Stutter/miss at WOT

[lky_3]

Hey Guys. Im new to Stangnet.com and this is my First post. Here it goes:

I have an 89 Mustang 306 with KB hypers, GT40 Tubular intake, 24# injectors, Paxton FPR, 70mm Professional Products TB, 4” AFM Tube with a 90mm LMAF attached and Complete MSD ignition (Blaster, Bilett Dizzy and 6AL). It also has a Tune and a Revolution chip installed. I do not have any EGR or AC equipment on the car.
When the car is at idle I can rev it and its fine, no miss at all and when its cold I can drive it and get no miss at WOT. As soon as it warms up I start getting a miss at WOT. I have replaced the AIC, TPS and done a base line idle reset both to no avail. TPS is set at .96V. I checked to see if I was getting spark to all the wires by pulling them off one by one as the car was running, I am. I Sprayed carb cleaner around to the intake area to check for leaks and there was no change in idle. None of the plug wires appear to be shorted or burned through. I did the “Salt and pepper” fix to ensure a good connection and checked for shorting out wires as well. None of the vacuum hoses are cracked or disconnected. When I pulled codes, this is what I got:

KOEO:
(In Order)
15 - EEC ROM test Failed / (C) status - power interruption to EEC KAM test failed
81 - Air diverter solenoid fault, intake air control circuit fault / air injection diverter
82 - Integrated relay control module
85 - Canister Purge solenoid circuit failure
10 - Testing Mode
11 - System OK

KOER:
(In Order)
21 - Cooling Temperature sensor out of range or ECT out of range
94 - Air diverter solenoid circuit fault
44 - Thermactor Air System fault
13 - RPM Idle out of range / LOW

I dont have any of the smog or AC equipment. When the code 13 came up during the running test, the idle was at 1700. I just replaced the Coolant temperature sensor in the lower intake manifold. Im worried about codes 15 and 82.

I was searching and thought it might be an EEC issue due to the Code 15 I got. Here is a breakdown on how to check and fix this issue, but before I buy another computer I wanted to check the thoughts of my fellow Mustang Owners.

This is from ‘Jrickhter’:

Code 15 - No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test
Failure). The voltage to the Keep Alive Memory (KAM) is missing (wiring problem)
or the KAM is bad. The KAM holds all of the settings that the computer "learns" as
it operates and all the stored error codes that are generated as a result of
something malfunctioning while the engine is running. Use a voltmeter to check
the voltage to the pin 1 on the computer - you should always have 12 volts. No
constant 12 volts = bad wiring. If you do always have the 12 volts, then the KAM is
bad and the computer is faulty.

If the computer has to "relearn" all the optimum settings every time it powers up,
the initial 5-30 minutes of operation may exhibit surges, poor low speed performance,
and rough idle.

Note that some aftermarket chips will cause code 15 to set. Remove the chip,
clear the codes and retest.

Before replacing the computer, remove the battery ground cable for about 20
minutes. This will clear all the codes. Retest after several days of running. If the 15
code is gone, then don't worry about it. If it is still there, then you get to do some
troubleshooting.

- I am getting a constant 11.6V to pin #1 WITH the chip in. Its a Revolution chip. I know its not exactly 12V....but I didnt know if it had to be EXACT or close. When I start the car, the #1 pin gets 14V with 3G Alternator.

Any help would be GREAT!

 

[stang9150]

Did you replace or swap out the tfi module could be breaking down under heat?

 

[jrichker]

The add on chip is usually the culprit in most code 15 problems. Don't be surprised if it doesn't go away.

As recommended, replace the TFI and check the shutter & PIP sensor inside the distributor. Check for wiggle or wobble in the PIP shutter wheel. MSD products are famous for causing problems, so if you still have the stock ignition, put it back in. Unless you are running NO2 or pressurized induction, the stock ignition works fine up to 400+ HP.

 

[SMOKEDYA]

The add on chip is usually the culprit in most code 15 problems. Don't be surprised if it doesn't go away.

As recommended, replace the TFI and check the shutter & PIP sensor inside the distributor. Check for wiggle or wobble in the PIP shutter wheel. MSD products are famous for causing problems, so if you still have the stock ignition, put it back in. Unless you are running NO2 or pressurized induction, the stock ignition works fine up to 400+ HP.

AMEN! that is the same thing that was going on with my POS MSD crap!peace






john

 

[lky_3]

Finally got around to pulling the dizzy today. Here is what I found. PIP and Shutter wheel were not loose or wobbly at all. Wheel looks pretty rusted and PIP looks old and worn. Tried pulling the gear off today so I could swap the PIP out, but couldnt get the gear off. I removed the cross pins as well. Tested the TFI module at Autozone, and checked it SEVEN times and it was good, with no fails. Check out these pics:
View attachment 212291
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Here what I was thinking:
Possible Fuel Related - I should check for 12V at the power wire for the FP while Under a Load, Double check the Fuel Pressure while under a Load at WOT and Bench Test all 8 Injectores to make sure they are flowing properly.
Do you know if a Stock PIP fits and MSD Dizzy or do I have to get a MSD one?
What do you guys think?

 

[Chrome_Rust]

the eyeball gauge says a stock one will work. I have a ProComp billit Dizzy in my car, I was having a simular issue and gutted it and installed all ford parts. the shutter was the same, the PIP sensor was the same.

 

[lky_3]

How did you get the dizzy gear off?

