stalling and speed signal pre serp - some testing results
Discussion
hi guys, finally getting round to having a look at this.
Symptom - intermittent! when coming to junction, on clutch and off throttle, the car sometimes stutters and cuts out, not always. It will do it if im driving along at say 70 dip clutch and take foot off gas. It re-starts straight away.
I set base idle the other night and also cleaned the stepper. Ive also started testing some of the sensors:
TPS (which ive read can cause issues) 0.28v closed 4.62v WOT so within spec
Fuel and Coolant sensors seem to be within spec at 20 deg and 80 (not fuel @ 80!)
AFM 0.31v with no airflow through it 1.61v on hot idle (blue/red wire = 1.64v engine off)
Car is a 1993 4.3 running on the "open loop" map
No Ive read there is a speed signal - which ive identified the pin on the ECU - which is used to keep revs up when above 3mph, but its different on the pre sep? serp had a conversion box, the pre didnt? is this correct?
When testing this I am looking for a pulsed signal to the ecu to tell it that its above 3mph - im wondering if mines is faulty and sometimes doesnt give the signal?
Best way to test/prove?
cheers
chris
Symptom - intermittent! when coming to junction, on clutch and off throttle, the car sometimes stutters and cuts out, not always. It will do it if im driving along at say 70 dip clutch and take foot off gas. It re-starts straight away.
I set base idle the other night and also cleaned the stepper. Ive also started testing some of the sensors:
TPS (which ive read can cause issues) 0.28v closed 4.62v WOT so within spec
Fuel and Coolant sensors seem to be within spec at 20 deg and 80 (not fuel @ 80!)
AFM 0.31v with no airflow through it 1.61v on hot idle (blue/red wire = 1.64v engine off)
Car is a 1993 4.3 running on the "open loop" map
No Ive read there is a speed signal - which ive identified the pin on the ECU - which is used to keep revs up when above 3mph, but its different on the pre sep? serp had a conversion box, the pre didnt? is this correct?
When testing this I am looking for a pulsed signal to the ecu to tell it that its above 3mph - im wondering if mines is faulty and sometimes doesnt give the signal?
Best way to test/prove?
cheers
chris
I had silimar stalling problems which turned out to be an engine earth strap which was starting to fray - it's about a foot long. It was also causing a bank to drop out very occasionally.
Not a solution often mentioned but maybe worth a look or at least clean up the contact points.
FFG
Not a solution often mentioned but maybe worth a look or at least clean up the contact points.
FFG
Edited by FlipFlopGriff on Wednesday 24th July 13:04
chrisdurham said:
Car is a 1993 4.3 running on the "open loop" map
No Ive read there is a speed signal - which ive identified the pin on the ECU - which is used to keep revs up when above 3mph, but its different on the pre sep? serp had a conversion box, the pre didnt? is this correct?
When testing this I am looking for a pulsed signal to the ecu to tell it that its above 3mph - im wondering if mines is faulty and sometimes doesnt give the signal?
Correct, for that Chim pre-serp (don't confuse with Griff pre-cat - thats different again) the ecu has speed signal from the rover gearbox sender & the speedo is a separate trigger from the diff nose.No Ive read there is a speed signal - which ive identified the pin on the ECU - which is used to keep revs up when above 3mph, but its different on the pre sep? serp had a conversion box, the pre didnt? is this correct?
When testing this I am looking for a pulsed signal to the ecu to tell it that its above 3mph - im wondering if mines is faulty and sometimes doesnt give the signal?
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