Problem Solving

[Veero 1]

Been around the houses now with the Mi.

 

Rebuilt the entire loom from scratch. Checked continuity many hundreds of times now. Replaced the following: plugs, leads. cap, arm, ignition amp, coil, crank sensor. It still will not idle properly on starting. It fires first time but needs nursing to get it idling right but once warmed for a minute or two it seems fine to idle on its own. Once idling occasionally it seems to miss a beat, and idles where it wants anything between 900 and 1100. TPS has the audible click when you move it from rest position and last time I tested it the readings were correct and the symptoms haven't changed since.

 

Tonight I got the voltmeter out and put it across the battery terminals. When it was idling happily and strong the voltage across the terminals was anything between 13.6v and about 14.5v. As soon as I heard it skip a beat the voltage dropped to 12.5v ish and sometimes to around 11.5v. After a few seconds it would pick up a little, sound strong again and the voltage would return to between 13.6 and 14.5v. If you manually hold the throttle open a little the voltage stays constant between 13.8 and 14.4v approximately and then doesn't sound like it's missing a beat every now and again like it does on idle.

 

Could my alternator be on the blink? Would a variation in voltage cause possible hesitation?

 

Since the random cutting out issue I have changed the crank sensor and ignition amp but have yet to road test it, partly as it's now almost dark when I get home and partly because I have lost confidence in it somewhat

 

Cheers

Veero

Edited November 4, 2009 by Veero

[luggy 13]

Since the random cutting out issue I have changed the crank sensor and ignition amp but have yet to road test it, partly as it's now almost dark when I get home and partly because I have lost confidence in it somewhat

 

Cheers

Veero

 

Had a similar issue, car would splutter and cut out after about 10 mins, tried a different battery same issue. Thought it must have been the alternator however the battery light wasn't coming on and the fan belt was a little slack but wasnt squealing, tightened the fan belt problem mysteriously disappeared

[Veero 1]

Actually I've got a spare alternator, shame it's such a royal pain in the arse to swap it. Might try tightening the belt...

[leon 1.9 0]

Could you not just take the belt off altogether, start it and check it idles ok? Then if it does, its got to be alternator related. Then try putting the belt on and tensioning it up correctly, trying again and seeing if it'll idle ok then?

 

Or am I talking out my ass (again)

[DrSarty 90 1 Cars]

Could you not just take the belt off altogether, start it and check it idles ok? Then if it does, its got to be alternator related. Then try putting the belt on and tensioning it up correctly, trying again and seeing if it'll idle ok then?

 

Or am I talking out my ass (again)

 

Good idea.

 

I would also propose swapping the alternator for a known good one AFTER you've ensured all earthing and power cables are hunky dory.

[Veero 1]

Well I've had all the earths off and given them a damn good going over to clean them as well as possible. Not sure what else I can do as far as earths go.

 

Tonight I tightened he alternator belt which was fairly slack it seems, now the voltage across the battery does not drop below 13v with the engine running, but it still misses a beat once evey 20 seconds or so. Still awkward to start. Going to pop the inlet manifold off tomorrow and change the alternator and starter (since that's playing up too even with a charged battery ), I will remove the 306 GTi resonator chamber as it just seems to get in the way. Wondering if I have an air leak or something.

[24seven 104]

wish mine would miss a beat "once every 20s or so". At idle if it misses 1 in every 4 beats it's having a good day, any less is a miracle!

[DrSarty 90 1 Cars]

Good luck Tris. It must be annoying the tits off you, but stuff like this often needs you to chase the problem through.

 

Next time you'll find it first crack, but on this occasion it seems you had to isolate it, which is the real bummer.

[Veero 1]

Ok well I've had the inlet manifold off and made a load of proper blanking plates with o-ring seals and adaptors so now the Mi16 ICV does not run through the GTi6 ICV etc and changed the starter and alternator and it starts a treat and idles spot on now. However the revs jump to about 3k before it settles down so it's the opposite of what it used to do Also removed the resonator chamber and there is soooo much space under the inlet now to get to things.

 

I'm thinking it could be the TPS not plugged in correctly it felt secure but who knows, darkness stopped play again today so tomorrow I will check it with the multimeter to make sure it's functioning properly and take the ECU out to make sure the signal is reaching where it should.

 

On a slight footnote, I've put an 8v starter motor in and I love the sound it makes turning over, nothing like the industrial 16v one, reminds me of the good old 1.6 days

Edited November 17, 2009 by Veero