1.9 8V; Fine When Cold, Cutting Out And Stop When Hot

[Bobbafett 49 2 Cars]

Just bought another 205. Was all fine on the test drive and most of the way home.

 

Got fairly close to home then when pulling up to junctions and depressing the clutch, the revs dropped low as did oil pressure, STOP light illuminated and the car cut out. It did this about 10 times.

 

I bought the car off a guy I know and he says it's never happened to him. The car has been sat for a little while. It's a Ph1.5.

 

I've tried adjusting the throttle screw but this still happens if I blip the throttle on tickovers (revs 'bounce' low and car cuts out, STOP on)

 

Any ideas?

Edited August 19, 2015 by Bobbafett

[Tom Fenton 1,542]

Sounds like it needs a good clean out of the throttle body and breather pipes then a setup by someone who knows what they are doing. Sounds like classic symptom of throttle disc set too closed to me.

[Bobbafett 49 2 Cars]

Yeah I think i'll give it a good going over at the weekend. I did try adjusting the throttle screw but didn't seem to make too much difference except when it was just smooth idling (before touching the throttle).

 

Worried a bit because I never saw the STOP light once with my Ph2 I had before but I'm guessing that's just illuminating due to the oil pressure dropping when the engine cuts?

[Anthony 1,003]

Worried a bit because I never saw the STOP light once with my Ph2 I had before but I'm guessing that's just illuminating due to the oil pressure dropping when the engine cuts?

Yep, if the engine revs drop low enough (or the engine stalls altogether) the oil pressure will drop to the point that the STOP light comes on. You'll likely find the charge/alternator light will come on as well, as the alternator will be turning too slowly to maintain charge.

 

I agree with Tom - it's more than likely an issue related to setup and/or the throttle body and breathers needing a clean. Jetronic management is very sensitive to both, hence some people thinking that such behaviours are "normal"

[Bobbafett 49 2 Cars]

haha, yeah I knew Jetronics were a bit temperamental compared to the motronic I had. I guess i'll just have to rev it a lot at junctions for the time being; which is always fun when it has a full Magnex stainless exhaust inc manifold

[Anthony 1,003]

You'll probably find that if you leave the car in gear as you slow and only dip the clutch as the revs drop to idle speed then it'll be less temperamental and the revs shouldn't dip so much as if you dip the clutch at higher revs.

 

Have a quick check of the breather and induction pipework for splits that might cause an air leak, as that can considerably worsen the issue and might explain why it's suddenly happened if the seller is telling the truth and it wasn't doing it before, given that typically this would gradually get worse rather than be fine one day and terrible the next.

[Bobbafett 49 2 Cars]

Nah he's proper sound, and a mechanic, I just think it needs tweaking a bit. I went for a blast tonight and it was literally like a switch flipping; it went from idling at 2000rpm when dipping the clutch or neutral then suddenly started doing the rev dropping and idling at about 1000rpm. I pulled over and adjusted the throttle screw a couple of times and it made things a bit better.

 

The sudden switch though, that wouldn't be anything to do with the SAD? I remember reading about them no-end but my PH2 didn't have one. Does this?

[ATK 142 1 Cars]

Your PH2 will have a SAD mate if its standard. Going from 2000 to 1000 is probably the sad closing up.

 

Getting a 205 GTI to idle nicely is quite a task and it took me a long time to get my head around the setup procedure. Alot of trial and error but mine is now running perfectly even when cold even though I am no mechanic.

 

Strip all the pipework out from the manifold back, take off all pipes etc. Take off the cold start valve, AFM, throttle body, air filter housing etc. Clean them all out with carb cleaner etc and refit making sure everything is tight and no holes or leaks etc.

 

Then try setting it up as follows (this is assuming your other components spark plugs fuel pump etc are all good):

 

1. warm engine up (until rad fan kicks in) and stop

 

2. turn AFM air bypass screw fully out (weaken mixture)

 

3. turn throttle air screw fully in (Larger screw on the throttle body)

 

4. Unscrew throttle stop screw so the throttle plate only just about 'clinks' against it when returning to rest position. start engine and set throttle stop screw (smaller screw on throttle body) to 600rpm (650rpm on 1.6)

 

5. turn throttle air screw out until RPM achieves required idle speed (900rpm +/-50rpm)

 

6. richen the mixture on the AFM by turning the screw in until the desired CO reading is achieved (1% - 2%) which will raise the RPM

 

7. turn the throttle air screw in until RPM is lowered back down to required idle speed in step 5

 

8. stop engine and adjust Throttle position sensor (on side of throttle body - rotates) to idle switch stop position (pin 2 and 18 continuity on a multimeter). Best way to get this done roughly is that to turn the TPS on the side of the throttle body so it just clicks as the throttle returns to rest.

 

Then set your ignition timing. for ignition timing don't bother with a light, wind the dizzy until it pinks in a low gear up a hill, then back it off slightly. You might need to wind the air screw in or out after doing the ignition timing.

 

If idle is still high either your ignition timing is too far advanced, you have an air leak or your cold start valve (SAD) is not closing up. You should be aiming for around 1400rpm idle when cold and 950rpm when warm. I set mine to 1000rpm when warm as it drops to 950 due to electrical load when lights fan etc is on.

 

Best bet is to a buy a Haynes manual from Ebay for a fiver if you plan to work on the car yourself and keep it.

 

Good luck!

[Bobbafett 49 2 Cars]

Sorted TPS wasn't clicking in the right place (throttle stop was preventing it from going far enough to click). Adjusted throttle stop so it clicks in correct place and set it up, and now idles perfectly.

Edited August 22, 2015 by Bobbafett