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Old 04-26-2021, 07:04 PM   #1
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Ruroh Raggy!

So, turned on the Boxster and it sounds like the engine is not getting gas. Almost sputters out then will rev to normal and sputter. It never dies, though. Throttle not really getting gas to the engine. Drove down the street hoping that giving it some juice would get the injectors going. Check engine came on. It’s back in the garage and waiting for the Code Scanner I bought. Giving it gas never got it above 1200 RPMs.
2002, 2.7 and was running like a dream last week. Thoughts?

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Old 04-27-2021, 05:16 PM   #2
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Sounds like it's getting gas, but it's the gas metering that's off. Maybe a dirty MAF sensor or some sensor wire that got chewed up by a mouse? But I wouldn't jump to any conclusions until you see what the trouble code(s) are.

Good luck.
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Old 05-03-2021, 08:37 AM   #3
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Well @piper6909 looks like you were right. I ran the codes and they showed P0121,P1121, P1122 and PO452. I decided to check out the throttle body and this is what I found was something had chewed up the wiring coming from my throttle body. So, at this point, I should be able to figure out what part to buy to connect to the throttle body but can’t figure out what the other end of the wires connect to. Looks like I may have to remove the top of the manifold?

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Old 05-03-2021, 09:57 AM   #4
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Well @piper6909 looks like you were right. I ran the codes and they showed P0121,P1121, P1122 and PO452. I decided to check out the throttle body and this is what I found was something had chewed up the wiring coming from my throttle body. So, at this point, I should be able to figure out what part to buy to connect to the throttle body but can’t figure out what the other end of the wires connect to. Looks like I may have to remove the top of the manifold?

Your codes are for the throttle position sensor.
Looks like the wiring may unplug from the sensor at the throttle body.
So when you find the other end there should be another plug-connection some where along it.
Looks like all you need is a new wiring harness.
Or splice the chewed wiring.
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Old 05-03-2021, 10:56 AM   #5
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Do not splice these wires with crimp connectors, solder and heat shrink only.
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Old 05-03-2021, 11:56 AM   #6
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To JPF's reply you can get Marine grade solder connectors that you crimp on lightly then heat with a lighter or small torch.
They solder to the wire and also have heat shrink as part of the connector.
So if you use them your connection is soldered and also moisture proof.
Napa carries them.
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Old 05-03-2021, 12:01 PM   #7
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Yeah, I will just get the new wire harness and that should take care of all the codes. My question is where the other end connects. I can see the connection to the throttle body sensor (?) on the plenum but not sure how much I will need to remove to get to the buried end. Looks like the whole upper manifold?



QUOTE=blue62;634557]To JPF's reply you can get Marine grade solder connectors that you crimp on lightly then heat with a lighter or small torch.
They solder to the wire and also have heat shrink as part of the connector.
So if you use them your connection is soldered and also moisture proof.
Napa carries them.[/QUOTE]
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Old 05-03-2021, 12:14 PM   #8
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To JPF's reply you can get Marine grade solder connectors that you crimp on lightly then heat with a lighter or small torch.
They solder to the wire and also have heat shrink as part of the connector.
So if you use them your connection is soldered and also moisture proof.
Napa carries them.
Don't like them. Several sensors in these cars, like the throttle body and MAF are fraction voltage signal systems, and ANY change in the resistance in the harness can throw the system off, which causes no end of problems. Simply strip off a short length of clean wire on each end, twist around each other, and solder. Afterwards heat shrink tubing will complete a fully weather tight connection without any difference in resistance.

We have repaired dozens of these cars this way, never had an issue; but nearly every one we have seen with any kind of crimp connectors in the harness has had issues, which were immediately solved by the soldering method above. It simply works.
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Last edited by JFP in PA; 05-03-2021 at 12:17 PM.
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Old 05-03-2021, 12:31 PM   #9
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Don't like them. Several sensors in these cars, like the throttle body and MAF are fraction voltage signal systems, and ANY change in the resistance in the harness can throw the system off, which causes no end of problems. Simply strip off a short length of clean wire on each end, twist around each other, and solder. Afterwards heat shrink tubing will complete a fully weather tight connection without any difference in resistance.

