as I mentioned in my posts. Thanks Z universe! I cant even believe how much I have learned. I know I got a million miles to go, but from where I was at last year, I feel like I have come a million miles to get here. And now many things seems sooooooooooooo simple to me.

In a movie called Dreamscape (one of my fav's) there was a Z car. I was watching it a few months ago, and for the first time I saw a z go driving by. I was like..wwwwwwwwwwwwwwwhatt....rewind that for a second. If you have netflix, you can stream it. Its towards the beginning of the movie after Dennis Quaid is running away from some thugs....and there the Z car goes driving right thru the middle of the movie screen. nice!

Yeah, a problem keeping it under 80 in 3rd gear, with two more gears to go. Sorry I couldnt help that. Seriously tho, when was the last time the Z did over 80? What has changed if anything, since then.

After I replaced everything from the gas tank to the fuel pump, fuel filter, all fuel lines, all fuel injectors, etc....I had to fill up my newly refurbished/cleaned/sealed gas tank for the first time. Well the engine just turned over and over and over, and I was very bummed out. A mechanic friend told me to unscrew the gas cap. As soon as I did that it STARTED immediately and I went off on my first test drive! There was something about a vacuum or pressure that was keeping the fuel from being able to flow through the system this first time. Once I did that, the car started, and has ever since....100's of times

Does anyone know a place that can make white lettered decals for the front window of the Z? I want something that says like Datsun 280Z, or maybe just 280Z with some simple flames on either side of it. I was thinking of the kind that you can just apply with water? so they would not be parmanent...

Yes, it is amazing and wonderful to feel this car the way it is supposed to be. Or at least very close. I figure I am about 80 to 90% back to original feeling of the 1978 280z car experience. Just a guess though. I arrived at this moment in what seems like an eternity, but I also was expecting a lot longer drwan out fight to unlock the mysterious problems with the car! So the fact I am up and running before middle of may was awesome! I also enjoy being a passenger, and feeling the power and accelaration from over there. I still have many little things on my list for the car, but its all very minor in comparison!!!! I am going to really learn about the AFM, since I have an extra one. And run it through all those tests, and tweaking and see where I can go with that. And I have a new TVS on the way. So that should help keep things more balanced. I just dont feel like messing with the TVS right now. I got a good list of instructions on how to test it (I am too busy to mess with it, a new one sounds a whole lot better, and in the winter I will do these tests): Here are some instructions from the Z wizard!: The best thing to do is adjust your TVS first. There are 3 pin connectors on it. The center one is the common link. If you've already installed your quick disconnect on your tvs, hopefully you saved your old connector. Put the old connector on the tvs (without the clip). If you don't have the old plug in then just touch the pin connector in the tvs. You just have to be more careful that you're only on the specific lead. The first test do with the engine NOT running. Using your ohm meter, touch the center pin connector on the TVS with one probe, and touch the rear pin connector with the other probe. There is no polarity on these tests so color isn't important. You should have zero continuity. Open the throttle linkage and you should get continuity about 2/3 to 3/4 throttle. That is the full throttle circuit. If that circuit is activated under half throttle or sooner, then send me the TVS for calibrating. I can usually fix that problem. For the next test you'll need to put a tachometer on the engine and then start the engine. The engine should be warm for the next test. Touch the center pin with one probe and touch the forward pin with the other probe. You should have continuity at idle. That continuity should break approximately 1400 rpm. Loosen the mounting screws just enough so you can lightly tap on the mounting tabs to move the switch one way or the other. Play around with it until you figure out the sweet spot for adjustment. It doesn't have to be a perfect 1400 rpm, 1375 to 1425 rpm for the switch to break connection will work just fine. The TVS is a very simple switch and it only performs 3 functions. It is an important part of the system, but it's ok to drive with it disconnected for a few weeks. The idle circuit richens the mix a little (approx 5%) and it also engages the fuel shutoff between 2800 and 3200 rpm on deccel. The full throttle circuit gives you 27% enrichment at 2/3 throttle.

