Need Expert Advise for Start up issues

55 is code for no faults stored .
Wiring/earthing is highly likely involved ...

As the gtirworkshop manual website no longer works does any one have a earting strap diagram for the engine bay.

Ive got the following ground wires in the engine bay between chassis and;
- gearbox
- righ headlight loom ground wire
- left headlight loom ground wire
- connector block next to fusebox loom ground wire
- injector loom eart strap going to the intake plenum

i believe that is all of them. Is there any more, does the alternator or starter motor case have a seperate earth strap.

Try connecting a couple of jump leads from engine to battery or chassis, that'll tell you pretty quickly if it's an earth problem as the issue should be better

@mike74 wrote:Try connecting a couple of jump leads from engine to battery or chassis, that'll tell you pretty quickly if it's an earth problem as the issue should be better

tried that but not with the engine cold. will try with the engine cold next time.

going to get my self a gauge to test fuel pressure and ensure the regulator is holding pressure even after a few minutes.

where can i connect up a fuel pressur gauge too. any links or information would be great.

Just buy a gauge and barbed tee kit and plumb it between the fuel filter and rail.
Something like this:
http://m.ebay.co.uk/itm/BLUE-0-100-PSI-RACING-FUEL-PRESSURE-GAUGE-3-8-INLINE-HOSE-END-TEE-ADAPTER-/251611165826?nav=SEARCH

car got taken to the welders the other day. it was driven there, about a mile an half. The guy put new fuel in. Since then he has tried to start when cold and its still got the same issue so thats the fuel out of the question.

Going to get a datalink cable and reader software to see if i can figure out whats going on.

Should not need one start with basic checks and go from there

@johnny gtir wrote:Should not need one start with basic checks and go from there

Without it I can't see what the ecu is reading from each of the sensors.

I am under the impression the ecu temperate sensor is partly the fault. So need to disconnect this and put a resistor across the matting connector and try cold start.

Also need to check fuel pressure.

Hi guys the car is in the garage having welding done, is there any thing I can get the mechanic to check while it's there.
It's got new fuel, new fuel filter.

I was going to get ignition checked but I am still thinking this issue is due to a sensor.

My car has been a pain in the arse to start recently, turns out my maf was coated in oil as the breather from the rocker is drawn in to my Intake, and that I had split vac pipes, very simple checks, may be worth looking at? Even if it's not those you can rule them out as a potential issue.....

will answer pm you sent shortly Joe, sorry fella not had time over last few days

now the car is back im trying to investigate the ECU water temperature sensor more.

With ignition on or off both pins of the water temperature sensor connecotr (loom) are GND. looking at the link below one should be 0V and one should be 5V.

This is probably half the reason i have an issue. i now need to figure out why both are 0V / GND.

https://drive.google.com/file/d/0B7Ub2apq5-pfMDRwZHhuRktnLVk/view

Im am going to disconnect both of the water temperature sensor cables from the ECU I can then check to ensure 5V is coming out of the ECU.

Another weird thing is with ignition on i am hearing a constant clicking noise coming from the relay box closest to the power steering resovior. Is this normal.

As the loom at the back of the engine is pretty ruined e.g. lots of cables and connector have broke so previous owner has use crimp contact instead or patched cables back together with crimps i think it may be best to source another loom and use that instead. will be a massive ball ache but may cause less headaches.

When you say constant clicking is it all the time or every say so many seconds

@johnny gtir wrote:When you say constant clicking is it all the time or every say so many seconds

every about 10 seconds

Has your rear wiper been removed ? Make sure it's not turned on on the stalk

@johnny gtir wrote:Has your rear wiper been removed ? Make sure it's not turned on  on the stalk

That's a very good point, yes rear wiper is removed. I will check the stalk.

Just back probe the ecu connector at pins for the water temp sensor .

@Mr B wrote:Just back probe the ecu connector at pins for the water temp sensor .

I guess this will lead onto the next question. If there is no 5V out of the ECU, I assume I will need a new ECU.

