looking for a tuning shop or a tuning guru in the San Diego County area
 

Hello all. I’m looking for a tuning shop or a tuning guru in the greater San Diego County area (or southern Orange County) that can help me dial-in the stochiometric air/fuel ratio on a 3.2 Carrera (it seems to have a slight lean surge in lower revs).

So far, all the shops I’ve called that are knowledgeable about air-cooled Porsches don’t have a WideBand O2 gauge or similar equipment. There is a dyno shop in my area that specializes in air-cooled VWs and claim they can help, but they are booking over 8-10 weeks out.

Thanks for any input!

Steve Wong is the man. SW Chips, in LA. Worth the drive and the wait. Any good shop will be scheduled weeks out. That’s normal these days. If you can just walk in today, run. Anyone who is good is busy.

Have you talked to Steve or Mark at Black Forest?

Assuming you have a stock chip and a relatively unmodified engine, i don't think tuning is going to do you much good because you will just be masking an underlying problem. In other-words, you shouldn't have to do any tuning on Motronic fuel injection to get rid of lean running.

Motronic is very sensitive to vacuum leaks and these cars have many components that can introduce one.

I recommend you perform an evap smoke test... basically a machine that pumps a dense white smoke into your intake or exhaust at a very low pressure. This will help you find all of the leaks you have.

Intake manifold gaskets, to include the plastic spacers are common leak points. Also all of the vacuum hoses that are behind the intake for the brake booster and air / oil separator. Evap lines for the fuel tank also leak points. Finally check the j-boot and also the hoses for the idle stabilizer valve.

And BTW, Black Forest in Clairemont are a great place to talk to if you haven't already done so.

The Dyno Shop in Santee can adjust timing and fuel and burn a new chip. It's not cheap so I agree with the other comments that you want to make sure everything else is in good order before going that route.

Matt Monson, Trackrash, Techno Duck and Cory M: Thanks for your time to offer thoughts.

QUICK ANSWERS: I spoke to Steve Wong about my needs. He's 2 hours away from me so I was hoping to find a guru closer so I don’t have to flat-bed the car. I also spoke to another tuner, Sal Carceller. Both Steve and Sal suggest I find someone here in the San Diego area who can verify the stoichiometric ratio on my rebuilt/modified 3.2 (964 cam and SW chip) is in the range of 13.8-14.2 at idle and 14.4 under steady-state normal load. (Note they both say it should NOT be 14.7.) One local San Diego guru I knew, Jae Lee, moved to Palm Springs. On Black Forest, when I called them I didn't get a clear answer if they actually have an air/fuel ratio test gauge and/or have a way to test the car at idle and under load. All they said was "yeah we can do it." Guess I'll call them again soon.

I was keeping the nature of my original post simple. I didn't want to give the backstory because I didn’t want to waste your time. However, since some of you have asked for more info, here's why I am asking about air/fuel ratio: It's the old low RPM bucking topic has been discussed before. Some even call it the “parking lot buckaroo,” but a remedy often remains unsolved. Now I have started to experience it as well, though I have an interesting twist that has not been mentioned in other threads that I've read. It has to do with DME chips.

THE CAR/ENGINE: a very well maintained 1987 Carrera with ~200K miles most of which I have put on (2nd owner). The engine was fully rebuilt 10K ago, which included a 964 cam, new catalytic converter, Fabspeed Maxflo one-in/two-out muffler, and a Steve Wong chip programmed for the 964 cam. This also included ancillaries like the O2 sensor, TPS, IAC, rebuilt distributor … the list goes on.

THE PROBLEM: For the first 8K miles after rebuilding the car ran beautifully in all RPM ranges up to redline. Then about 2K miles ago, I started to notice a stumble under very light throttle in 1st or 2nd in the 1600-1800 RPM range (parking lots, stop-and-go traffic, etc). This did not happen all the time, but it was quite often. Other than that, the car still runs perfectly all the way to redline.

TROUBLESHOOTING: I started to investigate the typical culprits. This, and more, have been done with NO appreciable change:

1. Checked that the idle switch "clicks" the instant the throttle lever moves -- it does
2. Replaced the throttle body with a newer one (the old one's action felt rough)
3. Re-tracked the original AFM
4. Checked/torqued the intake manifold bolts to 18 lb/ft
5. Changed the DME relay
6. Replaced coil with another new Bosh unit
7. Had the DME unit out and sent to Steve Wong for eval/repair
8. Engine out: Smoke inspection. Replaced a few culprit vacuum lines and connections behind engine near the fuel pressure regulator. Replaced the seal between throttle body and manifold. No other leaks found, including injectors and intake manifold. Gapped and replaced the spark plugs.
9. Engine in: stumble was still there. Swapped-out another AFM as a test -- no change.
10. I have also set/rechecked the idle per standard procedure. It’s set to 880-900.

