GUT Posted 8September, 2015 Report Posted 8September, 2015 I need a favour.I installed a MAF kit on my '86 Carrera, I'm getting hesitation just as I touch the throttle off idle. Not always, but mostly.I cleaned the MAF and saw very slight improvement but the problem remains.The MAF is Bosch part number 0280217809. This part was installed on the 993tt. The 993 na part is 02800217806 and this might also work.Im hoping a kind 993TT owner might lend me their MAF for 5 minutes to test whether it is a MAF problem or not. Process of elimination.Im in Melbourne.Any help would be greatly appreciated.Cheers,Luke
firstone Posted 8September, 2015 Report Posted 8September, 2015 I'd try cleaning it again, and check and clean the connection.
GUT Posted 8September, 2015 Author Report Posted 8September, 2015 Yeah will try again. I've cleaned it twice so far...Once more can't hurt I guess.Prices for new ones range from $350US to $1465AUD changeover!I'd rather be sure it's the problem before forking that out
911oclock Posted 8September, 2015 Report Posted 8September, 2015 Interested to know the reason for the MAF kit. Is it an upgrade to a stock 3.2?
GUT Posted 8September, 2015 Author Report Posted 8September, 2015 Seemed like a good idea at the time!Better throttle response, more HP, better fuel economy.It seems to have all of the above so far. I also put SSI's on at the same time so that helps too. Just that minor problem with intermittent hesitation moving off idle...Since it is intermittent, I know it can work properly - just a matter of resolving the cause. If I can't resolve it, I'll just go back to stock.
firstone Posted 8September, 2015 Report Posted 8September, 2015 Is there an ECU learn for the upgrade?
firstone Posted 8September, 2015 Report Posted 8September, 2015 I thought there may be a learn process for the ECU to recognize the installation.
GUT Posted 8September, 2015 Author Report Posted 8September, 2015 Just plug and play(with a minor mod to the DME for pre ~86/87 models)
firstone Posted 8September, 2015 Report Posted 8September, 2015 Does it have an electronic throttle or cable?
firstone Posted 8September, 2015 Report Posted 8September, 2015 Blows my theory. I was thinking TPS on an electronic throttle.
GUT Posted 8September, 2015 Author Report Posted 8September, 2015 It has a TPS which is a possibility. But the new parts to the car are the MAF, temp sensor and chip. Starting with MAF as a troubleshoot
firstone Posted 8September, 2015 Report Posted 8September, 2015 Ok. I was thinking if the TPS has been interrupted, disconnected whilst not in the 0% position it would have to be reset.
GUT Posted 8September, 2015 Author Report Posted 8September, 2015 Played with it this morning. I recleaned the MAF and connections.It still hesitates. Just off idle at the slightest throttle move.It 'seems' that maybe just when the TPS micro switch is triggered, the problem occurs.I'm clueless about that so its time for research about the a TPS really does...
GUT Posted 9September, 2015 Author Report Posted 9September, 2015 Ok. How's this for a theory...The micro switch is just on off to tell the DME when it's on idle or not.So, if the switch triggers without the throttle body moving due to 'slop' in the linkage, could this mean there's no change in airflow measured by the MAF sensor and so the ECU/DME doesn't add fuel and it leans out? This would cause hesitation until the throttle opens and air flow is measured triggering a fuel response?Guessing.The linkage felt a tiny bit sloppy- I'll have a play tonight.Thoughts?
GUT Posted 9September, 2015 Author Report Posted 9September, 2015 So...Tonight, lots of hesitation off idle until it warmed up. When warm there was very little hesitation. So that's good.I thought I'd check the O2 sensor. Went to disconnect it only to find it was not properly connected anyway. I disconnected it fully and there was some hesitation. When I reconnected it, there was no hesitation. But by this stage, the car was relatively warm.I'll see how it goes in the morning when cold.Fingers crossed.
firstone Posted 9September, 2015 Report Posted 9September, 2015 These things test you.Good thinking there.Hope it's sorted now.
P-Kay Posted 9September, 2015 Report Posted 9September, 2015 Good luck with it Luke, hopefully you have found the gremlin!
GUT Posted 9September, 2015 Author Report Posted 9September, 2015 Problem SOLVED!Here's a tip:Make sure your O2 sensor is properly connected.
Simonk Posted 10September, 2015 Report Posted 10September, 2015 Dammit! I read this yesterday and was going to say check your O2 sensors but then got side tracked. Well done on finding the problem. Oddly enough, I thought the O2 sensors because mine plays up but the opposite. I've got mine unplugged because it drives much better cold or warm. When it's plugged in, it bogs down a touch when cold but when warm the mixtures seem to be all over the place.
GUT Posted 10September, 2015 Author Report Posted 10September, 2015 I'm now very happy with the MAF upgrade. It's a really big improvement in terms of feel - crisper response.Mind you, it is combined with a chip and SSI's.The car is markedly more powerful, particularly at lower revs.Maybe your AFM needs attention? Mine was working fine before removal - if you want to swap mine into your car to test it, let me know
Simonk Posted 10September, 2015 Report Posted 10September, 2015 So you didn't use my DP11 muffler in the end?i had my AFM tested and it's apparently fine. My car used to stall when cold. I had it investigated and found out it had a chip in it and the O2 sensor unplugged. Plugging it in made it worse. We decided to put a standard chip in it and the car came alive and felt so much better to drive. The cold stall was still solved and initially I felt it was running better with the O2 sensor plugged in. It felt like it more power from take off also but after a while I realised it didn't have that power every time I took off. Sometimes it would take off like a bat out of hell and other times it was rather lethargic. Unplugging the O2 sensor made acceleration much smoother and consistent. I'd replace the sensor but I've been told it's safe to run without it so I haven't bothered. The car is running the best it's been since I got it.
GUT Posted 10September, 2015 Author Report Posted 10September, 2015 I stumbled across someone getting rid of various items including SSI's and matching muffler. So the DP11 didn't get used.
.jpg.657c304bb461fd42344461909adbbf83.thumb.jpg.f025b8d528e9785ca8ea461a70fc639a.jpg)
Recommended Posts
Archived
This topic is now archived and is closed to further replies.