Replacing the turbo hasn't been so simple...

[wholio94112]

Good morning all,
Thanks in advance for reading, and offering any insight to a fried mind...Little background: 1986 930, in the passed 6 months, gutted most smog equipment - still have thermo switch, added rarlyl8 headers w/o heat to already included Kokeln IC, Tial WG...Blew turbo seals about a month ago, and decided to buy another KKK/K27 turbo from TK...Thought it would be a simple switch, but found the 1/4 mile I continued driving after the turbo seal failure resulted in oil being blown and sucked into and through just about everywhere...Lots of cleaning, and then some more as it soaked brand new plugs right upon install!!!Car would not start until I blew all the crap out by turning her over w/o plugs...
So now she's starting, low 800 RPM cold, maybe a slight stumble...The warmer she gets the more sputtering and lean, I suppose, she gets and start backfiring, but more like fire cracking...AFR's go lean, 15's - low 16's, and when I come to a stop, idle stumbles and eventually dies...I let her cool down about 15 min. and was able to get home 3 blocks away...
This morning I found if I pull rear fuel relay, closest to windshield, idle increases...No change when pulling relay up front...All I did was switch the turbo, but I got soon much more...Maybe I'll try disconnecting O2 sensor???
I know I should check fuel pressures and flow...I am waiting on CIS tester gauge...I searched for air leaks, cracked lines numerous times, and - for my level of knowledge and understanding, I'm just about at the end of the road...Any suggestions are appreciated...

[flightlead404]

Others will have better info I'm sure. But, while we all try to apply the KISS principle troubleshooting, thinking "ok, what did I change?" remember is not unusual for other things to fail coincidentally or or possibly even caused by other failures or changes - especially on a 30 year old car.

Cold idle s/b faster than that, 1,200 ish, dropping to I think 850 +/1 50 after 2 minutes. The WUR does this by increasing control pressure, and therefore leaning mixture, as it warms up.

If you are idling at 800 and the sputtering and dieing or close to it as the engine warms up it sounds to me like like you are starting out ok-ish on mix and then getting too lean as the WUR increases control pressure.

In turn that indicates an intake air leak, or a fuel delivery problem. The fact that you have issues relating to your fuel pump could very well be related. I'd consider doing the fuel delivery/flow rate tests too. I find that 6 graduated baby bottles work well for that.

[wholio94112]

Thanks Flight,
I know its a process of elimination, but its a whole lot easier going through with the most recent changes made...I tried deleting the O2 sensor, no change...It feels like a fuel issue - as it looks in AFR's - but I hear the fuel pumps buzzing - but pulling the rearmost relay increases the idle...And it hiccups like a major air leak...Thermo-time valve???
Its starting to feel like Linear Algebra, not so straightforward - or too much so for me to grasp...Will try the fuel volume test while I wait on CIS test kit...By the way, if anyone has step by step procedure for cold pressure, etc tests, I would be indebted to you...I haven't been able to find The Idiots Guide to it!!!

[flightlead404]

When I resealed my crankcase breather cover and all the leaky switches and sensors back there I replaced my termo valve (is this the one you are talking about, there are several things with very similar names). After a week of driving one of the lines fell off causing a bunch of weird bucking, idling, and other similar issues. Its worth putting a hand on that or any other vacuum lines that you touched.

Do a search for the workshop manuals. There's several pages with pictures and diagrams. Somewhere they are on line.

[wholio94112]

Yeah, I've read quite a bit about that little double-nippled thingie back there...Some have deleted it, some have experimented by switching the lines...its essentially an emissions thing, but I try not to "fix" anything unless its broken, so to speak - so I leave it alone...It's just that the hiccups seem to come upon me as the engine warms up...I haven't taken her out since the last drive a couple days ago, where she went lean, started stuttering when I gave her gas, and firecracker-backfired like a .17 HMR varmint round...

[Alan L]

You must have had the IC off and maybe some other stuff, to clean out the oil. Would pay, as already suggested, to make sure all the plumbing into, behind and beneath the IC is intact. Sounds like an airleak, altho you cannot eliminate WUR pressures at the moment. But starting with KISS, I would be looking at the hoses.
Alan

[wholio94112]

Man, I've had the dang IC and airbag off so many times by now, I'm sick...Fuel output through injectors is good - equal through all 6...Had extra red relays, switched others out, now when I pull individual relays, idle comes way down - would probably die if I didn't pop relay back in...
So, right now as I finish the day, there seems a slight miss in the idle, both cold, and when warmer...Can drive around the block after cold start, but as she reaches temp, she goes leaner and leaner, and more difficult to get her home...The miss gets more pronounced, I would say, while trying to get her home and up the driveway...I CANNOT find a leak, a compromised hose, a leaky gasket or injector...All I can find is a thermo-valve in the back - with 2 nipples - that I can rotate by hand...not the metal base, just the plastic cap unit with the nipples...Does that tighten onto the base, or is that sign that it faulty???I can't find info on the specific physical properties of the enigma that it is...Thanks in advance...

[Alan L]

That double nipple unit is a thermo valve that delays Vac advance on the dizzy on a cold engine. Won't let it see vac advance til it warms up. Once the valve opens it will allow Vac to pass to the dizzy. If it has no hoses on it, then that is just a crankcase leakage if not sealed properly.
Alan

[wholio94112]

anybody know if this thermo-valve spins upon the base unit that screws into the case, or should it be solid on its base???does it tighten onto it, or does the fact that mine rotates mean its toast???
I've got hoses on it, going to TB and Dizzy creating the circle of confusion...I just wonder if its busted, can I delete it and send hoses direct to destination - and just make sure I never hit boost before reaching temp...I never do as a practice anyway...

