divil

A while back my 951 developed an intermittent idling issue - on startup, for the first 10-15 seconds it would stutter like it was going to stall. It usually stabilized by itself but on 1 or 2 rare occasions it actually stalled. It drove ok though.

It seems to have become more frequent and now I also have the occasional hesitation around 2K rpm when accelerating - this seems to only be when cold.

I started it up in the dark last night and had a look - I could see arcing from one of the plug wires to the distributor housing - it was fairly consistent as long as the wire was around 1/8" from the metal.

Would you just replace all the plug wires once you see arcing like this? What about the distributor rotor & cap - the impression I get is most people just go ahead and do the whole lot, plugs and all?

xsboost90

did you have the wire off when it was arcing? that would be normal.... If its arcing visually when the wires are installed then yes get a whole new set. I would also check the fuel pressure regulator and vac. lines as well to see if its running rich on start up. Mine did that and it had the vac. line unplugged.

divil

Nope I didn't touch anything, it was arcing through the insulation.

I suspect vacuum lines too because the arcing was still visible when the engine was running nice and stable, so I thought there must be something else wrong too.

I got a can of carb cleaner and sprayed around vacuum lines to see if I could find a leak, but I couldn't. That said, I don't know where all the lines are and didn't take the time to trace them. There are a lot of pipes and hoses with signs of wear around their connections in various places. I'll take pics and maybe someone can shed some light on them.

Don't know how to check fpr...will read up on Clark's garage now.

For now, I'll go and order a set of leads anyway.

KuHL 951

Replace the entire wire set. Have you checked that large vac line insert into the passenger side of the intake manifold? That large press fit hose barb needs to be sealed tight or it causes a small leak, especially when cold. I had a leak there on every 944/951 I've owned and ended up using JB Weld to seal and hold the barb in.

divil

Here are most of the places I checked for leaks:



I also checked a few other connections. Spraying a decent amount of carb cleaner seemed to have no effect.

I did notice just now though, that the 2 hoses on the bottom off the pic are very loosely fitted, especially the one on the left - which I presume is a vacuum line since that valve is connected to the intake mf? The larger hose on that line can easily be pulled away from the valve - it feels kind of loose. Is that bad?

xsbank

The bottom two hoses that you have circled are fuel lines. The right one is the feed and the left is the return. If they are loose you are extremely high risk for a fire and a total loss! Buy a silicone vacuum kit from one of the vendors and just replace all the hoses, AFTER fixing the fuel lines!

divil

Yikes...how should they be attached? As you can see the larger hoses are just pushed on over the smaller ones. I just took another look and I was able to push the left one on almost all the way to the hose clamp. The one on the right won't go on any further because there is no slack left in the hose. But it doesn't really feel loose.

The bottom ends of these hoses are attached to the metal fuel lines in basically the same way:

xsboost90

fuel lines are prob ok, the rubber is just for protection. I would be more worried about the jumper line which always bursts....

divil

Right, had a closer look and the rubber just covers the braided hose underneath so that looks ok.

But a close inspection at the jumper line looks kind of bad to me - the rearmost end of it is bulging out around the metal connector, and it feels very soft. I can see surface cracks in the rubber.

pops 83 944

I would replace the jumper hose before it bursts and causes a fire. We don't need a another one lost to a fire!

xsbank

The fat hose is just a heat protection cover for the fuel hoses... Take a close look at the actual hoses, as suggested.

John_AZ

+1

Notice the "buldge" in the jumper hose.

divil

Yep I had a close look at that bulge and there are lots of tiny cracks...I am ordering a replacement. I don't think I'll even drive the car until I replace that, it looks really bad up close.

The other fuel lines look fine, at least around the connectors.

HICKS

You really need to replace all the fuel lines under the hood. Buy them here: www.rennbay.com

divil

OK, got the fuel jumper line and all the ignition parts with the help of Scott from Banger Industries...

Now I have only one obstacle...I cannot get the new jumper line on. The old one came off easily enough, but I can't fit the end that connects to the damper. There isn't enough clearance between the threaded pipe coming out of the bottom of the damper and the engine block. I can just about get the jumper connector on there but not straight enough for the thread to engage.

On close inspection, the brass connector on the new one is slightly longer which appears to be why there isn't enough clearance. It's dark now so I'll have to leave it till tomorrow...maybe if I loosen the damper in it's bracket I can rotate it a little?