I have a lot of good news!!!!!!!!!!!!!!! Basically, my tvs must be bad. I was driving after all the fixes from last week, and changing afm screw, and it was making the afr's a little better, and then i decided it was time to pull of the throttle valve swtich (tvs), it was still on my todo list. Before when i did it, the car ran worse, so i was like ok forget that for now. As soon as i unplugged tvs, immediately while sitting there idling, the afr's went right to 1 lamba or 14.7!!!!!! And so we took off driving again. The afr's were showing a lot!!!! Better after that. And my god!!!!!!!!!!!!!!!!!!!! The car was driving amazing, i almost had to clean out the drawers, it was a night and day difference (even from the other day after getting the massive air intake leak fixed) basically, before removing tvs i was showing 9.2 to 10.2 while just driving around!!!! After removing tvs, everytime i hit a stoplight, it would quickly goto around 14.3 to 14.7, and sometimes when i pulled over and just let it idle for a few minutes, in went into 15's and 16's. I recorded all the data, and have it on my pc. Have reviewed it. I went on another test drive tonight because i just had to. I was more aggresive 2night, because i was alone. Im not saying i was speeding, but i definately took off from every stop light, and was like whoooooooooooooooooa now this is what a z car is supposed to feel like! Driving without the tvs, showed between 12 and 13 afr in most cases, and then included 30 to 45 and also on the interstate at 65. Sometimes it went to 13.5 afr when just kind of putting along 25 to 30 mph. This is by far the fastest the car has even been, and this time i could rev it up to 5000 rpms and i could just tell it wanted to do it now. With ease. I know these are not ideal afr numbers yet, but my god, considering where i have been, and how this car is handling now....its a total dream come true for real. I am extremely happy with how car is driving. I was hauling ##$*$$* sometimes, and felt the g forces this time. Like i used to feel in my 300 zx. And it really went from 2000 to 5000 rpms in the lower gears, much much more at ease, and more quickly. The engine is purring, and going vrooooooom like its supposed to. A totally different sound, its much quieter at idle, and sound sweet when taking off like a bat out of hell. Now with all that said, i still believe if the afr data is correct, i am still dumping too much fuel in there, and that could be beacuse i didnt have the tvs on there at all. I dont know enough about that switch yet, but maybe someone can tell me about it, and if it would control the afr's better, if it was working. Two other pieces of great data as far as i am concerned, i am now getting 20 miles per gallon. By far the best ever, and that was with modest driving, and a few romps only. And finally when i pulled into garage i let it cool down a little, and pulled all the plugs. Well all 6 of them are the same now. That is a first!!!!!!!!!!!!!!! And i think they look pretty good. Maybe not perfect yet, but so much better, and all exactly consistent. I am so excited right now i can barely stand it. I was also told by my relative who fixed it last week, that the more i drive it, the better it should get (like cleaning out the cobwebs from it running on 3 cylinders for god knows how long) so there you go, i just had to let ya all know! What happened past 6 hours. I would have done this sooner, but it has been raining for days, and i wont get it wet. Here are two of the current plugs, and the one on the right is what they looked like after the other problems were fixed last week. Keep in mind, after the EGR housing was fixed, the car was of course driving a lot better. But now the two plugs on the left of this picture is how they all look. Its not any coincidence that the mpg's are much better, the plugs are much better, the power and torque is much better, the overall purring engine, much quieter at idle, no more blub blub blub sound, only VROOOOOOOOOOOM VROMMMMMMMMM sounds. Its amazing this day has finally arrived. Now I still believe there is 15 to 25% more power to get, if I can get those AFR's into line. Im out of brain power now...will start anew tomorrow! And I know my valves will get done very soon now too. That should help too. Thanks again for everyones help on this forum. I couldnt have done it without you!! PS The reason my innovate meter wasnt working, blush, is because I was getting -12volts on the power adapter I installed....DOIH!!!! Red wire goes in back hehe, black wire on side. I whipped out the multimeter and discovered that, because I tested it on another car and it was working fine. So then I knew I had done something wrong. Um yeah -12volts aint gonna make it work very well. Plus I also discovered I had to push the sensor plug in a little hard, but then it snapped into place. So it was really those two problems. but now its working like a dream. And I love recording the data and coming back and watching it on the PC. And I cant believe they charge 450$ for the test. Crap you can buy one for less than half of that. What a frigging ripoff!!!

