T25 2.1dj ecu problem?

[boxxie]

For much of last year I have struggled to solve a sudden power loss problem with my 1990 2.1dj petrol/lpg transporter. I'm driving along on lpg and suddenly all power goes - the engine can just manage a pathetic idle and if I give it any throttle it stalls. After anything upto two hours the engine starts properly again (starts on petrol), though sometimes when this happens after a shorter time it does it all over again 50 yards down the road.

So far I have replaced the coil, ignition module, spark plugs, fuel filter, air flow meter, distributer/hall sender and generally tidied connections such as the engine block ground. Various VW garages and AA guys have looked at it but haven't been able to diagnose the exact cause (often it won't do it anywhere near a garage) though the consensus is now ecu wiring/connections.

Because the problem affects both lpg and petrol, I assume it is not fuel supply and the intermittent / heat related occurrences suggest electrical connection problems to me. My feeling is that the digifant ecu is getting duff signals from some sensor and deciding that the engine shouldn't be running, though I'm getting to the extent of my mechanical ability here.

I came across http://www.van-cafe.com a US company offering an ecu diagnostic kit for $225 (inc p&p) that looked promising, however it needs an ecu 025-906-022 or 025-906-022D whereas I have a 025-906-021F. Does anyone know where I could find out the differences between these models - if the pinouts are the same it may work.

Perhaps I should get the ecu itself checked or try to find another wiring loom.

I would be grateful for any suggestions as I've had to abandon the camper on the driveway. Unsurprisingly the family gets grumpy waiting at the roadside!.

[Mocki]

hi
i have a working full injection system here, complete, pm me if you are interested

[big red bus]

Had avery similar problem with a 2.1 van that I look after. Driving along sudden lose of power then stall. This would start immediately and then do the samer after another 3-4 miles. Found the problem was one of the ecu pins was corroded. Cleaned it up and no problems now. Also make sure all the enigne earths are good and clean.

[wasserleaker]

if it does turn out to be the ECU, or you want it checking out so you can rule it out, a firm called ATP Electronic Developments, cannock staffs 01543 467466 can test the ECU and may have an exchange reconditioned one, they are very helpful.
the site is www.atpelectronics.co.uk
had the exact same symptoms you describe in your 1st paragraph when i got my T25 2.1 (digijet tho)
my problem was the hall sender breaking down when engine was hot, but i changed a lot of parts unneccesarilly before figuring that out, but if you've changed that it cant be the prob. good luck with it , injectors can sometimes fail when hot too, but that would prob only lead to a misfire.

[Hacksawbob]

bentley has details for checking the senders. I think most can be done with a voltmeter.

[Hacksawbob]

bentley has details for checking the senders. I think most can be done with a voltmeter.

[Aidan]

work your way through the diagnosis procedure in bentley it's the only way to isolate the fault.

[Fritz]

Because the problem affects both lpg and petrol

The symptoms you describe have in the recent past been rectified simply by replacing the Lamba sensor.

These are available from GSF , nationwide.

Regards

Fritz,,,,,,,,,,,

[boxxie]

Thanks everyone for your help (and sorry I haven't replied earlier )

Thanks mocki for ecu and wiring loom. I plucked up the courage to install them this week and happily the van still runs. The petrol side is a bit lumpy but the lpg is fine and best of all I haven't broken down yet.

Due to the intermittent nature of the problem, I won't be able to say it's fixed until a few problem free months have passed. But if it happens again I'll try the lambda senser (thanks Fritz).

[boxxie]

I guess I spoke to soon because it's happened again
I looked for a lambda sensor but couldn't see anything in the exhaust pipes. Could anyone tell me where it should be if you have one.

[Mocki]

Sorry to hear it hasnt solved it.......
i may be wrong but i seem to think that the dj dont have the lamda sensor, its the mv and ss that do.....

[boxxie]

Yeah! I don't think I've got a lambda sensor, so the option to convert to a carburetor system is looking more appealing.
Could anyone advise me what the main parts are needed to convert a 2.1 dj to run on a carburetor.

[Aidan]

so what didn't you change ?
what wiring testing did you do ?
Have you checked the HT side ?
got to just work through it, it's basically pretty straightforward, going carb is backward imho and the time/money spent doing it could be properly applied to fixing the fault.

[boxxie]

You're right of course Beaker, I've just been getting frustrated
I've been in contact with Jim Schumacher of http://www.shoebox-electronix.com, who designed the ecu diagnostic kit I mentioned, and it turns out that my ecu (025-906-021F) is a digijet and his box of tricks will work fine with it. Better still, he reckons it may be a problem with the temperature sensor, so I'm going to test this theory out first by disconnecting it next time it happens.

[SteveW]

No point in changing to carbs as the problem is nothing to do with the injecters if you get the same fault on LPG the gas does not use the injecters to work. I would change the sensors next. Good luck.