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wjfk32 11-23-2009 07:05 AM


My car-89Turbo Engine was is modified-7006 Turbo-1bar-msd6al & coil-new injectors-ngk accumulator-magnecor wires,Hks fuel enrichment,Air-box-mod k&n,SC Cams,B&B dual exhaust.Timing 26degrees/.040 spark plugs..etc.etc.

The car ran great in 65-80+ degree weather....

Now the weather is getting colder,40's+50+'s degrees the car is acting up.

1. Cold weather-Starting not a problem. 1shot. Holds rpm 950 constant. Perfect.
Boost comes in no problem. Short burts-30mph-60+mph- Feels good.

2. Now when nice driving/cruising-hwy 2500rpms top gear..No boost. The car does not like crusing. Wants to attack. The car feels slight BUCKING.

3. At Top End. Intermittent Bucking on Holding Boost 5th gear-Long Top end run. Feel slight bucking/not smooth throtle

I checked fuses, lines/parts etc.etc.Seem to be fine..Do you guys adjust your CO during the cold moths??Should I play with the mixture screw??? Could it be the WUR?? Possible vacuum leak???

Input/Suggestions Please


mark houghton 11-23-2009 08:04 AM

Your title refers to "running rich". What makes you think that? If anything, running in colder ambient temperatures may lean things out a bit. How do your plugs look?

Possibly you've lost power to the WUR heating element, which would result in the warm control pressure staying too low and a rich mixture resulting. Do you have an AFR gauge to tell you that vital piece of information? Check all control pressures at the WUR with the proper gauge setup.

Also, your symptoms kind of sound like an intercooler leak. That would cause the bucking and poor running on even low boost and a rich condition.

wjfk32 11-23-2009 08:50 AM

True... I realized I might not be running rich.
+1 On the intercooler not having a good seal. I noticed last night my engine compartment was a little oily. The intercooler-pipe-TOP-was leaky. Not exactly a tight seal. Would that have that much of an effect??

I believe the WUR- is original part when I got my 89 engine. What is the average lifespan on WUR.???



JFairman 11-23-2009 10:32 AM

Mark covered it well, and you should see some black smoke out the exhaust in your mirror under acceleration if it's running so rich that it's bucking.
A wideband AFR gauge kit will tell you your AFR's when it's calibrated and in a good mood...

If you have oil spray leaking out of the charge pipe orings like you say then it sounds like the compressor side turbo seals are getting tired and starting to leak a little along with metered air leaking under boost pressure which will cause a rich mixture.

I'd also suggest you send your WUR to Brian Leask and have him make it adjustable, then it's really easy to dial it in exactly how you want it while keeping things simple.
Brian Leask is very personable and helpful to talk to and his turnaround time is fast.
His website: Adjustable 930 WUR Website

wjfk32 11-23-2009 11:07 AM


No black smoke on Top End. 60-130mph..
My 7006 only has 15,400 miles on it when I rebuilt the engine in 1994...Freakin A.
Making the WUR Adjustable, wouldn't that effect my Hks fuel enrichment. Is it possible just get WUR- with the stronger diaphram or adjustable??. I don't wont to get rid of my HKS.



JFairman 11-23-2009 11:28 AM

I don't know what the HKS fuel enrichment consists of but if it's a bolt on frequency valve bleeding off control pressure to enrichen the fuel mixture than it won't affect the WUR, and an adjustable WUR won't affect it.

They would be both doing the same thing - adjusting control pressure by bleeding fuel pressure out of the cavity on the top side of the control plunger cylinder and returning it to the fuel tank through the factory return line, but they would be doing it in parallel with each other so they wouldn't affect the operation of each other.

wjfk32 11-23-2009 11:38 AM

Thnxs for your help! :)


mark houghton 11-23-2009 11:45 AM


Originally Posted by wjfk32 (Post 5027731)
Thnxs for your help! :)


If your HKS is anything like my Andial (and functions as Jim just described), then I can tell you that since I went with the Leask adjustable WUR, my Andial enrichment device is no longer needed.

wjfk32 11-23-2009 11:57 AM

The HKS is similar to andial..But more controls/gadgets on it.
Mark r u running eruo lines? and euro fuel head??

I have stock 89-fuel lines and fuel head.. I am a little nervous not having the HKS on when going Top end..Don't want to blow up anything.


mark houghton 11-23-2009 12:29 PM


Originally Posted by wjfk32 (Post 5027773)
The HKS is similar to andial..But more controls/gadgets on it.
Mark r u running eruo lines? and euro fuel head??

I have stock 89-fuel lines and fuel head.. I am a little nervous not having the HKS on when going Top end..Don't want to blow up anything.


Nope, nothing Euro...all stock US version....minus the Lambda control system, air injection pump, and catalytic converter.

We all understand being nervous about melting down the engine. I would suggest that you invest in an AFR monitoring system to set your mind at ease as to where you're at mixture-wise. You may find that you're richer than snot on full boost and nothing to worry about, other than diluting your crankcase oil with fuel and/or losing valuable horsepower.

wjfk32 11-23-2009 12:39 PM

Mark I have a very similar set-up. No cat, Lambda. I have the euro headers still. I dont have the msd/retard ignition set-up..
Silly as it sounds....I don't want to give my flames/exhaust..!!.

Does your set-up shoot flames.???

Just e-mailed Brian-questions-WUR..see what happens...



mark houghton 11-23-2009 01:40 PM


Originally Posted by wjfk32 (Post 5027866)
Does your set-up shoot flames.???

