1987 GTA Turbo still not starting

Posted a message a while back to say that having problems getting GTA to fire up, well still having problems
Still no injector pulse or sparks. Have disconnected the ecu computer and tested the 35 terminals back through the engine bay large connector block and then up to the relevant sensors and no breaks in connections have been found. The relays (injector and fuel pump) located next to the ecu also appear to be working correctly and the fuel pump primes correctly. Have fitted a new pick up and tested this, returns 200 (ish) ohms as per manual so this appears to be ok to. Why is my GTA not working!!!!! anyone have any suggestions/ideas. My ECU has been disconnected for approx 2.5 years, has this killed it and I need a new one???? Does anyone have a spare I can try, dont want to shell out for a new one only to find it's not the cause of the problem! Does anyone have any diagnostic equipment that will identify the problem or have any of you guys had a similar experience??. Any help appreciated. Cheers PS Pin 29 on the ecu connection (white wire) didn't seem to do anything, is that correct as it looks like it feeds from the ignition key and should have power?

Hi there

I have a handheld diagnostic that should tell you where the problem is, as long as it is electrical (ecu based). It will give the readings and fault codes of all the sensors. I also have spare ECUs if you wish to try one.....but firstly..yes, pin 29 should go to ignition.

Hi David

Thanks for your response. Pin 29, when should it go live, constant or after key turned?

Wouldn't mind trying another ecu, problem is pointing to the unit I think as everything else seems ok (except pin 29). My car is an early 87 flat bonnet type.

How easy is the diognostic unit to use, I take it it works without the car running, may need to arrange use.

Damn car driving me round the bend!!!!

On my schematics, when the key is turned. Have you checked voltage and eathing to the ecu?

The unit is easy to use. A couple of buttons scroll through all the sensors and the values. Idiot proof.

What are you trying to suggest!!!!!!!!!!!!!!!!!

Will have another bash at solving the problem this weekend, failing that may need to use diagnostic unit and see if that sheds any light on the problem.

Hi David, have checked all the wiring from and to ECU, ignition relay, fuel pump relay, electronic ignition coil and everything appears to be fine with no breaks becoming apparent, but still no spark pulse or injector pulse. Can the ECU memory just wipe it's self if the battery has been disconnected for a couple of years? wondering if it's lost the data held as everything else is OK. You mentioned that you may have a spare ECU that I could try, this would confirm if mines gone up the spout if the car starts OK by using another. Does anyone you know have access to a Renault X25 diagnostics box or does your hand held one do similar functions? Also if my ECU has lost the program can it be restored?

Help appreciated
Cheers
James.

[simontaylor]

Why not ask David if you can send him your "suspect" ECU and perhaps his super-powers can confirm if it works and or diagnose what the fault may be?

My unit does all the functions of the X25. The ecu cannot lose its programming, because its a ROM and not an EEPROM.

David, as Simon suggests, can I send my ECU to you to test or can I hire your diagnostic unit and have a go at problem solving myself?

Let me know whats best for you and we can sort out the finer points.

Cheers

James.

Thats fine, if you hire the diagnostic unit, Ill send you an ECU too for you to try free of charge.

Thanks, be interesting to see if another ECU works, will indicate if mine is duff! Is there a link on your site to hire the diagnostic unit? And how will you get it to me? via post? would like to hire it ready for next weekend.

Cheers
James

David

Dont seem to be able to get into your website? are you updating it at the moment?

Nope, just gone into it fine. Sometimes hosting servers do maintentance on Sunday evenings, may have been a temporary outage.

Hi David

Your diagnostic unit and spare ECU are on the way back. Thanks.

Unfortunately I still have not resolved the problem and the car will not start due to no spark or injector pulse.

I ran the diagnostics and these are the readings:

ECU Code = 101.3
Battery = 12v
Engine Speed = 00
Coolant Temp = 4 degrees C
Inlet Air Temp = 0 degrees C
Throttle state = mid (Full worked OK) did not get idle but probably because flap was not fully closed.
MAP Sensor = 549 Mb
CO POT = 1.464 - 1.47v
Knock Sensor = 00 steps
Knock correction = 00 steps
Idle postion = 8.19%

The ECU was not talking (Postion sensor red and white leads round the wrong way) changed them and error cleared.

Only other fault was code 23 which said no engine RPM.

Any ideas as this is really becoming a pain!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

PS spare ECU didn't make any difference!!!!!!!!!!!!!!

Like I said before, the problem now can only be electrical/outer engine components.

If theres appears to be unburt fuel coming out of the exhaust then its ignition based....

Things it could be: Ignition module. Earth can fail, main core can fail (same unit used on all renaults) 3 and 2 pin plugs not connected to the ignition module, 1 plug is Pos/Earth and Tach, other is trigger earth and signal

TDC: Still could be a fault there, either sensor, faulty or very dirty, lead or plug failure

HT leads...rotor arm/cap

Knackered fuel pressure regulator..no pressure


If there is no fuel pumping through injectors...

All the injectors are grouped together, common earth, if this has failed then no pulse

TDC again....

Last resort.....

Does the rear fuel pump prime for a few seconds and then stop? If not, front pump may have packed up....or if it does stop priming, its far fetched, but maybe a completely blocked rear fuel filter??

BTW, when you said the position sensor leads were the wrong way round did you mean TDC leads?