Success! Missing ponies found.
10-18-2009, 05:32 AM
#1
Racer
Thread Starter
Join Date: May 2008
Location: Sierra Foothills, CA
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Success! Missing ponies found.
I finally discovered the missing piece of the puzzle of why my '77s 3.2 conversion never quite felt like it was running to it's full potential.
I started with all the obvious things and this is where the clues led me:
1) throttle blocked from opening more than 75% by clamp on intake boot
2) #3 cylinder plug connector badly corroded
3) fuel filter dirty
4) idle mixture incorrectly set
After a complete tune up including cap, rotor, plugs, new plug wires, air & fuel filters, valve adjustment, new O2 sensor, setting CO mixture screw, Steve Wong chip & cat delete, this motor still felt weak even in the lighter early car. Idle was rough, throttle response not very sharp; it just didn't "feel right".
BTW compression was 150-155 on all six cyls.
Finally, after much research and head scratching, posting here and on Pelican I realized that the original fuel accumulator from the previous 2.7 CIS system was still in place. When I removed it I realized the shop that did the conversion really didn't know what the F they were doing. With the credibility of the conversion now in doubt I became suspicious of the fuel pump. A check of part numbers revealed that the fuel pump was a CIS pump.
I ordered the correct fuel pump for the 3.2 motronic system and while I was waiting, sent the injectors to Witchhunter Performance for cleaning and flow testing. The injectors came back good, the new pump went in and ...........................SUCCESS!!
This car now lunges forward straight to redline and sounds like a healthy 911 should! It idles smoother and the exhaust smells better too.
The PO had this car so screwed up it's hard to believe he didn't do it on purpose! And I'm saving the suspension and handling ills for another post!
It's been a fun as well as frustrating 16 months sorting this car out but now I can finally start to enjoy driving it. Thanks to all on this forum for sharing your ideas and advice!
I started with all the obvious things and this is where the clues led me:
1) throttle blocked from opening more than 75% by clamp on intake boot
2) #3 cylinder plug connector badly corroded
3) fuel filter dirty
4) idle mixture incorrectly set
After a complete tune up including cap, rotor, plugs, new plug wires, air & fuel filters, valve adjustment, new O2 sensor, setting CO mixture screw, Steve Wong chip & cat delete, this motor still felt weak even in the lighter early car. Idle was rough, throttle response not very sharp; it just didn't "feel right".
BTW compression was 150-155 on all six cyls.
Finally, after much research and head scratching, posting here and on Pelican I realized that the original fuel accumulator from the previous 2.7 CIS system was still in place. When I removed it I realized the shop that did the conversion really didn't know what the F they were doing. With the credibility of the conversion now in doubt I became suspicious of the fuel pump. A check of part numbers revealed that the fuel pump was a CIS pump.
I ordered the correct fuel pump for the 3.2 motronic system and while I was waiting, sent the injectors to Witchhunter Performance for cleaning and flow testing. The injectors came back good, the new pump went in and ...........................SUCCESS!!
This car now lunges forward straight to redline and sounds like a healthy 911 should! It idles smoother and the exhaust smells better too.
The PO had this car so screwed up it's hard to believe he didn't do it on purpose! And I'm saving the suspension and handling ills for another post!
It's been a fun as well as frustrating 16 months sorting this car out but now I can finally start to enjoy driving it. Thanks to all on this forum for sharing your ideas and advice!
10-19-2009, 10:41 PM
#4
I haddah Google dat
Rennlist Member
Rennlist Member
I posted some data in the other thread.
https://rennlist.com/forums/911-foru...-question.html
Congratulations!!