1998 K1500 ides fine occasionaly won't climb above 2000RPM

[Chevy454572]

I have a 1998 Chevy K1500. Last year my dad was on the interstate when the Intake gasket blew out(168,000 miles) he limped it home by stopping to refill the radiator with water every 20 minutes or so.

Since we had to take the top half of the motor off anyway we replaced: all the top end gaskets, distributor, cap and rotor, plugs and plug wires, "spider" injector, air filter, and the serpentine belt.

Now it has this issue we have been fighting, which seems to be getting worse, where the truck will idle fine but once in gear won't accelerate. If you hit the gas it bogs down to around 8-900 RPM. On fairly flat roads I can floor it and get it to climb to 2500 RPM and then it will accelerate to 3500 RPM while sputtering a little before falling off again. If I try to go up hill it will sputter and backfire out the exhaust as well as in the intake. The weird part is that this is a random issue. Sometimes it runs fine and sometimes it won't Usually it will eventually pop then start running fine again and will be fine until the next time it's turned off.

There is a trouble code on but that is because we welded in a straight pipe where the left catalytic converter is supposed to be, but that was long before the run-ability issue started.

Any ideas??

[2018GMC]

Fuel pump may be bad. Especially if it starts hard or starts then dies or low idle when cold (below freezing temps)

[Chevy454572]

Fuel pump may be bad. Especially if it starts hard or starts then dies or low idle when cold (below freezing temps)

OK I'll check that. The weird thing is that it doesn't start hard or actually die even in real cold weather. It just bogs down to around 800 ram when in gear.

[98 chevyboy]

I'm having the same problem with my 98 right now

[THORX4]

is it throwing codes?

[green 788]

take it by an auto parts store and see if they can read some codes for you. there are probably more codes stored by now, one of which may help point you to the problem.

 

because it's sort of random, it sounds electrical rather than mechanical. by turning off the truck and re-starting it, you do a re-set which lasts until the faulty component "drops the ball" again.

 

throttle position sensor could be the problem, it's easy to get to and not too much trouble to change out

 

Fuel pressure regulator could be another possibility

 

get the fault codes and go from there. most auto parts stores will read them for free. since it's an older truck, you'll need to find a person who knows how to read the codes. if the guys says their unit won't read the codes, try another person, or another store

 

I doubt if your fuel pump is bad, I've had enough unfortunate experience with bad fuel pumps to know that when they go, they just shut off and stop pumping fuel. your fuel filter is probably fine as well, but it still wouldn't be a bad idea to change it out.