[robbie43]

My son just bought a 1995 z71 4x4 truck with a 350 engine with a 2 barrel Throttle body injection.. The truck runs good . The problem is if you barely press the gas pedel ,its starts to bog down ,and runs rough , but if you just press it , it drives fine . I dont have a way to check the fuel presure, but was wondering if it could be the fuel pump . any help would be great.. thanks..

[robbie43]

..........

[robbie43]

anybody !!!!!

[hpete]

It's not the fuel pump, you need to see if it's throwing any codes with a scanner. Just a thought, on a 94 you can check for codes with a paper clip, not sure about a 95.

[robbie43]

[QUOTE=hpete]It's not the fuel pump, you need to see if it's throwing any codes with a scanner. Just a thought, on a 94 you can check for codes with a paper clip, not sure about a 95.[/Q , I went and got a book on it today, and i believe that the check engine light bulb has been removed or something cause it should be on when it acts up.. thanks for the reply..

[T-bucket23]

Did this just start all at once, what have you done to it so far if anything. The more information you hive the more and better quality responses you will get.

I would look for vacuum leaks and see if the TPS resistance change is smooth when you move the throttle as a start.

[robbie43]

Originally Posted by T-bucket23

Did this just start all at once, what have you done to it so far if anything. The more information you hive the more and better quality responses you will get.

I would look for vacuum leaks and see if the TPS resistance change is smooth when you move the throttle as a start.

my son just bought the truck last weekend and he said it did it at the time he test drove it , and thought it might be the gas filter so after he bought it he changed it but it stills bogs when you barely start off. with truck in park ,and idleing , i can move the throttle at the throttle body just a little and it bogs and stumbles bad,but if i just rev it , it does fine.. Im going to ck for vacum leaks tomorrow and use a jumper wire to ck for any codes.

[F-BIRD'88]

Check the TPS sensor voltage sweep. Check the mounting position of the TPS.

[robbie43]

there was no codes stored , and i checked for vacum leaks and didnt find any. was wondering maybe if it might still be the fuel pump.. any suggestions ? thanks

[robbie43]

Originally Posted by F-BIRD'88

Check the TPS sensor voltage sweep. Check the mounting position of the TPS.

not sure what you mean, and how would i ? thanks

[F-BIRD'88]

Originally Posted by robbie43

not sure what you mean, and how would i ? thanks

get some one to show you. Its a simple test using a volt ohm meter to read the TPS sensor output when sweeping from idle to WOT.
a bad sensor will not have a smooth progressive voltage sweep.
The sensor voltage output must be correct at idle. ( mounting reset postition)

you can read the voltage output or disconnect and read the resistance (Ohms)
its basicly a rheostat. like a volume control or rotary light dimmer.
A service manual will tell you the voltages require at idle and WOT.

when one wears out, it does not read smooth as it sweeps off idle.
a jumpy sweep or dead spots='s replace

[Atx_21]

Its possible that you have a dirt ring inside the throttle body.Buy some B-12 fuel injection spray cleaner..Spray into the Throttle body and rev at the same time.You should be ok after that...