grantf

Arrg! Hey, my car is getting there.

the problem now is any scratch or blemish will be a drag. Nice car, You have done great body work. the bumpers look nice, I hope they don't need use (if you know what I mean).

I think I may purchase a cheap electronic scale. My identical twin brother is using one that works great for mixing epoxy hardener for his "flying Z" http://flyingbackward.blogspot.com/

Wow! now I know what my engine bay should look like.

Fastwoman, My car is registered as a 78, but another Z owner at a meet up here in Seattle looked at my engine and vin number. He suggested that my car was actually an early 77. He was correct. My car is indeed a 77. The shut off arm and wiper are linked so if I adjust it back to the correct setting I should have fixed two problems. I would like to do a complete recalibration of the AFM but I am a little confused regarding the pop can method. Looking at the Atlantic z article I can see how to do it but I am unsure how much weight/water should be used. Are his weights posted the ones I use or just what he found he needed. Can you clarify?

HA!!! I found something new. Thanks to fastwoman for making me to revisit the AFM. Remember my earlier post when I wrote how my fuel pump always ran? now I know why! Someone has mucked with the AFM in the past for sure. look at these pics the old one I posted and the one from the Atlantic Z site. notice how the wiper contact is about 8 mm from 0 volts when the meter is completely closed, and how the shut off switch is not even touching, and where it should be. I did a quick test by gently moving the fuel shut off and it works! I am down to about a half tank now and I think I am getting about 15 mpg. after I am on empty again I will calculate My mpg then make an adjustment to the afm. I really think I have found the two major culprits but still need to get my vacuum up, Stay tuned

Buy a 240z and put you're zx engine in it. It would be easer.

I believe I have my TPS adjusted properly now. Before the left contact was always closed. Now the right contacts when the engine is in idle and open at about 1200 rpm the right only when the throttle is wide open (punch it). I believe that this was the root of my problem. I am a little aprehensive of adjusting the AFM, I have read the atlantic Z article, perhaps this weekend I will carfully try to adjust it. Also a good time to revisit the yogurt. At work I use mapp gas not propane is this suitable for testing or to "volatile". When I filled up last I drove home, pulled my plugs and cleaned them so as to see how I am doing after the 10 gall. Thanks again both, for pointing me in the right direction. I wonder if the PO was trying to "hot rod" the engine now, 15 deg advance, tampered AFM and full trottle bent in on the TPS.

Arrrg! this is my own fault for posting the above so quickly. No I do not think I "shocked" any metal, nor cracked or re tempered, or stressed anything. Also I have not forced any bolts hard enough to snap anything, my "snugging" down bolts was by hand only using a box end wrench, little force if any. I would prefer advice on increasing manifold vacuum and leaning out the mixture on efi systems. Really! what would happen if I was driving on a hot day for 3 hours and then hit a mud puddle? Really now! come on!

Cool car. Where are the running lights? and what's up with the fuel filler?

update: So far I have rectified the sensor plugs being swapped, I am surprised my car ran at all. Adjusted the TPS, I am sure this contributed to my problem. Replaced the vacuum lines that were in doubt, I still only have between 15 and 16 in HG though it is quite the improvement over what I had before, also tightened down the valve cover bolts, they were really loose and tightened the PCV hose, I could turn it with my fingers before. Adjusted the timing to 10 deg at 800 rpm and tested the vacuum advance it advanced about 5 deg with vacuum applied using a mighty-vac, though "I had to keep pumping it to maintain vacuum, does this mean the dash-pot thingy is leaking? also I noted that after getting the water temp sensor to operate correctly my engine ran rough until it warmed up, this makes some sense though if it is enriching the mixture on an engine that already is running to rich. the ohm reading for the temp sensor makes sense now and seems to coincide with the chart pretty closely. I have been checking it hot (I believe around 180 deg to cold, around 75 deg and it seems about right. another thing I did was back out the idle mixture screw about 8 turns, it was about 6 turns out from bottom and the engine idles really well now. so next my car was on empty so I wrote down my mileage and put 10 gall in. When I am on empty again I will post my results. I am hopeful but a little pessimistic. Also I did do the yogurt cup test, It was inconclusive, I now understand how it can help diagnose a vacuum leak but in my case I could not pinpoint where it could be coming from other than the manifold gasket itself, I understand that this could be an unfortunate reality, but as my car is running good I will put this idea in my brain's closet for now. I have read up on Fastwoman's thread along with Cozeye's problem and mine seems to be coming from the opposite direction, though I now understand why you put the resistor in line from the WTS. I think I need an anti resistor!! anyhow time will tell (or ten gallons).

update:

