rattlsnak

3.6 engine misfiring.. help..
Yea!! I finally got my '95 993 3.6 installed in my project car,
Boo!! its not running right!

The engine has been sitting for @ 2 years and is now installed in a '72 with the Timmins kit.

It seems to be running on 4 cylinders. With the engine runing, I can:
1. disconnect the fuel injector connectors (one at a time) on cylinders #4 and 5 and it makes no difference in the way the car runs. All the other ones do.

2.Have taken a compression test on 4,5 and 6, being 150, 145, 155 on each.

3.Swapped #5 and 6 fuel injectors around, no difference.

4. 'noid' light shows a correct pulse.

5.Swapped plugs around, all to no difference.

6.Checked for spark at wires (plug end) both are good.

7.When its running every so often it will backfire.

8.Havent pulled the valve covers yet, but am thinking its the next step.

Help..!
Anyone???

StevoUK

Run until the ecu stabilises, check battery voltage - low volts can cause misfires, check fuses for clean connections and no resistance causing voltage drop. Check earths for clean contacts with no resistance, check all plugs for good spark.

Take it on the road and see if the missfire disapears after a few miles with awarm engine and charged up system.

rattlsnak

OK, for those who want to know.. I pulled the valve covers off and 4 of the 6 lifters on the right side are collapsed. I can literally easily squeeze them with my fingers over 1/4". So apparantly, they are opening enough to get compression, but under pressure, not enough to make it run properly. After I put the new ones in, Ill let you know aht happenes.

pjc

Surprised it didn't sound like a tractor! Sure did when my lifters gave up.

PJC

rattlsnak

New ones installed, problem solved, runs great. The o-rings were dry rotted and crumpled. When I took off the rockers, the HLAs fell out along with pieces of the old o-ring.
I couldnt tell if it was making any noise because I dont have a muffler on it yet! (just the Cat, and its kinda loud at the moment!)

Steve Weiner-Rennsport Systems

Don't be surprised if you wind up replacing all the others,....this is very common. If two of them have failed o-rings, in most cases so do the others. Its an "excessive operating temperature" thing,....

Porsche doesn't sell new seals and I've looked all over the US & Europe for a source with no luck.

rattlsnak

Oh yeah,.. Dont worry, I did them all !!
I have no A/C or blower box in the way, so its only @ a 1 hour job for each side.
Thanks!