1985.5 F150 5.0 EFI - Problem with fuel through injectors?

[sgauvry]

Steve, I recall a picture somewhere of spiffy new injectors on your engine, but darned if I can find it now?

What size injectors are you using? Are they leaking even without the ground? They should seal off tight when not actuated.

Hi Ray -

I'll be checking the size of the injectors once the weather clears. Raining cats and dogs for the next few days (and possibly a little snow tonight)!

I do not believe they are leaking at all, but I can check that again when I go to pull them.

Also confusing is that these are the same injectors I used on my old engine, and they worked just fine. Something is not adding up.

[sgauvry]

Steve, two suggestions, with the injectors (I would just do the driver's side) lifted up out of the manifold and the wiring harness unplugged, see if the injectors are spraying with the key on, if not, then you probably do not have an injector problem, if they do, unplug the individual injector connections and try the same test, if they do not, then it is wiring related. Second, same test again with the harness plugged in, if they spray continuously, then you have a wiring problem between the plug and EEC. Disconnect the EEC and repeat, no spray, EEC is kaput, spray, start looking for a ground in the two injector group wires, tan with a red dash and tan with an orange dash. Good luck, these are the kind of things that will drive you nuts.

Your injectors should probably be orange top and are 19#/hr, those are used on 5.0 and 5.8L engines and a lot of the later Mod motors.

Thanks, Bill! I will do these tests once the weather clears. We've got lots of rain forcasted here today and tomorrow, and even some snow tonight. Hopefully, I can get to this on Wednesday.

 

[NotEnoughTrucks]

Hi Ray -

I'll be checking the size of the injectors once the weather clears. Raining cats and dogs for the next few days (and possibly a little snow tonight)!

I do not believe they are leaking at all, but I can check that again when I go to pull them.

Also confusing is that these are the same injectors I used on my old engine, and they worked just fine. Something is not adding up.

If you had them running on your old engine, they must at least be close!

I agree, something does not add up?

I recall something about using a test light to check for injector pulses. Is my memory correct? Any chance you have a set of those "noid lights" that plug into the injector connector to test for pulses? Pretty much grasping at straws here.

[sgauvry]

If you had them running on your old engine, they must at least be close!

I agree, something does not add up?

I recall something about using a test light to check for injector pulses. Is my memory correct? Any chance you have a set of those "noid lights" that plug into the injector connector to test for pulses? Pretty much grasping at straws here.

Hello Gents!

Pulled an injector this morning prior to running any tests.

The injector reads 24 lb/hr. Me thinks way too much for my 302.

Not sure why my old engine ran, but I can say that I know I was leaking fuel through the fuel lines. Possibly, the leaking fuel relieved some of that pressure?

Fuel lines are now repaired and possibly, the injectors are working as they should but are now flooding the engine because of too much fuel. Thoughts?

[sgauvry]

Steve, two suggestions, with the injectors (I would just do the driver's side) lifted up out of the manifold and the wiring harness unplugged, see if the injectors are spraying with the key on, if not, then you probably do not have an injector problem, if they do, unplug the individual injector connections and try the same test, if they do not, then it is wiring related. Second, same test again with the harness plugged in, if they spray continuously, then you have a wiring problem between the plug and EEC. Disconnect the EEC and repeat, no spray, EEC is kaput, spray, start looking for a ground in the two injector group wires, tan with a red dash and tan with an orange dash. Good luck, these are the kind of things that will drive you nuts.

Your injectors should probably be orange top and are 19#/hr, those are used on 5.0 and 5.8L engines and a lot of the later Mod motors.

Good morning, Bill!

I performed the tests you recommended. Here are the results:

Test one - Unplugged injector harness and turned key to on position. Although fuel rail filled with fuel, injectors did not spray fuel. Passed.

Test two - Connected injector harness and put key to on position. Injectors shot a single spray of fuel. Passed.

I think we can say the injectors (24 lb/hr) are putting forth too much fuel.

Steve

[vjsimone]

Good morning, Bill!

I performed the tests you recommended. Here are the results:

Test one - Unplugged injector harness and turned key to on position. Although fuel rail filled with fuel, injectors did not spray fuel. Passed.

