Hey fellas! Had her for about two months now and it has been running really well. Took care of a leaky valve cover gasket yesterday, drove it for about an hour and parked it. No leak. One problem solved. Today I go to start it and it fires right up as usual, but died in less than 5 seconds. I immediately attempted to restart it but it will only crank, no fire. Nothing. I turn on ignition and can here the fuel pump working and if I leave the ignition powered on for a minute or more and then try starting her she will fire up and run for a few seconds; the longer i leave the ignition on before turning it over, the longer it will run before ultimately dying once again. Seems like its just not getting enough fuel fast enough. Bad fuel filter or fuel pump maybe? Any ideas? Appreciate any feedback.

 

Crusier will be up soon...

You could swap your 2'nd and 4'th relay's. They rarely fail, but if it runs and your AC goes out, it was the relay. (just cleaning the fuel pump relay plug/socket might do it.






The ECU only grounds the fuel pump relay a few seconds after ign is on. (to pump fuel until the CPS tells the ECU the engine is running) So the relay is grounded, (activated) in different ways. There is even direct power to the pump from your start relay while it's cranking. (a third).

You have a ceramic resistor on the inner fender near the airbox with orange wires. It can be bypassed, (check it's contacts). The rear wire on that goes straight to the pump. If you jump power to there with the ign off it will back feed into the system, not recommended.

Jump power to the rear of the resistor with the ign ON and see how it works. Disconnect the jumper before turning it off.

You can also juice the pump right from your start relay. I'm not sure which end of the resistor this juices though. >>

Here on our starter relay, the solonoid can be jumped. Also the five fusible links come of the big post.






It can take less than three minutes to check a CPS, if none of that helps.

 

*Anyone with an 87 to 90 Renix Jeep has two or three minutes to see that their CPS is putting out at least .35 AC volts. I don't mean to come off rude, but if you can't connect a meter and turn the key, we may not be much help. Easy as one, two three!
AC voltage CPS test; Small clips on the meter leads really helps. You need contact with those little pins while it cranks, maybe get someone to help.
#1 Unplug the connector at the back of the manifold with wires going down to the bell-housing/cps. (it's a three wire plug, with only two wires)
#2 Probe the two wires to the cps with the digital meter set on AC volts, a 200 scale on mine. Yours meter may have a lower 2 Volt, or “auto range”.
#3 Crank the engine and note the voltage. (jump it if your battery is low) .35 is minimum. .4 to .8 is more like it.

 

Thanks for the info. I will dig into it after work today and update you.

 

I'd be bypassing the fuel pump ballast resistor first.