We have repaired dozens of these cars this way, never had an issue; but nearly every one we have seen with any kind of crimp connectors in the harness has had issues, which were immediately solved by the soldering method above. It simply works.
I wonder if it is the small amount of metal in the connector that causes the resistance??
I have done it many times the way you describe, but also countless times I have forgotten to slide the heat shrink tubing on before soldering
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Old 05-03-2021, 12:42 PM   #10
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Either the difference in the connector itself, incomplete soldering, or "cold soldered joint" problems caused by not being able to see or test the joint before heat shrinking. This problem is particularly bad on MAF harness repairs; we have seen problems like wondering idle speed, and stalling, and measured weird voltage signals at the MAF itself; all of which totally disappeared the moment the repairs were cut out and just the wires soldered properly.

As for not remembering to slide the heat shrink tubing onto the wires first, everyone has done that at one time or another but once you have had to unsolder a repair just made in order to install it, you will remember to do it properly the next time, particularly if you are doing it on flat rate.....
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Old 05-03-2021, 01:37 PM   #11
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Soldering isn’t an option for me as the wires were chewed to bits. Does anyone know the name of that harness or connector? Pelican parts doesn’t list it and chat said Porsche doesn’t name a replacement.
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Old 05-03-2021, 02:13 PM   #12
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Soldering isn’t an option for me as the wires were chewed to bits. Does anyone know the name of that harness or connector? Pelican parts doesn’t list it and chat said Porsche doesn’t name a replacement.
You may reconsider that idea when you find out a new engine harness for your car is over $1600.
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Old 05-03-2021, 02:14 PM   #13
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[QUOTE=Blue devil;634567]Soldering isn’t an option for me as the wires were chewed to bits. Does anyone know the name of that harness or connector? Pelican parts doesn’t list it and chat said Porsche doesn’t name a replacement.[/QUOTE

TPS wiring harness.
TPS=Throttle position sensor.
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Old 05-03-2021, 03:12 PM   #14
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You may reconsider that idea when you find out a new engine harness for your car is over $1600.
Woody may be able to help you with an used harness..
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Old 05-03-2021, 03:59 PM   #15
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I could be wrong about this, but so far I have yet to see any connector in our engine bay that doesn't route directly back to the dme. What I mean by this is there is no "other end" to disconnect, unless to run the new wiring from the clip to the dme itself.

Jfp is correct about some sensors being very sensitive to VERY minute voltage changes, but I'm not sure that applies here. This is an actuator circuit with lots of learning/feedback modules downstream of it. If it were me I would find the other end and splice things back together. Use extra wire to interpose if needed. Use good shrink wrap crimp connectors to do it. Then drive. If there's a problem, the car will tell you.

I just did this with the MAP sensor on my wife's escalade, thanks to rodents. That was about 500 miles ago and there are no problems yet.

If you are super worried about this, just source the connector for any bosch TB. They all use (or at least the ones I have encountered all do) the same 6 pin diagonally oriented arrangement. Find a non porsche vehicle that uses them and I can almost guaranteed you'll find a replacement plug with plenty of wire to splice in.

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Old 05-03-2021, 04:17 PM   #16
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the wire is cut, the other end is where the cut is. It wont be hard to find, it will be right by the TB. Just solder the wire and be done with it. You dont want to replace the wiring harness, it isn't as easy as you might think it is and will need to drop the engine, at least a good amount if not all the way out.
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Old 05-03-2021, 04:19 PM   #17
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And if you aren't comfortable soldering, take it to a shop. They deal with this all the time, it's very common in all cars to have chewed through wiring.

Of course, if you have full coverage talk to your insurance agent but be prepared for them to total it out and/or your rates to go up if you file a claim.
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Old 05-03-2021, 07:08 PM   #18
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I may be bringing it into my local Porsche guy. I keep thinking there is another connector at the other end of the harness but maybe not. That gets above my pay grade for sure.
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Old 05-04-2021, 04:00 AM   #19
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I may be bringing it into my local Porsche guy. I keep thinking there is another connector at the other end of the harness but maybe not. That gets above my pay grade for sure.
There is no other connector on the other end, besides the main Engine Harness connector. Taking it to a shop is your best bet, if you don't feel comfortable doing your own splices. It shouldn't cost all that much. One, maybe 2 hours labor would be my guess.

Good luck!
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Old 05-04-2021, 06:31 AM   #20
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This should be a straightforward soldering job even if some wires are missing. If you add extra pieces they can be soldered into the original harness with no problem if you do it right, or if you get it done by someone who is good at soldering. Replacing the entire harness would be a tough task with the engine in situ. I had a similar issue committed probably by opossums, the section coming from the MAF was chewed apart just like in your case.








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