Check the inputs and earths to the ecu first and also check other sensors for power side signals .
I would assume it more likely fudged wiring, I never seen a ecu circuit issue on coolant sensor but indeed could be .
What I do is with plug off the sensor and couple back probes on the temp pins is bridge probes with a resistor to get cold water value and run the car, If this the reason the fan running the fan will be off as ecu now gets valid input on that sensor circuit.
Only 2 circuits that switch fan is water temp and aircon and as said before when water temp circuit dead the ecu runs a safe mode with a fixed value for water temp and runs fan permanently .
* Do review aircon circuit if fan still runs after water circuit fixed as lot of people make a right mess modding wiring or from removing it.

Thanks mr B your a star. The air con has been removed and believe nothing else was done to the wiring for it except from being disconnected.

@Mr B wrote:Check the inputs and earths to the ecu first and also check other sensors for power side signals .
I would assume it more likely fudged wiring, I never seen a ecu circuit issue on coolant sensor but indeed could be .
What I do is with plug off the sensor and couple back probes on the temp pins is bridge probes with a resistor to get cold water value and run the car, If this the reason the fan running the fan will be off as ecu now gets valid input on that sensor circuit.
Only 2 circuits that switch fan is water temp and aircon and as said before when water temp circuit dead the ecu runs a safe mode with a fixed value for water temp and runs fan permanently .
* Do review aircon circuit if fan still runs after water circuit fixed as lot of people make a right mess modding wiring or from removing it.

Cant trouble you to ask for what resistance the sensor should be at ambient temperature. Im at work at the moment and cannot open google drive files with the service manual. got a load of resistors at work so can take one home and try it with it connected on the back of the ecu connector.

about 3.5kOhm would be about 15degC
grab a few either side of that or potentiometer pot so can vary between about 5kOhm to 0.3kOhm

Ok so got home and made a bit of progress.

Checked all the GND for the ECU and they are all good; with ignition off it is approx 0.4ohm between battery - and all ECU GND terminals

Checked all the power terminals for the ECU and they are all good; with ignition off it is approx 11.4V between battery + and all ECU power terminals except control unit power source which is 0V. with ignition on control unit power = 12V+

With water temperature sensor disconnected i checked voltage between pin 18 which is water temperature sender signal + with ignition on with repsect to GND. Voltage should be 4V+ however measured value is 0.4V.

I broke the connection between the main loom ECU water temperature signal + and the ECU and measured the voltage out of the ECU on pin 18. The voltage = 4V+

I connected a 3.9K ohm resistor between the ECU pin 18 and GND. it started without any real issue. Revs were around 1.5K on idle but this may because the engine is cold. Normally it would be an issue with cold start so it is more pointing toward this being the issue.

This means with the engine loom connected but with water sensor disconnected the voltage is being reduced to 0.4V. thus indicating a problem with the loom.

Now i have to figure out why there is around 3.6V drop in voltage with the loom connected to the ECU.

Can anyone tell me what connector in the engine bay connects the ECU loom to the rear engine bay loom for the water sensors. I want to disconnect this loom to see if the issue is with the engine loom or ECU loom.

Potenitally fixed it....kind of.

Previously when the engine would idle the wideband o2 guage would read around 15 (amber indicator on gauge), thus running rich.

Now ive potentially fixed it after 20 seconds of starting it now reads around 13.5 which is good i beleive as the gauge shows it as green rather than amber.

The connector i had plugged into the water temp sensor was a white connector, i believe it should have been the red connector. The red connector was previouslly fitted to the sensor fitted directly under throttle bodies to the IACV (i think).

I have fitted a resistor to the temperature sensor loom connector and measured it at the ECU connecotr  (when disconnected from the ECU) and it reads the correct value. However when plugged into the temperarure sensor it does not read any value. THis leads me to believe the sensor is faulty as it reads open circuit thus needs replacing.

However this should hopefully be the all the wiring issues sorted. except the oil gauges not working.