I am rapidly loosing confidence in driving the Z. [1990 import TT auto]. It has been driving great for the last six months but now things are different. On Monday this week she cut out on a dual carriageway doing about 40mph I managed to coast into a lay-by. I turned the ignition off and it re started first time. I carefully drove the couple of miles home and it stalled on the approach to a roundabout. I eventually made it home with no more problems. I rechecked the likely loose connections I have seen mentioned on the site, cleaned the terminals etc.

 

I have recently noticed gauges not working for a while and then suddenly coming back to life [oil pressure, boost and temperature]. Today I stalled pulling a way at a T junction, the other road users less than sympathetic, again I nursed the car home and notice when the accelerator is depressed the revs drop and then pick up, perhaps this is why it staled pulling away.

 

Could it be that I need a new ECU?

Have you checked the MAF? one of the usual culprits also check your battery terminals as I had a similar problem and they had come loose.

I am rapidly loosing confidence in driving the Z. [1990 import TT auto]. It has been driving great for the last six months but now things are different. On Monday this week she cut out on a dual carriageway doing about 40mph I managed to coast into a lay-by. I turned the ignition off and it re started first time. I carefully drove the couple of miles home and it stalled on the approach to a roundabout. I eventually made it home with no more problems. I rechecked the likely loose connections I have seen mentioned on the site, cleaned the terminals etc.

 

I have recently noticed gauges not working for a while and then suddenly coming back to life [oil pressure, boost and temperature]. Today I stalled pulling a way at a T junction, the other road users less than sympathetic, again I nursed the car home and notice when the accelerator is depressed the revs drop and then pick up, perhaps this is why it staled pulling away.

 

Could it be that I need a new ECU?

 

sounds like what i had, but i also had a really bad hesitation issue as well.

 

Do a ECU check, open the panel at the passenger foot well to expose the ECU. get a flat head medium size screwdriver, there is a little turn screw on the left hand side of the ecu, turn that fully clock wise until you cant turn it any more, wait 2 seconds and then turn it fully counter clockwise until you cant turn it any more, this puts the ECU into diagnostic mode. now head to the dash, and watch the flashing engine management lights.

 

there will be a series of flashes followed by a medium length pause. and then it will start flashing again. it will flash long flashes first, then short flashes. long flashes are the first number, short flashes are the second number.

 

so for a all clear it will be

 

5x long and 5 times short, for a code of 55, if there are more than one code showing, it will flash the first code in the sequence, and then the second, after the short flashes of the first. so pay attention.

 

So to recap

 

ECU, turn fully clock wise, 2 second wait, turn fully counter clock wise.

 

Read the engine management light flashes. long flash first number, short flash second number.

 

Then reset the ECU, by unplugging the battery for 1 hour. replug it in, take the car for a 10min drive. then check the codes again see if any have reappeared.

 

get the code if any and put it up here. might be a PTU problem.

 

Reason for resetting the ECU and checking a second time, is just in case there are old codes that haven't been reset.

Thanks, I am away tomorrow I can spend a few hours trying to sort the car out on Friday.

 

Perhaps a silly question do you set the ECU to diagnostic while the car is running or when the ignition is off?

Thanks, I am away tomorrow I can spend a few hours trying to sort the car out on Friday.

 

Perhaps a silly question do you set the ECU to diagnostic while the car is running or when the ignition is off?

 

engine off ignition on or off, best off though.

Sounds like the speed sensor to me.

My car randomly stalled at times due to the CAS plug being slightly loose

sounds like a loose cas plug or even a loose battery terminal (had both before)

you may even have a timing belt problem. i had the same thing with the speedo and it was definately the speed sensor.

random stalling/poor running could be PTU, but i wouldnt suspect that first.

 

I would check under the carpet on the passenger side where the ecu's are to make sure they are dry weird stuff can happen if they get wet.

I took the floor panel up to reset the ecu and check any fault codes and this is what I found!?

 

 

Vodkashots mentioned a set screw on the left hand side?? I think I have a problem this appears to be an aftermarket component. Any advice?

I took the floor panel up to reset the ecu and check any fault codes and this is what I found!?

 

 

Vodkashots mentioned a set screw on the left hand side?? I think I have a problem this appears to be an aftermarket component. Any advice?

 

one screw on the left hand side, would of thought that would still have it, i have a Greddy ECU in mine and it still has the screw on the side and the fault code indicator.

The setscrew port was covered by a metallic sticky label that read – do not remove. I removed it and set the ecu to diagnostic mode and got the 55 code. I am wondering whether to risk a test drive – busy roads round here Friday afternoon! If you don’t hear any more from me that’s not good news.

doesnt sound terminal, chin up :D its a faulty sensor or connector.mine did it twice to me for no apprant reason. never happened again though. (after i sorted my boost leaks)

Cheers, I will keep going its just so frustrating cutting out at random times. Stalled twice this afternoon, nearly got written of once, not the way to be a ‘head turner’ on the high street. Other than the unreliability problem it’s a totally sound car. Perhaps I will replace the main sensors over the winter. Any one got a good PTU for sale?

Don't know about the stalling pulling away but mine was doing the whole cutting out thing, once at around 40 and a few times while slowing for roundabouts. also my speedo and stuff stopped working for a bit. I put redex in the fuel system and now use 99ron and have had no issues (touch wood).