# G60 rough idle and rich when cold, changed almost everything.



## Jaxone (Jul 4, 2008)

Hello forum.

I have just bought a Golf 2 G60 and I changed the engine as the old one was making pretty much noise from the valves and 2 of the exhaust screws were broken in the block.
Got another engine which had recently done the head and head gasket and installed it in the car.

The new engine has a "slight" problem.

When I first start the car when cold it would run pretty rough, like running on 3 pistons and it idles badly like almost stalling.
If I accelerate and release the RPM will fall hard and it would almost stop ... almost.
I can also smell unburned fuel on the exhaust and the spark plugs are getting black.

What I have changed and done in order to try to fix the problem:
- Checked compression it is 8.4-8.5 BAR (123psi) on all pistons.
- Cleaned all the ground points.
- Re grounded engine, battery, body with 6 Awg wire.
- Re grounded head with 6 Awg wire.
- Re grounded bolt on the back of the engine beside water hose directly from battery with 6 Awg wire.
Changed parts :
- O2 sensor with brand new NGK sensor. Tried also with another Bosch.
- Idle stabiliser valve from my old engine that was running fine but with noisy head.
- ALL vacum hoses. (the car has the charcoal canister removed)
- Spark Plugs with new Bosch Platinum.
- Ignition wires for all 4 spark plugs.
- Distributor cap and pipe.
- Thermostat
- Blue and Black temp sensor changed twice with original VW sensors.
- Knok sensor changed.
- Tried with 2 other different throtle bodies.
- Tried with 3 different ECU's, 1 standard and 2 tunned.
- Adjusted the MAF to 500 ohm.
- Ignition timing adjusted to TDC (don't have an ignition check light to test it while running but will have it checked monday).
- Re made the injectors wiring with brand new wires and connectors as it was old and started to crack.

I am now in the process of overhauling the G-Lader and see if the problem maybe lies there but at idle ??
The only thing I have not done yet is to take off the head and check the head gasket but the head gasket was done recently

As soon as the engine gets hot no idle problems anymore. Car pulls nice and no hesitations.(as far as I noticed).

Any idea what can cause the problem ? Anything that I forgot or overseen ?
I am pulling my hair now and don't know what I have missed.

Any new idea would be much appreciated.


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## G60 Carat (May 14, 2004)

The two grounds off the ecu pinout are very important. If one of them is bad or has high resistance the ecu will dump fuel at idle.


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## Jaxone (Jul 4, 2008)

This 2 grounds are located on the firewall beside the water hoses that go into the car if I am not mistaking, right ?
I checked the ground connection there and it is cleaned and ok. Will check again each individual wire but I am sure they are ok.


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## G60 Carat (May 14, 2004)

Use a multimeter and check the resistance at the ecu main plug. I was fouling plugs at idle when one wire was damaged somehow and showing a good ground but 80ohms resistance. Best place to ground the ecu to is the cylinder head.


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## Jaxone (Jul 4, 2008)

I re wired all grounds with 6AWG wire ! so the ground should be ok at one end.
Will check the ground at the ECU and and post updates later today but really hard do believe ground snapped at ECU end as that connector is rock solid.


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## G60 Carat (May 14, 2004)

WOT switch stuck on, will make it puke fuel at idle too. Be lucky if it even stayed running really.


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## Jaxone (Jul 4, 2008)

I tried with 2 throttle bodies, same thing, no change.
The other throttle body I tried with comes from an engine that never had problems at idle...


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## Jaxone (Jul 4, 2008)

Throttle body switches checked - OK
ECU Grounds checked - OK 0.2ohm


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## green_slc (Feb 2, 2001)

I've had similar spark plugs fouling up issue with the G60 turbo swap in my caddy. After checking all the stuff you mentioned, I upgraded to an MSD Blaster 2 coil and NGK plugs with a wider gap (0.030). So far so good, running on all four cylinders now.


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## Jaxone (Jul 4, 2008)

Spark plugs I use Bosch WR6DP0.
My problem is only when the engine is cold.

Also I noticed the car uses more fuel when cruising with 60-70 km/h than when going on highway with 120km/h.
Consumption on 60-70km/h would be around 11-13l/100km while on highway at 120 would only use 10l/100km.
Seems it likes is better over 2500rpm.

Can it get to much air and trying to compensate with fuel ?


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## green_slc (Feb 2, 2001)

There isn't a MAF on these engines. So if you have a vacuum leak after the throttle plate, you would also have a high idle problem.

