trottle body backfires and loseses pressure and cuts off on 1990 GMC Jimmy

my 1988 gmc jimmy backfires through the throttle body and looses pressure when driving , and cuts off. can anyone help me?

by in Detroit, MI on September 30, 2009
3 answers 3 comments
ANSWER by on October 01, 2009
is the check engine light flashing ? if it is count the flashes write then down those are your codes then you can take it from there.
ANSWER by on October 24, 2010
Had the same problem with my 1990. Check ur distributor cap and button.One or the other might be bad.
COMMENT by on June 02, 2011
i just put a new cap, button, wires, plugs, fulfiller, EGR, and cat. what can it be
COMMENT by on March 07, 2012
My 88 jimmy is currently in the shop now for the same thing. The exhaust valve seats were bad but that didn't fix it 100%... But there was some broken grounds... If u figure it out I would lik to know what it was
COMMENT by on March 08, 2012
remoove valve covers.Cech valve hieght.If rocker to loose on exhaust when intake opens the cylinder pressure release through intake causing backfire through throttle body.Seen this many times Doug dkmazur@telus.net
ANSWER by on March 08, 2012
Pull valve covers.Jimmy is good for broken rocker [real cheap to repair] push rod comes partially through causing exhaust valve to not vent. On intake when intake valve opens pressure releases through intake.Seen this often