New in tank fuel pump (OEM)$280.00 14-16 psi, great flow.
YES I CHECKED.
New fuel filter (fram) re-checked it, it's clean.
Starts every time, and stays running.
As soon as I try to go, it backfires thru TBI.
Some days works fine warmed up to operating temperatures, or cold.
Today, it doesn't want to go. Yesterday before I parked it, it ran good.
With no load on engine, it revs up to redline without a problem
In gear, it doesn't want to do KRAP! Hot or cold.
Is there another filter or screen inside the TBI?
Computer code 12-12-12-12....No faults noted.
Oil pressure over 30psi.
So, I'm thinking TPS.
What are your thoughts?
2006-12-13 04:33:52 · 4 answers · asked by Mr. KnowItAll 7 in Cars & Transportation ➔ Maintenance & Repairs
It could be the TPS, but I kind of lean towards the cap and wires........If the condition is prevalent on damp days that is probably it.......Check the cap very closely, very...If you have the coil on the cap pull it also and check for little fine carbon tracks.......If you are not sure about the wires wait till night.. Start the engine and mist the wires with a spray bottle..If they are leaking it will look like a Christmas tree......Also check the ROTOR for tra cking, underneath as well as on top..Underneath meaning inside the hole where the shaft goes... Let me know what you find..Might be more help.....
2006-12-13 04:51:56 · answer #1 · answered by buzzwaltz 4 · 0⤊ 0⤋
How long has it been since changing the pump. You can easily get defective ones as we have had several from time to time that didn't hold up. A scan tool will show clearly if the tps is working as should give even rising numbers of percentage of throttle as the pedal is depressed. Also should set a computer code as well. Crank Sensor can do this and not set a code. There is also major ground troubles with these pumps at the connector near the tank where they plug in. Don't forget to check the ignition coil. They can do this on a Chevy of that vintage easily. Also coil wire. Remember that it takes a lot stronger spark to fire the gasoline when the speed and compression are higher and the amount of fuel in the cylinder is more. A weak coil is having to charge up and fire much faster at rpm and while the weaker spark at high rpm might run okay with no load, you start dumping fuel down the cylinders and it might not work enough. You also mentioned that you had the throttle body system on that truck. Check the spray pattern on those as well and make sure that they are spraying cleanly and evenly. Last thing that I can think of is to check the gas itself and make sure that there is no water getting in it. Hope you can find the trouble soon!
2006-12-13 04:48:32 · answer #2 · answered by mohavedesert 4 · 0⤊ 0⤋
you could also check your EGR valve. I had similar problems with my 90 Camaro with the same engine in it and my EGR was stuck open, and i had to replace it. A way to check it is to start the engine and let it run for about 1 minute and feel the EGR valve, if it is hot than it is sticking open and will cause your truck to run poorly.
2006-12-13 05:28:47 · answer #3 · answered by Jason M 1 · 0⤊ 0⤋
Does that have vacuum advance? Could be something timing or spark or vacuum related.
2006-12-13 04:52:39 · answer #4 · answered by frigon_p 5 · 0⤊ 0⤋