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1980 resurrection...
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sat May 06, 2017 4:50 pm    Post subject: Reply with quote

Ok. Does not matter fuel mixture, at 3400-3500 rpm I get what feels like a misfire. Thing is, it ONLY happens in 3rd gear. What the heck?
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morghen  



Joined: 21 Jan 2005
Posts: 7729
Location: Romania

PostPosted: Sat May 06, 2017 11:12 pm    Post subject: Reply with quote

Too lean? go for 13.7 not 14.7...or even 13.0
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Tue May 16, 2017 4:15 pm    Post subject: Reply with quote

Had to make an emergency trip 500 miles for medical reasons for my dad. I think I need a coil to get home. 1980... Will a 1.5 ohm resistance coil get me home or do I need a 3.0 ohm? Thanks!
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sat Jun 17, 2017 3:53 am    Post subject: Reply with quote

One month later... Trying to tweak the injection a bit as it is still rich down low and lean up high.
Still trying to sort why my passenger window switches both failed.
Found out that my battery tray located drain tube for the sunroof is causing the passenger floor to get wet. Will do the bigger line fix soon.
Have a noisy throw out bearing. Not looking forward to that fix...
Love driving this car! Get to speed in the twisties and only braking for slower traffic is fun!
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Fri Jun 30, 2017 12:35 pm    Post subject: Reply with quote

I was finally able to get time to replace the water pump. That is tomorrow morning, so I'm very excited to get this done.

Can the pump be pulled without the timing belt being removed? Timing belt is only a year old. I'd rather leave it in its spot if I could.
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Tue Jan 30, 2018 2:50 pm    Post subject: Reply with quote

Pump replaced and car was driving until I found a chunk missing from the timing belt 2k miles later. New belt now and driving again, but... Still get a terrible misfire at 4000 rpm and up. Timing is good, no vacuum leaks, good fuel pressure.
Will a bad o2 sensor cause the high rpm miss? Now used to an o2 with mechanical injection.

Thanks!
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1445
Location: Not Detriot - NMI

PostPosted: Wed Jan 31, 2018 7:49 am    Post subject: Reply with quote

vwfye wrote:
Pump replaced and car was driving until I found a chunk missing from the timing belt 2k miles later. New belt now and driving again, but... Still get a terrible misfire at 4000 rpm and up. Timing is good, no vacuum leaks, good fuel pressure.
Will a bad o2 sensor cause the high rpm miss? Now used to an o2 with mechanical injection.

Thanks!


What are your fuel pressures? Proper CIS test pressures also testing the control pressure warm up curve?

With the O2 sensor hooked up you can't just set the AFR wherever you want because the lambda system is going to fight with all its might to put you where it wants you, then you will be screwed at WOT or wherever the lambda runs out of room..

Getting your CIS pressures in spec is first and formost..

The way you are going to want to et your AFR is with a dwell meter..
Find the electrical test port towards the rer of the drivers side fender, wire with round plug coming off of if..
Put your dwell meter on the black wire of that thing..
Adjust your idle to get about 90 rpm
Adjust your afr screw for highest idle
Finally adjust your AFR screw until your dwell meter is reading 45 % duty cycle..
Make sure you cover the AFR screw hole when you read your dwell and when you are finished, vac leak..

Now you should have a finely tuned CIS system..
Do some searching on dwell meter tuning and it might even be in the haynes, Iirc it should be set to 4cyl scale..


If you havent found a dwell meter yet, unplug your O2 sensor, then adjust your AFR for best idle/14.7, that should be pretty close, then plug your O2 sensor back in..

If you want to try tuning to AFR only to try to achieve something at some RPM and throttle condition whtever, run your car with the O2 unplugged but your frequency valve must stay running..

You can't tune it away from factory spec with the O2 plugged in because it will fight your attempted tune intil it is out of the systems bounds and then when you get way out of bounds for the system your AFR will be way out..


Proper spec CIS pressures and properly tuned with a dwell meter is the proper way to do it..

If you want to tune AFR differently than factory spec you will find yourself in a complex wormhole very fast because their are so many parts of the system and they rely on eachother so changing one thing can have other consiquences that you may not have accounted for..
You will need a good understanding of every thing the CIS system does in it's entirety to consider changing anything away from factory spec..

Factory spec is damn good anyway, I ran a lot of boost tuned by dwell and it ran goood..
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Wed Jan 31, 2018 8:36 am    Post subject: Reply with quote

Cool! I'll unplug the O2 and see where that leads me! Thanks!!!
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sat Feb 03, 2018 6:56 am    Post subject: Reply with quote

New issue today after working on the fuel tank sender. I now know how much fuel is in my tank! But now...

My turn signals do not flash and the dash light stays solid green when I try them. But... the hazard switch still works correctly!

I am away from my house/manual and the police escorted me to a parking lot and issued a fix it ticket. So, here I sit, trying to sort it.

Thanks!
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morghen  



Joined: 21 Jan 2005
Posts: 7729
Location: Romania

PostPosted: Sun Feb 04, 2018 3:27 am    Post subject: Reply with quote

Never seen such failure and I must say I'm amazed of the failures these cars get in the USA.

I recently started a 924NA that sat for 15+ years...I just added fresh gas, dismantled the metering head as it was stuck/gunked-up and tickled the injectors as they were also stuck...cleaned the ignition amp connections and it fired up...stuff works on it too...after 15+ years of sitting in the snow, rain and sun.

Regarding your misfire, could be fuel related...you should get a cheap wideband sensor and gauge to see where you're at. Then if the mixture is OK it may be the ignition amplifier on the driver's wheel well...swap that for a different one. If that does not help, new plugs, new leads, rotor and cap...or even new ignition dizzy.
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sun Feb 04, 2018 4:31 am    Post subject: Reply with quote

Ignition amplifier? Is that the silver box with the caution note? Mine is the Audi engine, not the Porsche...

Last edited by vwfye on Sun Feb 04, 2018 12:24 pm; edited 1 time in total
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sun Feb 04, 2018 5:03 am    Post subject: Reply with quote

I realized today that I lost my side marker lights (round ones). Would that knock out my flashers?
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Sun Feb 11, 2018 6:15 am    Post subject: Reply with quote

Started an all day project that covers only about 6 sq ft. The 924 FL fender is ugly, so I picked up a decent used one. Now I am sanding, priming, sanding, priming and....repeat. if it goes well, I hope to have the basecoats on when the warmth of the day hits. Then, on another day, I'll add the clear coats. I know it isn't suppose to sit like that, but it is the best I can do on these short windows of opportunity.
It will be better than it is!
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morghen  



Joined: 21 Jan 2005
Posts: 7729
Location: Romania

PostPosted: Mon Feb 12, 2018 12:12 am    Post subject: Reply with quote

vwfye wrote:
Ignition amplifier? Is that the silver box with the caution note? Mine is the Audi engine, not the Porsche...


Yes, thats the one.
The engine was engineered by Porsche, they used an Audi/VW engine block and bits and pieces but it was not Audi or VW who developed this engine, it was Porsche. The Audi/VW versions are different actually, though using the same block and similar head.
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vwfye  



Joined: 05 Mar 2017
Posts: 41
Location: Oregon

PostPosted: Mon Feb 12, 2018 9:16 am    Post subject: Reply with quote

re the symptoms of this failing the high rev misfire and...? Or just the misfire?


Oh, and thanks!
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