I don't think I am getting enough fuel pressure to #1 cylinder on my 1980 240D!
When the engine is running (on three cylinders) and I loosen the pipe to the #1 injector, fuel weeps out. When I do this to a cylinder which is firing normally-it really spueals out past the threads on the pipe threads. So I figger there is not enough pressure to fire this cylinder. Make sense?
I pulled the pressure valve at the inj pump and replaced the brass washer, cleaned everything etc. Also I pulled the whole pressure valve unit out of the pump and inspected the o'ring (OK), and reinstalled everything.
What else would cause low pressure to the injector?

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

I had an injection pump (IP) like that on a 190D. Only fix was to take the IP to a Diesel IP shop and get it fixed.

P E H

Well, I think I found my difficulty! When I was switching around different injectors in #1 hole, I apparently forgot to put back the injector seal in the bottom of the hole, and I was loosing the seal on the injector! So, if there is no seal on the injector, there is no pressure built up against the pintle valve, and therefore not enough pressure to fire the fuel into the cylinders compressed air.

Hoo Boy...

Now that cylinder fires, but only above 2000rpm

Tomorrow I will double check my valve adjustment. Seems somewhere I read that it can change rather quickly if the car had seen years of in-town driving and then run on the highway for 500 miles? Like my trip to Lake Tahoe?

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

I have seen injectors bench tested for spray pattern and leaks and there is no force against the end of the injector. The spray end of the injector is just in the air with a high pressure line connected to the fuel input end. The seal in the bottom of the hole is there to prevent the combustion pressure from leaking gas past the injector.

You can do a spray test of sorts yourself by removing the injector. Then loosen the injection line and turn it around so you can reconnect the injector so it hangs in the air. Then crank the engine with the starter and look at the spray pattern. Do a couple different injectors and couple different elements of the IP.
Make sure you crack the other the injection lines so the engine doesn't start.

Did you do a compression test? If the compression test shows the #1 cylinder is about the same as the others, I think the problem is in the injection pump (IP). A Diesel IP shop should check it out for you and give you an estimate. They might have to only fix the #1 element in the pump. Mark the IP and the mounting boss before the IP is removed so the timing won't change when you replace the pump. A chisel punched line will do. Don't rotate the engine until the IP is replaced.

Usually a bad injector will not cause a missfire because they always inject fuel but they leak and inject the fuel early and the engine knocks. But if the IP doesn't develope enough pressure (about 1500 PSI) to pop the injector open the engine will missfire.

P E H

P E H

hmmmm. So it is either low compression, or low pressure at the IP?

I have purchased a Compression tester at Kragens which reads to 300psi. The only place I can check with this tool is the glow plug hole, since there is not a large enough adaptor to use it in the injector hole. Will know tomorrow.

I checked the timing chain for stretch and it looks like I have about 6 degrees retard at the balancer. I also noticed that the crank can move before the cam moves, which would indicate a strecthed chain?

Took it for a test drive today and it runs along okay on four, no smoke, but it seems like it surges.

Oh well, for $200 what do you expect? It is such an enjoyable car to drive! New paint, new interior bits like headliner, and door vinyl, 138K on the clock. The engine is from an '82 of unknown mileage. I replaced the intake and exhaust manifolds with period pieces, thus eliminating the EGR stuff.
The biggest bugaboo was the altitude vaccum pot was leaking oil up from the pump and wouldn't hold vaccuum. This prevented the engine from revving up properly. The dealer wanted over $220 for it!! So I sourced a used pump from my local PNP for $22 and switched pots. Much better!!
Easy to do too, but you can't just unscrew the pot because the vaccuum hose connection will foul the bracket for the trans vaccuum switch, so you just unscrew the large bottom nut which is captive on the mounting plate while holding the vac pot still.

I have included a pic taken from Helgas command postion, running along Hwy 50 at Lake Tahoe, showing the quaking aspens in full song in November.

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

ED,

If your cam timing is 6 degrees late, you should replace the timing chain soon. Three degrees late is supposed to be the max. If the crank moves before the cam it means the chain adjuster in not doings its job. This could be because it is defective or has reached its limits because of a worn chain. Feel the chain on the passenger side of the engine. there should be no loseness. If there is, you are asking for trouble: the chain could jump a link and that can cause catastropic failure when the valves hit the pistons.

I know a lot of people call it chain stretch, it isn't a stretch like a rubber band. The pins and bushings in eack link of the chain wear slightly. The cumulative effect of this is that the chain becomes longer and the timing of the IP and the cames gets later.

Let me tell you a story about my 300SD. In 2000 I planned a cross country trip to the west coast. It was almost time for a valve adjustment so decided to do it befoer I left. When I removed the valve cover I could feel that the chain had a lot of loseness even though the cam timing was only about 2 degrees late. The problem was that the chain tensioner was stuck and was not keeping the chain tight. So I replaced the tensioner. I could just see the chain jumping in the middle of the desert and breaking the cam and cam towers and bending the valves.

You practically got that car free so you shouldn't mind spending a few bucks on it. I bought a "parts" car for $1200 3 years ago and its still running and I expect it to go 3 more years.

P E H

PEH

Thanks for that info!
I did notice that the tensioner had apparently reached it's limit, and it didn't seem stuck-I could easily move it in and out by prying on the chain with a screw driver.

I suppose this "stretched" chain could account for the slight surging Ifeel when on the road?
And it could certainly contribute to low power.
I know what it's like on a gas engine with a worn chain,-lots of pre-ignition and poor power.

I have about$250 in parts into it now, so it would be worth it to put a chain on it if the compression is okay.

I know that the 240 is going to be slow, but I don't think Mercedes would make a car this slow
I mean, this is ridd-ic-alus!!

__________________
Ed
1981 300CD (Benzina)
1968 250 S (Gina) 266,000 miles!
1983 Alfa Romeo GTV6 (Guido)
1976 Jaguar XJS-saved a V-12 from the chevy curse, what a great engine!
1988 Cadillac Eldorado (better car than you might think!)
1988 Yamaha Venture (better than a Wing!)
1977 Suzuki GS750B
1976 Yamaha XS 650 (sold)
1991 Suzuki GSX1100G (Shafty Gixser)
1981 Yamaha VX920RH (Euro "Virago")
Solex Moped
1975 Dodge P/U camper


"Time spent in the company of a cat, a beer, and this forum, is not time wasted!"

You think the 240D is slow. I started with a '59 180D that had a whopping 36 HP. It had a push rod engine and blew out a head gasket every 500 miles. I got tired of replacing the head gasket so I got a 190D and junked the 180D.

Change that chain ASAP. It isn't a difficult job but will go easier if you have 3 people when you feed the new chain thru. I think you can find the procdure here by doing a search . A new chain should give you more power but don't expect too much more.

You have to go to a turbo to get enough power. Once I got a turbo, I didn't want to drive the non turbos any more. I have 4 turbos now.

P E H