Erratic idle and cuts out

[The Baron3]

As per title, the car 1999 C4 Egas throttle.
when hot has an erratic idle and very occasionally cuts out, things I've tried:
Cleaned the MAF and the throttle body, not much change
I've unplugged the MAF no change
I've tried resetting the system by switching the ignition but not so the engine runs and letting it reset following a procedure! No change.
Oil air separator, tried removing oil cap whe hot and it screws off ok, with a release of a little pressure.

The only thing I can think of is air leak somewhere or the idle valve, and I think that is a ***** to get too.

Any suggestions? Thanks in advance

 

[Alex]

Variocam solenoid.

 

[The Baron3]

Variocam solenoid.

Good call, would that show up on codes if plugged into my Indy's system?

 

[YPVS]

So a 99 is a non cable throttle?

My erratic idle on my cable throttled 98 was a filthy idle control valve. It was easy to remove and clean, by opening it with a 9V battery and a couple of wires and plenty of carb cleaner.

 

[The Baron3]

Variocam solenoid.

Good call, would that show up on codes if plugged into my Indy's system?

 

[Alex]

So a 99 is a non cable throttle?

egas was standard on the C4 when released in '99.

 

[Alex]

Variocam solenoid.

Good call, would that show up on codes if plugged into my Indy's system?

I don't think you get a fault code from it, but if it's a proper Porsche tester your indy should be able to actuate each solenoid at tickover with his gizzmo. When they do, they should be able to diagnose its faulty.

 

[The Baron3]

Thanks Alex, your advice has been really useful.

 

[Bluebird911]

Hi Baron,

I had a Variocam solenoid failure last year and the Indy picked the fault up right away by the system having thrown up a fault code.

You don't describe how the car is running generally other than a rough idle / cut out. In my case, I did notice that low rev response was a bit sluggish, (worse when hot) but ran really well generally at higher revs. It was therefore a pig in slow moving traffic. If you have similar symptoms it could point to the solenoid failure. Have these symptoms just suddenly appeared, or have they gradually got worse? In my case, it was a noticeable difference in the low rev running over a couple of days, so I had to get it sorted out.

I would take the car to an Indy for a fault code reading. It could be as you say, an air leak in the system or something else relatively minor. Does the tickover change when you remove the fuel filler cap?

Best of luck with your diagnosis.

 

[The Baron3]

Hi Baron,

I had a Variocam solenoid failure last year and the Indy picked the fault up right away by the system having thrown up a fault code.

You don't describe how the car is running generally other than a rough idle / cut out. In my case, I did notice that low rev response was a bit sluggish, (worse when hot) but ran really well generally at higher revs. It was therefore a pig in slow moving traffic. If you have similar symptoms it could point to the solenoid failure. Have these symptoms just suddenly appeared, or have they gradually got worse? In my case, it was a noticeable difference in the low rev running over a couple of days, so I had to get it sorted out.

I would take the car to an Indy for a fault code reading. It could be as you say, an air leak in the system or something else relatively minor. Does the tickover change when you remove the fuel filler cap?

Best of luck with your diagnosis.

Hi Bluebird, it's been gradual but seem to have got any worse, it's fine in slow moving traffic, low revs and high revs.

Can I ask how much it cost to sort out the solenoid?
Thanks

 

[Alex]

I think I got a new solenoid cheap for £280 then 6 hours labour.

 

[Bluebird911]

Hi Baron,

Just dug out my invoice for the work.

Code was DTC P1341 Cam Adjuster Bank 1. There was no Check Engine light on the dashboard! The Cam adjuster stuck in the extended position. Apparently it extends to this position beyond 3000rpm, so I was running on a 'hot cam' at engine speeds lower than 3000rpm - hence the lumpiness at lower revs. If yours is not displaying this, it may be some other fault.

I'm afraid I can't give you a good price indication as I decided to get a lot of extra work done. Some Indys do the work with engine and gearbox in situ at a reasonable price. I wanted to futureproof my car, so while the engine came out, may as well do big jobs while it's out and the engine open - which I now believe was a wise thing to do.

I had replace IMS, replace RMS, Aircon pipework overhaul (wasn't working), remove exhaust manifolds and restud, replace waterpump and all hoses to rads etc, replace all earthing straps and alternator wiring, over gearbox brake pipe work replacement, replace oil air separator, replace oil filler tube and oil cooler tubes, replace chain tensioners, and sundry plus full service for just over £5.5K. While it's a big bill, there shouldn't be anything to do for the foreseeable and it is running really well now.

At the time I was thinking of keeping it a while, but that plan may have changed!!

Alex's price indication for the part is the same as mine. It looks like his price is an engine in situ one, so I would use his Indy if your problem turns out to be the solenoid.

If it's fine in slow moving traffic, I suspect it may not be the cam adjustment! I've had wild cams in escorts back in the day, it wasn't as bad as that, but had similar symptoms. I wasn't surprised when the diagnosis came through!

 

[Alex]

Yes, when I had mine done engine was in situ. Exhaust manifold has to be removed though and that in itself could be a costly bill.

 

[Alex]

This was mine:

The reving to avoid stalling was the car doing that, not me.

 

[The Baron3]

This was mine:

The reving to avoid stalling was the car doing that, not me.

Hi thanks for posting the video, good reference point, mine is not like that at all, so hopefully something simpler and cheaper to sort, but it's not to say that it won't end up like yours if it is the solenoid gradually deteriorating.