ECU pulling timing at 4000+ rpm with only 11 psi?

[Cellos88SVO]

I recently purchased a Hallman MBC, carefully installed everything, iteratively tested and found that the car won't let me run anything over 9 psi. I had set the pressure to roughly 11 psi (according to my autometer gauge) but the car keeps cutting out at just over 4000 rpm under WOT. I'm assuming the knock sensor is detecting some knock but I didn't think there would be some at only 11 psi... I have no desire to remove the KS.

Specs:

Fuel - 91 pump gas with Lucas Octane Booster
Engine - Has a two-stage Forge BOV, ported and polished turbo-coupe head, Esslinger cam (don't know the specs but doesn't sound too aggressive)

Is there anything I can check or do I have to wait to get an AFR gauge before I can have a clue on what is going on?

[MikeFleming]

First off, verify you have enough fuel flow (fuel pressure under load). Verify (replace) all secondary ignition components (spark plugs, cap, rotor, wires) Verify (repoair as neded) battery and charging system (where the igniton gets its power from).

Lastly, test it again with some real octane. Add one gallon of paint store Toluene to 1/2 tank of petrol.

[Cellos88SVO]

First off, verify you have enough fuel flow (fuel pressure under load). Verify (replace) all secondary ignition components (spark plugs, cap, rotor, wires) Verify (repoair as neded) battery and charging system (where the igniton gets its power from).

Lastly, test it again with some real octane. Add one gallon of paint store Toluene to 1/2 tank of petrol.


-The Cap, Rotor, and Wires were replaced less than 10k ago.

-Spark plugs can probably be replaced (which should I use and what should I gap them to?)

-Battery is brand new (replaced only a few months ago) and the charging system seems to work fine (seeing ~14.4 volts)


How can I check for fuel pressure under load without some kind of data logging apparatus? (I'm thinking about picking up an auxbox).

[MikeFleming]

How would you know if timing is being pulled? Do you have some instrumentation that indicates this?


-The Cap, Rotor, and Wires were replaced less than 10k ago. Depending on age and original product "quality", that's old.


-Spark plugs can probably be replaced (which should I use and what should I gap them to?) 0.030" is typical.


-Battery is brand new (replaced only a few months ago) and the charging system seems to work fine (seeing ~14.4 volts)
Sounds good.


How can I check for fuel pressure under load without some kind of data logging apparatus? (I'm thinking about picking up an auxbox). You will need to attach a mechanical gauge and find a way to observe it under load. Ther are no sensors to monitor here.

[Cellos88SVO]

How would you know if timing is being pulled? Do you have some instrumentation that indicates this?

I don't, I agree it's a poor title/assumption.


Depending on age and original product "quality", that's old.

They were replace in 2009 I believe so yeah it may be time to replace them. Is it still possible to get parts from a Ford dealer or is there an alternative?


0.030" is typical.

Any particular plug brand? or can I use Motocraft/Autolites?


You will need to attach a mechanical gauge and find a way to observe it under load. Ther are no sensors to monitor here.

Yeah that's what might be tricky. I was thinking of picking up the AuxBox and a pressure transducer to log the fuel pressure against RPM and possibly AFR and TPS.

[SVOJames]

You should be able to get all the motorcraft ignition parts from your local Ford dealer, including spark plugs which work well.
An inexpensive way to monitor fuel pressure is to buy a mechanical/analog fuel pressure gauge, pull the windshield wiper blades, remove that plastic "grid" (I forget the name of it) that sits underneath the wipers, route the house for the FP gauge through the exposed hole, put a wiper back on, use a zip-tie or such to secure the gauge, and take the car for a drive.
Bring a passenger to watch fuel pressure while you drive and watch the boost.

[Cellos88SVO]

I'm still waiting on parts hence why I haven't updated yet. I've order new plugs, wires, an autometer electrical fuel pressure gauge, code reader ($24 to not read blinking lights is money well spent :p ) and a new walbro 255 lph fuel pump (even if it isn't a fuel problem, it's worth upgrading anyway). I still need to track down a cap and rotor, I would prefer to not go through the dealer but I will if I have to.

[Cellos88SVO]

So I pulled codes...

KOEO: No codes (code 11)

KOER: Code 77

I realize Code 77 is an operator error for the WOT test but I pressed the throttle to WOT briefly as instructed. I repeated the test two more times but still the same code. So I'm not sure how to interpret that...

[MikeFleming]

... but I pressed the throttle to WOT briefly as instructed. "Pressing it briefly" is not going to work. During the "Goose" test ("Talk to me, Goose!") The EEC needs to see >50% throttle AND VAF movement at the same time (note the VAF will always be a few milliseconds behind).

So that mean you need to STOMP the throttle (from inside the car) and keep it on the metal until after RPM exceed 3K. Then immediately jump off the throttle and let the engine RPM come back to idle all by itself. It must be a VERY aggressive "stomping".

In any case no EEC related issue was found. So move on.

Do we know that fuel flow/pressure is correct? How much slop/scatter is there in the distributor timing gears/belt? You cna usually observe the scatter at idle and a steady 2000 RRM with a timing light. Does the mark stay rock steady or does it jump around? How far, in degrees, can the dist rotor be moved by hand from full clockwise to full anti-clockwise (engine off, btw)?

[MikeFleming]

Cellos88SVO - please to put a little more detail in your location. You know, just in case someone nearby was to offer to come by with their personal dead chicken to help.

[Cellos88SVO]

"Pressing it briefly" is not going to work. During the "Goose" test ("Talk to me, Goose!") The EEC needs to see >50% throttle AND VAF movement at the same time (note the VAF will always be a few milliseconds behind).

So that mean you need to STOMP the throttle (from inside the car) and keep it on the metal until after RPM exceed 3K. Then immediately jump off the throttle and let the engine RPM come back to idle all by itself. It must be a VERY aggressive "stomping".

I did stomp on the throttle and let off once it hit 5k rpm.


In any case no EEC related issue was found. So move on.

Sounds good.


Do we know that fuel flow/pressure is correct? How much slop/scatter is there in the distributor timing gears/belt? You cna usually observe the scatter at idle and a steady 2000 RRM with a timing light. Does the mark stay rock steady or does it jump around? How far, in degrees, can the dist rotor be moved by hand from full clockwise to full anti-clockwise (engine off, btw)?

I don't know the fuel pressure yet, still waiting on the gauge to come in. I haven't checked the scatter as I don't have a timing light but I'll see if I can get a hold of one.

[Cellos88SVO]

So I swapped plugs and wires:

The plugs were bosch units gapped to 0.045" and the wires weren't Motorcraft but they had a Ford emblem on the boot for the plug connectors.

From a little bit of driving, the car seems to be pulling a lot better at upper RPM and I haven't encountered a loss of power. This is at 11-12 psi of boost. So should I call this one solved? I haven't installed my fuel pressure gauge yet but, I'm curious to see what is going on there.

If all checks out with the fuel pressure, can I increase the boost to 14-15 psi?

[MikeFleming]

0.045" is a bit wide for plug gap on stock TFI ignition. 0.028-0.035" is the more desired range with a stock coil.

[Cellos88SVO]

0.045" is a bit wide for plug gap on stock TFI ignition. 0.028-0.035" is the more desired range with a stock coil.


I replaced them with Motocraft plugs and gapped them as best as I could to 0.030".

[MikeFleming]

... gapped them as best as I could to 0.030". Government work, as they say. It's just as important to have sharp edges on the end of the center electrode when using those old, large electrode types.