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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: SuperCab on March 19, 2010, 11:22:36 am

Title: tbi problems?
Post by: SuperCab on March 19, 2010, 11:22:36 am

on my '87 suburban 3/4 ton


if you are driving down the road - speed does not matter - it can speed itself up slightly then let back off.

this is not a toyota joke.

your foot does not move on the accelerator - it just revs then returns to the original speed...

I am wondering what the issue could be... I'm thinking the throttle position sensor maybe?

thanks for any answers you can provide

Title: Re: tbi problems?
Post by: jaredts on March 19, 2010, 11:41:19 am

Just a guess but it could be a lock up converter problem.  It happens at very low speeds too (under 45)?

Title: Re: tbi problems?
Post by: SuperCab on March 19, 2010, 03:58:56 pm

it's a th400 trans. it does happen randomly under and over 45.

does the 400 have a lock up tc?

Title: Re: tbi problems?
Post by: Da67goatman on March 19, 2010, 04:05:19 pm

I had a similar problem with my 700r4 and it was caused by low trans fluid.  i don't know if that is your problem but it won't hurt to check.