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[scm924s]

Glad you are getting a result.

As posted above, change the oil as a priority, if you haven't flushed the gas tank, be prepared to replace the fuel filter a couple of times, kjet and the pump do not like dirty fuel. Running with an induced air leak does suggest mixture is rich, it is difficult to get idle/mixture set accurately without the use of an exhaust gas analyser,
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1984 n/a Ruby Red Metallic
1988 924S Guards red- sold
1986 924S Guards Red - sold
1984 n/a Black - sold
1980 n/a Le Mans#1 - sold
1980 n/a Le Mans#2- sold
1977 Martini - sold

[Lakeview]

@scm924s
@Beartooth
@Raize

Car had the in tank pump that had been disabled. Tank had minimal corrosion and virtually no buildup. While waiting on a strainer I pump old pump back in and added 4 gallons of vinegar. After I got new strainer I flushed tank with water many times. Added 5 gallons of fresh gas and fuel conditioner.

Milky was probably not the right term. Cloudy probably fit better.

Car came with some removed parts including 4 old injectors. I'm going to add more fresh fuel and more conditioner.

Well, good news bad news. Friday I reinstalled all the the air piping. Car started and ran great. It has some deferred maintenance stuff that I'm slowly resolving. One that bothers me is all the rubber grommet/studs that hold the air cleaner and coolant reservoir in place. It causes all the air piping to be loose and may cause air leaks. Little things like that bother me. Throttle cable at the intake lever seemed a little slack so I adjusted it. And used the screw on the body to adjust the idle.

Saturday I cranked the car and amazingly it fired right up. Outside temp was about 90. Almost immediately it started running rough and seemed like it had a dead miss. Would not build any rpm. Then died and wouldn't start back. I moved on to other parts of items I want updated and let it sit for a few hours. Starts briefly, won't idle. In trying to feather the pedal to keep it running the pedal now hangs and won't return. Not sure if it has something to do with cable adjustment. I'm going to reverse what I did next and see. New cable is obsolete from Porsche and no aftermarket. I'm not even sure if the part number is correct since the PET doesn't specify RHD. If any of you European guys have any insight into Porsche having additional PET for RHD I'd like to know.
As for now it's back to head scratching!

[Raize]

Wouldn't worry about loose throttle cables, it just needs to fully open the throttle with the pedal on the floor. Any tighter and you are just stressing the cable.

I hope you are adjusting the right screw. This is the one you adjust for idle speed. Leave the throttle stop screw alone, or put it back to how it was if you moved it.

[scm924s]

This may help with setting the idle mixture https://youtu.be/1mA2BA598_4

The idle speed scew is on the throttle body, both need setting together.

Not to sure about flushing the tank with water? difficult to ensure all totally removed and dried out? Any residue could be causing problens.

To replace all the various rubber mounting bobbins google anti vibration mount bobbins and select right size, cheaper than Porsche, if they had them
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1984 n/a Ruby Red Metallic
1988 924S Guards red- sold
1986 924S Guards Red - sold
1984 n/a Black - sold
1980 n/a Le Mans#1 - sold
1980 n/a Le Mans#2- sold
1977 Martini - sold

[Lakeview]

@scm924s I have watched so many Youtube videos til I'm blue. I've had found the guys across the pond have a lot more knowledge it seems than here. I am hesitant to go messing with the fuel mixture yet. I removed the cold start valve yesterday to check. When I removed the line it seemed to have quite a bit of pressure. Not sure if that's normal. Removed the top line of the filter to relieve pressure and the fuel still looks milky. I'm going to drain the tank and start over. I think I have a water issue somehow.

Yes, those are available but costly. I have found alternatives. I have already spent a lot on new parts.

The car apparently had some damage low in the front. It didn't have the lower valance (Porsche calls it spoiler), my cost right at $700! It bent the sway bar mounts and broke one of the ones on the lower control arm. Bought all new bushings, etc. Now the struggle is trying to get the new ones in and not having much luck!

@Raize Yes, I have adjusted that way. Removed the throttle cable and it is not the problem. Removed, checked, lubed the throttle assembly. Not sure why it was working but now sticking. PET shows a return spring but for a Turbo. Assembly is also for a 944. I will be checking my parts car today.