Before I swapped in the Blaster 2 coill and new spark plugs, mine ran like crap when it was cold too, seemed like it was running on 3 cylinders and fouling up at least one spark plug. Once the engine got warm though it ran better. Guessing that the ECU got out of the cold start mode went into the closed-loop mode.

There isn't a center post on the Blaster 2 coil. So I took a crimped connector off some other old plug wire and wrapped it around the OEM coil connector before shoving into the new coil. I got a good tight connection so I guess it's ok. Other people actually cut off the OEM coil connector and crimp on a different connector to make a hybrid coil to distributor cap wire.


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## crazynorweegian (May 8, 2006)

My car was not as bad, but cold starting and idling was very iffy for me for a while. I changed everything and decided to live with it. I was bored one day and decided to do every test I could on my car, just for fun. I got to the ignition timing section and that is where I found it, WAY off. Ran perfect after that.... for a week and a half until I took the motor out again.


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## Jaxone (Jul 4, 2008)

Ignition is set to TDC as I do not have a timing light to make it while running.
I just delivered the car today to a workshop to have the ignition adjusted. It has to be done with he light and the car does not have an ignition module, just the coil.

It seems to me that it can't be the ignition coil but who knows ... the other engine I had in the car was runing ok with the same ignition coil.

I will try to look around for an aftermarket coil and try to install that also but still doubt that the problem is there.


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## green_slc (Feb 2, 2001)

Your coil is working. However with a stronger coil you can run a larger spark plug gap to keep it from fouling up. Older engines have leaky rings and/or valve stem seals which can foul up the plugs too


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## Jaxone (Jul 4, 2008)

Ok, so today I tested something.

I started the car drove until it got warm to normal temp and I have reset the MFA to see the consumption.
Under normal driving conditions will eat about 6-10l/100km - Everything ok here.
Then I have reset the MFA again and stopped the car and let it idle while warm.
Consumption was something like 27l/100km while AT IDLE !!!!!

So conclusion : Car is DUMPING fuel like nuts when idle ! This combined with cold engine would make it idle rough. When hot idles normally but dumps loads of fuel ?????

So now I narrowed down to extra fuel at idle.
Where do I start to solve the problem ?


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## rodperformance (Oct 9, 2010)

*Hi!!*

I would check the fpr and injectors,also my engine put 150 psi in all 4 cilinders but im not shure if those numbers are good or not!,i'll be watching and contribuiting,hope you resolve the problem,later mate! Roderick. Side note i have a cis fuel pump and adjustable fpr,still it doesn't overfuel the engine


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## green_slc (Feb 2, 2001)

Jaxone said:


> Ok, so today I tested something.
> 
> I started the car drove until it got warm to normal temp and I have reset the MFA to see the consumption.
> Under normal driving conditions will eat about 6-10l/100km - Everything ok here.
> ...


 I don't think you can use the MFA to monitor air/fuel mixture at idle. Of course it'll indicate extremely high numbers. If the car isn't moving it'll take an infinite amount of fuel to get there.

You need an accurate Air/Fuel gauge to see if engine transition from cold-start fuel enrichment mode to close-loop feedback mode. Once warm, at idle the Air/Fuel should bounce around the 14.7 reading. If it's stuck in cold-start mode you'll get bad mileage all the time, but you say under normal driving condition it's fine. 

Have you check the fuel pressure with a gauge at the end of the fuel rail? It's higher than normal, then sure in cold start mode more fuel will be injected in. However once warmed up in closed-loop mode, the ECU can correct the mixture by reading the O2 sensor.


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## Jaxone (Jul 4, 2008)

Don't have an AFR gauge, guess is time to buy one.
I did not check the fuel pressure either as I only have a gauge that can measure gases and not liquid ... maybe I can get an adjustable fuel pressure regulator with an indicator to check it.


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## crazynorweegian (May 8, 2006)

Jaxone said:


> Don't have an AFR gauge, guess is time to buy one.
> I did not check the fuel pressure either as I only have a gauge that can measure gases and not liquid ... maybe I can get an adjustable fuel pressure regulator with an indicator to check it.


Just go simple and get an inline fuel pressure gauge. No need to drop $$$ on an FPR with one built in. Also, you need a wideband AFR, the narrowband will just tell you the same bad info that it is telling the ECU if there is something wrong with the wiring or sensors. It is priceless on a G^0, seriously, get one and install it. the innovative lc-1 is what i have and I am very happy with it.


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## G60 Carat (May 14, 2004)

unplug the blue CTS when it is doing this, and report back if it gets better.


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## Jaxone (Jul 4, 2008)

Gets worse !

From my original thread : - Blue and Black temp sensor changed TWICE with original VW sensors.


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