Hey,
I'm getting the little cap from a friend so that I can test my injectors, just want to know if it makes a diferrence if truck is warmed up or cold ?

I have to use starting fluid to start it after it has sat for a few hours (5+ hours). Once started, it will stop and start just fine... So thinking injector.

So should I wait until the truck is cold and will not start to do the test, or does it not matter ?

 

Definitely do the test with a cold engine.

MikeyB

 

Are you sure you have the common rail? if not lots of damage can happen!It sounds like a heater grid relay problem to me. I did the cap test and found my suspicions were true two injectors keeping the engine from ideling down from 2000rpm.

 

Are you testing for excessive return fuel from injector? Or a no start condition? What year is your truck?

 

2003
Testing for no start condition. Thinking the cause is a leaking injector, leaking excessive fuel/pressure back to the tank.

Oil appears clean and level has remained consistent.
Stock injection pump is bypassed with the FASS system, no pump in tank, no chip or aftermarket intake.

Last night we capped off #1, then #2 truck still wouldn't start. Capped off #3 and she fired right up. Bad #3 Injector ???
We left it in, removed the test cap, etc... all back to how it was when it wouldn't start, and she fired right up.
Still going with our thoughts of a bad #3, replaced it with a new injector.

During all of this, we noticed that most of the injector tubes were loose and one injector bolt was only finger tight... Previous owner must have had some aftermarket goodies and pulled them out to sell it.

So after letting it sit all night in the cold, it started up great this morning.



The FASS system resolved my no starts the first time, but that only lasted a couple weeks then it started getting worse.
Replaced the O-ring in the Fuel Pressure regulator, same thing, Seemed to fix it, it started fine for about a week, then started getting worse.. I'm not overly confident that it is now fixed, but time will tell.

 

You might have found the issue. Loose injector tubes can cause a hard starting condition. I believe the tubes need to torqued to 37 ft lbs.

MikeyB