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Not getting injector pulse.

23K views 26 replies 14 participants last post by  Got Booost? 
#1 ·
so my car quit on me at a light the other night. i've been using Joel5.0's troubleshooting guide, but would like some other input as well. i've got good fuel pressure, its 43psi with the key on. when i turn the key off it bleeds down, but i dont know whats normal. it will bleed to 30psi in less than 5 mins, the 25psi in about 10, then 20psi in about 20. the pump has never quit whining with the key on though, even before the probs. it will whine all day if you let it with the key on. im getting visible spark at the plugs, and the car fires on starter fluid. the red wire on the injector plug lights my test light, but when i use the test light converted to a noid light it doesnt blink when turning the motor over. i am going to pick up a real noid light today and test it tomorrow. i plan on cleaning the salt and pepper shakers tomorrow. i've been told it could possibly be the TPS, or the TFI, or the PIP. when i try to start the car with the TPS unplugging and feathering the trottle it still wont start. i may buy a DVM and test some things if nothing else works.

heres the original thread that got me to this point. good background info on the issue: http://www.corral.net/forums/showthread.php?t=972055&highlight=injector+pulse

quick notes:
car wont start
getting spark (starts on starter fluid)
good fuel PSI
No injector pulse
 
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#3 ·
I apologize in advance for saying things that you probably already know. I'm just trying to help you talk through the whole thing.
Fuel pressure bleeding down that quickly may not be normal, but it's not hurting you now.
The fuel pump is supposed to run only a second or so to prime the system when you first turn the key on. If the engine is not running, but the fuel pump is, then either the computer somehow thinks the engine is running, or perhaps the fuel pump relay is mechanically stuck in the on condition.
An LED type test light would be better than a regular light bulb type test light because the LED will show far shorter pulses - either off or on - than a regular light bulb.
You could be getting spark, but at the wrong time if the computer or TFI module, or some other part is whacked. But of course that doesn't explain how it starts with starter fluid.
 
#7 ·
yes, the TFI will take a random dump. Testing them is a joke, because they will work cold, and heat up and fail again. There is a way to test the pip, but I don't have any of my books handy.

It's good to have a spare TFI, and most ford owners I know carry spares... I do.

Amusingly, I also had my car die and fail to restart and it was the fuel filter.
 
#8 ·
really? were you still getting fuel pressure when you had the fuel filter issue?

because money is extremely tight right now, i dont want to just start throwing parts at the car. i read if the TFI is bad, the car will fire with the spout out? any truth to this? will try it tomorrow.
 
#9 ·
thinking out loud here, could it be a moisture related issue. this was the first time the car has been in the rain since i started driving it regularly. but it has been 4 days since it died and its still not sarting, wouldnt the moisture have evaporated by now?
 
#12 ·
Take the control module to a local parts store and have it tested (you will need a tool to take it off). Make sure to put heat-sink compound on it when you put it back. At least you can determine/eliminate that possibility.
 
#15 ·
i did the salt and pepper shaker fix, still nothing. took the injector ground off and cleaned it good, scuffed the chead to make sure it was touching metal. bought a noid light kit, and the ford one didnt fit, but the GM one did good, i dont think the make should matter, as long as it fits? didnt flash. im getting a little frustrated with it, may just put it in the shop.
 
#16 ·
I had this exact problem once. There is the module on the side of the distributor. It was actually fine.

The part inside the distributor that it plugs into went bad. Tells the computer when to fire the injectors. You have to take your distributor apart and replace that module. They should sell one at the parts store.
 
#18 ·
the pick up coils are about 20 and the tfi module are about 40 i had a lot of trouble with the tfi module when i first got my fox and have had to replace quite a few in other 5.0s

if you hve to replace your tfi make sure you have a socket thin enough to fit down the hole since they are recessed
 
#19 ·
If getting fire but no spark the pip is working and it is probly the module. Would not get fire or injector pulse if the pip was out. Module takes a thin 5.5mm or special tool also available at parts store.
 
#21 ·
Sounds like a strait forward problem,

test your modules! it is free, after that we may be more helpful!

It it most definitely fuel related since it fires up with starting fluid.

You have SPARK and no FUEL. Yet your fuel pressure is good at the rails soo.....start turning wrenches...
 
#26 · (Edited)
PIP is used for coil and fuel injectors pulse genration.

If you have spark, PIP is OK within the TFI module confinement...... you only need to verify the PIP signal is traveling to the ECM for the fuel pulse part.

When you started the car and kept it idling with the SPOUT connector on, this usually means the PIP is traveling to the ECM and coming back through the SPOUT, with the timing advance added otherwise, the engine wouldn't run even if you use carb cleaner. Suggest to confirm the PIP pulse is present at the correspondent ECM pin (#56)......a LED from Radio Shack will allow you to confirm this if it blinks, connect red LED wire to PIP pin/wire at the ECM connector, and the yellow (negative) LED wire to a good ground and crank the engine.....if the LED blinks, PIP is OK.... if not, check wiring........and do the PIP check described at the end of this procedure..... LUK
 
#27 ·
yup it was the ECM, swapped a new one in and the car runs better than ever. exhaust note is alot more agressive sounding, and louder. isnt as hollow anymore. car runs much smoother too. shifts are now seemless without focusing too much on clutch/gas. also seems to pull a little better from a stand still in first.

thanks guys.
 
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