Seeking advice and thoughts oh wise ones
Discussion
As most regulars will know I rebuilt my engine over the last year. The car is now running, has passed it's MOT and is road legal so I've had a few drives in it and it is almost smiles all round. The almost bit is qualified below:
When first taken for its MOT the car had no guts but idle etc were all ok and where you would expect. This turned out to be timing, which has now been set correctly (by me first then checked and tweaked at a garage with the expensive gear). This has given the car all the power it used to have and it goes like a train. However when setting the timing and tuning the car the garage couldn't get the mixture up to where he would have liked and suggested one of my AFMs was defective. As I have spares and the garage is friendly he suggested I went swapped them around and just brought the car back any time to put it back on the machine for mixture setting. At this time the timing was correct, the car pulled like a train but it idled at around 2500rpm and surged when dropped a couple of times when dropped to idle before settling at 2500 rpm most of the time, occasionally it would drop and settle at around 1200-1600, but never at 850rpm where it should be.
Anyway sure enough the AFM he said wasn't responding correctly had signs of water ingress so I have changed it and this has left the car with the same power, the same surging issue (but it normally only surges once now) and an idle that is rock steady but still high at around 1600rpm vice 850.
I have followed the cologne diagnostics sheet from car mechanics magazine and this hasn't helped. In doing this I have checked and cleaned the throttle body, it all appears to work OK. I have changed the throttle pot with a know good one - this made no difference to the running. I have changed the idle speed control valve for my good spare - again no difference.
I have checked all connectors and all are secure. I now don't know where else to go, therefore please help with the following questions.
1. Any ideas of what else to check?
2. On my car the AFM electrical connections are coloured white and black, the black has 4 connections, the white three. Which one goes on top and which one on the bottom (my labelling tape came off these when re-assembling). I ask this as the car hunts less but idles higher with the black to the bottom.
I look forward to your guidance and advice
Mark
When first taken for its MOT the car had no guts but idle etc were all ok and where you would expect. This turned out to be timing, which has now been set correctly (by me first then checked and tweaked at a garage with the expensive gear). This has given the car all the power it used to have and it goes like a train. However when setting the timing and tuning the car the garage couldn't get the mixture up to where he would have liked and suggested one of my AFMs was defective. As I have spares and the garage is friendly he suggested I went swapped them around and just brought the car back any time to put it back on the machine for mixture setting. At this time the timing was correct, the car pulled like a train but it idled at around 2500rpm and surged when dropped a couple of times when dropped to idle before settling at 2500 rpm most of the time, occasionally it would drop and settle at around 1200-1600, but never at 850rpm where it should be.
Anyway sure enough the AFM he said wasn't responding correctly had signs of water ingress so I have changed it and this has left the car with the same power, the same surging issue (but it normally only surges once now) and an idle that is rock steady but still high at around 1600rpm vice 850.
I have followed the cologne diagnostics sheet from car mechanics magazine and this hasn't helped. In doing this I have checked and cleaned the throttle body, it all appears to work OK. I have changed the throttle pot with a know good one - this made no difference to the running. I have changed the idle speed control valve for my good spare - again no difference.
I have checked all connectors and all are secure. I now don't know where else to go, therefore please help with the following questions.
1. Any ideas of what else to check?
2. On my car the AFM electrical connections are coloured white and black, the black has 4 connections, the white three. Which one goes on top and which one on the bottom (my labelling tape came off these when re-assembling). I ask this as the car hunts less but idles higher with the black to the bottom.
I look forward to your guidance and advice
Mark
Probably not too helpful but I was advised to replace the afms as a pair.
If both are good shouldn't make too much difference though?
Good luck I will check my connections but again given the AFMs are identical? Shouldn't make too much difference. Have you tried it with them swapped round?
D S2
If both are good shouldn't make too much difference though?
Good luck I will check my connections but again given the AFMs are identical? Shouldn't make too much difference. Have you tried it with them swapped round?
D S2
Gerald-TVR said:
1. Are the butterfly valves full closed? Any air leaks on the induction side, vacuum hose, servo etc
2. Dont think which is connected to where matters
HTH
Thanks Norm,2. Dont think which is connected to where matters
HTH
1. Butterfly valve do fully shut, checked this when following the car mechanics article
2. Can't find any induction leaks but considering thicker gasket on the ISCV and possibly some sealant.
3. Servo is good and in tact, even underneath as this one is relatively new.
4. Servo vacuum hose is old but appears sound
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