The block. So this would be the intake and exhaust gasket. I actually tightened the rear most nut. surprisingly I got about a 16th of a turn out of it. Normally I would expect the nut to not budge at all being a rusty exhaust bolt. My vacuum is back to near 15 in Hg. So I am thinking that my vacuum being low may be due to the an intake/exhaust manifold leak. I believe that nothing detrimental occurred from my engine cleaning and that this may not be a new symptom. May I ask the forum administrator to revert this thread to my timing and mpg thread, My apologies

If you have been reading my timing and mpg thread you will get more info. I think I found the culprit being the TPS. My car was running good today up until I decided to clean some crud from the engine using simple green. The engine was still hot when I sprayed lightly on all sides of the engine block then I rinsed it with water out of a squirt bottle being careful not to wet the electrical components. the car sat for about 2 hours and then after starting up it ran like crap. I hooked up the mighty vac to test for vacuum and got about 10 hg :tapemouth I was getting near 16 before. after revving the engine I saw what looked like exhaust coming from the rear end of the manifold gasket. It looks like I need a new one. I have never replaced this gasket before and it looks like a TON of work to replace. Any advice please

Oh my, That car is going to be a thing of beauty. Already is really.

No prob

http://www.xenons30.com/reference.html

Ok sorry about so many posts. I revisited the tps and readjusted it. it looks as if the left contact was almost always closed. I noticed this by unplugging it and the engine ran better, also the vacuum jumped back up to about 15 hg. again I played with the AFM wheel and this time only a slight improvement but moving it cw by about 2 deg. (my vacuum climbed to near 16). I believe that my previous AFM test was compensating for the TPS not being set properly. So I have found two potential culprits, but I don't think I am out of the woods yet. yogurt cup test later today for shure (my girlfriend saved a cup for me).

Regarding the AFM: since swapping the sensor conections my vacuum has dropped back to 14 in HG, though I suspect it is due to a vacuum leak somewere. While the engine is idling if I jently move the wheel on the AFM clockwise I get better vacuum, around 16 in Hg the engine idle increases and sounds better . CCW and the engine sputters. I would say CW about 5 to 8 degrees at most before the engine starts to degrade. Here are some better pictures of my AFM guts. It almost looks like it has been set way on the rich side. Am I wrong?

Ok I drove around a little and warmed up the car (mostly I needed coffee). guessing that the water temp is around 160, tested resistance and got .26 k .So though this is not accurate as far as temp and it seems a little low this is closer than the .05 ish I was getting before. Regarding the tps: at idle both contacts are closed I adjusted it to open between center and right contact between 1300 and 1400 rpm, it was staying closed till about 1600. not much of an adjustment at all. one thing is that the left contact always seems to stay closed is this normal? no adjustment seems to effect the right contact. I verified these settings with a meter.

Ok I am trying not to run in circles, but I think I noticed something strange: It appears that perhaps the connectors for the thermotime switch and the temp sensors have been swapped. I checked for continuity between the connector that is plugged into the cold start valve and the temp sensor and I got continuity on each pin respectfully! I need to look again but this strange. Also I checked the continuity between one pin on the connector that was plugged into the termotime switch and got continuity to pin 13!

new wires, cap and rotor day before this thread was started, new plugs (and I gapped them) same day I posted the photo of them in thread. it's getting late. Also I am pretty sure I have a ZX dizzy (new cap for a 77 280 did not fit, new 79 cap was identicle to my old one. I have not really played with the TPS yet. Will do some reading on it tonight and look tomorrow morning. I am trying not to through parts at the problem for two reasons, 1: it is expensive and 2: I am really learning a lot about the efi system and my engine in general tracking this down systematically has lead me to make minor repairs along the way that I normally would not even look at for example the PCV hose I found out yesterday was so loose I could slip it off with my fingers on the crank case end (tightened up now).

here are some pics the soot is mostly around the tailpipe... and that is a brand new bumper installed after I was rear ended, washed 3 times

I really doubt that the injectors have ever been replaced. And my mileage really sucks, how accurate my odometer is? I do not know for certain but I am pretty sure it is close to accurate. I put 5 gall in yesterday and after a little driving around today I am on empty. about my tail pipe, it is coated in black sh!t. I can even see residue forming on the bumper and rear valance (pics soon). The funny thing is the car runs pretty good, no backfiring steady idle and pretty good power, no knocking. With the windows down I get the common exhaust fumes but they smell of gas.

Nice hot day (around 70 deg here in Seattle). Drove my car home, dash temp gauge is right in the middle, so about 180 deg (if that is accurate at all). measured between 13 and ground and got .045 k, this is with my meter set to the 2k range. double checked it with my other meter (a greenlee) it read 046. air temp measures .99, I understand that they should not be the same I am just testing both. Also I pulled the cold start injector, plugged to hole and ran the engine for about 1 min no gas came out. For shits and giggles I connected a 9 volt battery to the injector and gas squirted out. I am ruling out the cold start injector. Good to know though.