Carpokes Porsche Forum

Tom wrote: Wed Jul 01, 2026 8:03 am

NCGermerican wrote: Wed Jul 01, 2026 7:52 am

Tom wrote: Wed Jul 01, 2026 7:47 am What injectors from Five-O do you have? And what Fuel Pressure Regulator? Are your chips mapped for your injectors and fuel pressure?

D1150BA 50lb/525cc - Peak&Hold - 2.5 OHMS. The FPR is a 3.0 Delphi (Bosch no longer makes 3.0 FPR's). The chip is from John Behe. He actually created (3) chips for me to try, each one progressively adding more fuel and he recommended the injectors I bought. John is endorsed by Charlie at Evergreen Turbo and is also known by Joe at F9. Apparently John has been tuning these for years.

Did he know you were running those injectors when he supplied the chips? If you feel like humoring me, I'd suggested installing the stock injectors, chips, and FPR while you diagnose. The fewer variables the better -- otherwise it can become like playing billiards on a row boat... I'm wondering if you are so rich you are missing, which passes unburied gas to the exhaust along with unused oxygen the o2 sensors interpret as lean. Those plugs are not happy campers...

That's exactly what I'm thinking. Now I just have to dig around and see if I have the original FPR and chip somewhere....

NCGermerican wrote: Wed Jul 01, 2026 8:07 am

Tom wrote: Wed Jul 01, 2026 8:03 am

NCGermerican wrote: Wed Jul 01, 2026 7:52 am

D1150BA 50lb/525cc - Peak&Hold - 2.5 OHMS. The FPR is a 3.0 Delphi (Bosch no longer makes 3.0 FPR's). The chip is from John Behe. He actually created (3) chips for me to try, each one progressively adding more fuel and he recommended the injectors I bought. John is endorsed by Charlie at Evergreen Turbo and is also known by Joe at F9. Apparently John has been tuning these for years.

Did he know you were running those injectors when he supplied the chips? If you feel like humoring me, I'd suggested installing the stock injectors, chips, and FPR while you diagnose. The fewer variables the better -- otherwise it can become like playing billiards on a row boat... I'm wondering if you are so rich you are missing, which passes unburied gas to the exhaust along with unused oxygen the o2 sensors interpret as lean. Those plugs are not happy campers...

That's exactly what I'm thinking. Now I just have to dig around and see if I have the original FPR and chip somewhere....

And stock injectors!

Tom wrote: Wed Jul 01, 2026 8:08 am

NCGermerican wrote: Wed Jul 01, 2026 8:07 am

Tom wrote: Wed Jul 01, 2026 8:03 am

Did he know you were running those injectors when he supplied the chips? If you feel like humoring me, I'd suggested installing the stock injectors, chips, and FPR while you diagnose. The fewer variables the better -- otherwise it can become like playing billiards on a row boat... I'm wondering if you are so rich you are missing, which passes unburied gas to the exhaust along with unused oxygen the o2 sensors interpret as lean. Those plugs are not happy campers...

That's exactly what I'm thinking. Now I just have to dig around and see if I have the original FPR and chip somewhere....

And stock injectors!

I have those on my workbench in baggies.

@MoeMonney I saw your comment on the most recent NCGermerican's youtube video about the effect the storch MAF had on your tune. I think you said after adding the Storch MAF that your tuner had to add a lot of fuel. Although unexpected, this might be a "good thing" since the MAF is allowing better flow and possibly more volume into the engine.

However, Storch claims that the main benefit of the kit is response and accuracy, and not a large enough increase in the amount of air which would necessitate a fuel remap. Perhaps the kit behaves differently in NA vs. turbo applications? Could you share more information from your tuner?

Thanks, Chris

Another disappointing update, folks. What makes it worse is I really thought I was onto something.

All of the symptoms I'm seeing could all be caused by weak ignition or ill-timed spark. Since so many components have been replaced on this car, the one item that I didn't replace was the ignition switch.

