ecu issues?

Am I allowed to discuss my 25v6 turbo here?

Bought to help me work out the jigsaw puzzle that is my GTA turbo -but its got an irratating problem of its own.

Starts from cold - no issues. Runs beautifully, right through the range.
However, as it warms it starts to sound strained, and will eventually die when warmed through properly.

At that point it wont restart -although it always feels like its trying too. but I'll end up knocking out the battery, a jumpack (etc etc) without luck.

Following day it'll fire normally, first turn of the key.

I've swopped the TDC sensor (what a job!!) - no change.
I''ve replaced the coil pack - no change.

So - am I looking at an ecu swop out or repair - and if so, can anyone point me in a recommended Sussex/south coast type direction?

Is itgoing to cost me a bundle?

I've never had this car run properly. Bought (without MOT/Tax, off road several years) he clearly forgot to mention this issue -and it ran well in his garage.

However,I cant trust it to get to my MOT station -let alone back, so I need to solve this here. Any help truly appreciated - its driving me batty.

Thanks

Sounds like fuel starvation to me.........filters?......fuel pump/s?...worth checking in any case

Yep .
Sounds fuel related .Check water temp sensor for ECU .It's on the water pump.Could be air temp as well but check the water first .
Resistance values for water sensor .
20c.....283 to 297
80c.....383 to 397
90c.....403 to 417


Air temp sensor ( on throttle body )
0c.....254 to 266
20c...283 to 297
40c...315 to 329

Thanks
I'll check the sensors-didn't realise it had any!

I doubted its fuel - commonsense says that if it maintains sufficient supply when cold - it should have enough to tickover once warm!

Appreciate the 'heads up

If the sensors check out OK, I'd definitely look at the possibility of fuel starvation.

A friend of mine had an old VW Polo that started, ran reliably for about 20-30 miles then would splutter and die, not to restart. However, when you left it for half an hour to cool down, it would come back to life and run for another 20-30 miles. Bizarre and we couldn't get to the bottom of it.
My friend had to give up and take it to a garage that charged a lot to clear out all the fuel lines and so on and that solved it.

Didn't seem to make sense but it behaved like fuel starvation and sorting the fuel supplies out solved it...

As CLee mentioned the sensors are critical, more so the water temp and integrity of its wiring back to the ecu than the air temp. You can run without the air temp connected with out too much issue, as the ecu will run with calculation based on the initial block temperature from the water temp sensor if the air temp signal is absent; not ideal, but will run fine.

The water temp is quite critical and significantly modifies the fuel curve up to 80 / 90 deg C.

If you get really stuck I can connect to the ECU diagnosis port and read out directly what the ecu thinks is going on.

Thanks.

Its not fuel starvation.When it spluttered to a halt tonight, I disconnected a fuel rail, Full. Spun starter -petrol everywhere.....

Initial check seems to show the Water Temp Sensor to be too high,but constantly,right across the range.

The Air Temp didnt get checked until the engine was hot (couldnt find it....)when the reading was in the 800's. I'll check again, tomorrow.

Assuming one/both need replacing - where do I get them?
Are they compatible with anything else - might it be wise just to change as a way of further eliminating potential issues?

Thanks

Assuming one/both need replacing - where do I get them?
Are they compatible with anything else - might it be wise just to change as a way of further eliminating potential issues?

Thanks

I think you should find them with some digging, but they are PTC, same as the GTA, but later sensors were NTC temp coeff so you will need to get the correct type. Certainly worth changing the two in my opinion, and go from there.

Ok,thanks.TypicalRenault...

I'll give it another go -when its cold, tomorrow.

Are you local tome (south coast) -I cant see how you could read the ecu without the car being present.....telepathy perhaps?

Nigel, already you can see the value of joining and being part of such a wonderfull club.

Happy Motoring.

[BIG_MVS]

I have a spare water temp sensor you can try Nigel, if it fixes your problem cross my palm if it doesn't send it back to me.

No membership requests from me, call it a favour for an autoshite legend

.....Someday, and that day may never come, I'll call upon you to do a service for me........


Well ,that's my experience of Don MVS

DO NOT USE SECONDHAND SENSORS TO CHASE DOWN GREMLINS !!

[BIG_MVS]

I'm never helping you out

True about 2nd hand I suppose, it's worth a shout to try and resolve it, however if mine is faulty (it was OK when last fitted) and you eliminate it as your fault you could be pi$$ing into the wind again....

Agreed.Even if it is faulty -it'll have 'different' characteristics.

I'll give it another go later today-and get back to you.

I love Renaults (- got more than a few), but this one & the GTa are a right royal P.I.T.A

Didnt realise I needed to pay to join this Forum. I'll look into it,later.