eolson

Anyone? My engine started being inconsistent on start up for a while now. Livernois had it for a new tune, and checked this issue from the SC end, bypass valve, tune, SC(Saleen series VI ) all working fine.

My car is running fine as ever when warmed up, but the first couple minutes the idle is inconsistent and it falters with acceleration. Then it runs fine after warming up partially on the way to full warm up.

It seems as if the flow of fuel is being restricted somehow, or delivered un-evenly, then all is fine. There has been no engine warnings at all. Could anyone please suggest where to start. I've spent a lot of money assuring that the car has had quality tunes, I drive it kindly, and this issue seems to have grown more present since the mid summer. Livernois could'nt figure it out, or wasn't willing to. I don't feel it's a SC or boost issue anymore as I mentioned, more like fuel delivery or combustion response. What next ???

Thank you very much, very frustrated, Erik

VistaBlue

I had a huge post typed up, but my work internet tends to hate this site, so now I'll just keep it short. None of these below scenarios would really explain why it fixes itself once warm, but are still worthwhile and easy check/fixes:

-TPS: Is it dirty? Clean it.
-Fuel injectors: Same as above
-Fuel pump: Check the voltage, make sure it isn't on the fritz upon first use (cold)
-Spark: Make sure your spark is strong to all cylinders. Check when cold, and warm
-Of course, make sure the throttle body and etc is all clean and functioning properly. Remove the intake piping, and with the car off, make sure the throttle body is opening and closing properly when cold, and perhaps try to check once warm, as well.

Now, the one thing I can possibly think of that will 'cure' itself once warm, is an engine that is getting tired, i.e: low compression. Thermal expansion, or, the engine warming up, would cause the metallic and rubber surfaces to slightly expand, giving the appearance of a perfectly fine running engine.

The test: An engine compression check. Check each cylinder individually while cranking. You will want to disable the spark while doing this, as you don't want the engine to actually start, just crank. Do this while the engine is cold for each cylinder, and record your results. Then, put it all back together, go for a short drive to get it warmed up, then repeat the same test with the engine warm, just cranking.

That's about all I can think of at the moment!

moosestang

Have you pulled the spark plugs? How about disconnecting the battery for 15 minutes to reset the fuel trims? If it runs good after disconnecting the battery, then at least you know it's not a compression problem, but rather a sensor.

eolson

Thank you VistaBlue and moosestang.

As my car was at Livernoise Performance originally for a new tune, and it was put in successfully, the injectors are new,they changed out the spark plugs, they changed out to a more robust mass air, the intake system was checked and working properly, and the dyno session went fine with no parameters in the tune reading off or any warnings or problems.

They called and confirmed they were having cold start"driveability issues" and apparently checked all related possibilities based on their experience, and checked the SC Boost bypass valve, and that all worked well. I can only assume they would have at least checked basic fuel delivery systems as well, but I don't know. Maybe they concentrated on the SC possibility with boost and didn't investigate fuel delivery.

Since I am not a mechanic, and can perform none of the tasks you descriced above except removing the battery, should I go to a Ford dealer next??? Or do I risk another high performance shop that will cram their agenda down my throat, and not solve the problem again. What is your advice? Where do I go now??

I'd be happy to print out your suggestions, and show them to someone qualified to eliminate these possibilties, but who will honestly and systematically work through the check list until an answer is found? Heinz Ford deals with Saleens and has been very direct and honest in the past here West of Detroit, would that be better than another high performance shop? Please let me know what you all think. Thank you, Erik

kenthicken

Not sure if you have already done this, but clean the MAF sensor.

eolson

Thanks kenthicken,

I would assume Livernoise would have checked the MAF sensor as they replaced the mass air meter, and checked the entire SC set up, including all O/2 sensors in the headers, H-pipe for failure.

As I am not a mechanic, I can only suggest these things to a mechanic. The question is who is most qualified to systematically eliminate all of the above suggestions. Now that the issue does not seem to be related necessarily to the SC set up or boost delivery. Would qaulified Ford mechanics have more experience and training with this type of search and elimination of possibilities? The crew at Livernois did not seem to investigate into the broader or entire possibility range as suggested above. Who might do this most effectively? Anyone??

Thank you very much, Erik

157dB

Sounds like the open loop fuel parameter tables are not correct.
When did this start happening?
Do you have access to the open loop/closed loop PCM indicator via
an OBDII port reader?
What does the A/F ratio guage say when this is happening?

eolson

Thank you 157dB.

It started happening a while after I had a open tune written by JDM in the spring, which none of their previous tunes had this rough start up issue, and the open tune was customized by MRT. Now, the issue still persists, even though as I mentioned above, I had a completely independent tune written from scratch by Livernois. I would find it hard to believe that two independent tunes written by two well respected tuners would have missed the same calibration table settings.

