Fuel System Problem - HELP!
09-22-2006, 11:13 AM
#1
Three Wheelin'
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Fuel System Problem - HELP!
As previously posted, my 1992 3.3 (standard except Cat bypass) is poorly.
The symptom is:
Strange idle: ie. it starts OK from cold, runs for about 5 minutes, then the revs drop and it runs uneven, then 5 minutes later it goes back to normal. This pattern continues for as long as I run the car, and also occurs whether the car is idling or driving (in fact when I drive I feel flat spots and backfires too, but only when its in its 'down' period and not when in its 'normal' period).
The garage has replaced the lamda and checked the WUR and still not fixed. They have told me that the fuel mix changes from too rich to too lean and so on.
The tech bod at JZM is working on the case but getting nowhere fast (ie. has other jobs to do meanwhile).
Any Rennlist experts on here who can suggest to where he could narrows his efforts?
Your help greatly appriciated as being without my car is really killing me!!
The symptom is:
Strange idle: ie. it starts OK from cold, runs for about 5 minutes, then the revs drop and it runs uneven, then 5 minutes later it goes back to normal. This pattern continues for as long as I run the car, and also occurs whether the car is idling or driving (in fact when I drive I feel flat spots and backfires too, but only when its in its 'down' period and not when in its 'normal' period).
The garage has replaced the lamda and checked the WUR and still not fixed. They have told me that the fuel mix changes from too rich to too lean and so on.
The tech bod at JZM is working on the case but getting nowhere fast (ie. has other jobs to do meanwhile).
Any Rennlist experts on here who can suggest to where he could narrows his efforts?
Your help greatly appriciated as being without my car is really killing me!!
09-22-2006, 12:16 PM
#2
8th Gear
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I am suffering exactly the same problem but with the addition of missfire under boost.
I will be on the Dyno this Wednesday and will let you know how I get on. I am book at JZ in two week time.
I will be on the Dyno this Wednesday and will let you know how I get on. I am book at JZ in two week time.
09-22-2006, 05:02 PM
#3
Any Rennlist experts on here who can suggest to where he could narrows his efforts?
except for lambda sond and WUR the cold start valve and the acceleration enrichment are affecting the AFR.
if one of the three temperature sensors delivers temporarily misleading values you may have the described effect.
the temperature sensors are relatively reasonable priced and easy to replace.
fritz
Last edited by fritz k.; 09-23-2006 at 04:54 AM.
09-25-2006, 07:54 AM
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Three Wheelin'
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BIG NEWS!
Just received a call from the garage and they have at last found the fault.....
It was in the engine wiring loom. A connection was intermittantly earthing and this fooled the Lamda control. A big thumbs up to the techie there.
Just received a call from the garage and they have at last found the fault.....
It was in the engine wiring loom. A connection was intermittantly earthing and this fooled the Lamda control. A big thumbs up to the techie there.
09-25-2006, 08:16 AM
#7
Rennlist Member
Excellent news!
