Starting problems G60, again :-(

[Tempest 0]

Hi folks,

 

Need your help again :wink: .

 

After I recently thought I'd cracked my US-G60's starting problems, it wasn't to be :x .

 

My G60 Rado starts fine without a hitch if it's not been driven for say 2 weeks or so :) . But when I then start driving it more frequently again, say daily, then after an initial 2 to 3 seconds stuttering from the engine :mad: , the engine "catches" itself and all's fine again. After that the Rado drives normally, I can cane it without any problems, no juddering at all, all's fine 8) .

 

OK, a few facts:

 

Zoran-Chip in a CR-ECU, normal charger-pulley, airco (US-G60), I've recently rang through and cleaned all ground-points to the ECU ;

 

new blue temp-sender approx. 3800 miles ago;

 

new spark plugs 5300 miles ago (also recently cleaned them again);

 

checked the spark lead resistance, all OK;

 

ignition coil replaced 10000 miles ago;

 

checked and set ignition timing to 6° BTDC, all timing marks OK; reset idle speed to 850 rpm; this was done 3 weeks ago;

 

replaced fuel filter 10000 miles ago;

 

replaced FPR (new VAG unit) 3000 miles ago;

 

replaced the 3 fuel hoses in the engine bay 450 miles ago;

 

tested the fuel pump delivery rate, approx. 1 Liter after 22 seconds with a measured pump voltage of 12 V; should be OK;

 

compression test 90 miles ago: dry: 11, 11, 11, 11 bar; wet: 11.5, 10.8, 11.9, 11 bar; should be OK;

 

recently cleaned the ISV again (even used a 2nd hand replacement unit, made no difference);

 

checked the CO-value (512 Ohms);

 

changed the startermotor (GSF new) 2800 miles ago;

 

What else could be causing this problem? Knock sensor, ISV (yes, I'm running out of ideas, thinking about all sorts ... :roll: ) or what else ... ?

 

Thanks for any help :) !

 

Tempest

[Jim 1]

Have you tried giving g-man a call Eric.. he might have a few more suggestions for you seeing as you've tried virtually everything there is to try! :)

[g60pops 0]

ignition switch? ecu relay?

[samg60 0]

have you tried the good old dizzy cap and rotor arm, this sounds very similar to the way my car was before I replaced these, however I think my problem was made worse by the fact that the pulley bolt was about to snap and had thrown the engine timing out.

[Guest]

Do you mean it has trouble starting and slowly picks up or the starter doesnt turn engine over?

[steveo29 0]

id go with ign switch

[Tempest 0]

Thanks for the suggestions already, folks :D

 

Have you tried giving g-man a call Eric..

 

Not yet, as I was still hoping to get the problem fixed myself :oops: But I was thinking of that, if all fails :D

 

the good old dizzy cap and rotor arm

 

These were replaced approx. 8000 miles ago, and last time I checked them (3 weeks ago) they seemed OK.

 

pulley bolt was about to snap and had thrown the engine timing out.

 

I hope the replacement with a DX-bolt has cured that on my engine :) Will have another look at the timing marks tonight.

 

Ignition switch: How can I check that, as wriggling the key in the switch doesn't do anything.

 

The funny thing remains: If the Rado hasn't been driven for 2 weeks or so, she starts up fine straight away.

 

When she's started the next day (engine cold again), this stuttering occurs (which gets worse on subsequent days of driving/starting). When the engine is still warm (after having been to the pub, say :lol: ), she starts up fine as well. Very confusing.

 

Tempest

[StuartFZR400 0]

I take it you mean on a cold engine every time.

 

I cant understand it my self - doesnt sound like fuel directly, cos obviously that evapourates off after a few mins. Whereas my golf used to star very well on cold but poorly on a warm engine. I dont understand the daily use making it worse... as if it were sooting up; cant be. Electrical maybe?

 

Tried fiddling with the tickover?

Flush fuel - use different?

 

Good LUCK

[Tempest 0]

trouble starting and slowly picks up or the starter doesnt turn engine over?

 

Engine starts and then slowly picks up. I therefore doubt whether it's the ignition switch.

 

Electrical maybe?

