Hello, I have a 480 Turbo of 1992, when cold start the rpm remain at 600 and the car vibrates but once the engine is warm the rpm remain at 800-850. I have tried to disconnect the idle control valve with the car warm and the rpm stay the same with no variation, I have also checked the resistance of the valve and it is between 20-40 Ohms. What should I look? Because spark plugs, distributor cap and rotor, ignition cables and temp sensor are new.
I also cleaned the idle control valve but with the same result.
Also tried to start the car with the idle control valve disconnected and the rpm go up to 1200 but tried to repeat with no luck, with the idle control valve connected and disconnected the car has the same 600 rpm on cold starts.
Low idle on cold start Turbo 1992
Moderators: jifflemon, coyote1980, Rachel
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jamescarruthers
- 480 Is my middle name
- Posts: 2540
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Re: Low idle on cold start Turbo 1992
Can you interrogate the diagnostic port?
1987 Volvo 480 ES, 507274, 217 - Red (Ness)
2006 Citroen C6 Exclusive 3.0 petrol/LPG
2008 Mini Cooper convertible (Mau)
Previous 480's:
J123 CFU -- ES
J449 MNL -- ES auto
D864 CPV -- ES
L691 JFC -- Turbo
F70 MNR -- ES
H858 FGV -- Turbo auto
E981 KHM -- ES (509849)
2006 Citroen C6 Exclusive 3.0 petrol/LPG
2008 Mini Cooper convertible (Mau)
Previous 480's:
J123 CFU -- ES
J449 MNL -- ES auto
D864 CPV -- ES
L691 JFC -- Turbo
F70 MNR -- ES
H858 FGV -- Turbo auto
E981 KHM -- ES (509849)
Re: Low idle on cold start Turbo 1992
The diagnosis port doesn’t work
Re: Low idle on cold start Turbo 1992
Idle control is managed by the Jetronics ECU and starts when a switch under the throttle body connects a wire coming from this ECU to mass. Apparently this is working at higher temperatures. The throttle cable may be too tight and prevent the switch from acting at low temperatures. Loosen it a bit and see what happens.
Too old to bother
480 Turbo midst '91
480 Turbo midst '91
Re: Low idle on cold start Turbo 1992
I had this years ago with my old 480, it was the valve that runs from the control valve round the right hand side of the engine, no idea what its called, not even sure if you have the same engine or year as mine but it solved the problem for me though. This post might help..
viewtopic.php?f=11&t=12966&p=201561&hil ... rt#p201561
viewtopic.php?f=11&t=12966&p=201561&hil ... rt#p201561
'95 Storm Grey 323 Manual Turbo, Richmod
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'95 Flame Red Celeb, Nos.191, 2 litre, LPG, used to be Adams ;) SOLD
'95 Vase Green Turbo~ Vanessa~ 'Serendipity' manual, Richmod. RIP
'90 Light Blue 480 Turbo auto....RIP
'68 VW Type 3 1.6 auto Lotus White,Swedish import. SOLD
Audi 80 coupe Gold...pimp my ride! RIP
'76 Bug, Ocean Blue, lowered, Empi wheels.RIP
'72 Bay window VW Camper 1600 twinport. Sold
----------------------------------------------------------
'95 Flame Red Celeb, Nos.191, 2 litre, LPG, used to be Adams ;) SOLD
'95 Vase Green Turbo~ Vanessa~ 'Serendipity' manual, Richmod. RIP
'90 Light Blue 480 Turbo auto....RIP
'68 VW Type 3 1.6 auto Lotus White,Swedish import. SOLD
Audi 80 coupe Gold...pimp my ride! RIP
'76 Bug, Ocean Blue, lowered, Empi wheels.RIP
'72 Bay window VW Camper 1600 twinport. Sold
Re: Low idle on cold start Turbo 1992
Make sure the idle control valve is not bypassed by the bullet plugs being connected.. They are on the same loom as the horn and plug for the idle control valve on my car..
93 480 Turbo white
with Roboumod
91 480 Turbo white
with Roboumod..
91 480 Es silver
with Roboumod
91 480 Turbo white
with Roboumod..
91 480 Es silver
Re: Low idle on cold start Turbo 1992
Hi,
I agree with Rachel. the most probable culprit here is that diaphragm valve just before the ICV. Those give all sort of issues. Even if it has not gone bad, I would suggest replacing with a 710N valve.
I had a very similar issue (if not the same) in the past. Take a look at Rachel's link You'll see me there
The reason why disconnecting (or earthing) the ICV does not make any difference is because in your case there is not enough air reaching it in the first place since that diaphragm valve is closed.
The reason why the car seems to idle correctly when warm is because that small pipe that connects from the turbo inlet to the cranckcase breather has a valve which opens when the engine is warm which allows more air. I'm not entirely sure about this one but makes sense to me.
The good news: the valve is cheap.
The Bad news: it is not a direct fit. You'll have to adapt the pipe that comes from the turbo.
Hope it helps. keep us posted.
I agree with Rachel. the most probable culprit here is that diaphragm valve just before the ICV. Those give all sort of issues. Even if it has not gone bad, I would suggest replacing with a 710N valve.
I had a very similar issue (if not the same) in the past. Take a look at Rachel's link You'll see me there
The reason why disconnecting (or earthing) the ICV does not make any difference is because in your case there is not enough air reaching it in the first place since that diaphragm valve is closed.
The reason why the car seems to idle correctly when warm is because that small pipe that connects from the turbo inlet to the cranckcase breather has a valve which opens when the engine is warm which allows more air. I'm not entirely sure about this one but makes sense to me.
The good news: the valve is cheap.
The Bad news: it is not a direct fit. You'll have to adapt the pipe that comes from the turbo.
Hope it helps. keep us posted.