[nicktofferi]

well i have a chevy 350 small block in my jeep and have been working on putting on a gm tbi unit and harness. i have it running with the computer running the timing. the timing is set to zero. i have all sensors hooked up, knock,temp,o2.... everything: the jeep runs but it runs at about 80%. when in park and give it gas it runs pretty good. when you get going down the road and give it gas it just kind of misses and spits and sputters while i am feathering the gas. when u slow down to a stop the thing comes down to a real low idle where it seems like it might stall then it "adjusts itself" and the idles seems to go up. i installed a knock sensor this weekend because some one advised i needed one and when i first started it it ran amazing for the first 30 sec. once it warmed up it ran like it always did. it seams to always run good at the beginning? ?????


things i might think could be an issue:
1. where my exhaust meets the header there is a slight exhaust leak because of a blown gasket. it is just above the o2 sensor in the exhaust.
2. the header bolts could be a little loose. could this be giving the knock sensor a false knock?
3. the only wire i dont have hooked up that might be needed is the one that tells the computer what gear it is in
any info where to go form here would be great.
thanks nick

 

[Buggy_Tim]

I vote fuel pressure. Did you run a return line back to the tank? What fuel pump did you use?

 

[whiterhino]

I vote fuel pressure. Did you run a return line back to the tank? What fuel pump did you use?

x2

 

[TopHeavy]

things i might think could be an issue:
1. where my exhaust meets the header there is a slight exhaust leak because of a blown gasket. it is just above the o2 sensor in the exhaust.
This could cause the engine to think it is running lean.
2. the header bolts could be a little loose. could this be giving the knock sensor a false knock?
Most likely not.
3. the only wire i dont have hooked up that might be needed is the one that tells the computer what gear it is in
I have no clue where to hook that up
any info where to go form here would be great.
thanks nick

Good Luck.

 

[nicktofferi]

i bought a fuel pump at auto zone. i told them i had a 88 full size pickup and it is located in tank. yes i do have a returnline.

 

[clarkstoncracker]

Does it smell like its running extremely rich? Try unplugging your TPS and see if that affects the idle.

 

[Cartman]

So I'm assuming it has not set a trouble code? It just runs terrible?

 

[nicktofferi]

going to trouble shoot the codes next week.

 

[nicktofferi]

well have been tinkering with for a while now..... i have ran the trouble codes and it came up with high voltage tps sensor. changed the tps this summer and it fixed it for about 5 to 10 minutes but then started to run bad again. then i changed the pigtail and didn't help. any ideas? thinking my next step is to have the computer reprogrammed. thanks nick

 

[Bones]

IAC isn't adjusted right or is malfuntioning

or fuel pressure

 

[chevotass]

get a holley blue fuel pump. i put a 87 chevy throttle body setup on my motor and had the same problem. i bought an autozone pump and it would idle fine. but once its under a load it sucked. bought a holley blue and have had nothing but great experience with it.

 

[nicktofferi]

Fuel pressure is running at just above 11 psi......I have read that it is standard to be running around 11-13. Then i will read posts about needing more than that. Should i take the fuel pump out and by a holley?