3fe starting problems

[jcj_78FJ40]

I’m having some starting issues with my 91 3FE. The problem is that it is very hard to start when it is cold. After a lot of cranking, it will finally stumble to life unless you give it a shot of starting fluid then it fires right up. Then there is a lot of hesitation until it warms up. Once the truck has been running, it will drive and restart normally.

After doing some research, I started by replacing the EFI relay and doing a component check on the open circuit relay (tested OK) since these guys seem to be the culprit of a lot of problems. However I’m thinking this has something to do with the cold start injector not working.

I’m going to start troubleshooting the cold start injector and its components tonight. I was hoping someone might have had the same problem and can give me some insight where to start.

Thanks all!
JC

 

[Koffer]

On the 3FEs they have a few (3)temp sensor 1 is for the ECM to tell it how cold it is . You may have one thats crapped out in the "motor is warm" .
See if the ECM has any codes in it . I had a FJ62 that always thought it was "cold" and would dump fuel .
Also you could have the FPR maybe leaking down

 

[CJF]

This is going from memory, but I believe the initial check of the cold start injector is ridiculously simple; something like, "Turn the key and listen for a "click" at the injector."

Good luck,

Curtis