Might be worth to check whether it would run better if you disconnect one of the injectors and try to start it on 3 injectors connected. I did have an issue like that on my 924s and was suspecting DMe failure but it ended up to be bad injectors that drained too much current and the car run for just few seconds. Worth a shot, quick to test and at least you can cross out another possible cause. Good luck man
How does it run with the o2 sensor disconnected? When the o2 sensor is disconnected the DME will run a base map for the mixture and that will give you an idea of how well the AFM is doing its job. Second double check that J boot, the underside tends to get really brittle from all the heat cycling and if it cracks enough the car won’t even start. From the way it’s idling it almost sounds like it’s still being starved for fuel. Even though the pressure is good without the check valve the pump could be dying/ weak and giving just enough fuel to keep it barely running. The off throttle position is a different story but it shouldn’t have anything to do with your rough idle. In fact if all is well you should probably see a rough idle and then suddenly smooth running when the TPS is engaged because the DME is running a different fuel map. Lastly, just because you have spark and fuel injector pulse, doesn’t rule out your speed and reference sensors. I just got done diagnosing a sudden no start the sensor was in spec, I had tech bounce, and I had spark but no injector pulse because the plug on the harness was bent ever so slightly to where it was shorting or not operating properly. Check your sensors as best you can, funkiness with them will cause all kinds of weird issues. Oh and for shits and giggles pop the dipstick after you’ve run the car and smell the oil. It should smell like pure 1980s oil absolutely zero fuel smell. If it smells like gas that’s an indication the car is running way overly rich and the bad mixture is causing all of this. From there it’s just a matter of finding what’s causing the bad mixture. Good luck and keep up the awesome work 👍🏻
Sorry I forgot one more thing lol, coolant temperature sensor, there’s two that screw into the block, one is for the gauges the other has a fuel injection type plug that one sends a signal to the DME for adjusting the mixture between cold and warm. When they fail they can also eff up the mixture. Basically that’s the thing with the 944. There’s several thousand sensors that all control the same thing and when one of them breaks they all exhibit the same issues/ symptoms 😂😂😂😂 Gotta love that Bosch L jet tonic
Brand new speed and reference sensor, gapped accordingly, O2 sensor doesn't change connected or disconnected, haven't messed with coolant sensor other than doing the ohm test that Clark's garage shows from the amf pin and it looked good but I'll probably just replace it anyways lol. To me, it does feel fuel starved, brand new j boot, replaced all vacuum lines and did a vacuum test, no leak showing. Zero Rev with opening throttle plate. Car dies if I disconnect the amf and won't start it I unplug speed sensor. Of course. The TPS keeps giving different ohm readings so I'm thinking that's it but I'll probably swap coolant sensors as well. O2 sensor didn't seem to change anything hooked up or disconnected
@@Northern944 Okay good the car shouldn’t change how it runs with or without the o2 sensor disconnected with everything else you’ve tested and verified id also say it’s time for a new TPS. If the car still runs like shit after you’ve replaced it, I’d reach out on the forums to see if anyone has a spare DME they’d be willing to let you plug in it could be the DME itself. And for sure man no problem! I’m happy these cars are finally getting some love. It’s a lot of work but that first drive when you get it sorted is gonna be awesome!
@@TakeFlightGarage yeah installed new coolant sensor, no change. Unhinged tps and it ran the exact same so I'll let you know if that changes when I install the new one but yeah it looks like that's the culprit. Oh well. Time to work on other things lol
Thanks man, I honestly am not sure where one could be at this point. I replaced all vacuum lines, the gasket to the oil cap, the intake has new gaskets. I sprayed starter fluid around the block while it was idling and nothing happened. Idles rough and won't rev. Spark plugs are pretty black so it's running rich. I've swapped injectors and same result... I'm thinking dme at this point. Replaced TPS and unfortunately nothing changed
Clean all the fuses and ground s good man don't give up
Love the videos keep it up
Might be worth to check whether it would run better if you disconnect one of the injectors and try to start it on 3 injectors connected. I did have an issue like that on my 924s and was suspecting DMe failure but it ended up to be bad injectors that drained too much current and the car run for just few seconds. Worth a shot, quick to test and at least you can cross out another possible cause. Good luck man
I did do that, thank you. No change lol
How does it run with the o2 sensor disconnected? When the o2 sensor is disconnected the DME will run a base map for the mixture and that will give you an idea of how well the AFM is doing its job.
