I know I should just hook up a code scanner when it happens, but I dont have one and havent been near one.

Anyway, I have noticed this happening maybe once or twice before, and I just turned off the car, let it sit, and when I started it back up, it was fine.

Recently, I took a 100 mile trip. Halfway there, on the freeway, I had the problem again. I stopped, pulled over, got back on the freeway after waiting a while, and it was gone. 15min later, it popped back up. This time I figured it was just overheating, so I added some water and some antifreeze (mostly water). That helped a little, but then it popped up again. So then I just added only water. Then for the rest of the trip, I had no problems at all. The light did not come back on, even for the 100 mile drive back (didnt stop at all).

The next day, I went driving around the city for about 10 hours (not 10 hours straight, but parking at different stores, restaurants, bars, etc). It was fine the whole time.

Now, about a week later, just driving for about 15 min, then hopping on the freeway for 5 min, then the check engine light came on again. I just stopped and waited a little (not even too long, like 2 minutes at the most). It went away for about 20 min while I did some city cruising (actually I raced and beat a new mustang to a red light haha, so it wasnt all cruising). Hopped on the freeway back home, making sure not to go over 65 or 70, but the light still came on. I pulled off the freeway, pulled over and waited, then drove home on the streets, and there was no problems.

So maybe I have a coolant leak? It does keep turning a rusty brownish color, even after 2 coolant flushes.

I have done a full tuneup recently, plus replaced some other parts too.. Cap, rotor, wires, plugs, oil change, water pump, thermostat, air filter, starter, battery, and more Im forgetting about. Did not change o2 sensor though.

 

Check the codes.

 

you don't need a scanner to check the code. All that you need is a paper clip on the ALDL port. Search will reveal many threads on how to flash codes

 

Willing to bet it's EGR related.

 

32

 

it may well be but a paperclip and 2 minutes of his time and he'll know what codes were thrown

 

Yeah, pop the codes and report back.

Agreed it's likely an EGR fault code. They're one of those that likes to pop up on the highway. The ECM has no way of knowing DIRECTLY if it works, so the ECM has a little "test" it does while driving constant-pedal for a while (i.e. cruising on the highway). If it fails the "test", she pops the light. EGR issues are well known for cropping up on those engines, especially after a few decades in service.

 

Thanks everybody. Man you guys are smart.

I had 32 and 54. (Checked it with a paperclip, thanks for pushing me to do that). 54 explains why on warm starts, sometimes the car stalls out and dies when dipping to 500rpm, but never stalls during driving. I was having a rough idle too, which was fixed by replacing the EGR valve, which I read is common. Car is a lot smoother now, thank you.

 

Thanks for the kind words.

Smart?...... Maybe.

Getting through a maze is always easier the second time than the first! Experieince helps tremendously in situations like this.

Enjoy the car!

 

Idn if anyones still around on this thread but on my 88tbi 305 firebird i get the code 32 at highway cruising speeds. Car also idles rough from about 750rpm dipping to 600 or so and has a turbo like delay when flooring it from a dead stop. Already replaced egr valve no change. Figure its something to do with the vaccum system but already checked for leaks couldnt find any. If anyone has input would be appreciated.

 

Some Egr valves have a temperature switch built into the actual valve itself. Often time that switch goes bad and that's what triggers the code. Let me know if u have it. Looks like a small sensor with a single wire coming out of it

 

I replaced the EGR valve on my '88 TBI as well and it took care of the problem for a while. Got the code again and I found a hard vacuum line to the EGR solenoid had broken so I replaced it with flexible vacuum hose and it was good for a while. Now I get the code periodically and I believe that the flexible line may be collapsing due to the vacuum and throwing a fault but I haven't replaced it with a hard line yet. If the EGR is good and you don't have any vacuum leaks, check the solenoid. Good luck.

 

I replaced the whole egr valve there is no electrical connection to the egr just a vaccum line.

 

alright thx for the input ill check out the solenoid this weekend. Also gonna try fidaling around with my IAC cause this might be more than just the egr