Sorry.... Yet Another Won't Start Post.....

[weejp 0]

I am not much of a mechanic (but I do try) so please be gentle.

 

Have tried searching and found various suggestions and possibilities but there's always something that doesn't quite match my exact issue.

 

I have a well maintained 1989 1.9 Gti and well the story goes along the lines of:

 

Will not start after a few days of inactivity, I use car 1-2 times a week. Battery is good, alternator is good. Spark plugs are brand new.

It tries like buggery to start but just won't catch. I resort to bump starting and after that it starts fine until it is again left to lie for a few days.

 

I have new leads, rotor arm and distributor cap but have not fitted these yet, are any of these the most likely culprit?

Could it be a cold/damp start problem, if so - what methods should I try to get it going, WD40, or similar - what's the technique?

What evidence would suggest problem with Tachy relay?

 

This is baffling me and the 205 won't appreciate being left in the cold (it recently lost it's cosy garage) and I fear it will punish me further

[Anthony 1,003]

Tired/damp ignition parts will certainly give similar symptoms, and would tie in with why it only happens after sitting outside for a few days.

 

Fit the new leads, cap and arm and check that the spark plugs look OK (cheap enough to replace as a matter of course though if there's any doubt) and that they aren't fitting in water, and see how it behaves afterwards.

[weejp 0]

OK, will give them a go (haven't done any of them before, any tips?) also I replaced the spark plugs less than 100 miles ago, so one less thing to do I suppose.

 

I just need to get going as I can't work on it outside where I am, I have access to full garage facilites (but only for 2.5 hours per week) and need to get the car there, bit of a catch 22 at the moment. I'm unable to bump start as I foolishly thought I'd resolved problem and parked it facing uphill, bugger!!

Edited December 16, 2011 by weejp

[Anthony 1,003]

If you can get someone to help, it's easy to bump start backwards - just not on your own!

 

Swapping the cap and arm is easy - the only thing I'd say is to trace the HT lead position back to the cap one at a time and fit the new leads on the new cap as you go. That way there's less chance of getting the leads around the wrong way.

 

Also, remove the old cap and leads complete so that if you do make a mistake, you've got a correct setup to compare against.

 

It might well be something else, but in my experience tired or damp ignition parts causing a weak spark tend to make it difficult to start on cold, damp mornings, but often will run just fine once started and with a bit of heat in it.

[Carbs4me 45]

i had this problem last year, left my car out in the snow didnt use it for a full month n half.. it started fine but was missing like crazy... lifted the bonnet to find a whole load of snow and ice complety covering my engine bay... 20mins of it warming up and the ice was finally disappearing. but took a good 20mile run on the road to dry everything out. (about 30times around my block to be exact )

[weejp 0]

Can anyone tell me what evidence would suggest problem with Tachy relay?

[kyepan 291]

Hmm, if it's a dodgy relay connection, it can just cut out over bumps. They are mechanical to a certain extent, and do fail. They can be found on the fuse boards of many cars, and bought new I believe. Also the case can be taken off and given a squirt of wd40..

[soundguy 13]

Mine does something similar but I think it might be something to do with fuel pressure leak of some sort. It takes aaaaaaages to fire - to the point where I'm turning it over for so long that the battery is almost flat - then finally it bursts in to life, runs rough for 30 seconds and then is fine.

 

As long as I run it every day it starts pretty much straight away. I even have to go out and start it the night before, run it for a few minutes and then switch it off in order for it to start quickly the next morning.

 

I think my problem is that somewhere in the fuel system it loses pressure as it stands for a while. The fuel pump (AFAIK, could be wrong) is supposed to hold pressure in the lines so on the next start up, the fuel is ready to squirt out of the injectors. If the pressure drops, the fuel maybe goes back down the lines to the tank meaning the pump has to do a load of work to get the pressure back up and the fuel into the rail.

 

But I could be wrong!

[weejp 0]

Mine does something similar but I think it might be something to do with fuel pressure leak of some sort. It takes aaaaaaages to fire - to the point where I'm turning it over for so long that the battery is almost flat - then finally it bursts in to life, runs rough for 30 seconds and then is fine.

 

As long as I run it every day it starts pretty much straight away. I even have to go out and start it the night before, run it for a few minutes and then switch it off in order for it to start quickly the next morning.

 

I think my problem is that somewhere in the fuel system it loses pressure as it stands for a while. The fuel pump (AFAIK, could be wrong) is supposed to hold pressure in the lines so on the next start up, the fuel is ready to squirt out of the injectors. If the pressure drops, the fuel maybe goes back down the lines to the tank meaning the pump has to do a load of work to get the pressure back up and the fuel into the rail.

 

But I could be wrong!

 

Yep, sounds just like the same thing. I experienced the exact same thing with fuel pressure scenario, but I couldn't get mine going at all.

 

What would be the resolution to that kind of problem?

[Anthony 1,003]

Easy way to pressurise the fuel system before starting for diagnosing is to link the thick brown and thick white (wire 74) on the back of the tachymetric relay plug - you'll hear the fuel pump running and after a few seconds the system should be pressurised. Indeed, you can normally hear the tone of the pump change slightly.

 

Only link those two wires to test, as with it like that, the fuel pump will run continuously regardless of ignition or engine running.

 

Normally with lack of fuel pressure it will just turn over on the starter for a good few seconds without sign of life, then a couple of seconds of trying to start, and will then start. It won't normally keep trying to catch but not want to start, and it shouldn't bump start easily either (until it's pressurised of course)

[weejp 0]

Easy way to pressurise the fuel system before starting for diagnosing is to link the thick brown and thick white (wire 74) on the back of the tachymetric relay plug - you'll hear the fuel pump running and after a few seconds the system should be pressurised. Indeed, you can normally hear the tone of the pump change slightly.

