Have been getting a code 33 intermittently, thought I had it fixed, but it's back again.

Today I replaced the relays cleared the codes and the code came back.

Since I had already replaced the relays, I cleared codes and installed another MAF sensor and the code came back.

What's the next step? Replace the ECM?

This couldn't have happened at a more inconvenient time for me. I'm getting ready to move 1500 miles next week and need to drive the car there. I am in a bad spot.

 

I had an intermittently recurring code 33 that made me nuts, the car ran like crap after the code set...

It ended up being the TPS setting. I used to run the TPS voltage at the high side of the recommended setting (I think it was a .60 or something)

Turns out the new chip I had burnt was expecting a lot more air at this particular voltage than was actually coming through the MAF.

I reset the TPS to like .48 (I think that's the low side of the range, It's been a while since I ran the TPI, the Vette is carb'ed now)

Voila, problem solved.

 

Thank you for your answer. I have recently reset the TPS and will go set it a bit lower right now! Hopefully this will work.

 

Hey John, best of luck on that move!

I threw a code 33 when I put in the new motor......it turned out to be drawing more air than the factory threshold would allow and we re-adjusted the chip. I troubleshot it and like you, couldn't figure out anything wrong. Have you done any mods lately that would cause it to ingest more air?

Here's a good discussion currently going on re: code 33 issues.......hope it helps!

http://forums.corvetteforum.com/show...63&forum_id=82

 

Hey Tim, thanks for the good wishes. Moving to Kalispell MT, for at least the summer.

Well it would appear the TPS was the culprit, at least so far. Roads are crowded right now, so I just drove over to vatozone to drop off the core for the MAF. It's about 5 miles round trip and I managed to get on it heavy a couple times and vary throttle position a bit and it didn't set a code and the datalog looks good. Gonna take it out this evening when it's a little less crowded and cooler (95* here today ) Gonna keep the new MAF because it's a Bosh reman with a 3 month warranty, looked exactly like the stocker and was only $150, so for peace of mind I'll keep it.

Now if the car will only behave on the way to MT.

This code business started when I descreened the MAF a few weeks ago (car was running fine and I just can't leave well enough alone apparently). First it was throwing a 34. Swapped the original relays and that went away. Few days later, got a 33. Swapped the relays again and it behaved for a few days. About 10 days ago it came back and I put new relays in and it was fine until today. When I descreened the MAF I had also set the TPS and cleaned the TB and IAC. Set the TPS to .62 and I guess the computer didn't like that. I don't have a modified chip, just the headers and no cats. (I will put a highflow on it when I get a job ok Bogus? I promise.)

When it was setting the code 33 or 34, I noticed something strange on the datalogs. It would read 23 gms/sec airflow with the key on and engine off, and wouldn't vary at all. It even did that with the new MAF, until I reset it this last time and adjusted the TPS to .54, very strange. I could only put about 1/8 throttle in or it would start to bog and backfire etc... It works now, but I'm still confused.

 

It would appear that the code has been banished, for now. Gonna take it on a ride tomorrow and see how she does. The SES light would come on about 50 feet after moving the car and it hasn't come back in 10 ignition cycles, so I think I'm alright.

Thanks for your help guys, especially Trublue Chevydude.