Hi guys, I am new to the forums and am helping out a friend.

He has a 1992 5.0 GT.

About a month ago it just stopped running on the interstate and he had it towed to a shop for repair. The first mechanic said it was a bad feul pump, replaced it. The next guy said it was a bad distibutor, replaced it. Etc. I will run down everything that has been replaced up to the point that I started in on it.

Fuel pump
Coil
Distributor
Distributor module
EEC (the computer)
Battery (it ran dead)

I am fairly experienced in 12 volt, but I am stumped. I have checked at the EEC and I have a good connection out to my injectors. I have ignition positive to them but no trigger signal at all, not at the injectors, or at the EEC. I have fuel pressure, although I dont know the actual pressure. Would this cause the EEC not to produce a signal? In the schematics I didnt see an electronic pressure sensor?

I have a good spout signal out of the Dist Module. A good Tach signal before it hits the resistor. I dont know how to check this at the EEC after the resistor. The EEC relay is good. The EEC is getting good power and ground at the required points as well. I have checked the EEC power relay. I checked the MAF, but only to see if it got hot. It did, but I dont know what else to check on it.

Any ideas would be greatly appreciated to help get this sweet pony back up and running before he has to dump WAY too much money into it.

 

When it stopped running.
When you went to start did it crank?
Did you hear fuel pump run?

 

EEC needs to know crank shaft and cam shaft position before it can calculate fuel and spark. If you dont have those, there wont be neither fuel nor spark. Check connections to crank shaft position sensor, if you have it, the cam shaft position sensor.


If that dont help, let me know (email), Ill point you to a very good fuel injection mailing list.

 

Where are these located? the camshaft and crankshaft sensors?

 

Check on your manual. But usually you can follow the wires. The crank sensor or CPS, should be near the crank pulley. I think www.autozone.com has some repair manuals.

 

The fox body 5.0s ...EEC4 do not have crank or cam sensors.

 

It must somehow know when TDC is, so it can fire injectors.

Here, on the first page, almost at the bottom, EEC tuner mailing list is what you need. Ask away. Second link is just a good general reference for fuel injection.


http://www.austincc.edu/cloud/tc_eec.htm

http://www.austincc.edu/cloud/tc_auto.html

 

I have run some pinpoint diagnostics. I have come to a fault reference voltage from the BP sensor. Does anyone know if this would cause injectors not to fire? It seems to take th eplace of the MAP sensor in this car.

 

kelaan, I believe the BAP/BP only changes spark advance to compensate for altitude. Lets start over....(not all of this in in any order) it cranks , but no start, tries to fire? With key on, fuel pump primes? You do have rail pressure? You have spark......you stated new dist. has new tfi module and stator?(PIP sig) This is the crank/cam sensor for inj. firing !!
Is the dist. a few teeth or even 180 out?

I would start over there and put it at TDC. (5.0 roller motors use windsor firing order) I say this because these cars are not bank fire, they are sequential inj. fire. What year PCM is it? Have you double checked the inj. harness at the back of the plenum. The EEC4 is a basic simple system. These cars can start and run with the BP,ect,r MAF,etc. unplugged. How are checking to see if the inj. are/are not firing? Have you pulled any codes?

I would start with the EEC relay. you say it is good.. I would double check/replace it...fuel pump relay????

Fuel pump relay under drivers seat....green /black EEc relay pass. kick panel next PCM...brown/black

Let me know what you come up with.

 

check the emergency fuel shut off switch i believe that model has one it should be located in the hatch area on the right or left side under the plastic! i had a probe that done that once and the switch had cut off the fuel pump but the button looked like it was still pushed come to find out the button had flipped it was just stuck on/ on/!It couldn't hurt to check it