 

Only link those two wires to test, as with it like that, the fuel pump will run continuously regardless of ignition or engine running.

 

Normally with lack of fuel pressure it will just turn over on the starter for a good few seconds without sign of life, then a couple of seconds of trying to start, and will then start. It won't normally keep trying to catch but not want to start, and it shouldn't bump start easily either (until it's pressurised of course)

 

That's really useful information, if fitting the ignition parts doesn't help then I may have to give it a try. What ultimately does it mean though? An electrical issue or is the fuel pump goosed, what would be the pukka fix, or isn't it as simple as that?

 

I hope it's as simple as a new set of HT leads, pray, pray!!!

[kyepan 291]

I had a tird fuel pump, when hot it would not pressurise for about 20 econds of cranking, we traced it to a non return valve being rubbish. You say it will bump start fine... Brian when cranking it won't fire...

[Anthony 1,003]

That's really useful information, if fitting the ignition parts doesn't help then I may have to give it a try. What ultimately does it mean though? An electrical issue or is the fuel pump goosed, what would be the pukka fix, or isn't it as simple as that?

Lack of fuel pressure and the resulting time to re-pressurise is usually down either to a slight leak in the pipework, an injector or FPR that's leaking, or more commonly, the non-return valve inside the fuel pump being faulty and allowing fuel to drain back through the pump into the tank.

 

The system should give a brief ~1 second prime on ignition on, but many Jetronic cars don't (or only do so intermittently) and either way wouldn't be sufficient to repressurise the system if it is losing all pressure overnight.

[weejp 0]

I had a tird fuel pump, when hot it would not pressurise for about 20 econds of cranking, we traced it to a non return valve being rubbish. You say it will bump start fine... Brian when cranking it won't fire...

 

Bump starts everytime, does this not add up to fuel pressure/ fuel pump issue then?

 

More likely to be dizzy, leads or Electrical / Tachy Relays?

 

I would love to get to the bottom of this, I'm fed up with having to park at the top of a hill (just in case)

[Obey_R 23]

Surely bump starting it wouldn't be any different to turning it on the starter, as far as fuel pressure is concerned?

[jackherer 543]

If it bump starts with no problems but doesn't fire on the starter try fitting a new starter, even if the existing one turns it over fine they can fail in a way that interferes with the engine management.

 

http://forum.205gtidrivers.com/index.php?showtopic=123111

[DamirGTI 342]

Ignition amplifier replacement - fixed my problem which was very similar to yours .. also , i've bought a new coil few weeks after that and that made it start and run even better ...

 

Damir

[Dizzee stuff 33 1 Cars]

Ignition amplifier replacement - fixed my problem which was very similar to yours .. also , i've bought a new coil few weeks after that and that made it start and run even better ...

 

Damir

 

I second this, seen this sort of problem before, double check the wiring and earth points are all good before changing or borrow some known good ones for testing if possible.

[weejp 0]

Ignition amplifier replacement - fixed my problem which was very similar to yours .. also , i've bought a new coil few weeks after that and that made it start and run even better ...

 

Damir

 

Wow, that's a few different suggestions now. I've no idea what an Ignition Amplifier is, can anyone shed some light on the job or is it covered in the Haynes manual perhaps?

[Dizzee stuff 33 1 Cars]

Checkout this post,(Running Rough. by grahamlaw) in this section, has some info on the ign amp.

[weejp 0]

Checkout this post,(Running Rough. by grahamlaw) in this section, has some info on the ign amp.

 

Thanks, will check it out.

[kyepan 291]

I was going to reply to this yesterday, I agree with Jack herer. Because logically if you start the car without using the starter, and it fires and runs, the starter turNing the car over must be the issue.

 

Ignition amplifiers usually exhibit issues when they are hot, from what I have read on here.

 

Even a cheap second hand starter for a tenner on here and a couple of hours to change would be worth the effort, perhaps someone near by to you will be able to provide a test unit.

 

Then you can source a decent quality Valeo unit for a permanent fix.

Edited December 20, 2011 by kyepan

[weejp 0]

I was going to reply to this yesterday, I agree with Jack herer. Because logically if you start the car without using the starter, and it fires and runs, the starter turNing the car over must be the issue.

 

Ignition amplifiers usually exhibit issues when they are hot, from what I have read on here.

 

Even a cheap second hand starter for a tenner on here and a couple of hours to change would be worth the effort, perhaps someone near by to you will be able to provide a test unit.

 

Then you can source a decent quality Valeo unit for a permanent fix.

 

I wish there was a reference source local to me, that would be terrific, unfortunately not the case (AFAIK)

 

If this (the start motor) is the issue then why does it start up time after time once I've got it going? It's only when it's been sitting about for 3/4 days when this issue arises.

 

I'll check the service history (it's enormous) to see if a starter has ever been replaced.

 

Cheers again.

[Anthony 1,003]

I was going to reply to this yesterday, I agree with Jack herer. Because logically if you start the car without using the starter, and it fires and runs, the starter turNing the car over must be the issue.

There is one other key difference, and that's that cranking over on the starter pulls down battery voltage significantly.

 

(well, and that when the key is turned to "crank" the accessory circuit power is cut, which isn't an issue unless someone has made a mistake and wired something critical needed for the engine to run to the accessory rather than ignition circuit)

[kyepan 291]

There is one other key difference, and that's that cranking over on the starter pulls down battery voltage significantly.

 

(well, and that when the key is turned to "crank" the accessory circuit power is cut, which isn't an issue unless someone has made a mistake and wired something critical needed for the engine to run to the accessory rather than ignition circuit)

fair point.