No start situation .... please help

[90eliminator]

hey guys, got a 90 comanche...cranks cranks cranks, then starts and dies... it will continue to do this until the battery dies, or it just decides to stay running, no rhyme or reason... So whats the first thing you think of, CPS, replaced it, ok TPS, replaced that, no change, replaced the coil, again no change... I'm confused and now have dropped $150 into this thing that have made no difference, and the spousal unit is getting ticked off.... please does anyone have any ideas....thanks

[Pete M]

fuel pump resistor? white ceramic thing on the drivers side fender in the engine bay. you can try bypassing it by just hooking the wires together.

[Oizarod115]

do you have fuel pressure and hot spark at the plugs?

 

we can assume you have air, so all you need is fuel, spark, and timing.

if you have fuel and spark then your culprit is going to be either computer or cps/wiring. something isn't in time.

[Eagle]

The fuel pump ballast resistor is on the inner driver's fender, between the air box and the sheet metal. It's a white-ish ceramic thingie with a fairly heavy wire stuck on each end. Jumper the two wires together and see if it makes a difference.

[ComancheKid45]

Sorry for Hijacking but I'm kinda stuck with you now.

 

Alright mine decided not 2 start this morning. If i jump the 2 wires off the resistor together The fuel pump will prime with the key on but I still can't get it 2 fire. Its raining out so thats all i tried, ill look around more with it later :dunno:

[Pete M]

the resistor isn't used until the engine has already fired up. the fuel pump gets full power for the first couple seconds with a direct wire, then the computer switches over to the circuit with the resistor.

[ComancheKid45]

Ok....well for some reason my truck came back to life and i think it had something 2 do with the coolant level being real low, i unplugged the coolant sensor and replugged it and it fired right up. I swapped out my leaky pressure bottle tonight and refilled the system afterwards and all seems well again.....We'll see in the morning

[Geonovast]

I doubt it had anything to do with low coolant. I've started motors with the radiator not even being in the vehicle.

 

My best guess is the sensor was somehow sending out to the ECU that it was running too hot, triggering the auto shutdown. Unplugging and plugging back in probably reset it.