I measured that (and all the other tests in the EFI bible - and they were all good in spec or very close), Well after some experimentation last night and some fun driving, I have AFM screw turned counter clock wise 1 full turn, and most of the hestiations etc in the higher rpms are mostly gone. So it sure does seem like it made a difference. I cant get the Innovate to power up in the Z car. Dont know whats up with that yet. I hooked it up to a different car and it worked just fine. The car is more powerful than ever before, and starting to feel almost like a real sports car. I got several serious adrenaline rushes last night. I wont say why or how....but I did :-) hehehe Talk about bringing a big ole smile to my face, I was actually laughing like....wow!!!! now thats why I love the car. My gosh, the car handles phenomenal powering thru turns the new bigger eagle GT tires help to really dig in too. I upgraded one size with the 15's. Still though, it feels like the engine accelaration is drifting around at higher rpm's. Like it cant lock in and just go in a smooth line. I dont know the right words to use yet, to explain what I feel. But in other cars, when you romp on it, it just pretty much goes and goes and goes, and there is no hesitation in the higher rpm's. It seems to me the z car should just, for the most part, accelarate in a constant line from 2000 to 5000 rpms, and not feel like your power is hesitating or dropping out a little, and then kind of coming back, and going out, and coming back. I am not talking about a major event, but I can feel it happening for sure. I will be glad to get my Innovate working as soon as possible. So I can get some real data. And not just go by feeling and listening. It was good to watch it working on a different car. And I confirmed the numbers with a mechanic friend, and he said those sounded normal for the other vehicle. Its just like it cant power itself up in the Z car. I am going to basically cut the plug end off, and put clamps and hook it directly to the battery, it has to work then!! THe odd thing is I did get it to work before, two times, in the Z car. but now its being a stuboorn PITA.

Yes, I believe this problem will happen to others. Poor souls. I hope they find this place! I dont know why this happens. I mean since most people dont have the problem, there had to be some reasoning behind why my Z got infected with this crazy problem. And yup, I am understanding a lot better what the Z should be like. But I believe there is more to go as you mentioned. Cars should keep accelarating when you mash the pedal down, on the interstate or in town. Not be fluttery or wavering. So the next thing will be to see how my AFR meter and AFM screw can help me dial it in. I also wonder how bad a z car will run if its (AFR's and the AFM) out of whack. I think after driving again last night I am dumping too much fuel. I couldnt get the Innovate meter to work in the Z, but I stuck it on another car and it worked fine. But then I also found I out I had to really push the sensor plug into the computer black box. So I think that is what the problem was. 2night I should be able to collect the most important data yet, on the AFR's. THen I will come back and look at it on the computer. ANd see what is going on during all the different driving conditions. I mean, considering all the things that have changed to be correct now, I am anticipating that the AFR's are going to be a lot better than before. But I believe I am running too rich. And I got too wiped out last night and didnt have time to check my spark plugs. To me, that is the #1 thing to check because I have driven like 100 miles or more on them now, in all conditions. So before I go off on my next test drive I will check them I also believe they will be looking a lot better. The engine was kinda too hot, but I pulled #4 FI connector off, and sure enough car engine slowed down, just like I was hoping it would. So I am sure this time, before engine gets too hot, I am going to pull 6 and 5 off, and just be 100% sure its effecting engine when I pull them off. Now that I got the new bosch quick disconnect FI leads on there, they dont just fall off like before I will leave no stone un-turned in my quest to bring it back as close to specs as possible. I dont care how long it takes. HOWEVER, THIS SEASON I CAN DRIVE IT NOW AND ENJOY IT!!!!!!!!!!!!! If I didnt make it any better, that would be OK. However, I know for sure it has more to do. And I got to be sure I am not running around too rich or too lean. THEN I can head off into the sunset. PS And I think that getting valves back to exact specs will probably bring back a little more normalness too. Its still near the top of my list. First though, they are not that bad, and I can drive without fear. Im telling you, I am still in shock. After the kind of excruciating effort I have gone through since last november. Its so cool, now I have a much larger base of knowledge to operate on. And yes, this car IS very easy to work on now that I have had a taste of it. I always thought it should be when just staring at the engine. But from bumper to bumper, I commend the people who designed it!!!!! Thanks again for everyones help.

