varioram problems?

[kennyboy]

Hi

I was wondering if anyone could confirm I really do have varioram problems on my '96 993...

I recently had an ECU remap and the chap said one of the actuators wasn't working properly and I probably had a leak or something.

I read various things about this but was interested to hear what members thought...

Under full throttle power delivery is very smooth and the car scrambles to the rev limiter as you'd expect in a fully working car - i.e. there doesn't 'seem' to be any top end power problems as I've read you should expect when you have varioram probs. Also, the car will reach an indicated 170+ mph - again I thought this would mean the varioram system must be working atleast in the high rev range as the car would struggle to do anything like this speed if there was a problem?

However under a part-throttle, there is a very noticable surge in power at around 3500-400 rpm which I've read could be a symptom of varioram problems? I must say I thought this was actually a characteristic of varioram cars?

Before I get my local porsche engineers to start doing very expensive diagnostics and possible repairs I was hoping other varioram owners have similar acceleration characteristics or know of specific varioram problem symptoms?

Cheers

 

[kennyboy]

ha ha thanks Maurice, are you trying to baffle me!?

No print out I'm afraid as printer wasn't working at the rolling road... noticable difference though and 311bhp at the flywheel, very pleased. No torque figures either worryingly as torque measuring thingy not working on the r.r. either.

I can hear what seems like an electrical buzzing when I switch on, though this doesn't tell me whether the flaps are actually opening or closing does it?

I've just had some very helpful photo's sent to me from a rennlist subscriber showing where the actuators are and he said his left hand one sometimes gets jammed and can be free'd by hand - will try this tonight.

If I get someone to switch ignition on for me what am I looking for Maurice? that both of them move? also read somewhere that spraying with WD40 is a good idea - not sure?

 

[kennyboy]

Thanks Maurice, I'f I cant do any of these myself I'll atleast get my local specialist to do a test first before assuming there's a problem. Do you know if technique #2 will work by jut revving a stationary car - ie not on the rolling road?

Incidentaly - dyna run wasn't cheap though was done by a well known porsche racing specialist.. feels much torque-ier on the road too though would have liked to see torque gains on the screen. The possible varioram problem was got around my quickly de-throttling during each run to create some vacuum - so I'm told I won't need another run after any possible problems are fixed.....fingers crossed.

Yeah does sound suspiciously healthy doesn't it?..... I get the sound change at 3800rpm, the power surge plus it clearly wanted to push on past an indicated 170mph, I'm thinking even given the speedo error if the flap wasn't in the correct position power would be down by atleast 50bhp?

Thanks again for the info - between you and the rennlist guys I may well have saved myself a lot of money in diagnostics!

 

[LK_991GTS]

Do the actuators move at all when you turn on the ignition (without starting the engine)? I can't see any movement in mine when the ignition is turned on, just a whirring fan noise and what sounds like a flap moving on way or another.

 

[kennyboy]

Haven't looked yet Lawrence, will let you know. Looking at the tests above though this might not be a reliable sign anyway.... the real proof is that they move when the car is moving and the engine is under load at certain revs?

 

[LK_991GTS]

Kenny, yes, thanks, it will be interesting to see what you find. My car has seemed a bit "flat" lately under acceleration; either I'm just getting used to it or the varioram is not working. The lack of actuator movement under "ignition on" makes me wonder, but perhaps I'm just looking for a problem!

 

[kennyboy]

Lawrence, no movement I don't think when I turn ignition on but don't start it..... but then again I'm doing this on my own! Gonna try again tonight and get the missus to turn on while I look - I'll quite look forward to that coz she hates the 911! ha ha

 

[kennyboy]

yeah I regret insisting that I had my dyno run done on Easter Friday - the only guy at the rolling road was the remapping expert (the full team of experts would have been there on a normal business day) - he said that the problem is what you outlined above i.e. 'vram is switching, then the actuator doesn't hold as vacuum leaks away'. He reckons the reason for losing vacuum was a leak in the left hand side of the varioram - probably a hose or something that was out of sight.... But he said that be de-throttling vacuum could be created again, thus the 'get around'...

I'm perplexed too with all the info plus the car is running seemingly great - but you just can't tell can you coz it's the torque that you feel pushing you forward... maybe I need a well sorted vram to help me out with a quick drag race!

it's booked in to my local specialist in a couple of weeks - I'll let you know the outcome of this one..... if it's all a red herring I won't be amused!

 

[Guest]

Hi kenny, i hope i dont complecate the situation. i had the same problem it seems with a flat spot at around 3,000 revs. then it ran ok above that. I discoverd it was only fireing on one of the distrubitors. The belt was intact, the problem i traced to a faulty module under the front seat. It totaly cured the problem and now goes like sh-- of a shovel. I thought this would have shown up when you had the car looked at but it seem this car went through two major services with out it being detected.

 

[kennyboy]

Hi - thanks for the info. I'm pretty sure my problem, if it exists at all, is varioram only. lack of finances means it's still yet to go into specialist but the more I drive it the more I'm convinced the whole thing was me being paranoid, or a very intermittent problem. The car is running like a dream and is very fast compared to my non varioram of a few years back....

Bit worrying about service not highlighting the firing problem though - was that at OPC?