88 silverado rough on take off

[tdog]

Hi Guys,

Got an 88 silverado 4x4 5.7,...& it has just started running real rough when I first take off from a stop, like it wants to stall( surging kinda)......Runs fine once I give it more gas....Have changed fuel filter & wires recently.........any Ideas???.....some kina censor maybee??.........thanks...........T

[antirice]

is it throwing a code? if so, have teh MAP sensor checked, mine's doing the same thing, or it could be as simple as the cap & rotor on the distributor

[RyanZ71]

I'd check the air filter, PVC, Plugs, wires, (even though you said you already checked them, CHECK THEM AGAIN!) check for possible broken plug, check fuel lines to make sure none are rusted or pinched, run some Chevron Techron fuel injector cleaner in there (put a bottle in on a near empty tank and then fill up with 87 octane gas) see where that gets ya.

[RyanZ71]

02 Sensor, (no you will not always get a CEL when the 02 Sensor goes bad) possible plugged cat

[snoman]

Check for a leaky gasket between TBI unit and manifold.

[chuckp]

change fuel filter......................................

[tdog]

Ok heres what Ive tried, changed plugs & wires again, new cap & rotor, checked CAT (fine), checked pvc(fine), changed fuel filter again......still bogs & surges at low pressure on pedal........wheres the 02 sensor & how do u check it???......Im at a loss here.......thanks.......T

[rcj_houston]

Surging is usually a sign of a bad EGR Valve. That is what I have experienced in the past. Fords were the worst when it came to EGRs, but the problems sounds the same.

 

Also, youmight want to get a good can of B-12 Chemtool spray (or a good carb cleaner) and spray down the butterfly on the throttle body. Makes a big difference when the edges of the butterfly are clean on low end accelleration, surging and or stalling..

 

cheers...

[RyanZ71]

O2 sensor will be along the exhaust line, somewhere before the cat on that old of a truck.