Idle speed problem, R5 -90

[moonshield]

Tnks for a nice forum for our loved cars.
Im from Sweden, hope that you vill understand my bad english

My car is a R5 TS from 1990.

I have some problem with the idle speed. Its a bit high.

Have searched the internet for help. Got many tips.
About leakage in the vaccum system, leakage in the intake from the
monopoint "carburettor" to engine.
But i dont think its the problem.

The idle speed control engine is running, it withdraws and screws out.
Have disconnected it and totally overhaulded it. With grease and lube.

As you know, there are a nut on the top of the isc (idle speed control)
when i screw it out, the isc withdraw , when i screw the nut in, the
isc move the same distance outward...so the idle speed always be the same.

I have reseted the isc in the way it is told in haynes manual.
it lover the idle speed a bit, but after some starting its high again.

Two questions:

1.Is there any other equipment that control the isc in wich rpm the engine shall have?
Why does it always put the rpm on same level regarless how i adjust the top of isc?

2. Is it dangerous to disconnect the isc, and manually adjust the idle speed whit the top nut?
Is there any computerbox or any other equipment that can be damaged if i
disconnect it?

Hope someone can help me with this problem.

Thanks in advance

 

[Chris H]

I didn't think the 5 in 1990 had the fuel injection?

If it does have you pulled the pipe off the map sensor to see if that sorts it?

 

[moonshield]

I didn't think the 5 in 1990 had the fuel injection?

If it does have you pulled the pipe off the map sensor to see if that sorts it?

all cars in sweden from 1989 has fuel injection beacause of the
catalytic exhaust cleaning that was a law from that year.

my car has a monopoint fuel injection.

can you explain a bit more about the mapsensor, where is it placed,
and what pipe shall disconnect?

Tnks for helping me!!!

 

[Chris H]

the map sensor is a small black plastic rectangle, it has a vacuum pipe going to it and a wiring plug.

On the 5's if you pull the pipe off they start to idle right and drive properly.

Sadly when this occurs its because the ridiculous ecu is damaged internally, its very common.

 

[Chet T16]

Where is the ecu Chris? I couldn't find mine...

 

[Chris H]

inside on the passenger side.

I think project disaster has photos of it.

 

[Chris H]

no pics of ecu location, there is one of the engine loom :lol:



That plugs into the same bracket thingy that the diagnostic plug is on

 

[moonshield]

Im so grateful for the help! many tnks for it!

Sorry if i ask some silly questions, but:

1. Is it ok to disconnect the map sensor? i will not damage any other equipment?
2. Can i disconnect the isg without i damage the ecu or something?

i think if i can lower the idle speed i get better exhaust levels on the "bilprovningen",
the vehicle inspection.

What do you think, can i disconnect any of the items above without i damage anything?

 

[Chris H]

yes just pull the pipe off the MAP sensor, the ecu will compensate for it (to a degree).

isg? I assume you mean idle control valve? just leave that unplug the map sensor pipe and go from there.

 

[hooverphonique]

and note that chris said to remove the map *pipe*, not electrical connection