1988 Chevy Silverado?

Question

Overnight, my Pickup has lost GO power at take offs, it hesitates and does so even if I have the accelerator floored.

Once on the freeway/speeds, it feels just fine to problem-runs great.

I first thought it might be the TORQE converter. was not
Then i got TWO different COMPUTER DIAGNOSTICS- nothing found!

Checked: timming, EGR, Cap/Rotor/plugs/wires, Fuel filter, all wires top to bottom, O2 sensor, Cat-converter, transmission flushed, checked almost everything.

It's a 305 5.0 L V8, Auto, TBI-throttle body injection. i think my fuel pump might be the problem, or throtle position sensor? i don't what else to think, i will return to my mechanic on thursday... any opinions or knowledge would be nice thanks people.

Pleas feel free to ask me questions, i will be checking and answer at "Add details"

"/JOe

Yes, All regular Maintenence is on time. since off dealer lot. Never had any trouble untill now.

GMGUY:O2 sensor was determined to be running "LEAN" by computer test/readings... was replaced new. still keeped the troubles though.

* when at idle,-"in PARK-or-Neutral" it seems to "REV" without hesitation, but when in DRIVE or REVERSE, it gives me that hesitation...

Yet another thing, my "SERVICE ENGINE SOON LIGHT" comes on intermittently as it runs its roughest, and will then go off...if i shut off the engine it wil not appear until it wants or needs to again.

Answer 1

It sounds like a vacuum leak to me. They can be vexing to locate sometimes as the hose may look fine but have hidden crack. Good luck. Try a vacuum gage to see if you are getting full vacuum.

Answer 2

I think your headed in the right direction. The throttle sensor can do this as well as the fuel pump. There is also a air flow sensor that will cause this. Good luck. If it was one of the sensors there should be a code in the computer and since you've not found one it's a good bet that it's the fuel pump.

Answer 3

Well if fuel filter has been done.. might be a catalytic converter plugging up!!you say it runs fine cap rotor would make it missfire. Its Sunday pull the O2 sensor if will come out..take it for a ride if any improvement ..look for a restricted exhaust..just saw that you said it was checked but how was it checked?

Answer 4

on the 1988 form, you're a lot more beneficial useful off operating your human being wires for the floor, battery and from the ignition change for the ign. twine.. audio equipment wires should be new besides... that's healthier because the inventory twine harness makes use of 18 gauge and 22 gauge wires, which will have cracks and not in any respect carry the potential nicely to apply a cutting-aspect cd participant, particularly one with 4volt or more beneficial preouts for the amps, which may require 14 gauge potential and floor leads.

Answer 5

Your probably on the right track checking the fuel pressure.My experience is they need to run 14 lbs to perform it`s best,i don`t agree with specs which call for 9 to 14lbs.

Answer 6

I have an 88 chevy p/u and the same happened to me, It was an intake gasket sucking air.Spray penetrating oil where the intake meets the head and listen for the engine rpms to change.Do the same at base of throttle body.I'll bet thats your problem

Answer 7

My husband is a GM mechanic and said to check the fuel pressure. He is almost certain that it is the fuel pump.

Answer 8

are you up to date on all maintenance ? You can check the fuel pump pressure, you'll see the valve a little ways before the TBI. Good Luck. Maybe ya gotta tank of 'bad' gas?

Answer 9

check........t,p,s,....& the throttle body itself...check throttle plate for bushing wear, check temperature sensor for the on board computer....may be telling wrong temperature....therefore running lean.....be sure injector,s are clean & operating corectly........finally check your on board computer.......may be malfunctioning.......also check for any vacuum leak,s.........hope this help,s.........good luck!