GREAT NEWS!!!!!!!!!!!!!!!!!!!!!!!!!!!!! All the blood sweat and tears have come to end on this part of the project. I worked with one of the mechanics (at my cousins garage) that has worked on other stuff on my z car. The fix is done, and the car drives night and day different!!!!!!!!!!!!!!!!!!!!!!!!!!!! My wife just drove it for 2 hours and she was really enjoying it. She was patient and knew I would tell her when it was *ready* to actually enjoy. Let me tell you it was fun being over in the passenger side to. I could just listen to the engine purring like I thought it should, and feel the new found power too. It was a complete transformation. We did a lot of little stuff too, that needed to wait for this moment. BUt the main thing is the EGR tube is welded shut. An intake manifold replacement is not expensive, and whenever I feel like it, I will get it, and start tearing into the engine to replace it. It will teach me some more new things. But that aint gonna happen until I get in month and months of driving this year. Also I got my kick butt stereo done around the same time. So I popped in one of our old favorite DVD's and she didnt know it, and looked down and was like OMGGGGGGG you werent kidding. It was a kodak moment for sure. It rocks. This isnt the end of the story, but it is the end of a book in a series for sure. My cousin said engine is sounding sooooooooo much better, and it doesnt stink of course, anything like before. I just need to drive it a lot now and recheck plugs a few times. And tweak the AFM screw, because I think that needs to be done. I feel some heistation or maybe its flooding in the power band between 3000 and 5000. I mean dont get me wrong, but I feel like it has more to give and more smoothly at the higher rpms, but also we can climb up huge hills just fine while acclearting in 2nd gear. But on the interstate it seems doggy in the higher end. I am not complaining at all. I just want to make this engine run as exactly to specs are possible. Yes I will do valves pretty soon. But my 3 Z experts are telling me, its OK if I put it off a little longer anyway. I mea my god, there have been so many little problems that have added up to one BIG problem. The car ran like S*i% Oh well I could go on and on, as you know. I am going out to check the AFR's with my innovate meter, and see how they are and start the tweaking process. He figures the more I drive it, it will clean up those valves that were being assulted by the extreme amount of exhaust GOING RIGHT INTO THE ENGINE!!!! I am also going to use a little seafoam at some point, but maybe not for a month. WHAT WAS DONE ================ EGR housing fixed/remedied, Reserve light switch replaced (it was leaking because we found out the gasket on it was in bad shape) Fixed a bolt I broke off holding on the ignition coil oil change spark plugs cleaned New distributor adaptor (because of the other people working on the timing, broke the adjustment bolt off) They checked the distributor while they had it out, and reset timing They put oscilliscope on the car again-->primary and secondary ingition looked good/fine Removed the fuel pressure guage from the car, it doesnt need that anymore I hooked my vaccum lines for HVAC system again (and its still working - unbelievable) tweaked the idle and AFM bypass screw a little (backed it out a lot) Checked engine vacuum was between 16 and 17, and that was before they tweaked AFM, so I think it go even higher once I get AFM dialed in better Installed all new premium connectors on the fuel injector connectors (soldered on), they are bosch styl quick disconnect :-) New plugs, rotor and cap (Yec brand from japan, supposedly very high quality No more stinky exhaust either. Now that the engine is running fine. :-) Well this is already getting too long. I will post more later in a few weeks, I need time to test and tweak things. THANKS AGAIN FOR ALL YOUR ADVICE AND TIPS!!!