Jimbop90 Posted June 16, 2023 Report Share Posted June 16, 2023 Hello gents Having a problem with my car, that has only come about since I replaced the clutch, flywheel and RMS. Full timeline below Early Feb the car was started for last time with old clutch in it. Always fired into life ok, has an wobble in the idle every now and then. Car is back together at the end of April. This pipe was a real struggle to reconnect for some reason, and wasn't actually connected at all on the left hand side as it lies in the car (right side pictured) when I first removed it to gain access to top bell housing bolt. If it starts first time it's always a spluttery start, but then runs nicely, other than as before a very slight flutter about 50 revs or so in the idle when its usually in that 800-900 range. Sometimes it just won't start. I usually give it a moment and try again, worst has been about 5 goes before it comes to life. On one of these occasions where it took multiple attempts, when it did start it fired into life as you'd expect it to if it was perfect. Another issue the car has is it cuts the power at about 5.5k revs. Noticed one of the coil packs was looking very sad, so have replaced all of them. Car has also had fresh oil and filter since I started driving it again. Based off what I've read from others I'm thinking crank position sensor, I could have mucked it up when cleaning up the engine when doing the RMS etc? I have a CarSoft V2, and the only codes I have are related to ageing O2 sensors, which was another pre-existing thing. Should I try disconnecting the MAF sensor and starting it up, could that make a difference? Any advice appreciated before I fire up the parts cannon. Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted June 16, 2023 Report Share Posted June 16, 2023 Disconnecting the MAF is free, but I didn’t know that caused starting problems, thought it was running problems. Quote Link to comment Share on other sites More sharing options...
½cwt Posted June 16, 2023 Report Share Posted June 16, 2023 Can you confirm the year and engine in your car @Jimbop90? Disconnecting the MAF will if nothing else rule it out as the engine will run on a default map assuming a standard set of conditions. Position sensors do seem to be related to starting issues, particularly when the motor is hot. If you do suspect a MAF but are still not certain, you can pick up second hand genuine ones from the usual breakers for about £35, much cheaper than the Bosch part and a lot lot cheaper than the same Bosch part in a Porsche box. I fitted a second hand MAF to mine when it failed and it is still going strong nearly 4 years later. I'm happy to buy 2 or 3 more used ones and still not get to the price of a new Bosch one. Quote Link to comment Share on other sites More sharing options...
Everywhen Posted June 16, 2023 Report Share Posted June 16, 2023 The pipe you show is the Air Intake pipe. It connects the MAF sensor housing at the air filter box to the throttle body. As you mention it wasn't connected at one end I'm guessing that the car was not pulling in air via this pipe but now it is connected you are experiencing your starting issue. This pipe would be where I would look first. The pipe has what looks like a resonator in it, to cut down on intake noise presumably, was yours disconnected to make more noise by a previous owner? Is the resonator blocked? Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 16, 2023 Author Report Share Posted June 16, 2023 It's a 2001 3.2 Thanks I'll bear that in mind re. the used MAF Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 16, 2023 Author Report Share Posted June 16, 2023 4 minutes ago, Everywhen said: The pipe you show is the Air Intake pipe. It connects the MAF sensor housing at the air filter box to the throttle body. As you mention it wasn't connected at one end I'm guessing that the car was not pulling in air via this pipe but now it is connected you are experiencing your starting issue. This pipe would be where I would look first. The pipe has what looks like a resonator in it, to cut down on intake noise presumably, was yours disconnected to make more noise by a previous owner? Is the resonator blocked? I doubt it was disconnected by previous owner, he wasn't a car guy that would tinker with something like that. I'll take a closer look there though, thanks Quote Link to comment Share on other sites More sharing options...
½cwt Posted June 16, 2023 Report Share Posted June 16, 2023 10 minutes ago, Jimbop90 said: It's a 2001 3.2 Thanks I'll bear that in mind re. the used MAF For your reference, Porsche part no 986 606 125 01 is the up issued part, Bosch number for the same part is 0 280 218 055. Quote Link to comment Share on other sites More sharing options...
Dubdubz Posted June 16, 2023 Report Share Posted June 16, 2023 Ive had weird starting issues on my 987 and I am also leaning to the MAF as the ECU likely corrects the mixture and as it is intermittent and slight [ie within parameters] doesnt throw a code I de snorkelled - which I wonder has caused issue - I have the snorkel part but I cant locate them at the minute - as I am going to reverse - Could you remove MAF and clean it perhaps? This is my next task once the car is off ramps and I have dealt with the other maintenance I am doing at this time. Quote Link to comment Share on other sites More sharing options...
Fat Rat Posted June 16, 2023 Report Share Posted June 16, 2023 I presume your air filter is in good condition and not got damp or anything when laid up? Quote Link to comment Share on other sites More sharing options...
Menoporsche Posted June 16, 2023 Report Share Posted June 16, 2023 Usual comment is simply to disconnect MAF, then it reverts to default map. If it improves, you know the MAF is at fault and needs cleaning or replacing. Disconnecting is free and easy, then you decide the next step accordingly. Quote Link to comment Share on other sites More sharing options...