Or are you saying this issue is independent of these locked tunes in my tuner, and can be adjusted with my scanner, or someone elses with out scrubbing my present tune???

Please let me know 157dB. Thank you very much. Erik

157dB

I would guess that the open loop and closed loop
fuel parameter tables are both available to tuners
who write the tunes.
Maybe MRT and JDM didnt fool with the open loop fuel tables.
I would guess that they would for heavy modifications to the motor.

When MRT 'customized the tune', did the modify the already working
tune or dump it and start from scratch?

You paid them, right? I would start asking them detailed questions as
to how they went about writing this 'customized' tune.
Explain the problems to them. They would be far more knowledgable
about it than I am. If you could see the transition from open loop
to closed loop and notice the problems disappear once the transition
takes place, I would expect the open loop fuel table values to be off
or unaltered by the tuner. I never understood with so many FI users
around here dont use a data logger like a MSD DashHawk...
Tuners start with OEM tunes and modify
then for the purpose. The open loop fuel tables could have been left
untouched from OEM values.
Just guessing here.

Universal Parameters
Calculated Engine Load
Engine Coolant Temp (ECT)
Short Term Fuel Trim Bank 1
Short Term Fuel Trim Bank 2
Long Term Fuel Trim Bank 1
Long Term Fuel Trim Bank 2
Fuel Pressure
Manifold Absolute Pressure (MAP)
Engine RPM
Vehicle Speed
Timing Advance (Spark)
Intake Air Temp (IAT)
Mass Air Flow (MAF)
Absolute Throttle Position
O2 Bank 1 Sensor 1
O2 Bank 1 Sensor 2
O2 Bank 1 Sensor 3
O2 Bank 1 Sensor 4
O2 Bank 2 Sensor 1
O2 Bank 2 Sensor 2
O2 Bank 2 Sensor 3
O2 Bank 2 Sensor 4
Relative Fuel Pressure
Diesel/Direct Injection Fuel Pressure
Commanded EGR Duty Cycle
EGR Error
Commanded EVAP Purge Duty Cycle
Fuel Level
Evap Vapor Pressure
Barometric Pressure
Catalyst Temp Bank 1 Sensor 1
Catalyst Temp Bank 1 Sensor 2
Catalyst Temp Bank 2 Sensor 1
Catalyst Temp Bank 2 Sensor 2
Fuel Type (MultiFuel vehicles)
Alcohol %
Fuel System Status (Closed/Open Loop)
Module Voltage
Absolute Load
Number of O2 sensors
Number of WB O2 sensors
Commanded Equivalence Ratio
Relative Throttle Position
Ambient Air Temp (AAT)
Absolute Throttle Position B
Absolute Throttle Position C
Absolute Pedal Position D
Absolute Pedal Position E
Absolute Pedal Position F
Commanded Throttle Actuator
Wide Band O2 Sensor 1 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 2 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 3 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 4 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 5 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 6 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 7 Equivalency Ratio (FACTORY)
Wide Band O2 Sensor 8 Equivalency Ratio (FACTORY)
Auxiliary O2 Short Term Fuel Trim
Auxiliary O2 Long Term Fuel Trim
Wide Band O2 Sensor 1 Heater Current (FACTORY)
Wide Band O2 Sensor 2 Heater Current (FACTORY)
Wide Band O2 Sensor 3 Heater Current (FACTORY)
Wide Band O2 Sensor 4 Heater Current (FACTORY)
Wide Band O2 Sensor 5 Heater Current (FACTORY)
Wide Band O2 Sensor 6 Heater Current (FACTORY)
Wide Band O2 Sensor 7 Heater Current (FACTORY)
Wide Band O2 Sensor 8 Heater Current (FACTORY)
Wide Band O2 Sensor 1 Voltage (FACTORY)
Wide Band O2 Sensor 2 Voltage (FACTORY)
Wide Band O2 Sensor 3 Voltage (FACTORY)
Wide Band O2 Sensor 4 Voltage (FACTORY)
Wide Band O2 Sensor 5 Voltage (FACTORY)
Wide Band O2 Sensor 6 Voltage (FACTORY)
Wide Band O2 Sensor 7 Voltage (FACTORY)
Wide Band O2 Sensor 8 Voltage (FACTORY)
BOOST/VACUUM (Calculated and corrected for altitude!)

Ford Enhanced PID’s
Engine Oil Temp
Trans Fluid Temp
Cylinder Head Temp
Fuel Pressure
Torque Converter Slippage
Pedal Position

moosestang

Does it have a stock throttle body? There are so many things it could be and since you don't have the means to remove the plugs, there's little we can do from here. If one or more of the plugs are soaked in gas, then you could start looking for a spark problem and swap coil paks to see if it moves.

You are only 3hours and 27 minutes away from brenspeed.com. I'm sure they could find the problem.