1990 1.8 dropping back to idle issue

[marin]

Hi,

The GF has a 1990 1.8 soft top, issue atm (apart from the clutch lol) is that on starting and when you let off the accelerator and the revs are meant to just drop back to idle, the revs drop to almost stalling point before it picks it up again, revs it to about 1500 and then it drops back to idle, which seems to be a bit high, as in up about 800 to 1000 rpm (i have a nissan patrol, never dealt with these cars before, so sorry if i ask basic questions).

any thoughts?

marin

[WABIT]

exactly the same problem with mine... also same engine in a cabriolet

please help us!!!!!!!

wabit

[cab93]

I have had the same sort of problems with my '93 cabriolet.
I started with a service. new filters oil,air and fuel. New leads, spark plugs distributor and rotor. New oxygen sensor this made the best improvement.
Check for false air, Air leaks will also cause the idle to be wavy. This is air entering the system after the air filter, check clean or replace the hoses around the intake manifold, mine had cracks and were only found after i removed and bent the rubber hoses. This also made a big improvement. clean the filter in cylinder head cover mine was blocked - I brought a new one,
Idle speed should be around 900 RPM
While this has made things better its still not quite right. my next step is to replace the rubber O rings on the fuel injectors as these fail and let in air.
From what I have heard and read most problems come from dirty fuel/air filters and air leaks.

Michael

[Golf Loon]

Air leaks or the air valve that adjusts the idle when the ac is switched on.

[marin]

I have had the same sort of problems with my '93 cabriolet.
I started with a service. new filters oil,air and fuel. New leads, spark plugs distributor and rotor. New oxygen sensor this made the best improvement.
Check for false air, Air leaks will also cause the idle to be wavy. This is air entering the system after the air filter, check clean or replace the hoses around the intake manifold, mine had cracks and were only found after i removed and bent the rubber hoses. This also made a big improvement. clean the filter in cylinder head cover mine was blocked - I brought a new one,
Idle speed should be around 900 RPM
While this has made things better its still not quite right. my next step is to replace the rubber O rings on the fuel injectors as these fail and let in air.
From what I have heard and read most problems come from dirty fuel/air filters and air leaks.

Michael

Thanks, makes sense, will start to check out/replace hoses

marin