Question about 3.0 with 2.7 parts
 

So the car I just bought has a 3.0 in it, with a 2.7 dizzy, 2.7 permatune cdi, and 3.0 cis.
It runs well when warmed up, and decent when cold but doesn't like to hold idle until it's warmed up.
Warm starts (after taco bell or something of that nature), it misfires until it gets back up to 210*ish
Also, it sometimes holds idle at 2k when warmed up, and I can bring it down by using a gear to bog it down, then it drops to 1000.

A friend of mine is suspicious that cis vs potentially wur mismatch is an issue. Or that advance curve isn't right, etc.

Unplugging wur kills it, so it at least functions some. AAR functions. Also both get 12v running.
As a side note, fuel pump runs always with ignition on, and is not a bad relay, in case it makes a difference.

I plan to do some part number searching and further testing soon. Just thought I'd get preliminary ideas.

It's in a 77 targa, originally 2.7, but confirmed 3L by 4 journal cams and case stamped 930/06. Case was originally from a 68, and appears porsche re stamped it around 78 and used it for this.

The bottom of the engine is built like a 76/77 3.0 using the crank drive for the distributor and CD
You have to run fuel pressure checks to check the WUR.
Bruce

I read about pressure checks for wur. I thought unplugging was at least a semidefinitive test, no? I'll try to get hooked up and test correctly.
So are you saying 76/77 3.0 do not spin the dizzy opposite the 2.7?

Also, its a factory porsche part numbered silver permatune cdi, if that makes a difference.

When I run pressure checks I unplug the WUR to give me a base number that won't change until I desire to time the running system. The car should run unplugged. Did you ohm the WUR?
The 76/77 3.0 runs a 2.7 distributor.
I m currently building a long block 3.0 that will be set up to use your 2.7 CD and distributor. 9.3 CR, just add your Webers.
Bruce

Duplicate of previous post

Interesting situation. Your case casting number is an SC, not a '68 restamp. Which way does the disributor spin, the 2.7 distributor was not meant to run the same direction as the 3.0 distributor. As Bruce mentioned, the internal drive gear would have needed to be changed.

This motor gets more and more confusing!
The distributor spins clockwise

So what I find so far is that fuel spider is part number 0 438 100 077 which is 80-83 3.0

WUR is part 0 438 140 033 which is 76-78 911s

Just because someone else mentioned it elsewhere, intake runners are 911 110 169 4R which apparently references "the bigger ones"

Distributor cap is 1235 522 060
Distributor is 0231184007 which is 2.7s

The cdi box is permatune, and is silver, but my friend reassures me it was the blue one now faded. It has a part number starting in 911 but the rest is faded, so it is the porsche placed part

So it looks like my wur and spider don't match. That could be the problem. That distributor being a 2.7 could be an issue too

All distributors run clockwise except 78 to 83 and 78 on turbo.
Bruce

It seems a lot of different parts were used to build this motor. 930/06 1978 SC 930 101 103 4R case, but clockwise 1977 2.7 distributor. I would think the case was apart to change the distributor drive to clockwise.
What was used for the 77 Carrera 3.0 engine?

76/77 3.0 Carrera and turbo used a 2.7 crankshaft and rods
Clockwise drive on a SC, yes someone was in there..could have been me
Bruce

So is it agreed that the wur needs to be swapped to 3.0 to match FD?
What should I do about the 2.7 dist?

You need to do a fuel pressure check, if you don't you're wasting your time and money
What do you figure you want to do with the distributor, you don't have option unless you are willing to split the case.
The spark system you have works, fuel, weather it's the WUR or the fuel distributor needs to be sorted.
Bruce

Like Bruce said, without the CIS pressure gages to check the system, you cannot get things in order.
I think you will be better off starting a new thread in the Technical Forum. The problem I see is the mis matched system parts. I am not familiar with the later 80-83 CIS. Your fuel distributor is from a CIS that used a frequency valve and O2 sensor to adjust the fuel distributor to fine tune the mixture. I don't know how the later fuel distributor would work with out the rest of the components. You need advice from those more familiar with it.

Alright. The lambda and corresponding lines have been bypassed fyi.
I do have access to cis gauges so that's not an issue.
Instead of splitting the case, I can recurve the distributor correct?
I'll probably go with swapping wur as I'm sure it's the less expensive and easier route.
I appreciate all your info guys, thanks. Not sure why my projects cant ever be simple! :p

Distributor rotation shouldn't matter as long as the plug wires run to the correct cylinder when they are supposed to fire.

If you need a CO meter to set up your mixture I'm not too far away from you in West Salem.
I have a proper fuel gauge too.

Your car would be nicely warmed up (like it needs to be to make CO adjustments) driving it here. :)
Or, I could come see you.

Send me a PM with your phone number and I'll give you a call if you want.

I had a 3.0L that had 2.7L CIS and Distributor. It ran just fine. Not a huge HP motor (167whp) with the terrible thermal reactor delete exhaust but the car was very responsive with tons of midrange grunt. HRG 911 Baseline Dyno - YouTube

I would look for vacuum leaks and what not first. Mine had a high idle on cold starts (normal) but once warm was rock solid with all 2.7L parts.

Evan, did you have the 2.7 distributor running clockwise? I could see the advance curve from the 2.7 working in the 3.0, but only if running clockwise. The advantage of the SC distributor is no points.

You might be able to move the ignition wires to accommodate the different rotation, but If you reverse the rotation, the advance weights would retard the ignition, and the vacuum retard would advance the ignition. His 2.7 distributor is running in the proper clockwise direction.

Yes, whomever built the motor flipped the distributor drive gear.

If in the OP's motor this was not done, I would think putting in an SC distributor would be the solution.

My setup seems finicky. When I first start it, it idles perfect at 1kish.
When I start to drive it, it won't idle cold. Just dies when I clutch in.
Once it's hot it decides if it wants to idle at 2k or 1k. I can bog it to 1k if it stops at 2k.
Today it actually would NOT go below 2400 or so for a while after warmed up, but I parked and came back and it dropped to 1k every time.

Timmy- I have a shop I volunteer at that just moved from Dallas to amity. If you ever go to shell in West Salem, my god friend and previous 944 coowner is the manager!
Do you do cars and coffee Keizer? I regular at tigard c and cr.
I have access to cis pressure gauges, and I'm pretty sure a co meter. If not I'll let you know!
A few of us from portland area are driving out to bible creek rd past Willamina tomorrow after c and c to check it out for the hillclimb next weekend if you're interested.

I checked this morning actually to see if I had access to the afm mixture screw, and it looks like a previous owner took the plug out so I do. We will be starting with that tonight and possibly a pressure test.

Evan - maybe this is your old motor. Lol. Thermactors gone and the welds look like a third grade did them

Ed,
I wasn't suggesting he change the rotation, I was just stating that the rotation doesn't matter if it is correct for the distributor and connected that way. :)