Test two - Connected injector harness and put key to on position. Injectors shot a single spray of fuel. Passed.

I think we can say the injectors (24 lb/hr) are putting forth too much fuel.

Steve

I wasn't aware that when you turned the key to ON, that the injectors fired once. ?

[Gary Lewis]

I wasn't aware that when you turned the key to ON, that the injectors fired once. ?

Nor I, Vinny, nor I.

Steve - I'm having a hard time believing that the injectors are too big. But it appears that way from the testing. And your theory that they weren't being given full pressure may be the key. Is there any way to turn your pressure down in order to test?

I'm wondering if it is a case of the computer, because it was unplugged for a considerable period, having defaulted to a preset value of injector pulse width that is too long for those injectors. But, if the engine were able to be run for a bit then it might figure that out and reduce the pulse width.

I don't know how the computer's pre-sets work, but I'm just thinking.

[85lebaront2]

Nor I, Vinny, nor I.

Steve - I'm having a hard time believing that the injectors are too big. But it appears that way from the testing. And your theory that they weren't being given full pressure may be the key. Is there any way to turn your pressure down in order to test?

I'm wondering if it is a case of the computer, because it was unplugged for a considerable period, having defaulted to a preset value of injector pulse width that is too long for those injectors. But, if the engine were able to be run for a bit then it might figure that out and reduce the pulse width.

I don't know how the computer's pre-sets work, but I'm just thinking.

Yes, the injectors are too large for the computer's programming, it is set for 19#/hr injectors, 24#/hr are 126% of the size expected.

I do not recall seeing a single shot of fuel at the initial "key on" on any EFI system. Every one I have worked on requires some form of "engine is turning" signal. On the Ford truck systems we are dealing with it is the PIP signal from the distributor.

One more item to try, unplug the red/blue wire from the starter relay and repeat, only turn the key to "start" and see if the injectors spray without the engine actually turning.

[vjsimone]

Nor I, Vinny, nor I.

Steve - I'm having a hard time believing that the injectors are too big. But it appears that way from the testing. And your theory that they weren't being given full pressure may be the key. Is there any way to turn your pressure down in order to test?

I'm wondering if it is a case of the computer, because it was unplugged for a considerable period, having defaulted to a preset value of injector pulse width that is too long for those injectors. But, if the engine were able to be run for a bit then it might figure that out and reduce the pulse width.

I don't know how the computer's pre-sets work, but I'm just thinking.

If the Key On squirt is not normal, then what other inconsistencies is the ECA providing?

I do believe the Cranking Strategy provides the richest mixture, then less rich during Cold Start strategy.

So, if his injectors are oversized, he could be so rich that the fuel will not ignite. I believe that is what his previous testing showed by removing the fuel supply from the equation.

Another Shade Tree test he could perform is to leave the Drivers side Injectors electrically disconnected during a test, this will cut back the fuel delivery somewhat. But I don't remember if the lower intake is compartmented for each cylinder, if so, some will flood, and some will starve.

Or, put a 2K resistor in the ECT connector to fool the ECA that the engine is warm. This will apply the Warm Start Strategy, which should equate to a normal running mixture.

He will have to replace the injectors eventually.

[Gary Lewis]

If the Key On squirt is not normal, then what other inconsistencies is the ECA providing?

I do believe the Cranking Strategy provides the richest mixture, then less rich during Cold Start strategy.

So, if his injectors are oversized, he could be so rich that the fuel will not ignite. I believe that is what his previous testing showed by removing the fuel supply from the equation.

Another Shade Tree test he could perform is to leave the Drivers side Injectors electrically disconnected during a test, this will cut back the fuel delivery somewhat. But I don't remember if the lower intake is compartmented for each cylinder, if so, some will flood, and some will starve.

Or, put a 2K resistor in the ECT connector to fool the ECA that the engine is warm. This will apply the Warm Start Strategy, which should equate to a normal running mixture.

He will have to replace the injectors eventually.

Those would appear to be the proper size for my 460 in Big Blue!

I'm not sure what injectors I want to go with, but yours are big for a 302.