 

[lky_3]

Well....had to take it to a machine shop to press off the gear. Got it all back together and installed it in the car at #1 TDC Compression stroke and pointing at the #1 plug on the dizzy. Set base idle at 10* with spout OUT, then re-installed spout and did the base line idle reset (set @ .96). Everything was great until I went for the test drive. Within 3 minutes the idle was hanging around 2000 at a stop sign/light and still had the MISS at WOT. This only happens under load. Any other suggestions?

So far I have:
Checked MSD TFI on dizzy - Good
Replaced IAC
Replaced TPS
Replaced Rotor
Replaced PIP in dizzy with motorcraft
Cleaned Shutter wheel
Completed the 10 pin fix (making the pins fit tighter together)
Base Idle reset
Checked for vacuum leaks - None


Have not yet:
Bypassed the 6AL
Tried a stock Coil
Replace Cap
Checked Injectors for flow

 

[jrichker]

The hanging idle suggests TPS problems. You may have some wiring problems in the engine fuel injection wiring harness.

Some basic checks you can make to be sure that the sensor is getting power & ground:
Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.
Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same black/white wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery cable. It should be less than 1.5 ohm.

The following power on check requires you to turn the ignition switch to the Run position.
Use a DVM to check for 5 volts on the orange/white wire. If it is missing, look for +5 volts at the orange/white wire on the TPS or EGR sensors. Use the black/white wire for the ground for the DVM.

 

[lky_3]

On each of the 3 things I should check resistance on, where should I place the leads from the multi-meter? I know its the black/white wire, but where for the red lead and where for the black lead. Thanks.

 

[jrichker]

Note that all resistance tests must be done with power off. Measuring resistance with a circuit powered on will give false readings and possibly damage the meter.
Check the resistance between the black/white wire on the MAP/BARO sensor and then the black/white wire on the EGR and the same black/white wire on the TPS. It should be less than 1 ohm. Next check the resistance between the black/white wire and the negative battery cable. It should be less than 1.5 ohm.

 

[lky_3]

Measured resistance today. Here is what I did: Disconnected Salt on the Salt and Pepper Shakers and connected the negative lead to the center post, which is the blk/wht wire then connected the red lead to the TPS/EGR/MAP sensors individually, of course. I also checked the resistance in the TFI coil. Here is what I got.

TPS - 3.9
EGR - .39
MAP - No Reading
TFI - Primary - 1.1 and Secondary was 3.2

The Primary for the TFI should be no more than .68 and secondary no more than 4.6K Ohms. What do you make of this?

I have to find some wire so I can check the battery cable cause mine is in the hatch.

 

[jrichker]

The TPS reading is high - look for a dirty connection or bad wiring in the engine fuel injector harness.

No reading at the MAP/Baro sensor black/white wire is very bad - that should set code 22. If it didn't, them you made some mistake when you took the reading.

 

[lky_3]

Something didn't seem right, so I went back outside and checked the resistance on the on the MAP/TPS and EGR. They were all 0.9V. I had the leads on the multi-meter crossed (Red was in the COM location). What do you think now?

 

[jrichker]

It is becoming apparent that electrically you are in over your head. Some training would be very beneficial for you in order to troubleshoot the problems you are having.


Try Automotive Online Instruction for a beginning course. The course is very good and best of all, it is FREE!!!

The meter is color blind: It cannot tell one lead color from the other. Almost all DMM's are not polarity sensitive. You can reverse the test leads and not damage the meter or get any real difference in readings.

You need to have one lead (any color) plugged into the DMM common socket and the other lead (any color) into the DMM volts/ohms socket. Then you can measure resistance and voltage.

Only diodes and transistors will give different resistance readings when the DMM leads are reversed. The only diode is in the IAC/IAB, but that is not something you need to worry about at this time.

 

[lky_3]

Thanks for the advice. I will look into it, BUT for now is there anything else I can test or check to get this car running correctly. I may not know a whole lot about wiring, but i was just going off what the meter was telling me. I didn't know it didn't matter which color was what, I figured they wouldn't color coat them if it didn't. Anyway...I got those readings last ALL 0.9 resistance, which is what it should be at, so do you have another suggestion for me to check something?

 

[jrichker]

If you got .9 ohm between the black/white wires on the engine EFI harness, that is very good.

If you got .9 ohm between the black/white wires on the engine EFI harness and the battery ground, that is excellent.

 

[lky_3]

Then what should I try?

 

[jrichker]

Take a few minutes to post what you have tested and haven't tested. Include any measurements ( resistance, voltage, etc.). That will help me keep track of what you have done and what might be useful to check next.

 

[lky_3]

So far I have:
Checked MSD TFI on dizzy - Good
Replaced IAC
Replaced TPS
Replaced Rotor
Replaced PIP in dizzy with motorcraft
Cleaned Shutter wheel
Completed the 10 pin fix (making the pins fit tighter together)
Base Idle reset
Checked for vacuum leaks - None
Bypassed 6AL

Have not yet:
Tried a stock Coil
Replace Cap
Checked Injectors for flow

Readings:
TPS: 0.9 at Cold to 1.1-1.6 when warm
EGR: 0.9
MAP: 0.9
NEG Battery Cable: 1.2
MSD Blaster Coil: Primary - 1.36 & Secondary - 0.42

Bypassed the 6AL today and still have the same issue. Whats next on the agenda? I do still have the chip in and have kept it in the entire time, should I remove it and re-test or would it matter?