dwturducken

I have had this car for about 2 years. I bought it over a Volvo wagon four years newer for the same price because the Audi had 88K on the OD, while the Volvo had over 150K.

Unbeknownst to me, you're not supposed to run any kind of ethanol blend in this car. Here I was in Iowa, running the same 10% blend I've put into everything from MGs to my old Chevelle, and suddenly I have fuel leaking into my air box. Turns out it was coming through the plunger!

Got a complete air box assembly from a local salvage yard and performed the swap in about a day. Now, the car cranks fine but will not start. Based on fuel venting when I loosen fittings, I have pressure to the fuel distributor, from the distributor to whatever that thing is on the top of the airbox, kind of inside the fender where you can't really see it, and at the fitting where that attaches back to the fuel distributor. However, I have no fuel inside the solenoid valve on the "front" of the distributor and no fuel from the lines to the injectors.

I tried swapping solenoid valves, putting my original back on, with no change, and swapping the plunger from the salvaged unit into my previously working unit to no avail. Is that mystery thing in the fender something that is restricting pressure or bleeding off pressure somehow? I have been through some generic descriptions and diagrams of Bosch K-Jets, but nothing that really tells me what is which on my car. Lovely pictures of Porsches and Mercs, though.

Is there something I'm missing? The only Bentley manual I have access to is for the 89-92's, and it talks about using some specialized VW dealership shop test gear that I'm not sure how to improvise, plus it's in the reference section of my local library. Haynes manuals for this car are out of print, but the ones I've had for fuel injected cars I've owned in the past general punt to a professional about two steps prior to where I seem to have gotten myself.

dkarten

my '87 5000S has 384K, to the best of my knowledg all gas in the northeast has 10% ethanol, did you replace airbox/fuel distributor/differential pressure regulator as a unit?, try this site for troubleshooting:
http://www.sjmautotechnik.com/troubl...g/trouble.html

dwturducken

Actually, the salvage yard did just pull the entire assembly, so I swapped it in. I have discovered that site, but I also do not have a working laptop at the moment. What I need to be able to do is have all of these things that I've found on the interwebs out there in the garage with my while I poke through the plumbing, instead of running back and forth.

I will try swapping back the original assembly. In removing it, I pulled a three-way vacuum valve from the side of the rubber boot that runs from this assembly to the throttle assembly. I have the vacuum lines plugged at the moment as well as the opening in the boot, because the barb that was in the boot snapped off. I've found the part, and it's not expensive, but I'm trying to get the car running before I order a replacement.

This car has had every problem that I discovered in researching it before I bought it: the two driver side outside doorhandles have broken, the front passenger side outside doorhandle had the linkage break in the door, the front driver side window mechanism broke so the window won't stay up, the dash lights are out, and the sunroof leaks. Honestly, it's a bit like the English cars I've had, which I kind of enjoy.

I will swap the original assembly back in and see if that gives me fuel to the engine. I'm not sure why that hadn't occurred to me, but the plumbing is so confusing it's hard to just look at it and see how it's supposed to work. It actually makes me miss Strombergs.

dwturducken

So, I swapped all the original stuff back in, and it still wouldn't start. A quick check of various things, including vacuuming leaves out of the fuse box and checking the relay, turned up a missing fuel pump relay fuse. So, it almost caught, but I flooded it. Now it's sitting with the plugs out, drying out.

dkarten

you should get yourself a Bentley Manual, the fuse that goes in the FP relay is to run diagnostics, when you put the fuse in & left it in it primed the FP, installing the fuse for 4 seconds with the key on after cranking engine activates codes that blink the CEL light in the dashboard, not sure if SJM covers that, you can use search on this site to research how to blink codes

dwturducken

Not that fuse. The fuse for the fuel pump itself. I think it's #13 or 15; not sure off the top of my head.

I'm now getting fuel and spark. I have to start looking in other directions. Also, I'm probably going to have to shell out for a new fuel distributor; I'm not confident enough to try rebuilding one, and the replacement isn't letting fuel flow at all.

Yes, I probably will have to get the correct Bentley manual.

dwturducken

OK, I removed the fuel distributor and disassembled it, because it has screws and therefore should be disassembled!

On the center cylinder, a couple of the tiny o-rings had cracked and were kind of brittle, so a quick trip to 3 different Ace Hardware stores got me all six plus the two o-rings near the bottom of the cylinder (one on the cylinder and one in the housing) that seal the cylinder to the housing once it's in place. Got everything back together, and now the car will start but it won't stay running, particularly if I try to give it gas. I think I saw somewhere that that's the pin thing inside the cylinder sticking when the big dish thing below the rubber boot tries to lift it. Not the point; I think I can fix that with the center cylinder/pin assembly from the other distributor.

The revelation came when I checked the air box after the third or fourth stall: the original leak was never from the fuel distributor! It's coming from the odd-looking three-way valve thingy on top of the air box, back inside the fender. It seems to have a fourth way that is a tiny capillary-like tube that feeds down into the air box. That tube is dumping the fuel at what must be its max flow capacity. Not sure if that regulator (?) has failed on its own or if system pressure blew it out, but THAT is my problem, now.

But, it's mid-afternoon on a 98 degree day, so I'm done until morning.

one5k

u may want to search online for better o rings. my neighbor used hardware store o rings in his motorcycle and the ethanol in the gas ate right thru them in about 2 weeks.