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What was the advice regarding EVAP system? I've been meaning to delete mine too. Whenever I do I pressure test, the round black/white vacuum actuator that's part of that EVAP metering thing by the shock tower buzzes loudly.
What are you going to do to keep the tank venting--new 924 gas cap or leave the vent line below the car open?
I followed the above method - except instead of drilling the gas cap I used a small breather filter on the braided tank line as suggested in some other delete threads. Everything else came out smoothly and I removed a ton of vacuum lines and related valves. In all honesty the system had been capped anyway by the PO and was non-op so I was purely cleaning things up.
The only thing holding me back from disconnecting this system is this: on page 34 of the official DME/KLR test plan & troubleshooting guide, there is reference to a running issue with the vent disconnected:
I wonder if anyone has ever reported any ill-effects of disconnecting this system? It would appear other parts of the engine's systems have been designed around it?
Not sure - sounds like it's been done for years with success. Happy to report back if issue pops up - but can't imagine it changes fuel pressure at all.
Hmm. A TPS problem is an interesting thought. A couple things to look at:
- Check the wiring harness around the TPS. That bend to the TPS can lead to wiring cracks.
- You can check the TPS function via the procedure at http://www.clarks-garage.com/
- It's possible you may have leaks in your throttle body seals...and you may want to do a rebuild. While i doubt this is the root cause, it's something you can check during an intake track pressure test - here's a rebuild kit . Squirt soap water around the shaft and intake / TB connection
Well ladies and gents it's been several months and after chipping away at this I thought I'd post some updates. I did a lot of diagnosing and "while you're in there..." work.
As follows -
- EVAP system delete. Some cracked lines - and after tearing into it, it seems one of the charcoal canister lines had been capped off long ago anyway. Just wanted to simplify the entire vacuum system on the car too.
- New DME temp sensor
- New plugs NGK BPR-7ES
- New Bosch dizzy cap
- New Bosch rotor
- New 8mm plug wires from Paragon w/ BERU ends
- MSD blaster coil
- New GM MAP sensor
- New 3.0 bar Lindsey Racing FPR
- Cleaned MAF sensor
- Pulled + tested + cleaned injectors, checked harness, new o-rings
- Throttle body clean and rebuild with all new seals and hardware including TPS bolts (was apparently missing one!)
- All new vacuum lines including new tees (simplified the system significantly and wanted to go all black - PO had blue, red and some stock lines in there - reused red silicone lines to Tial wastegate)
- New intake manifold gaskets
- DEEP cleaned the intake manifold and jb welded the middle vacuum port (to brake booster) which I found was loose
- New AOS silicone line and cut/shaved/cleaned/painted hardline while removing unused ports
- Realigned and adjusted all the SFR intercooler couplers and hard pipes
- + 1000 other little cleanup and re-torque items
Buttoned everything up and after some serious cranking and willing she fired albeit on 3 cylinders. Was thinking one injector wasn't firing or was stuck open after the clean so I rechecked the harness and clips and cleaned pulled the plugs and cleaned everything. After more cranking she fired much much better. After depressurizing the fuel system including FPR removal etc my guess is it took a while and was normal? Especially with no prime before cranking. After warming up I went through the idle setting procedure and set everything as needed. The new throttle body race seals stick and delays TB plate closing all the way (disclosed in the rebuild kit) until broken in.
Went to take her out for a shakedown, she fired up great and we took off. Made it about 1/4 mile from the house and for the first time since I've owned the car she died in the middle of the street completely. Cranked and cranked and she wouldn't fire. Got a short push (almost blew my shoulder out trying to push from the door frame) into the gas station. I popped the hood and checked everything 3 times. Decided to make a DME relay jumper JUST in case before I left and low and behold - it WORKED! Put that bad boy in there and she fired immediately. I drove straight home and removed the jumper. Started wondering if DME relay was the root of all my troubles the whole time. Now I had in fact swapped out the relay previously (PO sent 3 extras in the glove box when I bought the car) and this was the first time ever where the car flat out wouldn't run. She had ALWAYS started fine which I had equated to a working relay doing it's job. I decided to order an Ftech9 Solid State relay after much reading and after a few short days I installed. I've gone on two short and one long shakedown runs and all I can say is WOW. Car runs fantastic. Idle is better, pulls smoother on and off boost, less backfiring on decel etc.
Not sure what actually did the trick - could be a combo or could have been a DME relay going in/out (sorta makes sense with the bucking etc previously) but I don't care. I did tons of needed clean up work and I know the car much better now and it runs awesome. Not sure anyone cares but I had to share. Now if I could only get this dumb data logger to hook up....
Couple pics below - before and after. Plus the mess of old EVAP lines.
And I'm back. Total fail. Car runs exactly the same as it did before all of the late Summer work. I'm at a loss (again). Will likely start a new thread to update symptoms and where things stand but frustrated to say the least. Car starts and runs fine. I can cruise around town all day, even under load (up hills) but the moment I go to get on the throttle (when vacuum switched to building boost it seems) the car falls on it's face. Burps, backfires and fights through it. Then if I keep on she will run like a raped ape through the rev range and I'm free to grab gears as needed. Ugh. Need to pull plugs to check where they stand. Need to video my AFR/Boost gauges whilst driving and or get my data logger finally working. Still haven't replaced O2 sensor - maybe related? DME/KLR? This has gone from a hot/second start only issue to a whilst accelerating issue under boost conditions.
Okay - so I made an LED blink tester and went through the Arnnworx/RacerX KLR blink code test after a spirited test drive in multiple conditions. No codes. I checked by unplugging the TPS and got the 4-1 code so I'm assuming everything was connected correctly. Few further observations - the car fires right away (I LOVE the solid state DME relay by the way - the 5 second prime seems to help immensely). Yesterday the car idled a little rough and I noticed idle AF/R on warmup was crazy rich. 10-11 for a good 5 min which hasn't happened previously. I blipped the throttle a bit in the driveway and she dumped a huge plume of smoke out the back end and backfired twice - sounded like anti-lag! Super frustrated I shut her off, checked plugs and wires and vacuum lines and then just decided to go for a drive. AF/Rs quickly leaned out to 13:7-14:9 as I cruised around town and idled. Went to get into boost once warm and what I'm noticing is the stumble happens during the transition from vacuum into boost. Usually 3500-4000 RPMs. I can stay out of boost and rev through the entire range with no issue. Then go to get on it - vacuum > 0 on the boost gauge for a second > then misfire/stumble and she fights through it and takes off HARD.
Trying to get an older version of Windows today so I can maybe finally get my TunerPro RT data logging **** to connect and I can read some logs realtime. Then go from there. Happy to take it to a local Seattle Porsche specialist but everyone I talk to seems much more informed on either old air-cooled OE stuff or modern Cup car level builds. Not a lot of transaxle/turbo love and I'm worried that the car is so bespoke (messed with) at this point whoever looks at it will be tracing through SO much of what I've already tackled and I'll be paying $120/hr for a goose chase.
Anyone had luck with shops diving in with success? SO hard to tell if this is Rogue MAF related, 30 year old harness and sensors, or just plain air/spark/fuel related. What am I missing? Feel like I'm going in circles and I WANT to love this car.
07-27-2018, 01:57 PM