[Lakeview]

Update....... I drained the fuel tank. What came out was interesting. It had some slimy/snotty looking stuff in it. Not sure but maybe the injector cleaner. Added 5 gallons of fresh fuel. Flushed line at under hood filter. Car would crank but still missing and not idle. I removed the cold start valve. Soaked in carb cleaner. Checked with 12 volts and can hear the solenoid.
I replaced spark plugs, cap and rotor. Same results. My usual rule is don't mess with something you know nothing about but I started adjusting the mixture screw to lean or rich. Should have probably left it alone. It was running good in the beginning. It changed nothing.
I'm now thinking the slimy looking stuff may have clogged some injectors. Only thing I haven't removed is the warm up regulator. It looks crusty so I'm sure it hasn't been off. Would it cause a no start/miss situation?
I guess my next step is remove all the injectors and see if they are squirting. I have a receipt where new injectors were bought in 2022. Bosch 62278. Looking at PET it shows 2 different part numbers with a serial number break. Other part number changes to Bosch 62277. Not sure which is correct for this car....

[Beartooth]

Absolutely remove the warm-up regulator (WUR), disassemble it, and make sure the passages are clear. Don't worry about screwing it up: as long as you don't lose any pieces and put it back together correctly, it's pretty hard to screw it up. After I got my lambda control properly connected and grounded (my frequency valve wasn't working initially), the fuel distributor rebuilt, the lines flushed out - and even after I'd cleared the WUR - I still ran into issues because the screen in the WUR got plugged up again a couple times. So I'd say if there's been fuel contamination, there's a very good chance of a blockage at the WUR. That would be more of a priority than the injectors - you could have a brand new everything except the WUR, and it'd still not run or run terrible if that's off.

As for the injectors, you can test those (and the fuel distributor at the same time) by removing the injectors and carefully manipulating the injectors lines so you can re-connect them with each injector in a little jar (ideally something clear). You should see a fine spray out of them; there are plenty of pictures and videos out there if you need a better visual. Ideally, they put out an even cone pattern, but a little uneven isn't a big deal. No flow, an obvious mismatch relative to the other injectors, or dribbling instead of spraying means you've got injector issues (although sometimes you can clear them).

That said, part of the reason people talk about fuel pressures, and especially control pressure, is that helps pinpoint common issues - like a bad fuel pump or blockage, bad fuel pressure regulator, or issues with the FD or WUR. To me, the WUR seems to be a common enough culprit (usually a blockage: I've replaced nothing except the o-ring on mine) that it's the second thing I'd dig into on a project car, after the fuel pump and filter.
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1980 931 diamond in the rough

[morghen]

If there was slime in the tank, there is at least slime or thicker, stickier or solid deposits in all the k-jet items, including the fuel distributor, possibly injectors, warm up regulator, 5th injector, fuel accumulator, fuel pump...all fuel lines.
So you need to remove everything, open it up and clean everything.
The fuel distributor has delicate parts inside which may or may not work after re-assembly, same for the WUR. You most likely need repair kits for both of them.
If you enjoy the journey and dont mind at the end possibly not getting a running car or not running well, this is fine.
But if you want to drive the car and forget about these never-ending rabbit holes, give me a sign and i'll send you an engine management system that looks like the old one but works like a modern one. You'll need a day or a weekend at most to get it installed and its nice drives from there on.
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Supercharger and EFI kits
https://www.the924.com

[Lakeview]

I removed all the injectors. Jumped pump relay. No spray and some dribbles. Removed all lines from injectors. When pushing up on the plate I get no fuel from the lines. Even pushing the plate all the way up, nothing. I can hear fuel noise in the distribution head. Apparently it stops there. I'm guessing the fuel contamination has maybe clogged it.

Beartooth..... It sounded easy to get off but after about 3 hours of cussing, sweating, bleeding I finally got it off. It's a curse to have big fat hands.Pushing on the coolant hose below the bottom bolt with a screwdriver put a nick and started a leak. I guess forty year old hoses aren't meant to be pushed on.

Screen had some buildup in it and the body has some of the white crusty stuff. Spraying out the disc that holds the diaphragm down a little orifice looking piece came out. Not sure if it needs to be oriented a certain way.

I have ordered a WUR kit and a fuel distributor kit from missing parts in Germany. Probably be a two week wait until I get back to this escapade....

[Beartooth]

morghen is right about the gunk all through the system: it's probably gotten into everything. There are several internal filters in the system, and while they're not prone to plug up, it could easily be the case with badly contaminated fuel. The WUR is a pain to get to - that's true! It gets easier after you've done it a few times - you figure out just what wrench to put where, but they certainly didn't put it in a convenient spot.