 

Checked the Hallsensor yesterday, supply voltage is OK (10.13 V). With ignition on and handturning the crankshaft the Hallsensor voltage nicely changes between 10.33 V and 0.11 V, so the sensor is OK.

 

Also checked the ignition trigger function (voltage between pin 1 and 15 on the coil) whilst starting the engine: Voltage OK, attached LED lights up.

 

Checked ground from ECU, nice and clean, no resistance.

 

Tried fiddling with the tickover?

Timing marks all OK (checked them again last night), timing set to exactly 6° BTDC, all OK. Rado runs sweet once running.

 

Flush fuel - use different?

That's about the only thing left, and as someone on a German forum suggested something similar, I'm starting to suspect BP's good old Ultima :roll:

 

Tempest

[Jim 1]

Hm I dunno Eric.. I found Ultimate to be some of the best fuel out there, without a doubt. My car ran the best on that stuff!

[samg60 0]

found this, you never KNOW

 

http://www.corrado-club.com/faq/detail_ ... ?FAQID=190

 

or this

 

http://www.corrado-club.com/faq/detail_ ... ?FAQID=109

[Tempest 0]

Thanks Samg60 for those links :-). I had already checked the little pressure hose from the FPR to the intake manifold, the hose is fine (one of the 1st things I checked :lol:), fuel filter on my G60 was changed around 10000 miles ago (still nice and shiny even on the outside :lol:).

 

I have noticed a resistance of 8 Ohms, however, between the negative battery pole and the ground point on the chassis, so will have to investigate that. The ECU, however, shows a nice 1 Ohm resistance between its ground and the battery negative pole (resistance of my multimeter cables; ECU has 2 ground connections anyway), but nevertheless.

 

I also noticed a voltage drop of 0.06V between the battery positive pole and the supply line to the ECU (measured at the line powering the ISV). Needless to say, this drop isn't there with the ECU diconnected. Might just try another ECU ...

 

Tempest

[RW1 0]

Eric,

 

This fault has the hall marks of a weeping injector. Worth eliminating.

 

Over night etc., when you expect it NOT to start. Take the plugs out at that point and sniff each cylinder. Also examine down each cylinder onto the piston crown. Obviously they should be dry but if wet or there is a strong petrol smell, then that injector is leaking.

 

The slow start/stuttering is because the injector has weeped away the residual fuel system pressure and so the pump has to build up pressure from nothing rather than 2 bar.

 

This fault isn't electrical, it's fuel related.

[GazzaG60 0]

i has similar with my idle valve or the circuit around it. in the end i removed it

 

to test get a wheel bolt and remove the isv and put that in its place. clamp it up a tad and try to start. only downside is a low cold start idle for around 2 minutes

[Tempest 0]

Thanks RW1 for your tip.

 

Well, after having observed the spark plugs for some time now, I can confirm having noticed a pungent smell from cylinder #2, very little if any smell from the other cylinders.

 

What's more is that I noticed oil traces around the spark plug thread.

 

Yesterday, after I'd moved the Rado 4 times 3 meters each (to get access to the garage where I keep my Mk1 Rocco, took that out for a spin yesterday), I even noticed oil on the actual electrodes :-(

 

Is this the sign of a head gasket failure? The compression values for each cylinder I posted further above would seem to indicate that the valve stem seals and the piston rings should still be OK, I would have thought.

 

I haven't noticed oil traces in my coolant, nor any smells of exhaust fumes through the oil dipstick tube, nor noticed any white smudge on the oil filler cap.

 

Given that my G-Lader was rebuilt back in November by Darran at G-Werks and having identified the reason why it needed one, i.e. one of the oil seals on the main shaft had gone, hence my Lader was pushing out oil. Could it just be a still contaminated intercooler (still got the original one)? Haven't cleaned it yet since the Lader rebuild :oops:

 

Tempest

[Tempest 0]

This fault has the hall marks of a weeping injector. Worth eliminating.

 

Having discussed this one again whilst meeting at Utterly Veedubberly at Donnington, I have now had a good look several times inside each cylinder through the plug holes, and can confirm that there is no injector weeping. All piston crowns were dry each time I looked :-)

 

Hence I don't think that's the root of my starting problems.

