Looked at a 95 Silverado ext cab, 5.7, 2wd yesterday guy asking $1800.00 son works at my company. Truck was in family nearby. Owner passed away and well the truck body is in excellent shape, motor clean no signs of leaks anywhere, underneath clean no evidence of oil leakage anywhere, interior needs some TLC but nothing major just cosmetic. He told me it had been sitting for about six months he had to buy a battery to start and changed the plugs to get it home. It starts right up and idles fine, but when you tap the accelerator quickly it hesitates and bogs down. Took the air filter off and throttled it up and down at the throttle body and did the same. Took it for a ride and it does not respond with the pedal, had it on the floor and would barely move the truck, it will get going with momentum but not right. Thinking maybe fuel filter, fuel psi regulator, maybe converter is blocked up?? Oh yea has 207k miles. I offered him $1200.00 and he accepted will bring the title and truck here this morning. I'm not looking for an everyday driver just something to pullt the boat and piddle with. Any thoughts?? Thanks

 

I would give the throttle position sensor a try. Fuel filter.
Also could be the coolant temp sensor located beside thermostat housing.
Clean the grounds in that area too. Fuel pressure 9 to 13 psi.
Have to have a gauge with tee adapter to check .
Take supply line off at throttle body hook adapter up there.

 

So spent the most part of the afternoon trying to figure out the problem...no luck. Replaced fuel filter, air filter, PCV valve. Poured a pint of Seafoam in the tank along with some Lucas oil after filling up with premium (ouch), truck starts with just a turn of the key and idles like it was built yesterday. No issues other than has a slight exhaust leak. Get in after letting run a bit and put in Drive step on the gas hard and barely moves the truck. Drive down the road and it will get up to 70 with momentum but no response on the accelrator, just holding foot to floor till it gets there. No engine codes at all. Almost seems like vacuum but cant find anything obvious. Don't mind taking it to someone but just wanted to fix it on my own and not get ripped off.

 

If he just changed the plugs I think I would finish the tune-up (wires, cap, & rotor) and verify that he has all the plug wires going to the right cylinders. Check timing, temp sensor & fuel pressure (like already mentioned). Sounds like you got a good deal either way. Good luck!

 

Try the coolant temp sensor, will not bring up code sometimes.

 

Yesterday checked fuel psi not sure cause getting mixed answers from experts this is what I got;
Initial before start key only have 14 psi. Drops to 0 after three seconds.
Start engine and stays at 14 psi all day.
Pinch return line and psi jumps to 20 psi, release and back to 14 psi steady.
Turn off key and immediately drops to 0 (should it stay at 14 psi and drop slowly??)Ive read an increase in psi when return line is pinched (shut off) means a bad pressure regulator at the TBI?? Also read that if the psi drops more than 5 psi in five minutes means faulty check valve in the fuel pump module??
Not sure what direction to go in, maybe cat is stopped up? Maybe TQ converter? Maybe fuel pump? Guess I'll troubleshoot them all and hopefully find a cure. Thanks for the replies.

 

needs a fuel pump it sounds like...14 psi is not enough to make that motor run well.....change the pump and the regulator...and you should be in business

 

Your fuel pressure is fine 14 little high for a tbi but good.
When you cut vehicle off on a tbi system will drop to 0.
They do not hold pressure. When you turn key on you start fuel relay , instant pressure.
And when you pinched line off, pressure will rise. Not your pump, or regulator.
Regulators on these hardly ever go out . I would try cts.

 

Problem solved......timing was retarded 20 degree, set timing and runs like a scalded dog. Now on to the AC system and cosmetics...so far have #$1275.00 in it. Thanks for the help folks, thougt the timing was ok being the engine cranked on one turn of the key and idled fine.....fooled me.