A CLUE: Before getting out-in-the-weeds any further, I decided to remove the SWong chip and put the OEM back in. The stumble was gone! That narrows it down. Three local Porsche shop owners I told about this said there must be a problem with the chip. I called Steve Wong. He said it wasn’t his chip and the OEM chip is covering up for a lean surge. I sent the chip back to get the chip tested and/or programmed a little closer to the OEM chip below 2K RPM for better drivability.

TESTING: I reinstalled the customized SWong chip back in. It stumbles at 1600-1800 RPM just like before. Dang it.

Since the car runs fine with the OEM chip, but now stumbles with the SWong chip, where do I go next? Speaking to both Steve Wong and Sal Carceller, I need to get the stoichiometric checked/set and drive tested before I go any further and this is why I asked for names in my general area. Thanks for reading.

I believe European Motorsports can help you in Vista.

https://emsautorepair.com/

Thanks Steve but I talked to the owner Joe yesterday and no, they can't help me. I know the shop well.

The Porsche shop next to where Jai Lee was located might be able to hep. I forgot their name.
Are the fuel injectors @ 200K???

Thanks for the reply. Are you referring to Jae's old shop that was west of the 5 near Costco and La Jolla Audio, or his newer shop over off of Miramar Road? And FWIW nobody I've spoken to anywhere suggests the injectors are bad because it starts and runs great otherwise. Not saying it couldn't be true but it just hasn't come up in conversation.

I think Ted is talking about Jae's place in Miramar. The shop next door does a lot of older Land Rovers and Mercedes.

I agree that knowing what the AFR is doing will help out a bunch.

Does this happen on a cold or hot engine?

Have you checked the cylinder head temp sensor yet?

For dyno places, the Dyno Shop in Santee and JBA Speedshop in Kearny Mesa all have dyno's with wideband (AFR) readout. You could probably just pay for an hour to run the car at various loads on their dyno and they give you a printout with rpm and AFR. The Dyno Shop is where Jae used to tune most of the cars and they do have the ability to burn custom motronic chips.

I'm not sure if the Dyno Shop does much for troubleshooting old Motronic cars but its certainly worth asking. JBA, i highly doubt they will work on it.

An alternative to paying for some dyno time is you can buy and install a wideband O2 gauge and install it on your car. The entire setup would probably cost you the same as what an hour or two of dyno time is. This can be easily installed in a 'temporary' manner, literally with wires taped to the fenders and run into the cabin. For the o2 sensor, there are clamp on brackets that mount on the tail pipe. Or you could just remove the narrowband O2 sensor and do the testing with just the wideband installed. As far as i know, the Steve Wong chip does not use the stock narrowband O2 sensor at all anyhow.

I think you guys are talking about Behr at Sport Utility. He does race and look after a few 911s.

Bob- I’d suggest giving a call to Wayne Baker’s shop (Personalized ********) on Commerce Street on the N side of Miramar Road. They have worked on my air-cooled cars for over 20 years and there is nothing they haven’t dealt with. Both mechanics in that shop Glenn and Eric each have over 30 years experience with these cars. Call Nancy (Wayne’s wife) and discuss your issue; she will likely get one of the tech’s on the call and help you determine if they can help. Nick

Ok this is strange; in my post above I typed in the shop name and somehow the Forum or Apple changed the word to asterisks. Huh? No clue as to why. A u t o h a u s is the name.

Some shops have had their names banned over the years, like Mmeister, among others.

+ 1

There are two sources in San Diego that I am aware of that can create custom 3.2 Motronic chips. We have personal experience with both. I already mentioned the Dyno Shop. The other individual does contract work with several shops and doesn't work directly with customers.

Techno Duck: Thanks. It happens cold or warm with the SWong chip, and again, not with the OE chip. I updated the head temp sensor years ago, but not replaced with the rebuild. The car runs flawlessly other than this 1600-1800 surge in 1st or 2nd. No one has suggested the sensor as the culprit. What are the symptoms? I forget.

Yeah, I think you're right about the wideband 02 gauge, etc. It'd be easier. Sal Carceller is encouraging me to get AEM Electronics' Wideband Air/Fuel UEGO Gauge Kit, pull out the car's existing 02 sensor and start gathering my own data at idle and at steady state 3K RPM in 4th. See: https://www.summitracing.com/parts/avm-30-4110

NickP: Thanks. I appreciate the input. I’ll give Auto Haus a call soon to see if they can test AFRs. I found their website.

Jae Lee is gone. Last time we talked, he'd moved his shop to Palm Springs. He said he wanted to concentrate on engines and suspensions. He also said he'd just built a 4.0 that dyno'd at 440 hp. Cool.