vjsimone

Sorry, i'm slow sometimes.... So, you had the gauge hooked up to the schrader valve. And, also a hose tap squirting into a jar via a clear hose type setup?

93Bandit

Yes. That's how I did it. It wasn't flowing very much though, I don't remember the flow rate but my professor didn't think it was enough and thought it might be due to the small clear hose so then we hooked up a pressure gauge hose to the schrader valve that didn't have a gauge on it and that's when we started getting air.

vjsimone

So, no air with the clear hose, but air with the other hose ?

Stock plugs?

93Bandit

Correct. Actually, stopping to think about it, if there is air getting into the system, shouldn't that show up even with the smaller hose?

I put the correct plugs that everyone always recommends for these motors in it. Motorcraft I believe

Chris_1

iTrader: (1)

No disrespect to your teacher but I don't see the lean code affecting the ICM.
My experience is black ICM for automatics, grey for manuals; just for reference.
I would suspect something else in the ignition system (like an aftermarket coil, or the like) (or a bad connector or incorrect wiring creating issues) to be the cause of several failed ICM units. Unless you just got several crappy ICM's - because generally that factory system is pretty bulletproof in it's stock form.
You just have to look at all the 20 year old F150's running around that still have their original ICM's and distributors and coils; and they're still running great, dependable as a new truck.
Bubbles aside, I don't think flow rate is a big issue with EFI (it was for carburetors) because EFI is more about pressure.
Now you said you had 38 psi - is that KOEO or idle ? because KOEO is generally your max pressure; at idle you can expect that to drop 5 to 8 psi which would put you pretty close to the not enough pressure to run the engine mark.
Low pressure could give you a lean code. It could be caused by a weak pump, a clogged filter or a faulty FPR.
Just food for thought.

vjsimone

So, is your ICM Grey or Black ?

Do you have an automatic or Manual ?

Your transmission is operating Normally?

How many miles do you estimate on your engine?

How many miles on your oxygen sensor?

When you temporarily remove the vacuum line from the FPR (plug it), how does it effect the pressure? @KOEO? @Idle?

Oh, check the vacuum line for signs of fuel if you have it off.

vjsimone

Does this "misfire/detonation" occur during; Initial Cold Start? Warm Idle? Cruising? Deceleration?

93Bandit

I'll check the FPR vac line and check psi this afternoon.

The detonation is more obvious once the engine is up to operating temp and the TC has locked. It detonates under partial throttle acceleration at low vehicle speeds, mostly in 3rd and 4th gears. As for the missfire, when the engine is warm idling, the motor shakes at constant intervals which causes the whole truck to have a slight shudder. If you sit in the cab you can feel the truck shaking, and you can see the door mirrors shaking as well. I can feel the shake while cruising too, and it's much worse once you try to accelerate without the trans downshifting.

93Bandit

Is it possible the detonation issue could be due to a faulty knock sensor?

vjsimone

So, providing you have replaced your Fuel Filter & FPR, I will have to agree with other lads that you probably don’t have a fuel delivery or pressure issue up to your injectors. The ranges I have read are (KOEO; 35-45psi)(@ Idle; 30-45), so you are well within these 2 ranges @ 38psi.

The Injectors are another story (Dirty? – May cause a lean condition, yadda yadda yadda).

So with that assumption;
Wouldn’t you receive a Lean Code if your Oxygen Sensor was recognizing a lean condition? You might want to monitor O2 voltage output at Pin 29 on your EECM//Computer.

Concerning your “detonation issue”, (spark knock)
Detonation Causes;
Can be caused by Low Octane under load, try putting in a tank of 92 temporarily to eliminate this possibility.

If your EGR is not opening during cruising/higher RPM, Detonation may occur from the increased chamber temp. Prove that this device is opening during cruise rpm.

Over-advancing ignition timing may also cause Detonation, try retarding the timing temporarily a few degrees to eliminate this possibility.

If your Knock Sensor is defective, it may not be sending the pre-detonation signal to your EECM/computer, this may cause Detonation. No Knock Sensor Codes?

A lean fuel mixture – Check for Vacuum leaks, Injector issues, Restricted fuel filter or a weak fuel pump.

The wrong plug heat range may cause detonation, you might want to put in a cooler heat range plug than what you have been using (copper).

Pull a plug and photograph the Tip & Insulator end and post.

Concerning your misfire issue; No Misfire DTCs?
Misfire; This is a loss of proper ignition in the chamber.

Misfire Causes;
If the fuel mixture becomes too lean, "lean misfire" may occur
No Spark/Weak Spark may cause a Misfire.

Crossed Spark Plug Wires – Use wire separators.