phoenix70
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| posted on 30/7/05 at 11:29 PM |
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Pinto Idle Problem
Hi All,
I've got a little problem with my engine. All seems fine until the engine warms up, then it starts hunting. When I start it, the revs sit
about 2K and all is fine, but after it has been running for a while, the revs drop, and then jump upto 2K again, it just keeps doing this, dropping
then jumping back up . I haven't really looked for a cause yet, but any ideas gratefully accepted. I haven't fully fitting the exhaust
manifold, so back pressure could be the problem I'm not sure if it could have anything to do with this.
The engine is a 2L Pinto using Efi.
TIA
Scott
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bob
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| posted on 30/7/05 at 11:48 PM |
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could be the idle valve control unit which is bolted on the side of the plenum chamber,whip it off and WD40 it.
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gazza285
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| posted on 30/7/05 at 11:48 PM |
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If it uses a lambda sensor then it'll never settle down until you fit the exhaust properly.
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phoenix70
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| posted on 30/7/05 at 11:51 PM |
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quote:
Originally posted by gazza285
If it uses a lambda sensor then it'll never settle down until you fit the exhaust properly.
no Lambda Sensor
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Brook_lands
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| posted on 31/7/05 at 08:13 AM |
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A couple of things to consider.
How old is the petrol in the tank – this unleaded stuff seems to “go off” a lot quicker than the leaded stuff did. I was
having idle and running problems until I added 2 galls of new fuel to the ½ gall or so that had been in the tank for a few months and suddenly it was
like a new car.
Second on, had a similar effect with a Rover Efi engine. Nearly stalled and then up to 1700 rpm back down to nearly stalling etc. Turned out to be one
of the sensors (throttle position in my case) and the rest of the electronics (particularly the anti stall) were trying to compensate for the original
fault. That’s the problem with electronic controls the symptoms you are experiencing may not be completely indicative of the actual fault.
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rusty nuts
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| posted on 31/7/05 at 09:31 AM |
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As Bob suggests idle speed control valve may be sticking , clean with carb cleaneruntil all black gung is off then retry. Also test for air leaks,
using WD40 spray around manifold to cylinder head gasket , if revs rise you have a leak . Look for vacuum pipes not connected as well . Probably
better to finish fitting exhaust first though
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andy d (rizla)
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| posted on 31/7/05 at 10:31 AM |
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 this is a easy fault to clear
take the induction tube off at the throttle end on the inlet manifold,then with a wrag and a bit of brake fluid clean the inlet to the manifold
including the throttle vane(hold the throttle open to do this)
the problem is the throttle vane not seating properly and the air not going through the bypass valve to the idle control valve
this is a common problem and was a service task that was done when i worked for fords
and it works
[Edited on 31/7/05 by andy d (rizla)]
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phoenix70
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| posted on 31/7/05 at 06:37 PM |
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Thanks for all the suggestion, I will give them a go, and hopefully it will solve my issue.
Cheers Guys
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phoenix70
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| posted on 4/8/05 at 02:19 AM |
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Finished Fitting my exhaust, and had a chance to try all the above comments, but still no joy. I have investigated a little further, by trying some
tests. First Thing I tried was disconnecting the Idle valve control unit wiring, this sounded promising, but after a few seconds it started to hunt
again.
Next Thing I tried was to remove the throttle position sensor, now this had the desired affect, albeit at 2000 rpm. Not sure if this mean there
could be a problem with the TPS, or not?
The only other thing I will try, is swapping my Airflow meter, with a spare one I have.
Any further suggestion I can try.
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CairB
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| posted on 7/8/05 at 07:33 AM |
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U2U sent
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