I've read every thread I can find about my situation. Here goes. Friday, I pulled a running car that had no codes or drive-ability issues other than what I thought was a failing/low pressure fuel pump. (made a horrible grinding noise a couple of times and acted like it was fuel starved at highway speeds) I dropped the tank, no issues there, replaced the original fuel pump, re-installed the tank, again no issues and the car won't start. The pump comes on and stops after 2-3 secs, the tach jumps when you crank it, The fuel pump cycles when you bump the starter, the fuel filter is new, and when I cracked the fuel inlet (I don't have the pressure gauge adapter) fuel sprays to the ceiling, and using a test light had a pulsing signal at the fuel injector. SO at that point I changed the injector. When I went to start it, it fired, coughed and went back to just cranking. Through all of this if you dribble gas or spray starting fluid it would start and run fine as long as you were feeding it fuel.
Has anyone every seen or heard of the ecu burning up an injector? Overloading it?
I have tested or replaced just about everything in the control system that would cause the car not to start. I've used the manual and all the advice I could find here on the forum. I have checked fusible links, grounds, everything I can check. I've replaced, ecu, rebuilt the brick, I even have a new chip coming. I'm out of ideas.
You mentioned cracking the fuel connection and getting spray. Have you tried pulling the injector right after cranking? You should get spray then also. If not, something's blocking fuel to the injector.
You mentioned cracking the fuel connection and getting spray. Have you tried pulling the injector right after cranking? You should get spray then also. If not, something's blocking fuel to the injector.
Yes, If I pull the injector right away it will spray there too. When I crank fuel drips out of the injector. I'm not 100% sure its coming through the injector or past the o-rings. I coated them with silicone spray and they sure feel like they are fully seated though so I don't suspect them at this point.
The only other thing I can think is maybe a bad connector. The noid light lights and cycles but it is a dim yellow. I don't know how bright the noid light is supposed to be.
So temporally hot wire the fuel pump to run and then apply 12v to the injector. Does it spray?
Key on engine off does the injector spray if you ground the blue wire? It should.
Cranking what voltage do you get on the red injector wire? What voltage do you get at the battery during cranking? They should be close to the same. If the injector red voltage drops off during cranking your problem is going to be a high resistance connection to the injector.
[This message has been edited by phonedawgz (edited 08-26-2014).]
87 P4 ECM is known w/ this problem... works normal, cools off after shutdown, won't get Injector signal later trying to start. use search Get another ECM. See my Cave, ECM Heat
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
I wish I could tell you that my issue was something cool like a blown ecu... Sadly, in my haste to finish the fuel pump swap so I could finish the work on my motorcycle, I mixed up the fuel lines. The fuel pressure I was seeing was on the return line. Operator error strikes again. That said, after replacing everything the car runs fantastic! It's never started as fast or idled as smooth!
I wish I could tell you that my issue was something cool like a blown ecu... Sadly, in my haste to finish the fuel pump swap so I could finish the work on my motorcycle, I mixed up the fuel lines. The fuel pressure I was seeing was on the return line. Operator error strikes again. That said, after replacing everything the car runs fantastic! It's never started as fast or idled as smooth!
I still feel like a total dumb ass.
Good night all. Thanks for the help.
Do you have a gear reduction starter on it, like one from a mid-1990s or newer 3100 V6? If not, pick one up, you'll be pleased with even faster starting and a starter motor which is not as loud.