[billjam]

w......2
This wiring diagram might help. It shows all the wiring and emission control devices that can be removed to setup the car to pre-86 (non-emissions) configuration.
This removes all the unnecessary junk and might help narrow down the problem.
Some of my other diagrams are also available from links in this thread setup by Tremelune.
Good luck

[T77911S]

Originally Posted by Alan L

That double nipple unit is a thermo valve that delays Vac advance on the dizzy on a cold engine. Won't let it see vac advance til it warms up. Once the valve opens it will allow Vac to pass to the dizzy. If it has no hoses on it, then that is just a crankcase leakage if not sealed properly.
Alan

I don't like this thing on the advance side.
it also blocks vacuum RETARD to the dist if you go on boost when cold.
I connected mine to the vac retard. gives a little more idle when cold.

[T77911S]

get use to removing the IC. if you have the stock air breather/filter that will be just as bad very soon.

with the air filter off and engine running you can push down or pull up on the air sensor plate to do a rough check of the mixture.
down makes it richer
check power at the plug to the warm up reg (WUR)
did you get the vac lines crossed going to the dist
the one that has vac on it at idle goes on the inside port
are the Orings on the IC good
90 degree boot to the turbo connected good
rubber boot from turbo to IC tight

[wholio94112]

while waiting for the new turbo, there was ALOT of oil to drain out of the exhaust...the O2 sensor was drowning in it...I also changed oil, air, and fuel filters...Could the O2 sensor be compromised? could the fuel filter be faulty enough to cause a rough running? O-rings are good, lines and hoses good...the connection from K27 turbo to adapter was not like the fit with the former turbo, but I got it on there completely, O-rings intact...No one knows about the turning of the thermo valve plastic upon the metal plug base, huh???

[T77911S]

i would have to look at mine.

I dumped a few qts of oil in my exhaust too. it should NEVER rust out.
man what a smoke screen. I did try to clean it out but it still smoked like crazy.

check to make sure the frequency valve is vibrating.
I know my brother runs his WO the O2 and it is fine.

[flightlead404]

Originally Posted by wholio94112

anybody know if this thermo-valve spins upon the base unit that screws into the case, or should it be solid on its base???does it tighten onto it, or does the fact that mine rotates mean its toast???
I've got hoses on it, going to TB and Dizzy creating the circle of confusion...I just wonder if its busted, can I delete it and send hoses direct to destination - and just make sure I never hit boost before reaching temp...I never do as a practice anyway...

That thermo valve is normally inline between the vacuum port on the TB just below the throttle plate (front of TB from perspective of normal vehicle motion), to the left hand pot on the dizzy. In the stock config there may also be some other doodads in that line, I wouldn't know as most of that stuff is long gone on mine.

I do how however that that thermo valve is solid. Nothing should be spinning. My recommendation to you is to nip off to Pep Boys and get their Whitman's Sampler of vaccum line fittings. In among all the bits and pieces will be a straight through piece that you can use to simply take the thermo valve out of the vac line and hook up the two ends together.

Those thermo valves are made of almost-unobtainium. When I re-sealed my crankcase breather area last year I had to special order from Germany and took for every and I think $130 or something. Should have just plugged the hole.

A crank case leak there will eventually cause a nasty oily mess, but won't cause the poor running, but a vacuum leak could definitely contribute to that observed behavior.

[Alan L]

Yes, it should not be spinning. It suggests the press fit seal is no longer. Which may be able to initiate a small leak. I suspect that is not the cause - something bigger. But you can in fact eliminate it by hooking a tube over both ends of the nipples - ie looping them together. Then join the two tubes you had running to it. You have then disabled the switch and any small leak it may have had will not feed into your air/vac system. But given the lean issue seems related to the engine hitting temp, I would look closely at those lines. It may be a clue something not right in that part of the system.
Alan

[wholio94112]

Thanks guys...will try when I get home from work...I remember exactly how the nipples were oriented before I found they "clicked" clockwise...I suppose, if it IS at least part of the issue, a little sealant and some cure-time might keep me from creating a "Parallelogram of Death" in the future...We'll see...By now I've futzed beyond all recollection with mixture and idle adjustments, so that'll be another task...

[Alan L]

I don't think it matters which way the nipples. It is simply a temp activated switch interrupting the vac/boost signal from the TB if my memory is right. I am nowhere near my car right now.
Alan

[Alan L]

You could try testing that line from the switch to the dizzy, to see if it can hold a vacuum or boost signal (Mighty Vac pump). If the can or the line had a leak, that would explain the symptoms - air leak into the TB when the switch activates.
Alan

[wholio94112]

OK guys, I tried bypassing the switch, immediately setting the engine into a low, sputtering growl, with an intermittent miss - like a good kick in the pants...something new, or more pronounced is now amiss...Fuch...So I went ahead and included the switch in the loop, since its definitely not the primary culprit - but I didn't lose the bucking at low sputter to death idle...I'm tired, I can't even remember if that's too rich or too lean...I went through and checked exhaust nuts and bolts...evrything I address is fine...I am chasing a ghost...