It's been a year or two since I had mine apart, and I can't picture the piece you're talking about unless it's the little pusher "hat" that goes against the metal diaphragm. That has a little recess on the smaller end that faces inside the WUR, and the wider, flat end pushes against the diaphragm. The metal disk with the four screws holds it against the diaphragm, and the pin pushes on it. The only other orifice I can picture is on the other side of the diaphragm where the fuel actually flows through, but I thought that was all one machined piece. If it's not that little pusher piece, a picture would help. Otherwise, the rebuild kit should have a pretty detailed explanation of how it goes back together.

It'd be nice if running enough fresh gas and fuel treatment through would eventually clear it up, but if you can't get fuel flowing it's probably just a waste of time. It definitely sounds like the FD will have to come apart too, but the good news is that of the three FDs I've worked on, I've never found one with any major corrosion issues; typically, replacing the o-rings and diaphragm will get them working again. The kit I fixed mine with was also from missing parts, and I was happy with it. Lastly, I'd recommend removing all the lines to/from the WUR and injectors, soaking them in fuel system cleaner (I actually mixed some Techron, Sea-Foam, and Isopropyl alcohol for that purpose), and then blowing them out. It's kind of a job getting it all cleaned out, but you'll probably be pleasantly surprised at how well it runs once you get that taken care of.
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1980 931 diamond in the rough

[Lakeview]

Beartooth...... Yep, it was the lower bolt in WUR that gave me fits. Hopefully I won't be doing it several times! After I removed the coil, bracket and the hose I poked a hole in the bottom bolt was accessible.

I sent missing parts a message when I ordered the parts. All the videos I've watched the little center didn't come out. Of course mine did. He explained how to orient it back. One side touches the diaphragm and the other has the pin/hat. Not a big deal.

Since I'm a tool hoarder this gives me an opportunity to buy more! I feel I need an ultrasonic cleaner.

This last time after I drained the tank I refilled with five gallons of fresh gas and Seafoam. Last time I used the Lucas brand. I'm not sure about these fuel additives. I'm still seeing some funky looking stuff while checking for flow to the injectors. I may drain and refill with just fresh gas only.

[Raize]

That's a shame after it was running.

Does sound like the FD is blocked because you tested it with the injectors removed (so cracking pressure not relevant).

Do you feel resistance when you lift the plate (with pump running) or is it just light and floppy?

I have the (absolutely wild) idea that you might have backed out the mixture screw so much that it came off its threads. Only other thing that could cause this apart from blocked FD.

[Lakeview]

Thanks @Raize........

I'm back on the project. Got my parts in from Germany for the fuel distribution head and the WUR. And, have been working on my 944 in the mean time.

During the previous process of troubleshooting the starter started giving problems and then just quit working. Bought a high torque off eBay from a guy actually not far from me in Tennessee. He bought it for his 924 but never used it. After struggling for hours just to get the heat shields off I finally got to the starter and I won the fight to get it off.

The high torque starter came originally from Britishstarters.com and I guess not supported anymore. I suck at wiring schematics. The old starter has two smaller wires on two posts on the solenoid. New starter only has one terminal other than the main hot lug.

My question and guidance needed is can I comblne the two wires or??? They were separated on the original starter for a reason I guess. I just got the old starter off yesterday and haven't started chasing wires yet.

Got to get the starter problem solved so I can move on to the fuel rebuild.

[Lakeview]

Thanks for all the insight into my problems but I have another question.

@Beartooth
In a previous message you said you had done three FD's. I got my parts in from missing parts. WUR went together easy. FD head not so much.
What I experienced was first a problem with the small orings and clips on what I'd call the barrel. When I pushed it in the orings seemed to squeeze out. I finally put a little light oil inside and they went in ok. Following missing parts video it showed putting the center piston in the barrel during assembly. I did that. Looking back at some of the YT videos they didn't first. I did use some sealer on the halves as I wasn't sure if it would seal and didn't want to do it again. I could see some moisture and rust inside when I disassembled it was the reason for sealer. It wasn't leaking when removed but the halves had some rust in the ports and discoloration on the mounting surfaces. I used some scotchbrite and did run them through the ultrasonic cleaner.

Where I think I may have a problem..... When I went to mate the two halves it was said to "squeeze" the halves together by hand and install the nut. I couldn't get the halves to squeeze together enough to install the nut. My mistake may have been not putting a little lubricant on the orings first. I used the bolts in small increments alternating around to pull the halves together. I was watching to make sure nothing got cocked. All the springs and such looked good going together.

Before I mount it back in the car my question is...... Should the piston move freely in the barrel? Mine won't. Does fuel pressure control the movement or do I have a big problem?

[scm924s]