Newly rebuilt engine and tranny

LOUI2SOX

MEMBER
1994 PONTIAC GRAND PRIX
183,000 MILES

I just installed a fresh rebuilt original 3.4L DOHC motor into my grand Prix, and it runs fine until it warms up. After that it starts missing and when put into gear it dies. If I force it to run by keeping the rpm up, when in gear, it sounds like it is running on maybe 4 cylinders. Can you help me? I have about $6,000 into this project and am running out of money and patients.I`m sorry, I can`t donate this time, but I will as soon as I get the funds. Thank you, Robert S.

2 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Look for vacuum leaks especially at the pcv valve.

Does it rev up good in spark?

Did you do a back pressure test on the exhaust for the cat?

Roy

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Friday, July 6th, 2012 AT 1:21 AM

LOUI2SOX

MEMBER
2 POSTS

Thank you Roy for the input. The answer was found in the engine timing. Toms Performance in Vancouver WA. Put the timing belt in with two of the cams in the wrong position. I needed a professional to fix this, in case there was more damage as a result, and We have to go to court. Marcelo's Auto repair in Toledo, WA. Knew right away what was wrong. Evidently it happens frequently. However Toms performance wouldn`t fix it and told me that Marcelo was full of it.I paid $3900for Tom to build this engine. I may take him to small claims court, to reimburse me in the amount of $530 for Marcelo`s services. There is a revision that says two cams up, and two cams down on this GM motor. Now she runs beautifully. YA-HEW.