Non Start/no Pick Up From Gti6 Engine.

[welshpug 1,683]

this is starting to annoy me somewhat!

 

I've had my gti6 engine running and driving nicely (without Lambda as yet) then I managed to run out of petrol as I was driving it up the lane.

 

 

ever since then it doesn't want to pull at all, I.E if you give it WOT it'll just give loads of noise but not accelerate like it should.

 

I have fitted a new fuel filter and there's fresh fuel in it, it will did start ok and rev up in neutral, but as soon as it had any load it doesn't want to go.

 

in my process of trying to work it out I unplugged the MAP sensor and it simply dies, if the ECU temperature sender is unplugged it will pull much better, but still not as well as it used to, but the sender is fine as its brand new!!

 

 

now however it wont start, it just cranks and doesn't catch properly, giving throttle doesn't help at all.

 

 

so what should I do apart from fit aftermarket management?

[BuD 0]

Have you tried getting a fault code from the ecu or disconnecting the battery for half an hour?

[welshpug 1,683]

disconnecting the ECU yes, no change at all

 

 

fault code? its in a ZX now, and I didnt get as far as figuring the fault code wiring out, either way i haven' got a fault code reader.

[BuD 0]

Dunno at all then, maybe it ran better with the coolant sensor unpluged because this made it run richer? Maybe pointing to something in the fueling side?

[welshpug 1,683]

that's what my thoughts were, this would indicate the fuel pressure regulator, part No 198505, £60.70 retail price form pug, £42 plus from a fuel parts supplier so about the same as pug trade price (which I can get)

 

if it was the pressure reg I wouldn't get any fault codes as there's no pressure sensor like a common rail diesel, but I think it may be worth testing what pressure I'm getting in the rail.

[pugrallye 0]

Have you checked your flow rate from the pump, sounds alot like fuel starvation

[welshpug 1,683]

  pugrallye said:

Have you checked your flow rate from the pump, sounds alot like fuel starvation

 

 

not sure how I'd do that, sure as hell pissed out when I didn't tighten up a clip on the fuel rail!

[pugrallye 0]

thats just pressure, not actual litres per min. should be stats somewhere poss haynes manual on your rate of flow from your fuel pump, then find suitable container etc and measure, checking for colouration and how steady the stream is (disconnect supply line and put into container)

Edited November 9, 2007 by pugrallye

[welshpug 1,683]

update, removed fuel rail and cleaned it out, there was some crud in there, also there was a tiny lump of what looked to be blue rubber in the top of one injector.

 

stuck the feed hose into a bottle and switched the ignition on, pretty good flow and nice and clean.

 

stuck the injectors back in the rail and cranked her over with the injectors skywards, quite a good pattern all round.

 

tried it without the ECU coolant temp sender and its a lot better, but still doesn't pull like it used to.

 

going to get some injector cleaner and more fuel in it as the orange light is on now.

 

bloody french cars

[welshpug 1,683]

right it has fuel (about 12 litres of fresh)

 

it has a new ECU temp sender.

 

a known good set of injectors.

 

a new fuel filter.

 

cleaned out fuel rail.

 

clean air filter.

 

 

It will idle fine, revs will pick up in neutral, but under load in any gear it sounds like its bogging down or as if its got no fuel going through, it doesn't miss though.

 

this is baffling me now, as I don't know what to try next, as I mentioned before, the first few times I fired it up and moved the car around it went like stink, but not anymore it happened the day it ran out of fuel, so I think it must be something to do with that but what?!?!

[jonnie205 1]

sounds like ignition break down under load, you could try coil packs

[welshpug 1,683]

bollarks! just what I wanted to hear they're even more expensive than Mi ones arent they?

Edited November 22, 2007 by welshpug

[pugrallye 0]

These enigines really do suffer with map sensors going down too, might be another avenue to go down

[welshpug 1,683]

hmm, but how would I test the MAP? if I unplug it the engine dies!

 

what I need is another gti6 that runs so I can swap known good bits!

[pugrallye 0]

Thats the trouble its hard to test a visual inspection may be an indication, but not necessarily the prob, as even clean ones play up! If I remeber rightly there are two types...

[welshpug 1,683]

yeah, IIRC the older type is more expensive too, guess which I have...

 

 

I'm going to whip the plugs out later and see what they look like, got a new set to go in.

[welshpug 1,683]

new plugs in, old plugs weren't too bad, just slightly black. not made a difference though.

 

Removed the MAP sensor and gave it a blast with brake cleaner, startup was better but it still doesn't pull.

 

 

one thing to mention, I gave it full throttle in neutral and it seemed hesitant to rev right up to the limiter, in fact I don't think it did hit it just ran out of go!

 

s/h coilpacks will be tried next, thanks Miles, but I really dont know what is wrong!

[welshpug 1,683]

I think I've found the problem, TPS!

 

I've got 5.5 volts at the plug between pin 1 and 3, but when I probe the sensor on the ohms setting on the same 2 pins I get nothing at all (stationary and moving the throttle spindle)

 

I drove it up and down the lane with the sensor unplugged and it was exactly the same!

 

what does the middle pin do?

[pug_ham 245 3 Cars]

  welshpug said:

what does the middle pin do?

Its from the ecu, pin 16; 5v output signal to TPS.

 

TPS plug has wires from the ecu to all pins.

 

Pin 1 goes to ecu pin 53, pin 2 to 16 & pin 3 to ecu pin 23.

 

ECU pin 53 is shared by CTS plug pin 2 & TPS plug pin 1 so I think its an earth pin.

 

Graham.

[welshpug 1,683]

so middle pin is 5v output, pin 1 is earth, what about pin 3?

[pug_ham 245 3 Cars]

input signal to ecu.

 

Graham.

[welshpug 1,683]

DOH! umm so why an earth? sorry for the questions, I'm just trying to get my head around how it all works!

 

diesel is soo much easier.....

[pug_ham 245 3 Cars]

Because the TPS is a variable resistor?

 

Graham.