LiveIt!

Hey guys, I know this is a third gen forum buttttt.......

The other day my 3800 fourth gen had a slight stumble/misfire to it when I just got back from a trip, and just didn't sound healthy. It threw an SES but you can't pull the codes like you can on our cars and the ALDL wouldn't give any data to a scanner for some reason. I've had this happen bad once before and it was a frayed wire on a fuel injector. Fix and no problems since. That was the first thing I checked but didn't see anything wrong. It's weird how this only happened for a little bit when I just got home from a trip, and on the 3rd startup minutes after it started acting up it ran fine with no stumble. 4th startup even got rid of the SES light. Car's been fine since!

I just wanted to know if anybody knows anything I should look into first. Car's definitely overdue for new spark plugs and such so I'm hoping they had just had a long workout and starting going out. Easy fix, but what to check also? Anyone also know why the ALDL wont show any data on any scanner? Any fuse to check?

Pro

U need something like a breakout box


And how to use:

GTA88

Hey LiveIt!,

It might just be your plugs. I have a bogging issue with my 88 GTA, and I haven't changed the plugs yet, Champion copper plus, even though they have at least 35,000 miles and 15 years on them, since I pulled one at it looked very clean. But apparently the inner part of the plug can wear out too, so I guess I ought to change them.

That frayed wire to your injector. Was it frayed all the way through? Shorting out on something? I ask because I have rodent chewing damage to one wire going to one injector. The plastic has been chewed off for about 2 inches, and the copper exposed. But I think it is OK as long as the copper is still there, and not shorting out.

BTW, my GTA bogging was coming and going. I thought it cured itself, but now it's back.

Good luck.

LiveIt!

Hey there! I ended up putting in new NGK Laser Iridium plugs, problem hasn't shown up since! Before too long I need to change the wires too though, just to be sure they're not shorting out against metal or anything. Had that cause a intermittent misfire on a lawn tractor before, and the wire wasn't even worn through.

The injector wire just had the plastic chewed off, both wires had been chewed and they were shorting on each other. The copper still looked in good shape so what I did was put a few coats of liquid electrical tape on them and let it cure overnight. Good as new-especially since the 3800 doesn't have a separate harness for just the injectors-it has one entire harness for all the engine goodies-so a big PITA to change out

Best of luck with your GTA! Check your spark wires if you haven't already, just to be sure

BTW just for future reference if anyone reads this in the future-ALDL wasn't showing data because of blown cigarette lighter fuse

LiveIt!

Just knew I was going to jinx myself....It's back! Next on the list: Plug wires, Ignition coils, new harness for injectors. Fun fun fun

GTA88

Sucks that it came back! Have you looked for vacuum lines leaking?

I have solved some driveability problems by finding vacuum hoses that had worn off at the connection, cutting off the bad end, and reattaching.

Once had a spark plug wire that somehow was leaning against the exhaust manifold, and burned through the plastic, and shorted out on the exhaust, causing stumble and misfire. I tried for a month to figure that one out, and it was a friend (who was also a mechanic) who noticed it right away when I asked him to look at it. Right in front of me all the time!

And thanks for the tip about liquid plastic to coat the exposed copper wire. Never heard of it before.

86LG4Bird

iTrader: (1)

LiveIt, We just went through a similar issue last week with my son's '96 3800.
Idled perfectly, but would have a dead miss on one cylinder whenever under load (in gear, any throttle above about 10%). Scanner said #2 cylinder. So we replaced that wire first...no change, plug next....no change, coil pack....bam-that was it!

LiveIt!

Bingo on the vacuum lines- I looked into it and the code it was throwing is P0300 Random/Multiple Cylinders misfiring, most common cause is vacuum leaks. Something told me to check the vacuum reservoir. Dropped the plastic air deflector thing flap, pulled on the line to it and found it had been chewed in half (lmao) Fixed with entirely new rubber line, car's been driving fine today....I hope that doesn't jinx me again