Second double check that J boot, the underside tends to get really brittle from all the heat cycling and if it cracks enough the car won’t even start.
From the way it’s idling it almost sounds like it’s still being starved for fuel. Even though the pressure is good without the check valve the pump could be dying/ weak and giving just enough fuel to keep it barely running.
The off throttle position is a different story but it shouldn’t have anything to do with your rough idle. In fact if all is well you should probably see a rough idle and then suddenly smooth running when the TPS is engaged because the DME is running a different fuel map.
Lastly, just because you have spark and fuel injector pulse, doesn’t rule out your speed and reference sensors. I just got done diagnosing a sudden no start the sensor was in spec, I had tech bounce, and I had spark but no injector pulse because the plug on the harness was bent ever so slightly to where it was shorting or not operating properly. Check your sensors as best you can, funkiness with them will cause all kinds of weird issues.
Oh and for shits and giggles pop the dipstick after you’ve run the car and smell the oil. It should smell like pure 1980s oil absolutely zero fuel smell. If it smells like gas that’s an indication the car is running way overly rich and the bad mixture is causing all of this. From there it’s just a matter of finding what’s causing the bad mixture.
Good luck and keep up the awesome work 👍🏻
Sorry I forgot one more thing lol, coolant temperature sensor, there’s two that screw into the block, one is for the gauges the other has a fuel injection type plug that one sends a signal to the DME for adjusting the mixture between cold and warm. When they fail they can also eff up the mixture.
Basically that’s the thing with the 944. There’s several thousand sensors that all control the same thing and when one of them breaks they all exhibit the same issues/ symptoms 😂😂😂😂
Gotta love that Bosch L jet tonic
Brand new speed and reference sensor, gapped accordingly, O2 sensor doesn't change connected or disconnected, haven't messed with coolant sensor other than doing the ohm test that Clark's garage shows from the amf pin and it looked good but I'll probably just replace it anyways lol. To me, it does feel fuel starved, brand new j boot, replaced all vacuum lines and did a vacuum test, no leak showing. Zero Rev with opening throttle plate. Car dies if I disconnect the amf and won't start it I unplug speed sensor. Of course. The TPS keeps giving different ohm readings so I'm thinking that's it but I'll probably swap coolant sensors as well. O2 sensor didn't seem to change anything hooked up or disconnected
And thanks for the comment man!! Love your videos and appreciate the help! @@TakeFlightGarage
@@Northern944 Okay good the car shouldn’t change how it runs with or without the o2 sensor disconnected with everything else you’ve tested and verified id also say it’s time for a new TPS. If the car still runs like shit after you’ve replaced it, I’d reach out on the forums to see if anyone has a spare DME they’d be willing to let you plug in it could be the DME itself.
And for sure man no problem! I’m happy these cars are finally getting some love. It’s a lot of work but that first drive when you get it sorted is gonna be awesome!
@@TakeFlightGarage yeah installed new coolant sensor, no change. Unhinged tps and it ran the exact same so I'll let you know if that changes when I install the new one but yeah it looks like that's the culprit. Oh well. Time to work on other things lol
Check for vacuum leak
Thanks man, I honestly am not sure where one could be at this point. I replaced all vacuum lines, the gasket to the oil cap, the intake has new gaskets. I sprayed starter fluid around the block while it was idling and nothing happened. Idles rough and won't rev. Spark plugs are pretty black so it's running rich. I've swapped injectors and same result... I'm thinking dme at this point. Replaced TPS and unfortunately nothing changed
I tested vacuum pressure also with a gauge and it holds pretty steady