lost smooth idle circuit - 914/6

[porschesix]

HELP! This 1970 914/6 is new to me - carbs supposedly rebuilt in February of this year. I have put about 100 miles on it (entirely stock engine with 130K miles) and all has been well. All of a sudden, the idle circuit seems to have evaporated - meaning that it went from 950/1000 rpms to less than 500. When it hits about 2,000 rpms all is well and it drives nicely once underway. Getting it away from a stop light requires feathering the gas, bringing up the revs and riding the clutch to pull away. I pulled the idle jets and cleaned them but each looked fine. Could this be an ignition issue that only effects low rpms, and if so what is the mostly likely culprit? Thanks to all who respond.

[J P Stein]

If you have points in the distributor, check em'.
Changes in dwell effects timing, effects idle...among other things.

[John Rogers]

JP is right, check the points and even better replace them. On small and high reving 6's the points have a pretty heavy spring and wear the rubbing block down very quickly. On my car it happened in a 20 minute practice session at PIR this past Jan.

[porschesix]

JP and John - thank both for the prompt response - greatly appreciated. Do either of you have an opinion about going to a breakerless setup and do away with the points entirely? Thanks again, Stephen

[red-beard]

Usually not necessary, as the points are "trigger only" in a 6 and carry no current. I do like my MSD upgrade, except for having to screw around with the tach to get it to work right.

[John Rogers]

James is right but on my race engine it was not points pitting but the wearing block that wore really quickly, changing the dwell.

[porschesix]

Red Beard and John - thanks again! I discovered tonight that my car has the Marelli distributor, and I understand that some of the parts (i.e. rotor and cap) are hard to find. I also understand that the Bosch distributor (1970 E) is a better replacement. Any opinion? Thanks!

[J P Stein]

I use the Pertronix and have had excellent service from it.....4-5 years worth. I hate dickin' with points.

[red-beard]

I just purchased an S distributor from local parts house. As we went through the application, the only difference between the S, the E and the T was the rotor and it's setpoint for over rev protection. the Base Distributor was identical. I Purchased a rebuilt Bosch unit for around $400 plus core charge.

James