924Board.org

[chaparral2f]

I have owned this car for a year and a half, and have managed to get it to limp almost 60 miles. So far I have changed the injectors twice, replaced the auxillary air valve, rebuilt the WUV, bought a new fuel dist, replaced the air boots and the crankcase breather hose. It has spent time in a local shop (The shop claimed the car had no compression in Number 4 cyl and claimed to have replaced the plugs and wires though they didn't.) I took the car home and ran compression all 4 cyls were between 165 and 170 lb. Today I installed the new fuel dist. Is there a starting point to set the mixture ahd idle as a point to tune?
_________________
If you're gonna be stupid, you gotta be tough.
1980 Porsche 924
1997 GMC Jimmy (DD)
1984 300zx Tube chassis, Jag suspension, 400hp sbc

[joejax]

Hey chap, be sure to go through fuel system thoroughly and clean everything. Reassemble anything taken apart carefully. Clean tank.

Research setting air/fuel mix, you will likely have to start from scratch. Check valve clearances, mine were pretty whacked out causing poor performance.

Make sure top dead center lines up correctly, be prepared to fiddle with ignition timing, a/f mix, and idle at the same time following instructions on your data tag if and when you get it running.

Good luck!
_________________
I got nothin'
Uhhh...you got any pics?

[pmcaya2]

I shudder when people attack the fuel system first. It's usually not the jet tronic injection system, although the plastic air duct can give problems if it has a vacuum leak like mine did - the fuel injection depends on a good vacuum to work.

My 82 924 non-turbo has 190K miles and is one of the most durable sport cars you can own. Most running problems are electrical and might relate to alignment of timing mark/cam mark/distributor.

This is a very helpful forum - could you tell us more about how your car is not running? Have you done anything with the timing belt? Did it run when you bought it? Please provide some general history and symptoms. I'd like to see you driving it when the snow melts. - Peter

[joejax]

Establishing good fuel operation was on the top of my list, everything else seemed to fall into place; vac leaks, timing, etc.

My car would not run good at all with crankcase hose hooked to intake, took it out of intake, plugged intake hole, left hose end open and it runs fine.

I may need to look further into this, it was not connected when I got it, so there could be some hidden issues.
_________________
I got nothin'
Uhhh...you got any pics?

[chaparral2f]

Here is some background. I bought the car with a dead cylinder, brought it home ran compression and leakdown test and found a bad intake on number one. I had the valves ground and replaced the bad valve. I installed a new timing belt, changed the plugs and plug wires. I found the auxiliary air valve was bad and replaced it. I rebuilt the WUV, tested the thermo time switch, checked the vacuum lines, and the vacuum advance on the distributor. I found two leaking injectors and replaced the entire set. When none of this helped, I had the new set of injectors checked and had to replace them.(Luckily they were warrantied) Still there was no improvement so I gave up and took it to a "factory trained" Audi mechanic. He said that there was no compressiion on number 4 cyl. He also claimed that he replaced the plugs and wires, billed me $400 and I limped the car home. The next day I pulled the plugs and found the wires were still marked with the numbers I had put on the boots. When I checked the compression all cylinders were within 5lbs.
I took it next to a shop that had been recomended to me by a mechanic who I have a great deal of respect for. This shop found a cracked intake boot, and a cracked vacuum hose from the crank breather, which they replaced. They tested the entire system and told me that the fuel distributor needed to be replaced. (FWIW these people charged me $200 and put a lot of time and labor into the car.) I brought the car home and pilled the fuel dist. and sent it off to be rebuilt. That's where it stands to date.
Next I am going to follow joejax's suggestion and clean the fuel tank if I can figure out how to clean it without pulling it.
_________________
If you're gonna be stupid, you gotta be tough.
1980 Porsche 924
1997 GMC Jimmy (DD)
1984 300zx Tube chassis, Jag suspension, 400hp sbc

[joejax]

I cleaned mine out fairly well by disconnecting battery, removing fuel sender, and removing in tank fuel pump. It's best to wait until tank is nearly empty.

Be prepared for a big stinking, dangerous mess. I poured clean gas through hole sloshing it around trying to get build up out. I reused the gas by filtering through a tee shirt.

I used a rubber hose on a funnel to try to reach all areas. Got about enough stuff out to fill a 2 liter bottle half way. The best way to clean it would be to drop it, however difficult that would be.

Have you tried running with the crankcase hose not hooked up? It may be worth a try, however controversial that may be.
_________________
I got nothin'
Uhhh...you got any pics?

