HELP! '92 Thunderbird 3.8L SC
Hi all, and thanks for looking here. I NEED HELP!
I have a '92 Thunderbird 3.8L SC. It won't start.
The other day, I cranked and cranked and cranked, and it turned over and spat and coughed and wanted to go...
and then it cranked and cranked and it spat and coughed and wanted to go...
After about 10 minutes of intermittent cranking I FINALLY got it to start, but it wouldn't idle. I had to keep the RPM's above 1200 for it to stay running. Below 1200 RPMs it would begin to stall.
For the first 5 minutes it sounded like it was missing a little bit, but after that it smoothed out and ran well. I kept it at 1200 RPMs for about 15 more minutes. I goosed the throttle a couple of times, bringing it up to 5000 RPMs and it DIDN'T backfire or bog down. It sounded really good.
BUT... when I went to drive it, it stalled on me because it didn't want to idle. I was able to start it back up with about 5 seconds of cranking, and it sounded similar to the cranking and coughing from before. I think it started quickly because the engine was nice and warm.
THEN... it stalled out again because I tried idling it. This time, the starter had burned out and I had to put it away for the night.
SO... after changing the starter it is going back to the crank crank crank cough cough crank crank crank and I haven't been able to get it started for 2days now.
HERE's what I've done in the last 2 days to try to fix the problem:
Changed all the spark plugs and verified that all plugs are getting nice blue spark
Changed the coil pack (One of the cylinders wasn't getting spark, now it is)
Emptied the fuel tank (In case there was bad fuel)
Changed the fuel filter
Installed 10 gallons of new premium fuel with Gumout injector cleaner (which hasn't been able to take effect because it won't even start now)
Checked the fuel pressure at the schrader valve (found it to be 40 psi which is in spec)
I have not used an OBD1 code scanner yet... I'm trying to figure out if that is the next step.
What are your thoughts?
Considering the engine ran well once I got it above 1200 RPM, I really don't think it's a spark or timing issue. I don't think it would run that well if it were either of these.
Also, I don't think its a plugged catalytic converter because, again, I was able to goose it without it bogging down, popping, or backfiring.
I have good fuel pressure, but I don't know the condition of the injectors...
If the injector screens are clogged or if the injectors are spraying correctly, could this cause problems on startup? If the problem is with the injectors on startup, would it run so well at 1200 RPM and fail to idle well?
Basically, what is the most likely culprit for non-starting, poor idling, and then running well after the engine RPMs are up?
I really appreciate it if you made it this far and would greatly appreciate your responses. I hope I've expressed my problem clearly. I'll be in touch.
PS Just a further note, I pulled 2 of the driver's side spark plugs and smelled them to make sure they are getting fuel and they came out looking black. They are not fouled, but they do have a black residue on them. It does not look like oil, it looks like carbon with gas on it. It could be oil, I really can't tell. It doesn't seem tacky enough to be oil. Like I said, carbon with gas on it. Maybe I'll go do a compression test. But would it run so well at higher RPM's if there were bad compression? I will go do a compression check on these cylinders and post my results.