mbz

OK here are the photos of the new spark plugs. I have to get to work, so please review photos and let me know your questions and/or comments, I will review & respond later this evening. THANK YOU ALL! I APPRECIATE THE HELP & INPUT VERY MUCH! ? (ps: MadKaw - I did a quick visual inspection of the outside of the distributor cap and saw no cracks, will do a more thorough inspection when time allows).

Thank you ZH!

Well if you call a car that starts, idles roughly, then dies, and will not start again drive-able... then yes it is drive-able. I wouldn't take this car out on the street because it will die, not start and then I'd have to try and push it up the hill of my driveway back into the garage. In my book, that is not drive-able.... and therefore not running. (meaning NOT SUITABLE FOR ROAD DRIVING). Never asked for, nor expected a 'miracle cure'. I do expect to have to run through the FI system diagnostics. Thanks for your input ZedHed, I'll take it into consideration and let you know when I got it all sorted out!

The lean mixture notes concern me as well.... I reviewed the recent (10 years) worth of service records and those notes were on the last bit of work performed before smog and sale to me. Sounds a bit suspect. Best to get this sorted out now. I understand that a properly maintained FI system is pretty much bulletproof, so I'd rather get this straightened out first.

It may very well be the original coil.... the car is very very stock and original. One family, 2 owners (passed from father to son). I'll get a look at it this weekend or sooner and let you know what I find.

DaveWM, I am picking up a stethoscope this week, will check injectors this weekend. The rough idle makes me think of a cylinder misfire, possibly injector related. I really think you are onto something with the air / fuel mixture being incorrect and a problem with the idle adjust / throttle not functioning properly. Suspect the engine is getting too much fuel and flooding, hence why it will not start after it dies. Will check distributor and quality of spark as well to be sure. I did gas up once at the local Costco after purchasing it, still have 2/3 of a tank left. I usually get good gas from Costco and never had trouble in any of my cars with their gas. The electric connectors and wires look very old and brittle as do some of the hoses. I am trying to be very very very careful when working in the engine so as not to cause any new problems. Hoses I will replace as I find cracks and splits. I Completely agree with this and suspect that the core of the problem lies somewhere in here, but need to do some more diagnosis first. Thank you for the great advice! Much appreciated.

Zed, I'm trying to keep it simple. I never said it was a shady smog guy (please don't put words in my mouth, I'm not accusing anyone of illegal activity or intentional wrong doing). To clarify my statement, I suspect that the mechanic knows another mechanic in the same area that has a smog testing machine, that would smog it for him until he gets the proper readings so that it could be taken to a DMV facility for smog check pass. The car has not been running much at all for 2.5 months, I drove it a whopping total of 4 times....... mostly neighborhood drives less than 10-15 miles aside from the 75 miles drive home after initially purchasing it. I have not had a chance to beat on it, I would like to really drive it.... BUT IT'S NOT RUNNING! The oil levels are fine, coolant levels are fine, brake fluid fine. The only things I have done to the car was listed above. Here it is AGAIN for convenience: Replaced air filter, fuel filter, 6 spark plugs, a gashed fuel line and a dried up split and cracked air hose. Is there something I'm missing besides showing the condition of the new spark plugs? I don't want to over-react to this, I just want to diagnose and fix the problem so I can get on with the suspension work that is waiting for me next. Again here is my diagnostic game plan so far for my next opportunity to work on the car: Check distributor cap for cracks and moisture, as well as checking spark color for blue spark. Remove oil filler cap when engine is idling to determine if engine is running rich or lean. Check fuel pressure. Check injectors, make sure all are working. Check Water Temperature Sensor. Check Fuel Pressure Regulator. Check Cold Start Valve. Check boot from AFM to Throttle Body for cracks. Will probably also inspect the throttle body while the boot is off.... anything I should be looking for? This all seems pretty simple and straight forward but you know more than me.......so any thoughts on this? Your help and input is appreciated. Thank you.

