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Be patient: replace fuel lines, regulators and dampeners. Have the injectors checked for leaks if applicable (witch hunter if he's still around). The aforementioned plus idle stabilizer valve, breather hoses and vacuum hoses should all be replaced at the same time. But Any questionable hydraulic hoses and fittings should be replaced 'stat'!
FYI - This is CIS. It has the Warm up regulator but no dampeners. It's better to just replace the injectors with Mercedes version. Those are probably toast from sitting. No idle stabilizer valve on this car. The nice thing about the early cars is that MOST of the fuel system is made of metal. Most likely the input and return fuel lines which are rubber on the passenger side are probably shot. You will also need to evaluate the accumulator to make sure it's not leaking. That will effect hot-starts. Also verify your cold start injector doesn't leak and and do the resistance test on the temp sensor to make sure it's in spec. If out of spec, that will create a very hard cold start condition. I would also get the proper CIS fuel gauges to check cold/warm/hot pressures. The Bosch fuel distributor may be corroded and non-functional also. These have alot of rubber o-rings that can dry up and crack.
Could you elaborate on the Mercedes injectors? Are they different/better, or just cross referenced as a lower cost alternative to Porsche OEM?
these are what Brad is talking about. I have a set awaiting for me to install them on my euro S engine. engine fuel lines should be GB's that can be purchased through Precision Motorwerks or Roger. Pricey but lifetime guaranteed. Come to think of it, I need to buy maybe another set before you go buying! (3 sets left)
Just made a bone head $550 mistake while cleaning the innards of the fuel sender. Cleaning with a Dremel and wire brush, I got careless and the bit slipped and snapped one of the tiny bare wires. Has anyone had any luck soldering one back, or am I ordering a new one? It wasn't even that bad, but the float was hanging up slightly at times.
Rebuilt one rear caliper last night, been collecting new parts, fuel pumps, master cylinders etc. Changed the oil... have never owned a car that holds 8 quarts! New clutch slave is on, soaked cylinders with some Marvel Mystery oil. Fuel tank will be flushed one last time and reinstalled this weekend with new pumps and lines.
Anyone have a source for power window motors that don't cost $300 each? Cross referenced to a cheap Vw perhaps?
Could you elaborate on the Mercedes injectors? Are they different/better, or just cross referenced as a lower cost alternative to Porsche OEM?
Yep - just as good but lower priced alternative. I had them on 5.0L hybrid engine and they worked like a champ! Now getting them is out a different story!!
Just made a bone head $550 mistake while cleaning the innards of the fuel sender. Cleaning with a Dremel and wire brush, I got careless and the bit slipped and snapped one of the tiny bare wires. Has anyone had any luck soldering one back, or am I ordering a new one? It wasn't even that bad, but the float was hanging up slightly at times.
Rebuilt one rear caliper last night, been collecting new parts, fuel pumps, master cylinders etc. Changed the oil... have never owned a car that holds 8 quarts! New clutch slave is on, soaked cylinders with some Marvel Mystery oil. Fuel tank will be flushed one last time and reinstalled this weekend with new pumps and lines.
Anyone have a source for power window motors that don't cost $300 each? Cross referenced to a cheap Vw perhaps?
BTDT - Did you break the wire or at the solder joints? I was able to resolder at the joints but needed a heavy solder since the wire is so thin. If you broke the wire in half, that's a different story. You can buy very thin wire, e.g. 40gauge, but I'm not sure if it will work and provide the correct resistance. Resistance values should be around ~5+- to 75+-ish... (empty full)
Oil - Almost 9 if you pre-fill the oil filter!!
Clutch slave - you are going to have a heck of a time bleeding that if you haven't done before on a 928. They like to trap air bubbles. Motiv power bleeder is a recommended tool/procedure. Reverse pumping the slave is another.
I have a used power window motor tested/working. PM if interested.
Just made a bone head $550 mistake while cleaning the innards of the fuel sender. Cleaning with a Dremel and wire brush, I got careless and the bit slipped and snapped one of the tiny bare wires. Has anyone had any luck soldering one back, or am I ordering a new one? It wasn't even that bad, but the float was hanging up slightly at times.
Fuel sending unit wires are best replaced completely, rather than trying to rejoin. You can also use a sending unit from a Porsche 968, or a late 944. I think they are the same length. I've replaced the wire before, and it's a sensitive job, best left to a person with good electrical skills. It doesn't need to be that thin either, you can use a slightly bigger wire, but be careful about the small conductor on the bottom of the plate.
Another great resource is Jim Doerr (Jadz928) ... he's one of the most knowledgeable about the early cars. If memory serves, he is somewhere in Michigan these days ?
Another great resource is Jim Doerr (Jadz928) ... he's one of the most knowledgeable about the early cars. If memory serves, he is somewhere in Michigan these days ?
Update- Bought lots of parts: Engine bay fuel lines and fuel accumulator from Roger at 928srus, brake and clutch masters and hoses, fuel filter from Pelican. Tom at 928intl supplied a new fuel tank spider.
Got the fuel tank clean and re-installed with the good spider today, waiting on the hose from the strainer to the pump from 928srus.
Ordered the correct nichrome 40 gauge resistance wire to repair the fuel sender for 3.99 on Ebay! fingers crossed I can successfully solder it. Got 10 feet of it coming, so I have enough to screw up multiple times.
Here are a few pics:
Rusty fuel accumulator
Rusty fuel tank spider -- must've had a leak in the fuel hose between the pumps.
Pic of the underside with the tank out. Having a lift is a godsend, worth every penny I paid for it.
Should I be worried about this area of the rockers? There appears to be a wipe of filler on both sides under the rear edge of the door. Did Porsche do this poorly to hide a seam, or should I assume there has been a repair here? Magnet sticks across the whole area.
I would replace the fuel level sender hose as well while you have everything out. Mine was leaking recently. Don't want to have to drop the tank twice. Roger has a kit. $15 I think. The spider 'may' have been salvageable with some tlc and die grinder brush. The accumulator area looks nasty. I would be soaking the fuel lines for a week with pblaster or something of the sort. Btw -!my window motor is a driver side with 78 part number....
take your time! It can get exciting to fix all at once but don't want to overlook anything. Keep posting your progress. This alsoba good time to spruce up those other areas.
Re-did my fuel tank installation today after realizing that the vent hose had pulled through too far to attach to the filler neck. Hopefully the last time the tank comes out... I'm getting "good" at it though.
Cranked the engine to blow out Marvel Mystery oil, installed new NGK plugs and cleaned the engine compartment. Only bummer really is the cracked fan shroud.
Update: I'm ready to put the fuel system back together now, tank is in and new pumps are set to install.
Question: What is the hose that goes into the top of the accumulator? There seems to be a lot of extra length stuffed in behind the accumulator and pump, then it exits at the top of the inner fender. Is this an overflow or vent hose, or does it fill with fuel?
It's a vent of sorts. When the accumulator fails, fuel will leak out of that hose. Did away with it on my 78. On my 79, it runs around the fender well , connecting to a hard pipe, and dumps out center of car beneath bumper.
Did you replace that accumulator? I would also replace the line from the pump to the accumulator. The accumulator on my 79 looked like yours, I wire brushed it (lightly) primered it with rust oleum, and painted it. Good luck, and keep posting. I am in the middle of repiping the fuel systems on the 79 right now as well. Already done it on my 78 and my 82.
Last edited by AirtekHVAC; 09-16-2017 at 11:02 PM.
08-29-2017, 10:28 AM
