Typical Just As I Go To Get An Mot

[Weser 30]

So my Gti has been stood up for a year but has been started reguarly and driven around with no problems. Yesterday I wanted to get an MOT on it as I want to insure it in May when I am 25. I thought best do it early to sort out any little problems it may have so I can then just use it when its insured

 

Anyway started it up fine from cold but it was running rough. It seemed to be overfuelling. If you held the revs it runs fine. Once warmed up the overfuelling was worse it would tick over and then cut out.

 

I have checked fuel and spark all good.

 

I am thinking its either a coolant sensor of AFM. Not 100% sure about the AFM as it shouldn't get worse when its hot if the AFM was the problem should it? Also I have adjusted the AFM before and it was then spot on.

 

It had a coolent sensor a couple of years ago as well. Before when that was causing trouble it ran fine when it was cold but overfueled when it was warm. Similar to now but it was much more obvious which makes me wonder if its not the coolent sensor?

 

I havent had time to play with this yet hopefully at the weekend I will get a bit of time but I was wondering if anyone else has any ideas of what I should look at that could cause this problem.

[Weser 30]

Oh its a 1.9 8v

[Weser 30]

So had a little play when I got back from work. Looks like I made a bit of a error. Turns out it was running rough because there was a lack of coolent in the system. Looked in the header tank saw some but the black ones are hard to see the correct level. Anyway its not running rough.

 

The problem I still have is the fact it will be ticking over the suddenly stop. No dying/rev dropping. No spluttering it just stops like someone has turned the key off. Then it wont start. Checked its got fuel and a spark but still wont start. Anyone shed any light?

 

I am wondering if the injectors are not opening. can anyone explain to me how the injector come on and off what controls them. Is it a crank shaft sensor or the ecu?

 

Anyone else have any other ideas of what it could be or have had a similar problem?

[Carbs4me 45]

Hows the horn working? could be a problem with the ignition amp?

 

When my amp was dying the horn was rubish and it uset to run ruff every now and then, and pop and spultter at junctions every now and then, it uset to start and stop working as and when it wanted. Usually the hotter the amp gets the worse the problem becomes.

 

Id get the engine running untill its warm and check the sparks again.

Edited March 13, 2012 by Carbs4me

[Weser 30]

Havent tested the horn actually. Will give it a go and see what its like. It doesn't seem to be running rough anymore it just cuts out. I want to test the spark when its warm but i am struggling to get it up to temperature as it cuts out

 

When you had the problem with the amp when it cut out would it start again straight away or did it need to cool down first?

[Carbs4me 45]

it would start and stop as it wished, i had to wait for it to cool on afew occassions, even pushed it down a hill to get cold air flowing though the engine bay.

[Weser 30]

Ha ha what a nightmare! When it cut out did it die slowy or just stop dead. Mines stops dead as if someone has turned the key off. Even does it if you are holding a steady revs.

 

Everytime it does stop it still has a spark so I presume its not the ignition amp? However I might get one to be sure. Can anyone tell me how the Injectors are controlled? Is it the ECU? Whats the wiring circuit? Thanks

[Carbs4me 45]

well mine was still sparking it was just really weak! and yes it uset to just stop dead. But on the other hand if you can keep your car running at 4,500 to 5,000 RPM it will stay running with a faulty amp. maybe very rough though!

 

There is some info here about injectors - http://www.205gtidrivers.com/articles/e3-injection.html

 

From my understanding it basicly says its ecu controlled but i would have thought they where anyway.

 

I dont think this will be your injectors, it sounds like something is tripping when its running. could be a relay or anything!

[Weser 30]

Hi thanks for the help. Yer dont think its the injectors themselves but what controls them. Had a bit of digging around found out that the fuel pump relay provides the power to the injectors and the ECU earths them to open/close when needed. I think anyway. That gives me enough to be getting on with looking at! I will keep an eye on the spark but at the moment it looks pretty healthy.

[Carbs4me 45]

Everytime i have taken a engine out of a 205 the fuel pump relay always sticks! Nightmare when your wondering why it doesnt fire up on the first start.

 

Let us know when you have solved the problem. Good luck!

[Weser 30]

Will do. Thanks!

[Weser 30]

Annoyingly tried to sort this out at the weekend but started the car up Sat morning and it hasn't missed a beat since!

 

However after a bit of a play I think its the fuel pump relay on its way out so I have a topic in the wanted section now

 

On the up side it now has an MOT!