I ordered a new, Porsche unit and installed - no change.

I then tested my 1 year old, Bosch coil. Key on voltage was 12.2V, whereas battery voltage was 12.3V. That's not enough of a voltage drop to be concerning. I then removed the coil and tested primary and secondary resistance:

Primary: .6 ohm
Secondary: O/L

That's where I thought I found the smoking gun. Bought a new Bosch coil and tested it:

Primary: .6 ohm
Secondary: 6.4K ohm

I installed it and fired the car up. NO CHANGE WHATSOEVER. I'm flabbergasted at this point.

Another thing that I can't seem to resolve - when I blip the throttle, I hear a loud screeching sound at first, then a whooshing sound. It sounds like it's coming from the throttle body, but I literally just replaced it with a known good rebuilt one. Right underneath it is the j-boot where it meets the turbo, but I verified through a smoke test that it's good and sealed.

I ran the F9 ODB+ log through chat GPT and the only thing it really pointed out was the ICV is at 93% open at warm idle. The main causes of that could be:

1) Vacuum leak
2) Weak detonation in the cylinders

The disappointing saga continues. I'm even starting to wondering if it could be bad gas, since it's been in the tank since November.

Can you post a short video of the screeching and whooshing sound? Are there any shops nearby that could take a look at it for you?

NCGermerican wrote: Sun Jul 12, 2026 12:15 pm All of the symptoms I'm seeing could all be caused by weak ignition or ill-timed spark. Since so many components have been replaced on this car, the one item that I didn't replace was the ignition switch.

I ordered a new, Porsche unit and installed - no change.

I'd appreciate it if you could eleborate on your removal/install procedure and what tools you used as I'm grappling with that now. So far I have removed only the top screw, which in my case was slotted, not Phillips as others have claimed.

Latitude48 wrote: Sun Jul 12, 2026 6:37 pm

NCGermerican wrote: Sun Jul 12, 2026 12:15 pm All of the symptoms I'm seeing could all be caused by weak ignition or ill-timed spark. Since so many components have been replaced on this car, the one item that I didn't replace was the ignition switch.

I ordered a new, Porsche unit and installed - no change.

I'd appreciate it if you could eleborate on your removal/install procedure and what tools you used as I'm grappling with that now. So far I have removed only the top screw, which in my case was slotted, not Phillips as others have claimed.

I tried to film it but unfortunately my microphone died so there was no audio. The only way I was able to get the bottom screw out (also slotted) was to get it from underneath. I took the gauge pod out. The top screw wasn't....horrible, but was a pain. The bottom was a nightmare. I used 2 extensions with a wobble and a 1/4" drive ratchet with a standard screwdriver bit. I looked down from the top while guiding the extension (attached to a 1/4" ratchet). The rest was all by feel and using a small mirror.

I have no idea why the engineers decided to use slotted screws. I replaced them with 2.5mm allen screws. Made it MUCH easier to reinstall and will be easier to remove again in the future (in 30 years or so.....).

It's not fun, but you'll get it out.

Tom wrote: Sun Jul 12, 2026 2:00 pm Can you post a short video of the screeching and whooshing sound? Are there any shops nearby that could take a look at it for you?

I'll record a video and post it up. Unfortunately, the only shops that will work on it will only do general stuff like A/C work, alignments, wheel bearings, etc. They wouldn't touch it even when the car was stock. Everyone is either afraid of it, or they don't want to work on a car they can't plug a scanner into.

I'm about ready to start putting stock parts back in - injectors, chip, AFM, etc. I'll start with the "easier" items (while still a pain) and if worst comes to worst, I'll put the car totally back to stock.

I just can't believe there was no change at all after replacing a verified bad ignition coil.

Since you are out of ideas, getting some fresh gas seems like a good plan. I really think you may get some more clues by going for a gentle drive vs just testing in the garage.