I have seen a lot of people getting advice just based on pics of their spark plugs so I thought I'd give it a try.

Before changing anything the car would start, sputter, and die. As I would let out the clutch and give it gas it would not move at all, just rev up and then die. The interior lights would also dim while this was happening. There was a lot of backfiring.

Today I changed the plugs,wires, and air filter. I had advance auto check the battery and it was no good so I replaced that also. I also put in about 8 gallons of fresh gas since the car has been sitting some.

Now the car starts right up but still runs rough. I was able to drive it up the driveway and into my garage which was my main goal for the day so I'm happy about that at least. It did die once but started right back up. I can leave it in nuetral and let it idle and it runs without stalling, but sounds like it is on the edge. Lots of smoke coming out the muffler.

The old plugs are covered in black. They all seem pretty consistant. I have no idea how old these plugs were but they are at least 4 years old. I'm not sure if it is carbon or oil deposits. Baseon on some pictures and descriptions I have seen online I hope it is just carbon but with my luck its probably oil.

Please take a look at the following pics and let me know if you can tell anything. The plugs are in order 1-6 going form left to right.

 

its just carbon, dont worry, the car prolly just needs a good run and get all the old gas out of the system, also check the alternator out put and belt condition, cause a new battery is no good without a good charge. also do a bigger tune up, fuel filter, cap, rotor, oil change, and check all hoses, such as the vaccum ones, also check and clean all electrical connectors cause its such a common overlooked problem. also adjust the timing. and is it fuel injected or carburated

 

I've got a rotor, cap, fuel filter, and oil filter in my garage, waiting for it to cool off outside a little more before doing some more work. I'll get those knocked out and then I'll start tackling some of those other items.

Its fuel injected.

The tach doesn't work. Its stuck on about 2500 even when the car is shut off. Never budges.

 

Looks to be on the rich side if you ask me. That or those plugs are awefully old.

 

hmmm having the tach not move may be a problem too, the negative is what controls the tach, could just be a loose wire or fubared tach itself, might affect what the computer gets for info for the fi

 

Car won't start again. It ran fine for a while so I thought I'd take it down to the end of the court and back. Made it about 3/4 of the way back and it died. Wouldn't start again. I let it sit about 20 minutes and it started again and I got it back home. It died as soon as I got it in the garage and wouldn't start again. I tried to restart it and stopped when I saw a little smoke come out of the right hood vent. Not a good sign there. There was a slight burning electrical smell when I opened the hood. It seemed to be coming from around the starter.

There is a shop down the road that works on Z's so I think I'm going to let them take a look at the engine. I can handle the basics but I think I need some help with this one.

 

Sounds like you're running extremely rich and fouled the plugs. Take a propane torch and clean the plugs off. Check your start and make sure you haven't fried anything (spray a little carb/electrical cleaner in the drain hole of the starter). Now start attempting to find you problem. Here's some helpful pointers. Look at the EFI bible specifically for tests.

 

yup the sooty black deposit is from running rich.

The soot eventually builds up and stops the plugs from sparking at the gap and then your car won't even start.

Running with carboned plugs is typically akin to riding on the verge of a stall

The first job for you is to find why all cylinders are rich.

Here are the common causes:

Coolant or Head Temp Sensor is not geting read correctly by the ECU. Corroded or loose wires between the two are the usual suspects. Check the bullet connections ~ 1' back from the sensor.


Clogged return fuel line causes fuel pressure to skyrocket and then injectors spray too much fuel on each pulse.


Faulty FPR causes too much fuel pressure.


AFM could be set incorrectly

Read this page http://www.atlanticz.ca/zclub/techti...ich/index.html

 

Thanks for all the help. I won't be able to do anything with it until this weekend but I have a lot of things to check now.

 

Nice white Z

Mine is also a 77 and I had similar problems. I can walk you through your problems so feel free to email me at philip@atlanticz.ca

I can even call you if you need extra support (we have a great long distance package so it is pretty much a free call for me). You should be able to tune that puppy pretty fast.

Good luck!

 

Thanks a lot. I'm sure you will be hearing from me soon.