I might have missed it here on in some other of your videos, but what would you say was the one definitive sign (if any in particular) that made you realize you needed a MAF rebuild? I'm asking because I haven't driven other 928s than mine and my trusted specialist hasn't brought it up as work to be done soon, yet I feel a clear hesitation when giving it full throttle and a general laziness at low revs, which I know could both be symptoms of a misbehaving MAF. Thanks!
Hi Fabro, the "one definitive sign" was how much I had to set the potentiometer (pot) on my old MAF to get my air/fuel ratio to read somewhat normal. I'll explain, before installing the AFR meter, I was just shooting in the dark when adjusting the pot on the MAF, which I set around 350 ohms (between pins 3 & 6). After installing the AFR, it showed I was way lean, so I proceeded to adjust the pot until the AFR was close to stoichiometric -under normal driving conditions. However, I didn't feel good about how many turns I had to adjust the pot, because I knew it was well over 750 ohms. JDSPorsche and opinions on Rennlist say the pot should be set between 300 and 600 ohms (between pins 3 & 6), -I guess one has to increase the ohms as the MAF gets older. Even at this 750+ ohm setting, I felt my AFR was too lean. Additionally, my engine was doing this weird thing where every three or so consecutive warm starts, the idle would dip so low I thought it would stall. I adjusted the idle screw to compensate, but my gut told me it was something to do with the MAF. I was kinda nervous after installing the new (rebuilt) MAF because if I didn't see a change in the AFR and/or the weird start/idle issue was still there, I'd be at a lost (which is not uncommon btw). However, to your experience, regardless of where I set the pot on the MAF, I never really felt anything "wrong" when driving the car, it seemed to pull hard consistently and with no hesitation at full throttle. I just noticed different AFR's when not at WOT. Did you see my air temp mod? I ask because I noticed a smoother engine response and a more stable idle after doing it, therefore, you might want to try that first. I assume since you have a "trusted specialist," you don't work on your own vehicle. If so, I would highly suggest you consider wrenching on your own vehicle -for so many reasons. If the verbiage above is intimidating, don't worry, I didn't know a lot of this a month ago and I'm happy to help you along. No one will care about your car as much as you. Hope this helps.
@@OCDHAUS First off, thanks for taking the time to post such an in-depth and detailed reply! I saw your AFR meter videos and now I fully understand you weren't alerted about the faulty MAF by any strange behavior on the road. My 928 has been sitting for a long time before I bought it and I'm still in the process of learning the car and driving it to see just what comes up to fix next: clogged or worn out injectors are also a possibility in my case. It might also be that it'll overall start to feel and drive better as I put in more and more kilometers. As for wrenching, I am occasionally tempted to do it but the 928 is bit daunting as a first car to get my hands on; also, I'm already doing diy on other stuff and time is sadly limited when it comes to pick up yet another hobby. My mechanic has been working on both road road-going and track Porsches for longer than I've been alive, so he gives me all the peace of mind I need.. yet I deeply admire the huge amount of work you've done yourself on the car. Kudos and keep these videos coming!
Hello. I don’t think your model year has the same exact MAF based on some research I did just now through 928srUs. However, there can be a number of reasons why you’re 928 is feeling sluggish. You might consider looking through Rennlist for troubleshooting ideas. I suggest being as specific as possible when conducting your query, cause “why is my ‘83 928 sluggish?” will send you all over the place. You can also email me at motoocd@gmail.com and I’ll help however I can. I’m no 928 expert, but have stayed at a Holliday Inn several times.
I might have missed it here on in some other of your videos, but what would you say was the one definitive sign (if any in particular) that made you realize you needed a MAF rebuild? I'm asking because I haven't driven other 928s than mine and my trusted specialist hasn't brought it up as work to be done soon, yet I feel a clear hesitation when giving it full throttle and a general laziness at low revs, which I know could both be symptoms of a misbehaving MAF. Thanks!
Hi Fabro, the "one definitive sign" was how much I had to set the potentiometer (pot) on my old MAF to get my air/fuel ratio to read somewhat normal. I'll explain, before installing the AFR meter, I was just shooting in the dark when adjusting the pot on the MAF, which I set around 350 ohms (between pins 3 & 6). After installing the AFR, it showed I was way lean, so I proceeded to adjust the pot until the AFR was close to stoichiometric -under normal driving conditions. However, I didn't feel good about how many turns I had to adjust the pot, because I knew it was well over 750 ohms. JDSPorsche and opinions on Rennlist say the pot should be set between 300 and 600 ohms (between pins 3 & 6), -I guess one has to increase the ohms as the MAF gets older. Even at this 750+ ohm setting, I felt my AFR was too lean. Additionally, my engine was doing this weird thing where every three or so consecutive warm starts, the idle would dip so low I thought it would stall. I adjusted the idle screw to compensate, but my gut told me it was something to do with the MAF. I was kinda nervous after installing the new (rebuilt) MAF because if I didn't see a change in the AFR and/or the weird start/idle issue was still there, I'd be at a lost (which is not uncommon btw). However, to your experience, regardless of where I set the pot on the MAF, I never really felt anything "wrong" when driving the car, it seemed to pull hard consistently and with no hesitation at full throttle. I just noticed different AFR's when not at WOT. Did you see my air temp mod? I ask because I noticed a smoother engine response and a more stable idle after doing it, therefore, you might want to try that first. I assume since you have a "trusted specialist," you don't work on your own vehicle. If so, I would highly suggest you consider wrenching on your own vehicle -for so many reasons. If the verbiage above is intimidating, don't worry, I didn't know a lot of this a month ago and I'm happy to help you along. No one will care about your car as much as you. Hope this helps.
@@OCDHAUS First off, thanks for taking the time to post such an in-depth and detailed reply!
I saw your AFR meter videos and now I fully understand you weren't alerted about the faulty MAF by any strange behavior on the road. My 928 has been sitting for a long time before I bought it and I'm still in the process of learning the car and driving it to see just what comes up to fix next: clogged or worn out injectors are also a possibility in my case. It might also be that it'll overall start to feel and drive better as I put in more and more kilometers.
As for wrenching, I am occasionally tempted to do it but the 928 is bit daunting as a first car to get my hands on; also, I'm already doing diy on other stuff and time is sadly limited when it comes to pick up yet another hobby. My mechanic has been working on both road road-going and track Porsches for longer than I've been alive, so he gives me all the peace of mind I need.. yet I deeply admire the huge amount of work you've done yourself on the car.
Kudos and keep these videos coming!
Hi there, my 1983 928s feels a little sluggish. Any idea if the 1983 models have the same MAF?
Hello. I don’t think your model year has the same exact MAF based on some research I did just now through 928srUs. However, there can be a number of reasons why you’re 928 is feeling sluggish. You might consider looking through Rennlist for troubleshooting ideas. I suggest being as specific as possible when conducting your query, cause “why is my ‘83 928 sluggish?” will send you all over the place. You can also email me at motoocd@gmail.com and I’ll help however I can. I’m no 928 expert, but have stayed at a Holliday Inn several times.