AMF misfire

philward

A2OC Donor
Suddenly in the middle of a large junction in the center of York on a busy Friday afternoon my AMF just turned off and stopped. It wasn't abrupt like a stall it felt like I had, but I hadn't, turned the ignition off. It did start and get me home but it has developed a misfire under load.

A scan with VCDS Lite has revealed nothing, but I'm far from being an expert user. Suggestions gratefully received.

Albert scan.jpg
 

philward

A2OC Donor
Injector loom or fuel filter.
Fuel filter is good but I have one and could easily fit it to be sure.
My first thought when the car shuddered was injector loom. I have replaced it once. About 70k miles and 10 years ago. It could well be failing again.
I’ll bet it is another NLA part ?‍
 
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audifan

A2OC Donor
Injector loom does not always trigger an error. With vcds then you could possible see different injector values IF THE FAULT WAS PRESENT AT THAT MOMENT..

Darkside Developements still had them last time I checked

 

philward

A2OC Donor
Thanks @audifan I've got one on order. My tendency is to assume the simple has failed, on this occasion this is about as simple as it gets; fuel filter aside. A bit of a bill for a car that I'm about to replace as my daily but not to worry I'll be keeping him on for towing duties and playing in the snow.

I'll be looking into injector tortion values, I will fit the new loom when it arrives and report back. Thank you all for your advice.
 

audifan

A2OC Donor
Although loom is favourite, you have already checked the earth lead BUT only where it connects to the chassis. These leads have been known to corrode inside the insulation and even break, so just because the chassis end is good does not confirm the earth lead as good. I like many others run a secondary earth between the cam end engine mount and the belt tensioner and have done so for many years now.

The whole injection system on the A2 is one area that VCDS / car does not get enough diagnostic information. Tandem pump and fuel filter being other areas.
 

philward

A2OC Donor
Your right @audifan the earth leads do corrode and fatigue inside. I fit a new one and split the old one. The potential problem was at the earth point, there was no issue inside the cable.
The tandem pump is a recently new Bosch. Hope no problems there but not looking any further untill the new harness is in place. If I change too much too quick and I’ll never know what the problem was.
 

Catnip64

Member
A temporary repair you could try would be to close up the terminals on the loom where they contact the injectors to improve the connection and hopefully eliminate the misfire.
 

philward

A2OC Donor
A temporary repair you could try would be to close up the terminals on the loom where they contact the injectors to improve the connection and hopefully eliminate the misfire.
If I go that far I’ll crimp on new terminals. Have a new harness on order but will keep the old. Will look at repairing.
 

Howey

Member
When mine dropped an injector due to wiring it didnt stall

Wonder if the crank sensor could be an issue
 
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