1985 SE Fuel and Spark, no start (Page 3/4)
hmmhunter JAN 27, 12:52 PM
I finally was able to do the diagnostics from the GM service manual and found all the connections are good between the ICM and ECM.

I went to try and check timing and realized I can’t use my timing light when it isn’t running, so back to your suggestion, what is the best/easiest way to crank the motor by hand?
Rexgirl JAN 27, 02:42 PM
My suggestion is to 'static time' your engine. You can find the timing mark here:
https://www.fiero.nl/forum/...030531-2-030839.html
IIRC, it's the widest of the three marks on the harmonic balancer. To verify that the balancer is still accurate, you may wish to use a straw through the #1 spark plug hole and confirm that piston is at TDC..
hmmhunter JAN 28, 11:21 PM
I read through the entire GM service manual today and made a list of things to check, timing being the first thing, but before trying any of it I decided to try starting it with starting fluid again. Each time it started it would sputter huge clouds of grey and black smoke but it ran a little longer each time. Finally after four or five attempts it kept running but sat at ~2500 rpm. The exhaust manifolds started glowing red so I shut it off and the next time I started it they didn’t glow at all.

It will now start on its own (but takes a really long time to sputter to life) and idles at about 2000 rpm. The check engine light came on and I got code 35 and 45. I started to diagnose it but then the light went away. I also found that when I let off the gas at all it will leave huge clouds of grey/black smoke from the exhaust that smell terrible.

Do any of these things seem to point to anything obvious?
Is it possible this would be a sign of the oxygen sensor being bad and causing the engine to run rich?

Thanks!
hmmhunter JAN 29, 03:12 PM
I just tried to start it again today and it would not fire. Guessing it requires starting fluid again but I didn’t even try.
Rexgirl JAN 29, 03:34 PM
Glowing exhaust manifolds can be a sign of retarded timing (Dist too far clockwise).
CSM842M4 JAN 29, 03:53 PM
Hey, 'hunter - red-hot exhaust manifolds and really fast idle kinda sound like a vacuum leak to me. Check all your vacuum hoses and replace any that look the least bit cracked or broken. Include PCV and MAP hoses, fuel pressure regulator hose and fuel evap system plumbing. Don't overlook any tee's or couplings that might be lurking around. 18 years is a long time for the elements and small fur-bearing mammals to inflict harm on plastic and rubber bits. Gaskets can also deteriorate over that kind of time; a compromised throttle body gasket can let in more un-metered air than might be expected. Just my $0.02... Keep us in the loop - Chris
hmmhunter JAN 31, 07:40 PM
Well I got it started again and began pushing on wires and seeing if anything changed, when I pushed on the two-pin tach connector on the distributor cap the idle went back to normal, and I noticed that one of the pins on the connector had come loose. I bought a new one, installed it, and it started up and ran perfectly.

Once it was starting and running well again I let it idle in the driveway for awhile and pretty soon the idle dropped even more and immediately I got codes 35 and 45 again. I cleared them and let it run again, this time they didn't come back but when I drove it around the block the idle got really rough and then it died on me. Now it'll start but idles horribly but doesn't throw any codes. I had to leave the house then so I haven't done any diagnosing yet but figured I'd let you know what I'd gotten to so far.
hmmhunter FEB 02, 09:08 PM
I went back to try and do some diagnostics today and am not really sure what to do. It was running again but very rough, and then it stalled, and won't even start anymore. It still will fire once every few seconds but that's it. But this time starting fluid doesn't help at all, which tells me it's probably an ignition problem. I pulled a plug and found it is completely black (looks like it was running rich) but still gets spark. These plugs were just changed too, so I know they're good.

I ordered a new O2 sensor just to make sure it's getting the right fuel/air mixture and because one of the codes involved that sensor. Anyway, I'm not exactly sure what else to check if I'm getting spark and starting fluid won't even help. It's annoying too cause I had just gotten everything out to check timing but now I'll have to do a static time. I can't imagine that's the problem though since it hasn't been touched since the car started running.
cyrus88 FEB 03, 12:22 AM
Sounds like you are having fuel flooding issues. Maybe you have leaky injectors? Or massive vacuum leak?

[This message has been edited by cyrus88 (edited 02-03-2022).]

hmmhunter FEB 10, 10:42 AM
How would I check for leaky injectors?

I finally had time to go through and test each vacuum line and replace the ones that don’t leak, but it still won’t run. I also just got a new O2 sensor in, the original one was black and covered in soot but I assume that’s normal after so many years.