[chaparral2f]

joejax
I haven't tried unhooking the crankcase breather but I will this afternoon. The prosess you used to clean the tank is about what I had in mind because I think I would rather be beaten with a baseball bat than having to pull the tank,
Thanx
_________________
If you're gonna be stupid, you gotta be tough.
1980 Porsche 924
1997 GMC Jimmy (DD)
1984 300zx Tube chassis, Jag suspension, 400hp sbc

[joejax]

Hee hee, Yeah, don't look like fun. Whatever you do just be careful with gas. I got it pretty clean this way.

Now struggling again with a hot start problem and a bad vibration at highway speed, just changed tie rod ends. Starting to think my alignment is beyond home remedy.

I have not figured out reason for problems with hose connected, had researched awhile back but moved on to other problems. Been running OK.

From what I remember, it was not a big deal, some people were saying put hose into catch can to prevent a mess. I would need to try to research more for a final analysis.
_________________
I got nothin'
Uhhh...you got any pics?

[bkantelis]

Having done this on two separate cars, this worked best for me:
1. Disconnect Battery
2. Remove in-tank fuel pump and drain tank
3. Get 2 gallons of denatured alcohol
4. Take the first gallon and run it through the tank several times 5-6
5. Set aside 1st gallon and repeat with second gallon (fresh batch)
6. Run a gallon of gasoline through a couple of times.
7. Make sure the filter is clean on the in tank pump, carb cleaner will get the gunk off of it.
8. Button it up and do not forget the gasket on the fuel pump.

Note: If the car has been sitting many years, go to the local hardware store and purchase a 1 gallon plant sprayer. The kind you pump up and then spray. Remove the gas guage sender from the top of the tank and use the sprayer with the alcohol to spray all around the inside of the tank. I also would put a rubber plug in the fuel pump hole, and let the alcohol sit there for an hour or so.

Be sure the area is well ventilated!!!!
Hope this helps
Regards,
Bruce
_________________
1979 NA 924
Georgia, USA

[chaparral2f]

Yesterday I pulled the in tank pump and found the sump had a lot of crap that looked like a disintigrated plastic pot scrubber. I used a spoon and then a bottle brush to scoop out as much as I could. Then I flushed it with gasoline through a tee shirt until no more junk came out. I'm going to get a new fuel filter for it this afternoon then recheck the system (again). I'll post if it works, and if it doesn't just look for a large mushroom cloud with a Porsche emblem over southern Oregon. Thanks for all the help and good advise.
_________________
If you're gonna be stupid, you gotta be tough.
1980 Porsche 924
1997 GMC Jimmy (DD)
1984 300zx Tube chassis, Jag suspension, 400hp sbc

[Joes924Racer]

I only shudder a little when i think of this task. one really idealy have to get a cis pressure tester first. I replaced my wur and car ran great. Its not
legal right now though i keep the gas fresh. I pulled the tank and resealed it once .. by just pulling it out after loosening the tranny mounts. Its a chore.

I need to flush the tank a few times to see what comes out because a few days after taking this vid. I start it up it sounds like its on 3 cyl.i check the plugs and dizzy cap and wires ..( new cap plugs and armature. So i need
a tester maybe. You can get
tank reseal kits at motor cycle shops though if you encounter rust..


http://youtu.be/8fMG42G9CbQ
_________________
1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

[joejax]

Hey chap, any luck? Be sure to try it without the CC hose attached to see what happens. I was also remembering how bad I was running using cheap gas.

Started using 93 octane from Chevron again with a noticeable difference in how it runs, won't run so good even with the mid-grade stuff, but that's just mine so I don't know.
_________________
I got nothin'
Uhhh...you got any pics?

[chaparral2f]

The fuel dist came back, and is installed. Checked the pressure from the fuel pump It reads 125 lb. I next tested the system pressure it also was 125 lb. So next I removed the fuel pressure relief valve and took ALL the shims out, still no change. Everything in the system has been replaced, rebuilt, or cleaned.
The only thing the car is lacking is the FUEL ACCUMULATOR. Is the accumulator in any way responsible for the high pump pressure? If it isn't what suggestions does anyone have?
Thanx, Joe
_________________
If you're gonna be stupid, you gotta be tough.
1980 Porsche 924
1997 GMC Jimmy (DD)
1984 300zx Tube chassis, Jag suspension, 400hp sbc

[Ozzie]

how about a blocked fuel return line?
_________________
Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[joejax]

Accumulator is to keep pressure on system during off periods to assist in warm starts, I am in need of one for my hot start problem.

I'm sure you have read this thread, http://www.924board.org/viewtopic.php?t=36429, in which ideola has linked a very informative thread about the CIS.
_________________
I got nothin'
Uhhh...you got any pics?