Zed, I showed the old spark plugs because the old spark plugs tell what the conditions have been present in the engine in the past. My bad.... I thought it was obvious they were the old ones because of how worn out they are. I can pull the new ones later tonight, take some pics and upload for review. Regarding work done so far, I have not gone crazy. I did some basic routine maintenance as a preliminary trouble shoot. I don't think replacing an air filter, a fuel filter, 6 spark plugs, a gashed fuel line and a dried up split and cracked air hose constitutes going crazy, nor creating an EFI nightmare. I can assure you, I am not looking for any more trouble than I already have. I'm pretty upset that a car I just bought (that is supposed to be in good running condition) is not idling well and dies and won't start. ? I am turning to this group for help (because of the size and combined knowledge of this group) in an effort to quickly and efficiently trouble shoot the matter.... without creating an EFI nightmare. However the possibility that an EFI nightmare was already there and waiting to happen is very real, although one I would like to avoid if possible. If unavoidable, then I'll just have to deal with it because the car needs to be able to pass smog every 2 years until California changes the law (not gonna happen). Regarding PO's mechanic getting it to pass smog, I suspect it was just a matter of tweaking it until a fellow mechanic's smog machine said it was good to go, then running it past the DMV. Doing just the bare minimum to make it pass for registration and sale. Dump the problem on someone else and be done with it. It's not a pleasant thought, but it happens. If you believe that something broke recently, do you have any suggestions on what it may be so I can take a look at it? ? I posed 3 videos with audio above showing what is happening..... no comments on that so far, has anyone taken a look and listen to the videos? I posted them to provide a better representation of what the problem is in the hopes that someone who knows better than me (probably most people on this forum) can see it/hear it and say "Oh it sounds like it might be _____________", check the "_________________" first, then check the "________________". I know it's not usually that simple, but then again, sometimes it really is that simple. DaveWM brought up a really good point above about the idle adjuster not having any affect: "Still don't like the idle adj screw not having any effect. There is something wrong there, ...... If its not working I would suspect a mechanical problem with the throttle not allowing the valve to completely close, thereby rendering the idle air bleed useless...." So far I've gotten pretty sound advice from this group and I think my plan for the next round of diagnostics is pretty solid.... again, not going crazy and creating an EFI nightmare, so I don't think it's time to go into panic bros. mode just yet. ? I have downloaded and am reading both the factory service manual and the fuel injection service manual (or the FI bible). I also have a Haynes manual (not very helpful as it pertains mostly to 240's and 260's, but does have some updated FI info in the back supplemental section, however that info is also in the FI bible). Is there something I'm missing besides showing the condition of the new spark plugs? I don't want to over-react to this, I just want to diagnose and fix the problem so I can get on with the suspension work that is waiting for me next. Again here is my diagnostic game plan so far for my next opportunity to work on the car: Check distributor cap for cracks and moisture, as well as checking spark color for blue spark. Remove oil filler cap when engine is idling to determine if engine is running rich or lean. Check fuel pressure. Check injectors, make sure all are working. Check Water Temperature Sensor. Check Fuel Pressure Regulator. Check Cold Start Valve. Check boot from AFM to Throttle Body for cracks. Will probably also inspect the throttle body while the boot is off.... anything I should be looking for? This all seems pretty simple and straight forward but you know more than me.......so any thoughts on this? Your help and input is appreciated. Thank you.

BR6ES I’ll replace them again soon enough and didn’t want to get spendy with the spark plugs until I have the issue sorted out. Sent from my iPhone using Classic Zcar Club mobile

DaveWM, yes the large phillips head screw running through the spring that sits on top of the throttle. jonbill, the old plugs were Bosch, the new plugs are NGK.

Zed, those in the photos are the old spark plugs I removed. They were installed by PO's mechanic. I did not use never-seize when installing new plugs today. Also in the service notes from PO's mechanic, he adjusted the mixture a bit leaner to pass smog. In addition to re-sealing injectors, notes state all mount holders and fuel hoses replaced. Upon inspection that appears to be the case. PO's mechanic resealed thermostat upper housing. So I'm thinking I should do this for next weekend's trouble shooting: Check distributor cap for cracks and moisture, as well as checking spark color for blue spark. Remove oil filler cap when engine is idling to determine if engine is running rich or lean. Check fuel pressure. Check injectors, make sure all are working. Check Water Temperature Sensor. Check Fuel Pressure Regulator. Check Cold Start Valve. Check boot from AFM to Throttle Body for cracks. Is that about right? If so, I'll start reading up on the procedures and getting tools / parts in order for next round of testing.

DaveWM, solid thinking. I'm right there with you on that. Testing fuel pressure and listening to injectors next weekend. Service records indicate fuel hoses and fuel injector seal kit were last work performed in July of 2018, about 150-200 miles ago.

Madkaw, thanks for the advice. At this point, my weekend time to trouble shoot car is done, but I am trying to narrow down what I should look at next weekend. I agree on the battery, but I want to get stable start and idle sorted first. Yes I have EFI manual (thank you calssiczcars) and have been reading it. Doing the routine maintenance stuff seemed like the first logical step and it needed to be done anyway (fuel filter, air filter, spark plugs, and found a fuel hose and air hose the needed to be replaced while I was poking around). I'm leaning towards checking fuel pressure / fuel pump as the next step in trouble shooting and I guess I'm looking for guidance/agreement from the group before committing to that as next weekend's project. If that checks out, then air intake/throttle system seems like the next logical step. Am I on the right track or missing the point completely? The one thought that is nagging me is that the rough idle makes me think there's a misfire, but.....?

