Fuel Injection Problem

bellagt · #1 (**permalink**) 08-29-2007, 05:07 PM

I'm asking for a friend who just rebuilt his 3.0....

The fuel injectors are not injecting fuel.
There's is fuel pressure; the cold start injector works; the engine will fire up when starter fluid is injected into the plenum (so there is spark); the ECU, AFM and thermo timer switch have been checked; all grounds have also been checked.

Any ideas out there on what else might be wrong or worth checking?

TIA

**AR4me** · #2 (**permalink**) 08-29-2007, 05:39 PM

Sounds like either
1. the injectors aren't being triggered, or
2. the injectors are clogged/stock.
Jes

slyalfa · #3 (**permalink**) 08-29-2007, 06:10 PM

it is very common for the injectors to stick. when removed and dry. I had this happen when I did the heads.
I pulled the injectors out still connected to the rail. and used a small rod to push the steel small rod on the bottom of each injector. I could feel the stuck one go kinda like they were glued a bit.

I also had bad contacts on some. so clean the contacts. might want to try that first.

bellagt · #4 (**permalink**) 08-29-2007, 08:39 PM

Thanks guys. I'll pass on your thoughts. I know the injectors and fuel rail were sitting on the bench for several weeks before everything was re-assembled again. I'll keep you posted.

**alfaparticle** · #5 (**permalink**) 08-30-2007, 06:05 AM

I would check to see if the injectors are getting firing pulses before you go to the trouble of pulling the injectors and fuel rail. Someone sells Bosch test lights on ebay, but a board member posted a simple design for one that consisted of an LED and a resistor in series. You may want to search the archives for it.
Ed Prytherch
79 Spider
88 Verde

bellagt · #6 (**permalink**) 08-30-2007, 05:25 PM

It sounds like the injectors are not getting a pulsed signal. The injector ground wires have been checked and the ECU was swapped out with a good unit from a running car. Advise on what to check next?

slyalfa · #7 (**permalink**) 08-30-2007, 07:28 PM

if you do not get a pulse.
is the injectors setting at 12V or 0V?
they shoud be at 12V and one side is gounded for a very very short time when cranking.
as you are geting spark that is what drive the ECU.
check the white tempsender and the AFM are they pluged in and the contacts clean?
is all the grounds wired up to the block next to the firewall?
there is not much to a L-jet one step up from sticks and stones it shoud be easy to check each part.

how did you check for a pulsed signal? scope? LED?