yahh

I have an 82 911sc ROW that we pulled the motor out for service. The motor is now back in and we can't get it to start. Here are the issues I am having. First, it seems that we only have spark on Cylinder one. Secondly, it doesn't sound like the fuel pump is running while cranking unless I have unplugged the lift plate. The CDI box hums the entire time while we are cranking. So far I have found replaced a relay because the old one appeared to be arcing occasionally. Another strange thing is that it seems like when the pin for 86 is inserted, it cuts power to the fuel pump. If I angle the relay and don't touch 86 the fuel pump will prime.

theiceman

Firstly make sure you don't have the csv and air plate connectors mixed up.
Make sure the firing order is correct as the rotor spins ccw on the sc
Make sure the rotor is rotating also
Also make sure the distributor isn't 180 degrees out of phase
What did you do while the motor was out ? Did you Remove the distributor ?

dlg993

If spark is available on one cylinder, it should be available on all cylinders even if the distributor timing is not correct. The CDI box humming is a necessary but not completely sufficient evidence that it is working properly, but, again, it is probably not going to be selective about which cylinder receives a spark - if it sparks for one it should spark for all. A possible "divide and conquer" approach is to spray a small amount of starting fluid into the air intake. If the engine starts briefly, the problem is fuel delivery, such as the fuel pump relay; if it doesn't fire at all, begin diagnostics with spark delivery.

theiceman

Unless his distributor isn't turning.

yahh

We have spark all the way around now. The distributor cap wasn't all the way snapped in. So we have spark now and the fuel pump runs ONLY when SIR connector is unplugged.

theiceman

But does it start ?
Fuel cycling through the fuel system isn't a huge deal. So does it start up ?

Dave Inc.

Maybe dumb question--SIR connector?

theiceman

it was actually my typo originally . I think he means air plate safety switch connector.

Dave Inc.

Ah, I thought I knew my CIS pretty well, was really scratching my head there!

yahh

Got this resolved a while back! Runs like a dream now. Had a grounding issue with the engine.

theiceman

so which ground was it ? its always good to hear feedback on resolutions.

Trakrat

My guess is you forgot to put the ground strap back on from the trans? I've heard this can cause problems.

theiceman

I wouldn't even expect it to crank if that was the case no ? that's why I was asking.

yahh

I never removed the ground strap as the transmission stayed in the car. Seems like between pulling the engine and bad engine mounts, the strap was torn like 70% of the way through. Put a new ground strap on and set the CIS system properly and it fired right up. I've put about 4k miles on it since including a trip to the dragon after some Bilstein club sports, torsion bars, and RE-11's!

theiceman

Good to know .. did you use fuel pressure and CO gauges ? what did you do to " set the CIS properly " ?