Jaysome

iTrader: (1)

Hey guys, I seem to have this issue with my 88 Firebird Formula that it just seems to run however it feels like, and today I got a code 32 and 43 while accelerating between 50 to 60 mph. How the car runs, it sometimes likes to idle low around 500 rpms. It seems like when it does this it wants to correct it, so it will start to surge up to 650-700 rpms and back down 500. If I dont hold the brake and give it gas it starts to get more aggressive with it and stalls. All my problems seem to be when the car warms up, my guess would be when the O2 sensor is "ready". Other issues are that I seem to have a low vacuum, about 15 in. hg. at idle, and I have recently somehow burned through 2 ICMs. When the first one went bad, I replaced the distributor cap and rotor. Any idea's why it seems like my car has this intermittent problem, where when its warmed up, I seem to get a check engine light which sometimes gives me just a MAF high circuit code, and/or egr fault, and/or electronic spark control code?

When the first ICM burned out on me, it had codes for EGR and Knock sensor. Just trying to throw out as much as I can, and see if anyone more knowledgeable can piece it together.

Jaysome

iTrader: (1)

Well, I had to let the engine cool down quite a bit before I started messing with anything under the hood. It always seems to be quite hot in there lol. But I found the connector for my knock sensor fell off. It has done that in the past, but without any symptoms. Cut out a connector from the harness of a junk fiero, plan on putting that on the firebird tomorrow. Would be nice if this is the answer to my problem, but I'm doubtful.

Jaysome

iTrader: (1)

So I finally got around to repairing that wire so I could get a new pig tail connector on there. Once I finally got underneath the car, I saw what looks to be my actual knock sensor that looked good as far as the connector being on and wire in good condition. So, now I am stumped as far as what sensor I just replaced the wire and connector to... It's on the right side of the engine and threads into the head (thats left side if youre looking in from the front of the car). It looks like a coolant temp sensor, but I know of two already: One on the front of the engine just below the TB thats a two wire, and one on the left side of the engine that controls the gauge inside the car. I wouldn't imagine there's a third?

I guess a better way to put it, is it looks like a knock sensor, but doesnt have the big round metal piece to it.

MrPackstin

iTrader: (9)

That is the fan switch. One below TB is the temp. sensor for the ECM. Driver side head is for the gauge. Currently messing with my car, 15 on vacuum is a bit low. I would suggest checking for leaks.

Jaysome

iTrader: (1)

Yea I finally figured that out about the switch. It was just a pain to find in the book, because the wire was black, but in the repair manual it said green/white. And yea, the 15 in. hg. of vacuum is a bit low, but if i raise the idle just a tad, like if I bring it up to 650 or 700 rpms I believe it did sit around 17 and didnt flutter or anything. I'll have to do it again sometime to double check. But when i hooked up a smoke machine to check for leaks, the only one I got after waiting for quite some time was some smoke coming up from under the intake, but somewhere above the intake manifold and in the middle. I thought maybe the intake manifold gasket was leaking, and it might be since there is a little bit of coolant that collects on the side of the engine and doesnt look like it could come from the heads. But I'm thinking where that smoke was really coming from was maybe my EGR valve.

Jaysome

iTrader: (1)

One of these days I will be ambitious enough to tear it down to the intake manifold and just replace all the gaskets and everything, but its my daily driver so don't feel like messing with it just yet. I also plan on changing over from the TPI to a Weiland Stealth Ram intake, since it supposedly would handle better with the ZZ9 cam that I have in the engine, so I probably wont concern myself with the vacuum til then.

I would like to just know what is tripping these codes randomly. I'm at the point that I'm about to just replace most of the ignition system, such as the distributor and the coil, and maybe the ESC and knock sensor.

tjrriffic

Hmm. glad i came across your thread. I am experiencing somewhat the same problems. ive already replaced my whole ignition and am getting the same code 43. what i havent done yet is a tps and egr leak test.
stock 305 with just a hollowed out cat that came when i got the car. prev owner said the same symptom that i am having happened and that is what her " mechanic" did(blow out the cat) to fix. it ran just fine for a good while but then going up a hill one day, it lost power(timing retard/advance?) and the check engine light came on. checked the code and it came out to 43.
now it happens all the time when trying to accelerate just going up slight grades or just getting on it. replaced the knock, coolant temp, and fan switch(connector had broken also and was just crammed in there).
i'll spray the maf and all my air fittings for leaks later today.
thanks to any suggestions.