Over fueling on 350i

[PaulMarshall]

Hi new owner in need of help.

I have a overfueling issue. The injectors are being energised for 20 ms instead of 1ms max 12ms. I have replaced the throttle potentiometer with no success. My local garage has had the car for two weeks and can't identify the problem.

Anyone any ideas or come across this problem before.

Thanks

Paul

[shpub]

Last time I heard this the fault was a dodgy ECU.

Steve
www.tvrbooks.co.uk

[tvr350i]

Same problem happend recently to a friend of mine. His 350 was constantly MASSIVELY overfueled and the problem was the ECU. Don´t forget to changes oil also ! There may be some extra litres now down below...
Bengt

[REV-EREND]

I had the same problem with my 400se (same ecu) - the
best way to dianose the problem - was to swap ecu's
with a friend with the same car.

Hey presto - it is either better or no different

Lucas recondition them for about £199 !

Good luck.

Rev

[mark.tideswell]

Forgot to mention paul i think the ECUs are programed different depending on what vehicle they are fitted to maybe the one fitted was designed for a rang rover

[mark.tideswell]

Forgot to mention paul i think the ECUs are programed different depending on what vehicle they are fitted to maybe the one fitted was designed for a rang rover

[PaulMarshall]

Hi Mark

Are you saying the ECU fitted is a Range Rover ECU?

Thanks to everyone else for their help and advice

[JohnL]

I'm sure that on another thread (maybe under Rover V8) someone said that the ECU basically is a Raneg Rover unit, and there was a resistor somewhere that changes the setting so that it delivers the goods for a TVR.

Without the resistor the engine thinks it's in a range rover.

[PaulMarshall]

Has anyone got any idea if the ECU was common with other cars. I would like to try one out before buying a new one or getting the old one repaired

[mark.tideswell]

I am can not be sure if its range rover or not but it was suppled by lucas{and then repaired by lucas}for a TVR so who knows what they supply unless you take it to bits and know what you are looking for you would never know I think Tim Lamount is the ECU guy if hes on he will Know

[mark.tideswell]

Paul just found the box it came in! the label on it says LRZ123 as part no but it says underneith
Replaces 83986 so maybe there is a difference somewhere down the line!

[GreenV8S]

quote:
I'm sure that on another thread (maybe under Rover V8) someone said that the ECU basically is a Raneg Rover unit, and there was a resistor somewhere that changes the setting so that it delivers the goods for a TVR.

Without the resistor the engine thinks it's in a range rover.

There is a tune resister it's true, but the rest of this explanation is pretty misleading. I suggest you check out Mark Adam's description that is reproduced in at least one of the bibles. Bottom line is that no TVR ever left the factory with the ECU thinking it was in a range rover, or an automatic. I doubt the tune resister is the source of your problems, although if you muck about with it you can certainly introduce another variable into the melting pot.

[JohnL]

quote:
There is a tune resister it's true, but the rest of this explanation is pretty misleading. I suggest you check out Mark Adam's description that is reproduced in at least one of the bibles. Bottom line is that no TVR ever left the factory with the ECU thinking it was in a range rover, or an automatic. I doubt the tune resister is the source of your problems, although if you muck about with it you can certainly introduce another variable into the melting pot.

I've obviously misunderstood then, sorry if I've caused any confusion.

What sad buggers are we, doing this at this time of night?

>> Edited by JohnL on Thursday 23 May 00:38

[shpub]

quote:
I had the same problem with my 400se (same ecu) - the
best way to dianose the problem - was to swap ecu's
with a friend with the same car.

The Wedges use two different ECU typeswhich are based on the developments that occured with the Range Rover. The 4CUX is pseudo digital in that it has analogue circuitry that can go wrong and do strange stuff with pulse timing and so on.

There is a company called ATP that can test the ECU and confirm a fault as well as recondition/repair it. There have branches more or less every where and have a website. That is the easiest (and probably cheapest) way forward.

All this talk about tune resistors I think is a red herring. There are pins used on the original ECU to indicate gearbox type and if a cat is fitted but Wedges were never catted and according to TVR this auto setting is not used.

Steve

[PaulMarshall]

Thanks guys.

The garage agrees with the diagnosis on the ECU and has sent it to Lucas for testing. Hopefully this will be the proble. I will let you know what the outcome is.

[PaulMarshall]

Hi Guys

Got the feedback from the garage todaqy. The ECU was sent back to Lucas who sent it out to their repair company. Feedback from them was 'It tested ok but the symptoms are known with this type of ECU'
The garage's problem and mine is if they can't find the problem with their test equiptment now, how can they be sure of repairing it.

Help any idea's guys

[paulmarshall]

Hi Guys

Finally got the car back on Friday. It dosen't over fuel any more but does occassionally cut out. It starts again with no problem. The garage changed the fuel filter and disconnected the cold start injector.

[mark.tideswell]

Hi paul are you sure that the cold start injector is not leaking it is constantly under pressure,if i remember correctly the wire connector going to it is from a sensor in the cooling system when the water temp is cold it completes the circuit and operates the solonid on the injector{it is also timed for the amount of time it injects the extra fuel}and feeds it with extra fuel,and when the water temp is hot the solonoid is not operated so no extra fuel is not injected, but like i say the injector could be leaking .As for the filter i am sure i put one on not so many miles ago!also check the wires on the pump they could be causeing it to cut out,it could even be the fuel pump itself!

[Euphoria]

what is overfuelling?

[paulmarshall]

Hi Euphoria

Over fueling is when the injectors are energised for too long pumping excessive fuel into the engine. Usually this will flood the engine and petrol will find its way into the exhaust.

I should say that that is my definition. Any takers on a better explaination(preferably more techincal)