½cwt Posted June 16, 2023 Report Share Posted June 16, 2023 5 minutes ago, Menoporsche said: Usual comment is simply to disconnect MAF, then it reverts to default map. If it improves, you know the MAF is at fault and needs cleaning or replacing. Disconnecting is free and easy, then you decide the next step accordingly. There's a 5 hour old echo in here.... Quote Link to comment Share on other sites More sharing options...
EXY Posted June 17, 2023 Report Share Posted June 17, 2023 17 hours ago, ½cwt said: There's a 5 hour old echo in here.... It has improved immensely since you came off the vino Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 21, 2023 Author Report Share Posted June 21, 2023 Well that's 3 hours I won't get back. MAF sensor connector is welded on. I've pinched and pry'd and pulled and pushed and wiggled and jiggled and it will not effing move. I'm sure I'll just break the connector If I try any harder not that I've got any extra strength to use. So I decide to take MAF sensor out completely and deal with it that way. Oh no you won't. Both screws are rusted to hell and are already half rounded off. Probably why that pipe was disconnect. I've rounded off one completely trying to undo it, so then I found an old hacksaw, took the blade off and snapped a piece of it off so that I could get my hand in there and start cutting a slot on the outer of the two screws. No good, its too rusted the flathead just shreds through rust. Fed up now and don't know what to do. Maybe get a fresh hacksaw blade, break a piece off, cut much deeper into the screw and try again? No idea what to do with the "inner" screw on the other side of the connector, there's no way I can get a blade on that. Quote Link to comment Share on other sites More sharing options...
½cwt Posted June 21, 2023 Report Share Posted June 21, 2023 That's a proper problem as the duct it mounts into is an integral part of the air intake box. Did you note that it requires a security bit with a hollow tip to remove the MAF screws? (sorry about the hind sight there) Ultimate worst case would be get a replacement air box assembly go to one of the usual breakers but it is a pain to change that much of the induction system and you'd still need to get the plug off. Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 22, 2023 Author Report Share Posted June 22, 2023 8 hours ago, ½cwt said: That's a proper problem as the duct it mounts into is an integral part of the air intake box. Did you note that it requires a security bit with a hollow tip to remove the MAF screws? (sorry about the hind sight there) Ultimate worst case would be get a replacement air box assembly go to one of the usual breakers but it is a pain to change that much of the induction system and you'd still need to get the plug off. Yep I was using the correct security bit. I'm going to superglue a removable bit into the other screw (the one thats not completely mullered) overnight and hope that works, and go with the fresh hacksaw blade for the one that is ruined and then hope a big flathead gets it off. I've at least found 2 other forum posts from people who couldn't get the connector off. Misery loves company and all that. Quote Link to comment Share on other sites More sharing options...
bally4563 Posted June 22, 2023 Report Share Posted June 22, 2023 I’ve chiselled them off in the past nice sharp narrow chisel and tap them around once you have them moving a pair of pliers on and turn out Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 25, 2023 Author Report Share Posted June 25, 2023 MAF 'tested' and ruled out. Persevered with the hacksaw blade and managed to get a deep enough slot in both screws to undo them. Took me several hours. The connector mechanism where you pinch part of it to lever a bit of plastic over another bit just doesn't work. Once the MAF was out I could use a screwdriver to gently prize it apart. Really thought I'd cracked it as car started up 3 times in a row on the driveway with MAF sensor disconnected, but I drove 10 mins to get fuel and then it failed to start for a few minutes. Was glad I'd had it on the CTEK this weekend. When the car did start, I'd turned it over a couple of times without it catching, then took key out banged it back in again quickly and went straight to start position and it was like I'd caught it out and it fired up. Is it feasible that fuel pump isn't priming well enough and so by priming it twice in quick succession it's more likely to start? Quote Link to comment Share on other sites More sharing options...
iborguk Posted June 25, 2023 Report Share Posted June 25, 2023 (edited) With the MAF back in play stick it back on the iCarsoft. What actual code values are then reported ? Let's see if anything new is logged. Edited June 25, 2023 by iborguk Quote Link to comment Share on other sites More sharing options...
Jimbop90 Posted June 25, 2023 Author Report Share Posted June 25, 2023 8 minutes ago, iborguk said: With the MAF back in play stick it back on the iCarsoft. What actual code values are reported ? There weren't any codes before other than regarding O2 sensors but I'll scan it again. Father in law has pinched the iCarsoft so will have to be in a couple of days. Quote Link to comment Share on other sites More sharing options...
iborguk Posted June 25, 2023 Report Share Posted June 25, 2023 (edited) 2 hours ago, Jimbop90 said: There weren't any codes before other than regarding O2 sensors but I'll scan it again. Father in law has pinched the iCarsoft so will have to be in a couple of days. If no new clues are logged then it might be case of zero'ing in on the right live values with the iCarSoft to help point the thinking in the right direction. No electrical gremlins exhibited ? Ignition switch can cause some interesting stating behaviour when going bad although that wouldn't account for "wobbly". Other candidates could include CPS, Fuel pump, Fuel pump relay. There could always of course be more one factor in play and the right targeted live data from the iCarsoft might help the aim of the parts cannon. Edited June 25, 2023 by iborguk Quote Link to comment Share on other sites More sharing options...
iborguk Posted June 25, 2023 Report Share Posted June 25, 2023 Interesting video, see at 14:00 a bit of visual diagnosis re CPS, don't know if that's valid or not... Quote Link to comment Share on other sites More sharing options...
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