Cj5 with tbi 350 conversion

[Tyler Bates]

I have an 81 cj5 with a chevy tbi 350 conversion. I have replaced sensors the computer checked timing including base timing and cant track down the problem. When the engine is cold it starts up perfect but wont stay running unless it has an open vaccuum which Ive been unplugging the pcv valve. it also when you rev it up or if your driving and get on the throttle it just cuts out if you release the throttle it will stay running but if you do not it will die.And when the engine heats up it wont run at all starts and dies any suggestions would be much appreciated... thanks

 

[superj]

probably because the cj5 is a drop in for hte 302 ford motor?? just messing with you.

you replaced hte temp sensors. and it dies unleass you have a free source of air? sounds like something is not wired right and is reading hte wrong sensors if you replaced them and they are all good. what controls idle on that motor? an iac like ours?

 

[Tyler Bates]

probably because the cj5 is a drop in for hte 302 ford motor?? just messing with you.

you replaced hte temp sensors. and it dies unleass you have a free source of air? sounds like something is not wired right and is reading hte wrong sensors if you replaced them and they are all good. what controls idle on that motor? an iac like ours?

thanks for the advice and ive replaced the iac as well what confuses me is after running for a few minutes it wont run anymore so Ive been wondering if the fuel pump gets hot and shuts off and it cant get proper vaccuum because it never runs correctly but still not sure

 

[superj]

Nah, it starts making vacuum as soon as it cranks. Have you checked to see if the pump is keeping pressure up while the jeep runs? That might be your whole problem

 

[Tyler Bates]

Nah, it starts making vacuum as soon as it cranks. Have you checked to see if the pump is keeping pressure up while the jeep runs? That might be your whole problem

The pump was bad I replaced it and rebuilt the throttle body and runs better but is running rich not sure why and still wants the free source of air maybe because its running rich but I have no idea if thats why or how to change fuel mixture on these motors or even if you can or if something else is telling it to run rich

 

[superj]

temp sensor will make it run rich. check it with a multi meter to make sure the sensor is reading right. its got to be something small since it starts and runs for a bit. probably right under your nose but your over looking it. are the vacuum lines hooked up right?

 

[Tyler Bates]

temp sensor will make it run rich. check it with a multi meter to make sure the sensor is reading right. its got to be something small since it starts and runs for a bit. probably right under your nose but your over looking it. are the vacuum lines hooked up right?

I will check the temp sensor today and recheck all my vacuum lines thanks for the advice

 

[Tyler Bates]

I will check the temp sensor today and recheck all my vacuum lines thanks for the advice

I hooked up a scan tool and its not running rich like I thought is is swithching back and forth between rich and lean like its suposed to, tested the cts and its tests out good when it heats up it will throw a code for a knock sensor but not exactly sure why or what that does. And it still wants an open source of air