Hey Walt,

I don't know if she belches flames or not - have never had the opportunity to talk to the person I just blew away in a hot pass (they, the passee, generally just slink away and lick their wounds). Guess I'll have to get the wife to pace behind me some day. But I'm not running really all that pig rich at full boost (around 11.5 AFR) so I'm not sure if there's enough residual gas lurking in the turbo to flame on.

wjfk32 11-24-2009 04:39 AM


When I got home last night-(Garage Night) I started searching and taking off the intercooler.
So, what do I find.......Freakin intercooler comes off with no problem...etc..etc.. I see the orange O' RING'S -(stock unit)-attached. The two orange rings are attached in the front/throttle body...The one leading down the turbo pipe....well ....looking at it in the front the orange/ring looked good...OK..I turn the intercooler to the side...Freakin almost half of the ring in the back is missing.!! Man I was pissed.. I Immed. got my small vacum cleaner. Flex-2inch hose/thinking the ring/piece went down the turbo..I couldn't see anything with the work lamp. But for safety, I said why not. Didn't suck up anything..I guess that was a good thing. Frantically searched the engine bay for that piece and anything that looked wacked..(No find-----good)
Everything looked normal. I inspected the orange ring, and it was still flexable in good shape what I could see....Well today, going to find a Porsche dealer for parts. Change the 3 rings .Hopefully this will be quick fix for now.....

Mark-For me- walking a ZO6 and having my flames on PRICELESS....


Shadetree930 11-24-2009 06:36 AM

Did someone say flames .... :eek:

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wjfk32 11-26-2009 04:00 PM


Changed the orange rings, what a bit$h to make the intercooler flush and make it right. Took it for a test run,,,Felt good but still feel the bunking and stutter on top end. Put different fuel in, maybe bad gas???..Did more chking...boost is coming in good/better..

Still not happy...Took it back to the garage...Checking everything i could think of..up and down the freakin engine..Now i was chking the distb. cap spark plug wires..One was not fully pushed in, approx 2 inches. for a tight fit..Checked all connnections....

Took it for another TEST RUN....Big difference!!!! Man it made my thanksgving day special...



mark houghton 11-27-2009 05:38 AM

Par for the course, we first over-diagnose then look for the obvious. Glad you found the culprit!

wjfk32 01-19-2010 04:55 AM

Greetings: Happy new year everyone!

Well, my sputter, breakup, started up again under load. AHHHHHHHHHHHHHHH..
Finally had some time to bring it to the shop. The weather finally warmed up in the 40's and sunny. I did a CO-CHK...Running in AFR'S- 3.0 when the the car is warmed up..My mech. checked hoses, timing,,,Took it for a test..ALL seems to be in order..He did make a simple hose/s change do by the distributor. After all that, l Lowered the rpm..a little high..etc.etc..It didn't feel all that great when leaving the shop....Not happy......Maybe its the wires, wur, etc -something expensive that I didn't change...

Sat in front of the pelican forums and started searching--searching etc...etc..for answers...

Sunday...I decided to take out the sparkplugs--suggested by this forum. I am currently running-NGK .040, (Had theses plugs less than a year) All six plugs were grey on top, tiny soot, on top of the electrode..Not oily...Everyone consistant. Maybe the plug is to HOT for my set-up. Not sure...

I switched to DENSO-W24 Stock gap. .024 See what happens...Installed them..

Monday the test..Started it up no problem.....I noticed the car needed a little more time to warm-up, in order to drive away.... Once the car got warmed up to temps. MAN--It just took off like a mother.....Stays at 1bar...Haven't seen that in awhile...
Maybe I thought it was a fluke...But WOW...The car just pulling on top without a stutter, miss, hickup, or whatever u call it....

Opened it up late afternoon---60-130--mph.....NO MISS --JUST TOP END-great torque.. Sounds different-more aggresive. The cars' nose just stays up and feel it come down when finishing max output...Total MADNESS!

I Think a colder plug works for me 90% is hwhy--Top End-----Oh--I have new Bisteins HD- front and sport/ yellow-back. (stiff)

911st 01-19-2010 06:41 AM

Sounds like you have it under control.

Just a note.

These cars do not compensate for air density / air temp very well. That is 'part' of the reason we run them a little richer than EFI cars.

Do you have AFR monetering?

One can set a CIS 930 up in warm weather and it will have enough fuel to support it through the operating range only to find that in the cold they do not have enough fuel.

That is, one might be able to stay in the high 12's at 6500rpm and find they are in the 13's or so during the winter.

It was a good idea to reset you CO but it is possible that at peak HP you are past the FD's ability to deliver fuel.

wjfk32 01-19-2010 07:04 AM


Greetings. No I don't have a afr monitor... ;( I started searching on line for one good money..But will save u in the long run...

Man- u really have to be a mind reader to figure out these cars..So much crap in my head --maybe this, maybe that or...etc..etc..

Just so happy to have so much Torgue!! Spin the freakin tires in 2nd..(915-transmission),,I don't want to do that..$$$$$$ expense/break...

Question::: Would the plug gap from .040 to .024..make such a diference or just going to 7 range or 8 range can make such a DRAMATIC DIFFERENCE...Or just all of the above...

I am leaving it now---god willing...

What works for some Turbo set-ups could be nightmare for others...

mark houghton 01-19-2010 08:08 AM

I've been running the same NGK racing plugs as you for about a year with no problems, but looking at them I think I'll go one step colder.

So what you're saying is that by changing your plugs and going to a .024" gap, all your problems went away. You can run .040 (I do), but you need a pretty substantial spark energy to sustain the spark without "blowing it out" (figuratively) on boost. My MSD provides the energy...I don't know if the stock CDI will support the wider gaps. That (the gap, not the heat range) may have been your whole problem.

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