So, I have an 87 Comanche with an odd throttle cut out.
Specifics:
4.0L (Unknown year, not original, Renix)
AX-15 5sp (Suspect this is why the PO did the engine swap, Pukegoat died)
np-231 (also came with the swap, date code is around the tranny's)
It's still a Renix motor, it has three bolts at the intake rather than 4.
On to the problem,
When driving, in any gear if I give it WOT at above ~3K RPM then the motor just dies. If I let off the throttle it instantly comes back to life. If I am at 3/4 throttle the motor will go above 3K all the way to the redline with no problem. If above 3K at 3/4 throttle you jab it to the floor the motor will die. I've not determined if it's an ignition or fuel cut off. Since it only happens above 3K at WOT it's not something I can look at in the driveway. It seems like it's a fuel thing though, since I can goe above 3K at partial throttle. I think the ECU is cutting the injectors off for some reason.
THings I have checked:
TPS voltage: Within spec, .85 to 4.85
All electrical connections have been cleaned and checked for continuity with the ECU plug.
IAC has been cleaned.
TB has been cleaned
I just bought this truck, so in the past two weeks I've replaced these items:
PLugs, Wires, Cap, Rotor, Air Filter, Fuel Filter, Oil Change w/ Filter
I've changed the Tranny fluid, diff fluid and t-case fluid, I didn't see any wires hanging from sensors down there. I've pulled the negative wire a few times while doing tun eup items and it's made no change.
I've not yet replaced the O2 sensor, but it's on my list. I suppose that could be it, but it was my understanding that at WOT the renix ignores it anyway and uses the map sensor. Speaking of the MAP sensor I've not done anything with it but clean it's electrical connector. Should it be cleaned or maintenanced in any other way?
I appreciate any ideas, I've tried to be thorough, if you've made it through this much of the post you deserve a cookie.
Specifics:
4.0L (Unknown year, not original, Renix)
AX-15 5sp (Suspect this is why the PO did the engine swap, Pukegoat died)
np-231 (also came with the swap, date code is around the tranny's)
It's still a Renix motor, it has three bolts at the intake rather than 4.
On to the problem,
When driving, in any gear if I give it WOT at above ~3K RPM then the motor just dies. If I let off the throttle it instantly comes back to life. If I am at 3/4 throttle the motor will go above 3K all the way to the redline with no problem. If above 3K at 3/4 throttle you jab it to the floor the motor will die. I've not determined if it's an ignition or fuel cut off. Since it only happens above 3K at WOT it's not something I can look at in the driveway. It seems like it's a fuel thing though, since I can goe above 3K at partial throttle. I think the ECU is cutting the injectors off for some reason.
THings I have checked:
TPS voltage: Within spec, .85 to 4.85
All electrical connections have been cleaned and checked for continuity with the ECU plug.
IAC has been cleaned.
TB has been cleaned
I just bought this truck, so in the past two weeks I've replaced these items:
PLugs, Wires, Cap, Rotor, Air Filter, Fuel Filter, Oil Change w/ Filter
I've changed the Tranny fluid, diff fluid and t-case fluid, I didn't see any wires hanging from sensors down there. I've pulled the negative wire a few times while doing tun eup items and it's made no change.
I've not yet replaced the O2 sensor, but it's on my list. I suppose that could be it, but it was my understanding that at WOT the renix ignores it anyway and uses the map sensor. Speaking of the MAP sensor I've not done anything with it but clean it's electrical connector. Should it be cleaned or maintenanced in any other way?
I appreciate any ideas, I've tried to be thorough, if you've made it through this much of the post you deserve a cookie.