Mechanics

TRASNSPORT WON'T REV OUT

1998 Pontiac Transport • 6 cylinder •

After some work was done on my van I noticed it would hesitate at 4000rpm. I thought it was something to do with the engine work but could see anything out of place. So I checked the fuel filter (replaced it), even put a fuel gauge on the engine and drove it to see if fuel pressure dropped and it didn't. The plugs and wires were all good.

After further inspection I found it prevents it from revving over 4000rpm in 1st, 2nd, or 3rd, and in Park load or no load. I assume its supposed to do this in Park to prevent over revving of the engine. I then borrowed a scan tool to check for codes - no codes.

I then pull the air intake off and unplugged connectors, tps, MAF, air temp, trans connectors etc. Looking for maybe a bent over pin or something. Couldn't find anything out of the ordinary so I put it back and test drove it again. Bingo it worked and worked fine for 10 months. Then it started again. And I can't seem to find what's wrong.

Does anyone have any suggestions. I have drove it as is for sometime (30,000 miles)as its fine most providing you're not trying to race someone off a red light! However I now want to sell it and I would like it in working order to get more money for it.

thanks
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Sawyer99
April 14, 2011.




There was a bulletin that said you needed to put dielectric compound between the connectors on engine harness as it would lose connection. By pulling them off and on again this may be the problem. Also check the ground by the back of engine as it could be corroded, so clean that as well. It'runs off of a stud on the back of engine/trans.

Tiny
Hmac300
Apr 14, 2011.
That's what I did the first time and it worked. Of course it could have just been a "luck". I tried that again and it didn't work. I think maybe I'll swing the engine ahead and check at rear of the engine for a loose ground like you say. I've only found a some ground wires down by the started bolted to the block so far. I'm thinking I have some sort of electrical issue. Yesterday after I fooled with it all was well idling. Then I went of a drive to town and it wouldn't idle! I parked it came out of the store 20 minutes later and all was well and has been since. Also I noticed at the time it was acting up my fuel gauge went to empty and my low fuel light came on! After it sat and I started it up it was back to normal!

Tiny
Sawyer99
Apr 15, 2011.
Found a loose connection down on my starter (the main positive cable. Explains why it "clicked" once when trying to started it and why maybe the idle went screwy the one night! I also checked the ground wires for stuff. This however didn't fix my hesitation issues. I tried it again and first thing this morning leaving the driveway it worked! It down shifted for passing and revved over 4000rpm. Drove a few miles and turned and tried it again. Back to its old self. I tried in 1st it will rev out past 4000 but "seemed"to have a hick up at the 4000 mark then continued on to 5000. I put it in 2nd and it drove fine but wouldn't let me get above 4000 it would limit it to like 3800rpm.

Tiny
Sawyer99
Apr 16, 2011.
Just drive it, the computer when not given correct voltage screws up so that may have bene your hesitation among other thing. The computer will have to relearn your driving habits which it will in time, no big deal. At least you found the problem. I'd bet the work done on your car was a starter or something wher it had to be dropped.
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Tiny
Hmac300
Apr 16, 2011.

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