mclark
SHO Member
From first posting , mechanic stated that fuel pressure was good, and he stated that everything seems to be pointing back to the PCM, that's why I asked was there other recommendations besides the dealership for PCM replacement.
Fuel pump
- Thread starter mclark
- Start date
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IMO, fuel pressure was good when the pump was running but maybe your pump is not always running, or getting weak as it warms up. Your module could also be failing once it warms up.
I went through months of troubleshooting, read here:
shoforum.com
When my issue ocurred, Forscan did show a code for low fuel pressure, have you checked yours?
I suggest you first determine if the pump is getting power or not. If it does, they check fuel pressure when the car is dead. Also check for spark.
I went through months of troubleshooting, read here:
Fuel Pump Issue?
Went to the local scrapyard and was able to get all 3 connectors with about a foot length of wire on each. Cut and spliced the wires going to #3 and soldered the new one in place. Used heat shrink on each individual wire. This morning car died again. Disconnected and reconnected #3 and...
shoforum.com
When my issue ocurred, Forscan did show a code for low fuel pressure, have you checked yours?
I suggest you first determine if the pump is getting power or not. If it does, they check fuel pressure when the car is dead. Also check for spark.
mclark
SHO Member
Codes was pulled p0106,p0234,p0642, fuel pump drive module replaced, was able to get hands on a good used fuel pump same results.
Ta2dResqr
SHO Member
I would start down the P0642 path. If the wrong voltage is sent to other sensors, they will read incorrectly.
Did you check that sensors were getting 5V as @luigisho suggested?
Did your mechanic use OEM or high quality sensors? I've seen videos about people unable to fix issues and then finding out the "new" sensors were bad.
mclark
SHO Member
All replaced parts were Ford parts, no aftermarkets.
1O years old, it probably is due for an LPFP, the filter too at this point is used up.
I've dealt with two PCM replacements , my opinion your just suffering from a fuel delivery issue. With module already replaced, and MAPs, which probably just needed a good cleaning, If you do it yourself, swapping out the LPFP is just a couple hundred bucks.
mclark
SHO Member
Fuel pump assembly replaced as well same results, I'm not hearing the pump come on at no point, mechanic had it for two weeks checking all possible issues, from pump pressure to sensors, he pulled codes again and p0642 was found, his final analysis was a possible PCM failure , anything else to look for, dealership is just going to just throw parts at it and charge me for it,
Ta2dResqr
SHO Member
If he has checked everything, he should be able to tell you what the voltage coming out of the PCM on the sensor circuit is. If voltage going in is good and coming out is bad, then yes, I would suspect a PCM.
Sorry another SHO owner suffered a PCM failure. If it is found to be that. I saved money by already removing cowl, and purchased a PCM off eBay. I bought it before my SHO went to dealership. What I did for my interceptor too. You can get them for under a hundred and dealership will charge for round $100 for programming.
p0642 troubleshooting routine
this trumps p0106 as without a proper voltage reference, most of which comes thru the PCM, the powertrain cannot be properly controlled.
Gasoline Engines PCED
P0106 - Manifold Absolute Pressure (MAP/BARO) Sensor Range/Performance
Gasoline Engines PCED
P0234 - Turbocharger/Supercharger A Overboost Condition
this trumps p0106 as without a proper voltage reference, most of which comes thru the PCM, the powertrain cannot be properly controlled.
Gasoline Engines PCED
P0106 - Manifold Absolute Pressure (MAP/BARO) Sensor Range/Performance
For Vehicles With 3.5L GTDI Engine | |
Description: | The PCM continuously monitors this sensor for concerns. This DTC sets when the MAP PID does not correlate with the BARO or the TCBP PIDs at ignition ON. It will also set if the MAP and TCBP PIDs fail to correlate when running and the TCBP PID does not correlate with the BARO PID at idle. |
Possible Causes: |
|
Diagnostic Aids: | The VREF voltage should be between 4.0 and 6.0 volts. |
Gasoline Engines PCED
P0234 - Turbocharger/Supercharger A Overboost Condition
Description: | The PCM continuously monitors the turbocharger system for an overboost condition. The PCM checks for a maximum TCBP PID reading during engine operation, which indicates an overboost condition. This DTC sets when the PCM detects that the actual TCBP PID value is greater than the desired TCBP PID value by 27.6 kPa (4 psi) or more for 5 seconds. |
Possible Causes: |
|
Diagnostic Aids: | Check tubing for obstructions, cracks and incorrect fitting connections. Check the turbocharger wastegate regulating valve solenoid for correct operation. |
mclark
SHO Member
Hey guys thanks for all the support, before making decision to see the dealership I had once last resort, a few years ago I had some work done on my 94 Sho by a mechanic who worked for the Ford dealership for years, I told him what happened, what the car was doing and codes that was pulled, I didn't tell him the parts that I had replaced. He stated drop it off to him and he will check it, had the car transported to him late Monday evening, got a phone call Tuesday saying car ready for pickup, big smile . Went over to pick up the car he stated that after pulling the code p0642 he pulled the intake manifold and found the wiring short , repaired wiring replaced intake manifold gasket and wallahhh, Sho back on the road, two days in with no problems, once again guys thanks for all the support .
luigisho
SHO Member
This is sound advice for everyone. A quality mechanic is worth paying for sureyou got a good one. dont let go
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