 

I have temporarily fitted the original chip (ending with 189, 1990 VAG G60-code) into the original ECU (B-ending) again, and the Rado started each time on first key turn (although I couldn't help but notice that as I didn't drive the Rado during these tests, starting did get a little worse each time / each day).

 

I have not driven the Rado with its old chip yet, however. Currently I have refitted Zoran's chip again but into the old ECU (B-ending, was using one with a CR-ending), driven it, and yes, it did stumble ever so slightly again on starting when cold.

 

Tomorrow I will create another chip with the 636-code (1991 G60 VAG code), and further test Zoran's chip in my old ECU to rule out a potential fault in the ECU itself.

 

Tempest

[Tempest 0]

Doesn't seem to be the ECU or chip either. Fitted the 636-ending chip, tested it 2x, first time my Rado started fine (after a 13 hour stand still, this or longer is where it typically will play up), 2nd time, yesterday, it stuttered again for a few seconds before the engine caught itself on the first turn of the ignition key.

 

Waiting for my fuel pressure testing kit off ebay to arrive ...

 

Anyone any further suggestions?

 

Tempest

[Tempest 0]

Fuel pressure kit has arrived and wayhay just before the showers today (and a bit during :lol:), I got cracking.

 

This time I correctly followed the procedure in the Bentley to determine the fuel delivery rate with 4 bar pressure (1990 G60 Corrado, single fuel pump)over a 30 second period, repeated the test several times, and each time I only had 400 ml instead of the stated minimum of 500 ml.

 

I then did a pressure test, and with an initial pressure of 3 bar, this did drop down to 2 bar (not lower) after 10 minutes (OK according to Bentley), so the check valve etc. of the pump seems to be fine.

 

The pump therefore seems to be ageing, I guess.

 

Now I do have some documents from VW of America (VWoA), listing my US-G60 Rado as having 3 open recalls, one of them pertaining to the fuel pump!

 

Having had no luck with VW of GB in MK with regards to one of the open recalls (they initially couldn't find my Rado based on either of the 2 VIN numbers, US Rados have 2 VINs, then said the recall had expired, blabla, basically just fobbing me off big time :mad:), I might just send a letter to VWoA.

 

Problem is that I'd like to get this sorted before the RR day at Stealth end of the month :roll:

 

Oh well, one more test to do with my new pressure gauge toy :-) Check the fuel rail and FPR.

 

Tempest

[stevemac 0]

Tempest, What make is your fuel pump ?

I have a (brand new) spare "Pierburg" pump that I can lend you for testing. Won't fit if you have a Bosch pump - fuel level sensors are different.

[Tempest 0]

What make is your fuel pump ?

 

Not taken it out yet, as I can't get that blasted white plastic ring off (even tried the screw driver and hammer trick).

 

Reading the recall documents from VWoA and looking up the listed part numbers to be replaced seems to say that it's a Pierburg.

 

Would you have a bit of time potentially next weekend, if I came up, as I need help to get that retainer ring off ? :roll: I'll bring along the fuel pressure tester, though :-)

 

Tempest

[stevemac 0]

Eric - I'll be home all next weekend, you're welcome to call round.

[gibber 0]

Tempest got my US G60 engined Golf back now mate what did you want me to look at so you could compare? was it the isv part number?

[Tempest 0]

was it the isv part number?

 

Yes please. Thanks :-)

 

Although today when it had stopped raining once again, I wanted to measure the fuel pressure at the pressure switch end of the fuel rail, and wanted to start the engine my battery decided to call it a day. I had already noticed the battery starting to fail, crank more difficult etc. This is a trip back to Elliot's, my local autofactors, as they after lots of huffing and puffing back in May, finally replaced the then just 1-year old battery (that I had initially fitted to my Mk2 Rocco, where it failed, then tried in in the Rado, where it also failed, AA even did some checks on it, said it didn't take charge anymore, which I had already determined anyway :lol:) with a dodgy-looking 2nd hand unit, which has now failed. Let's see what they're gonna say tomorrow :mad:

 

Steve: Thanks for the offer, will come back onto that nearer to the weekend, once I have a new battery for the Rado (hopefully before Tuesday, when I've gotta go to another Coventry meet :roll:).

 

Tempest