engine warm-up

[arjunior45]

These days, with ambient temp near to 0 degrees, I noticed that I MUST warm up the engine for at least 45 - 60 seconds {at 1500-2000 rpm} before the car can maintain the idle speed!
Is this normal?

p.s.
My idle is at 900 rpm.

[#84]

No, that is not normal. Check idle when it is hot by disconnecting the idle-cotrol-valve cable.

Leaking EGR hoses or gasket between inlet manifold and EGR valve.

In some way your mixture is not correct and it might be due too much air (leaking inlet manifold), too less air (idle control valve stuck (listen to it when you turn on the power), too much fuel (leaking injector) or too less fuel (fuel pressure too low, maybe becaue of defect pressure regulator).

The start up map runs for 255 revolutions = 10 seconds at 1500 rpm. So, lambda related issues should not affect the performance before the 255 revolutions are elapsed.

/A

[arjunior45]

No, that is not normal. Check idle when it is hot by disconnecting the idle-cotrol-valve cable.

Leaking EGR hoses or gasket between inlet manifold and EGR valve.

In some way your mixture is not correct and it might be due too much air (leaking inlet manifold), too less air (idle control valve stuck (listen to it when you turn on the power), too much fuel (leaking injector) or too less fuel (fuel pressure too low, maybe becaue of defect pressure regulator).

The start up map runs for 255 revolutions = 10 seconds at 1500 rpm. So, lambda related issues should not affect the performance before the 255 revolutions are elapsed.

/A

Thanks for the infos Andreas.
A couple of days ago I believe I saw a leak over the 4th injector, not knowing what it was - water or fuel}. When I check it later there was NOT any leak.
Today I saw the same leak and I'll start from there. Besides, from time to time, on idle, it gives me the impression that it works like 'just 3 cylinders'.

Nick

[wrinx]

The water temperature sensor can cause idle problems...and smoking.

wrinx

[arjunior45]

well,
today I've cleaned the 'idle valve' and stabilized the 'vacuum' tube that goes from the inlet manifold to the fuel pressure regulator.
My problem is fixed, no need to warm up the engine any more and keeps idle very well. I can not say if the problem was a dirty idle valve or the loose {leaking} vacuum tube.

Though, the leak from the 4th injector is still there and I might say even heavier. I also realized that the fuel pump barely gives 2 bar {engine running} and it is brand new. So I'll have lot of homework for this weekend!!! First of all I must kill my mechanic for mounting this pump, for the fuel leak and for the loose tube! Lobotomize him will be better I think.

Anyway, what do you think for a Walbro fuel pump? Any recommendations?

Nick

[wrinx]

These days, with ambient temp near to 0 degrees, I noticed that I MUST warm up the engine for at least 45 - 60 seconds {at 1500-2000 rpm} before the car can maintain the idle speed!
Is this normal?

p.s.
My idle is at 900 rpm.

I'm experiencing this now...after resetting the valve clearances???

Trouble is I'm running a C&B inlet cam so this might be the reason, anyway, cleaning the ICV just to be sure it's not that.

There's a "slight" possibility of an inlet leak (see "Hissing Sid" thread) but it was fine before the shims were replaced.

Any thoughts?

wrinx

[wrinx]

Bit better now, but not 100%...still need to find Hissing Sid :doh:

wrinx

[na15575]

well,
today I've cleaned the 'idle valve' and stabilized the 'vacuum' tube that goes from the inlet manifold to the fuel pressure regulator.
My problem is fixed, no need to warm up the engine any more and keeps idle very well. I can not say if the problem was a dirty idle valve or the loose {leaking} vacuum tube.

Though, the leak from the 4th injector is still there and I might say even heavier. I also realized that the fuel pump barely gives 2 bar {engine running} and it is brand new. So I'll have lot of homework for this weekend!!! First of all I must kill my mechanic for mounting this pump, for the fuel leak and for the loose tube! Lobotomize him will be better I think.

Anyway, what do you think for a Walbro fuel pump? Any recommendations?

Nick


this is walbro gss342 with 255lph but is high pressure

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120437189965&viewitem=&sspagename=STRK:MEWAX:IT


this is the difference from the other

[arjunior45]

Thanks for the reply Nick. It's a year old this post and I've already replaced the oem fuel pump with the walbro gss342.

BTW, with engine running at idle what fuel pressure do you have? I know that with engine off the pressure must be 2,5 bar, but what about when engine is running at idle?

[arjunior45]

Bit better now, but not 100%...still need to find Hissing Sid :doh:

wrinx

For the passed 2 months Q4 is locked in the garage and will stay there till my mood is better, the proper one to deal with its idle problem.

Did not find any leak at the small bore hoses and I need to check plenum and inlet manifold.
Inlet manifold gasket is out of production and that was the 'reason' to lock her {q4} in the garage.

[wrinx]

I think I'll be doing the same soon...the hissing is getting worse :roll:

wrinx