86 Turbo Running Rough when hot/injector questions

Talk and Tech about turbocharged 924/944/968 cars
Glassmuseum
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The issue was actually happening on cold start today and persisting.

I decided to grab a couple of the aftermarket EV1 connectors that I had laying around. I did a very crude test and plugged 2 of those connectors to the injectors and pigtailed them to the OEM connectors.

The car started fine after I did this and idled fine for a while. I pulled the pigtails off and plugged the old ones back in and the issue persisted.

So I guess my questions are:

1. Should I just go ahead and replace the EV one connectors? They fit snug on these knock off injectors and they fit the NA OEM injectors that I had laying around as well.

2. Do we know if these injectors are safe to run in the car at 14ohms? I know you mentioned @Tom that we can run higher impedance injectors. Just want to make sure there isn’t anything else to consider here before I just change these connectors out? Having a really tough time finding any Bosch OEM injectors and they are ungodly expensive.

I do also feel like installing the new connectors is maybe just covering up the actual issue of likely counterfeit injectors. So .. 🤷‍♂️
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rheidtman
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Yep - fake injectors...
As noted on FB, these will run lean and melt a piston in short order.
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#12

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Tom
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Glassmuseum wrote: Thu Mar 26, 2026 3:23 pm The issue was actually happening on cold start today and persisting.

I decided to grab a couple of the aftermarket EV1 connectors that I had laying around. I did a very crude test and plugged 2 of those connectors to the injectors and pigtailed them to the OEM connectors.

The car started fine after I did this and idled fine for a while. I pulled the pigtails off and plugged the old ones back in and the issue persisted.

So I guess my questions are:

1. Should I just go ahead and replace the EV one connectors? They fit snug on these knock off injectors and they fit the NA OEM injectors that I had laying around as well.

2. Do we know if these injectors are safe to run in the car at 14ohms? I know you mentioned @Tom that we can run higher impedance injectors. Just want to make sure there isn’t anything else to consider here before I just change these connectors out? Having a really tough time finding any Bosch OEM injectors and they are ungodly expensive.

I do also feel like installing the new connectors is maybe just covering up the actual issue of likely counterfeit injectors. So .. 🤷‍♂️
I wouldn't be concerned about the 14 ohms, per se, but I would be worried that they likely flow too little to be safe with stock/typical chips. I also wouldn't change the injectors connectors personally -- unless you get new injectors and they have the same issue. The factory injectors were an early/shallow style so probably less forgiving of ill-formed knock off that the newer/deeper connectors. That said, if you need to drive the car while working on getting new injectors, replacing the connectors is straight-forward. I solder and use adhesive lined heat shrink tubing to protect against corrosion. I'd also flip the FQS to add fuel and not push the motor hard until you get new injectors.

#13

Glassmuseum
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okay. I’m going to sit tight and hopefully I’ll find some new injectors soon. Appreciate all the support from everyone. 🙏

#14

Glassmuseum
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Update: Solved! after sourcing a set of OEM Bosch injectors, the car is now running beautifully. I did want to post a couple of pics of the fake injectors so others might know what to look out for. You will notice that the nozzle looks a little different on these. And as Tom mentioned, they were missing marks and were a brighter green color than the deeper green that the OEM injectors have.

Appreciate all of the help! Now on to the other list of issues I’m chasing! - AC compressor not engaging and hvac flap not moving, installing new turbo, not getting proper boost, rough shifting, battery tray rust remediation and lots of other fun!
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Tom
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Did you get a chance to weigh one? I may do an official PSA in the 944 Handbook about them. Great picture of the spray holes -- that may be the easiest way to tell at a glance they are fakes...

#16

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Tom wrote: Mon Apr 06, 2026 10:02 am Did you get a chance to weigh one? I may do an official PSA in the 944 Handbook about them. Great picture of the spray holes -- that may be the easiest way to tell at a glance they are fakes...
Looks like the fakes are approximately 1.75 oz. I weighed a NA injector (0 280 150 168) that I had around and it is roughly 3.25 oz. Pics attached. Not sure if the turbo injectors are the same. I was too excited to get the new ones installed and didn’t weigh those.
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OEM Bosch 944 injector weighs 3.25 oz.
OEM Bosch 944 injector weighs 3.25 oz.
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Fake Turbo injector. Weighs considerably less than oem. 1.75 oz.
Fake Turbo injector. Weighs considerably less than oem. 1.75 oz.
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#17

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