Mechanics

SHIFT IT INTO DRIVE ENGINE BOGS DOWN UNTIL WARM

1988 GMC C2500 • 175,000 miles

Gmc Sierra dies when shifted into drive. We have made sure the tbi is working properly the only way you can keep the truck where it will run and drive is to advance the timing to 12 degrees but the when you shift it into drive it bogs down until the truck warms up

There is also a thump that comes from the front passenger side but I do not think they are related because the thump is so spastic and the idle and drive problem is constant.

Kick ass site : -)
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Appplianceguy
February 8, 2012.




Your question was cutoff "where."

Check power to the fuel pump and TBI system when transmission is shifted into drive. This most likely has a vacuum solenoid to control shift points. Make sure it isn't leaking vacuum.
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Rivermikerat
Feb 8, 2012.
I really appreciate the idea Iam sorry I think I was not very good in my description so I will try again here goes the truck starts sounds okay in park then I put it into drive and as long as my foot is on the gas it will stay running but if I come to a stop it starts to sputter and then dies I have replaced the pump relay the pump and wiring I have checked for vacuum leaks by spraying around the tbi and on the intake I have also changed the vacuum advance and the transmission has been rebuilt but the problem has not gone away right now the timing is advanced 12 degrees to keep the truck running and with it that way I can shift it into drive and put my foot on the gas and the truck barely goes tell it gets to the end of 1 st gear then at the top end of the gear it starts going faster then I don't know for sure but it seems to do it in every gear but it Is really difficult to tell because the truck is going at a higher rate of speed than from a dead stop but it also from a dead stop will not go up hills and the tbi has been rebuilt

Tiny
Appplianceguy
Feb 8, 2012.
Ok. Make sure you've got good spark to all cylinders. Check the compression on all cylinders. Look down the throat of the throttle body assembly and check the spray pattern of the injector. Does it look clumpy or well atomized? What does the exhaust smell like? What do the spark plugs look like?

Rivermikerat
Feb 8, 2012.

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