Zackman1995

So, i just bought this truck for 275 bucks. its in rough shape. the tranny was slippin and it took forever to get it started. well i figured out it was overfull on tranny fluid, so i drained that and that stopped the slipping. well now,when i drive it and get to about half throttle it falls flat on it face and wants to dye. i cant get it over 2000 rpms now. ive tried filling the tank and puring some sea foam in, still same thing. i put sea foam in the oil for a couple days before i changed it. still same thing. i tried replacing the TPS (throttle positioning sensor) and still nothing. im stumped and dont want to spend tons of money tring to figure this problem out. could it be a vacume leak? something. i dont know. ive already stummped one mechanic. its a 305 TBI (non vortec). let me know if youguys have any information that could help me! thanks!

jesse06

fuel line pressure test it, compression test and check the timing, would be the first things to do.

AaronIROCZ

Also could be a weak ignition coil.

MDTAHOE

Try a fuel filter, Try unbolting the exhaust in front of the cat converters. Take a good look at the cap, rotor wires and plugs. The fuel filter is cheap. It will cost you nothing to unbolt the cats. If the ignition system is shot bad enough to be causing your problem then it will be obvious to the naked untrained eye. All of the above thing are either very cheap or free and do not require any testing or special tools. If the problem is not taken care of by above then you will need to do some technical trouble shooting and may need special equipment. Note: It is not easy to check the fuel pressure on a TBI as there is no schrader valve (test port). Also the fuel pressure is so low (9-13 lbs) that you would need a good (expensive) fuel pressure tester to get a good reading, 2 pounds could make the difference (cheap gauge reads 9/10 actual is 7) in diagnosis. Does it get any better after the engine warms up?

Zackman1995

nope. cold or hot, still does it. checked ignition coil. its fine. ill start with the cheap stuff first.. oh and no cats its true dual straight pipes. no cats no mufflers, nothing.

Zackman1995

it actually got worse after replacing the tps..

Zackman1995

could it be something electrical? my gauges do a bunch or wierd **** now too...

Zackman1995

could the plunger be stuck open too? it almost sounds like its starving for fuel..?

jesse06

did you do a pressure check on the fuel line and a compression check on all the cylinder?

Zackman1995

not yet, she sat outside last night and it was -20 this morining.. what i dont understand is how it sits in the garage and takes forever to start, but its -20 outside and it starts right up. but it will definetly be in the garage today for me to check everything.