Cannot find weird fault in 986 S
07-13-2017, 04:41 PM
#1
1st Gear
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Cannot find weird fault in 986 S
Hi All
the first 400 miles were okay. Then the car would not react to commands with the gas pedal. The rev counter stayed at idle and the engine could get started at all times. It just would not rev. As if starved for petrol.
Had no cell network in Belgium. Tried to drive on after half an hour parked on the motorway. Could drive on another 70 miles. Then loss of power... And again, and again.
A friend thought it was the throttle valve poti, but this 986 doesn't have one!
Fuel pump relais overheating?
After a cooling down period, the car would drive normally. Alas, when I started it parked on the tow truck with an angle, it revved exactly 3,000 and then went to 3,500 and stayed there, without me touching the gas pedal.
I shut off the engine and upon re-starting, it idled normally.
Am at the end of my wits and would like to ask for suggestions.
Will replace the complete fuel pump with relais next. And the Air Mass sensor.
Suggestions, please?!
the first 400 miles were okay. Then the car would not react to commands with the gas pedal. The rev counter stayed at idle and the engine could get started at all times. It just would not rev. As if starved for petrol.
Had no cell network in Belgium. Tried to drive on after half an hour parked on the motorway. Could drive on another 70 miles. Then loss of power... And again, and again.
A friend thought it was the throttle valve poti, but this 986 doesn't have one!
Fuel pump relais overheating?
After a cooling down period, the car would drive normally. Alas, when I started it parked on the tow truck with an angle, it revved exactly 3,000 and then went to 3,500 and stayed there, without me touching the gas pedal.
I shut off the engine and upon re-starting, it idled normally.
Am at the end of my wits and would like to ask for suggestions.
Will replace the complete fuel pump with relais next. And the Air Mass sensor.
Suggestions, please?!
08-20-2017, 04:27 AM
#5
4th Gear
Join Date: Aug 2017
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It's a 2000 "S" (3,2 liter) 6-gears stick shift with about 110,000 miles.
I had bought it and the issues occured on the way back from Birmingham UK to Germany.
* the diagnostics says "unknown error"
* in the mean time, it got all new brake disks and pads, some suspension parts and a loose drive train fixed. The disks were too thin to get them refurbished. (Man, I am adding stuff to my check list. the next Porsche I buy, I will be thorough
I had bought it and the issues occured on the way back from Birmingham UK to Germany.
* the diagnostics says "unknown error"
* in the mean time, it got all new brake disks and pads, some suspension parts and a loose drive train fixed. The disks were too thin to get them refurbished. (Man, I am adding stuff to my check list. the next Porsche I buy, I will be thorough
08-20-2017, 12:36 PM
#7
Race Director
Hi All
the first 400 miles were okay. Then the car would not react to commands with the gas pedal. The rev counter stayed at idle and the engine could get started at all times. It just would not rev. As if starved for petrol.
Had no cell network in Belgium. Tried to drive on after half an hour parked on the motorway. Could drive on another 70 miles. Then loss of power... And again, and again.
A friend thought it was the throttle valve poti, but this 986 doesn't have one!
Fuel pump relais overheating?
After a cooling down period, the car would drive normally. Alas, when I started it parked on the tow truck with an angle, it revved exactly 3,000 and then went to 3,500 and stayed there, without me touching the gas pedal.
I shut off the engine and upon re-starting, it idled normally.
Am at the end of my wits and would like to ask for suggestions.
Will replace the complete fuel pump with relais next. And the Air Mass sensor.
Suggestions, please?!
the first 400 miles were okay. Then the car would not react to commands with the gas pedal. The rev counter stayed at idle and the engine could get started at all times. It just would not rev. As if starved for petrol.
Had no cell network in Belgium. Tried to drive on after half an hour parked on the motorway. Could drive on another 70 miles. Then loss of power... And again, and again.
A friend thought it was the throttle valve poti, but this 986 doesn't have one!
Fuel pump relais overheating?
After a cooling down period, the car would drive normally. Alas, when I started it parked on the tow truck with an angle, it revved exactly 3,000 and then went to 3,500 and stayed there, without me touching the gas pedal.
I shut off the engine and upon re-starting, it idled normally.
Am at the end of my wits and would like to ask for suggestions.
Will replace the complete fuel pump with relais next. And the Air Mass sensor.
Suggestions, please?!
From memory the factory reference guideline is to do an error code clear then do an E-Gas calibration then check for any error codes. If any (and if they apply to the E-Gas/throttle body) then that's the problem.
You'll need access to something that can pull codes and report them even codes that are not standard OBD2 codes. For instance codes like P1XXX. The '1' means the code is manufacturer specific.
However, and I don't have my error code reference handy, some E-Gas/throttle body error codes may be of the P0XXX variety which are standard specific not manufacturer specific.
My experience is even an older Actron unit can pull these codes (P1XXX and also the P0XXX codes, too) but of course can't offer any "hint" as to what the P1XXX code means. Durametric can pull these code and may even be able to offer a "hint" as to what the code means.
Otherwise you'll have to take the car to a shop equipped with the Porsche diagnostic computer and someone with the knowhow to use it properly and to make sense of what it reports.