New 3.4 engine from carmero problem

[ant10383]

Hi my name is aaron. Now I have an 86' jeep commanch and have replace the 2.8 engine with an 3.4 camero engine. Now my problem is that I have gotten to where she starts with no problem. But when she starts she runs for about twenty seconds then dies. My father and I have checked all the sensors and wiring to the fuel pump and back and they are all working fine. So what seems tov be happening is that the injectors work when you turn the key but afterwards they shut off cause the engine to turn off. All I want is some thoughts on what you might think is the problem. Their is one more bit of information my throttle postioning scensor is stuck in one spot and it does not matter if I have it plugged in or no she still starts up. So could that be the problem? Well thanks for listening to me.

later,
aaron

[oljeeptek]

Originally Posted by ant10383

Hi my name is aaron. Now I have an 86' jeep commanch and have replace the 2.8 engine with an 3.4 camero engine. Now my problem is that I have gotten to where she starts with no problem. But when she starts she runs for about twenty seconds then dies. My father and I have checked all the sensors and wiring to the fuel pump and back and they are all working fine. So what seems tov be happening is that the injectors work when you turn the key but afterwards they shut off cause the engine to turn off. All I want is some thoughts on what you might think is the problem. Their is one more bit of information my throttle postioning scensor is stuck in one spot and it does not matter if I have it plugged in or no she still starts up. So could that be the problem? Well thanks for listening to me.

later,
aaron

Let's see. If I remember correctly the commanche was carburated, so you probably used the camaro ecm. Did you also install the VATS parts? (antitheft) If no vats/passkey ok signal gets received by the ecm, it shuts down injection thinking its being stolen. Research prom/eeprom calibrations for a possible non passkey/vats application. (This might not apply if you have an aftermarket ecm system.)

An out of range map sensor could also do the start and die. Unplug the wire connector and see if it now runs with the ses light on.

Are you also maintaining correct fuel pressure as it dies?

[oljeeptek]

One more comment:

If you have a code set in memory, the tps may show a default reading. Clear it and retest. You should also backprobe the sensor wire (dk blue if I remember correctly) and see if it goes from around .5v closed to 4.5v appx at wide open throttle. If it is locked on the voltmeter you have a circuit problem.

It should run with the tps disconnected.