Zed & site, diagnosis help much appreciated! Exhaust does not smell like coolant, it smells like gas. Head gasket is clean, no leaks. Last replaced in February of 2010. About 11k miles since head gasket replaced. Car has not overheated since I have owned it. I have driven it about 125 miles. First drive was an extended drive (75 miles) in Friday rush hour freeway traffic. No overheating. Yes car has catalytic converter, was last replaced in March of 2014. About 7K miles on new Cat. Battery is 10 years old. About 15K miles on current battery. Charge seems OK. When it was towed home 2 weeks ago upon initial onset of trouble, AAA tested battery and alternator. Results are Battery Test: 669 CCA, it is rated for 675 CCA, temeprature was 60° F, voltage was 12.36V. Starter test: Cranking normal. Voltage 11.97V, Time 10mS. Charging system Test: No Voltage. No Load: 12.72V. Loaded: 12.69V I have video!!!! Tapped on the ECU as suggested then started the car.... it idled this time for several minutes. Idle is rough, however this is the longest it has idled (about 3-4 minutes). It ran longer than the video shows (see video 1). Opened throttle, then let go back to idle and car dies (see video 2). Try to start engine again and it won't start. (see video 3). See old spark plugs in attached photos. They all look the same. Black, not wet, a bit worn out. video_1.MOV video_2.MOV video_3.MOV

Yes, fuel line seem stiff, but I'm planning on testing fuel pressure next weekend to be sure. That was next on my list of things to check.... the fuel pump. But it stands to reason that fuel pump is working fine if engine fires up and runs for a few minutes while foot is on gas pedal.... no? Also, see photo above regarding 2 white wires found unattached behind the ECU kick panel. Any thoughts on what they are and if they should be attached to something??

The smoke smells like car exhaust. Not gassy, not oily. Just like a large amount of exhaust. Yes I pulled the old ones and replaced. Same problem persists with new spark plugs, it just fired up faster. High RPM is between 2000-3000 Hmmm, tap on the ECU? Really? Can I ask why before I do it? ---------------- a few minutes later ------------------ OK so I just took the kick panel off the ECU so I could tap on it and I found these 2 white wires just hanging there. (see photo) Any idea what these are for and if they are supposed to be connected to something (or each other)?

SORRY - I THOUGHT I WAS LOGGED IN AND POSTED THIS AS A GUEST. ADMIN PLEASE DELETE THE GUEST POST AND USE THIS ONE. Need some help on what to do next, here's the story so far. 1976 280z California edition (manf. date Sept.1975). Bought the car in late Jan. 2019, car passed emissions test and it started and drove fine until 2 weeks ago when problem first occurred. Engine runs very rough for about 1-3 minutes at high RPM when gas pedal is pressed, and exhaust kicks out white-ish / light gray fumes. When gas pedal is released, engine dies, car will not idle. Try to start again and engine cranks but will not start. Let it sit for 1-2 hours and it will start again, same as above. Makes me think it is flooded with gas and needs to sit before it will start again, but not sure. Reviewed service records and saw that several basic maintenance has not been performed for a long time (anywhere from 2 years - fuel filter, to 8 years - spark plugs & air filter). Here's what I have done so far: Replace fuel filter. Replace air filter. Replace spark plugs. Replaced fuel hose from tank to fuel pump (found it had a couple of gashes, but not dripping gas.... figured it should be replaced). Replaced air regulator hose (appeared to be original equipment that was dried and appeared to have fresh crack in it). Adjusted idle screw (tried 2 turns counter clockwise, no affect. tried 2 turns clockwise, no affect. set it back to original position.) Did visual inspection of air and fuel hoses. Tightened up all connections. Inspected carbon canister, replaced under filter. Anything I am overlooking? Anything I left out in the problem description? Any advice on what to test next?

Well it does not look like it can be taken apart without cutting it open..... I do not want to try this until I have a spare canister on hand.

I found this video on the intrawebs that shows a screwbottom canister for MGBs..... A threaded screw on / off cap on the bottom would sure make it much easier to refresh the carbon. I'll be swapping out the fuel & air filter and spark plugs this weekend, will take a look at the canister too while I'm at it and see what I can figure out. grannyknot: yes I agree, not comfortable taking it apart unless I have an extra replacement on hand in case I mess it up. Found another video where a guy completely trashed his canister. And yes, granulated carbon for aquariums is pretty cheap on ebay. zKars: yes, please let me know what you find and if you need a referral for carbon I can look something up.

I know this is an old thread, but I just came across it last night and had some thoughts on it.... Has anyone opened the carbon canister and refurbished it? Meaning; clean the diaphragm/spring assembly, open the carbon cannister, dump the old carbon, replace with new, fresh, rinsed, activated granulated carbon, replace the filter pad on the bottom and re-seal the whole thing. Does the canister unscrew? Or is it sealed shut? Any advice or comments are appreciated (mostly).

No worries! Thank you! Sent from my iPhone using Classic Zcar Club mobile

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