I have a 1990 4L that starts, runs for a few seconds and stalls. I can repeat this cycle over and over again.

Tested CPS, TPS, EGR and all the relays and all are fine. By-passed the Resistor, cleaned all the connectors connectors.

I replaced the ECU with a working unit and nothing changed.

The Gas pressure with the vacuum line connected is 36psi. The unconnected line measures 38psi.


Any ideas?

 

Try holding ignition switch forward just a little see if it stays running ...

 

This!

Or if you want to get crafty run a jumper wire from an always on positive source to your ignition wire on your ignition switch and then see if it stays running.

 

When you tested your cps, did you use the "ac" test? If so, what was the voltage?

 

You're such a stickler for details!!!

I love it.

 

Check your IGN Timing

 

The devil is in the details!

 

And then what?

 

Love the comment! (timing is controlled by ecm for those not in the know)

 

Well, I'll give you the thumbs up in my 25,000th post!!

 

Hey Cruiser, great that you stayed with it for 25,000 posts !

Bill

 

I never even look at that, and lo and behold I happened to glance up at 24,999. Weird, eh?

 

Bullphit!

 

Come'on guys.....It's his first post! Gary might be on to something. Allot can be learned at the fuel pump relay socket, but if he jumps bat + to ether end of the ballast resistor and it runs...that might mean the pump is only getting power from the starter solonoid while cranking, but not from the fuel pump relay.

Dug, in that row of four relays, swap your second with your forth. If it then runs and your AC quits, you had a bad fuel pump relay. If the AC still works, it was the relay connections.

And Agreed in spades! Not just here but in other forums, Cruser54 has been a huge benefit for us all!

(but the letters for the trans side of the TPS connector are still not "clearly embossed")

 

Would you fellas like a room?