Pacific Fuel Injection

I've been trying to follow along with your troubles, so I don't know if you've mentioned this or not, but have you tried cleaning, rebuilding, or replacing your injectors first? I've had some shaking and bad low end power in mine, but I think that it is because I have at least one injector that needs to be rebuilt. I did a diesel purge the other day and that seemed to help tremendously. Although my fuel mileage has not improved as much as I'd hoped. If they have been rebuilt, were they pressure tested and balanced? My next big project on my car will be to get new nozzles and a pressure tester and replace the nozzles and balance all the injectors.

Sorry if this has been discussed before. I have no actual info to the topic at hand.

I don't know about charges because I got my pump which was rebuilt by Pacific Fuel Injection Service as a part of a complete engine remanufacture by Metric Motors of Canoga Park, CA. But I can state with certainty that Gus, the owner of Pacific Fuel Injection and brains of the operation stands behind his work and honors his warranty and does what he can to help you get your car working right if there is a problem. He is very patient with answering questions, etc.

Paul Fretheim

Not all, as this specific issue has not really been examined. My engine has recently been rebuilt, but that does not mean that the injectors were rebuilt, and in fact I know that the pump was not rebuilt.

I am thinking that perhaps at this point it would be prudent to take the car to my previous shop and have them examine the entire fuel delivery system and then decide. Rebuilding the pump and/or the injectors is beyond my capability, and I do not want to just start sending out parts for rebuild or replacement without knowing what is actually causing the problem.

Thanks again!

=A0pm, " snipped-for-privacy@mac.com"

Thanks very much. I have been very impressed with the volume and nature of the recommendations that this shop has received. I am planing a Southern California trip soon and may just take the car down there to have it evaluated.

=A0pm, " snipped-for-privacy@mac.com"

P.S. My $5k engine rebuild did not include rebuilding the pump or the injectors, or any work whatsoever on the fuel delivery system, as I would have expected.

=A0pm, " snipped-for-privacy@mac.com"

Thanks very much. I have been very impressed with the volume and nature of the recommendations that this shop has received. I am planing a Southern California trip soon and may just take the car down there to have it evaluated.

Not all, as this specific issue has not really been examined. My engine has recently been rebuilt, but that does not mean that the injectors were rebuilt, and in fact I know that the pump was not rebuilt.

I am thinking that perhaps at this point it would be prudent to take the car to my previous shop and have them examine the entire fuel delivery system and then decide. Rebuilding the pump and/or the injectors is beyond my capability, and I do not want to just start sending out parts for rebuild or replacement without knowing what is actually causing the problem.

Thanks again!

An advice from a super old timer who worked on Mercedes Diesel engines for a long time... wuth a near full tank of fuel, pour in one gallon of premium unleaded fuel and drive until empty.

It will clean up anything that may be wrong with the fuel system.

If I had heard that from anyone else I'd say they were FOS. Have *you* ever done that?

It's a rather strong action. We used to do the same thing. Only we used kerosene.

EJ in NJ

Tiger:

The shop that did my rebuild keeps blaming the injector pump for a host of power and vibration problems, referring to the injector pump as "weak". Does this make sense to you--bearing in mind that the car has only 218K? I will certainly be willing to do the premium fuel if you think that will solve the injector pump problem, assuming that it is a problem!

Thanks!

Along the lines of what Doug suggested, I'd want to know more about the injectors too. We know the injectors were not rebuilt as part of the engine rebuild. Have you asked the rebuild company if they were at least bench tested? How many miles are on them? If they are original, or you don't know the history, I'd start by having them tested or rebuilt first. They are well known for causing rough idle and around 120K is typical life. There are videos online of engines shaking like hell and just changing the nozzles, not even correctly pressure setting them, quiets the whole thing down.

Where is Pacific Fuel Injection located? I was planning on rebuilding my injectors myself, but haven't gotten around to it yet. I'd be interested in giving them a call and find out how much they would charge.

Thanks for that info. Pacific Fuel Injection Service is located in South San Francisco.

Tel. 650.588.8880

I think 218,000 miles is alot on injector. As for injection pump being 'weak,' I would have to say no. The reason is that the injection pump has a specification that it must achieve... so with a diesel fuel pressure gauge, you can tell if the pump is strong or weak.

The injector is also the other 50% of the system. The injector must not release any pressure until it achieved the set pressure release to squirt... so if the injector is 'weak' that releases too early... will cause the vibration that you described... more like predetonation...

As for the gasoline, I have not tried it myself. I thought it was insane too but I got to tell you, I wasted tons of money on diesel injector cleaners to know that it is only a temporary improvement.

The safest way is to use Lubro Moly Diesel Purge technique. But if you rather not get 'messy' to do that job, then go for the gasoline route... if you are scared of 1 gallon then go half gallon.

I have personally met this person. He does not BS you... he has survived WW II as prisoner... he was not in military at all and he has been working on MB since then.

Understood.

I think, though that the gasoline procedure would not result in any improvement in this particular case, because the pump and injectors just went through a very thorough Lubro-Moly cleanse just prior to the engine rebuild. The system probably has around 3,000 miles on it at this point. Prior to the engine rebuild, the old engine purred like a kitten at idle, and that is one reason why I really do not understand this theory that my shop has about the injector pump being "weak"

Nevertheless, I will get started, first with injector testing, and then, if necessary, by sending the pump out for rebuild.

Thanks very much for the help in trying to troubleshoot this annoying problem.

Thanks for the info. I may give them a call and see what they charge to rebuild my injectors. I was planning on doing mine myself. The only big obstacle is you need am injector pop tester and they are expensive. I was in the process of building one myself. I found plans online from a guy that built one using a bench mounted hydraulic pump. I got as far as buying the pump. Got a great deal on a brand new one on Ebay for $50 that would have cost $300 retail.

The only remaining part I may need is an old diesel injector line so that I have a fitting that mates with the injector. The rest is standard fittings, gauge, etc that are readily available. If anybody here has an extra one they are willing to part with, let me know.

Keep us posted on what you find out about your problem. The most curious point you make is that the car ran fine at idle prior to the rebuild. Another question, why was the engine in need of being rebuilt?

It is curious, indeed. The only theory I have come up with is that the changed displacement of the engine may have affected the way it runs, but the rebuilt engine is certainly no improvement over the way it ran prior, and thus to your question, why the rebuild?

I'll try to give a shortened version of the story as it has been posted here before: The engine wouldn't start when cold weather began in the late fall of 2008. I changed glow plugs, to no avail. I was traveling extensively and didn't have time to deal with the engine, and so had it towed to a Mercedes shop I knew nothing whatsoever about (my regular shop is 35 mi. away). This technician conducted a compression test and reported no- or very low compression in all cylinders. It is worth noting here that my long-time shop had done a valve adjustment previously; the work was done by a new employee I had never seen before. The shop that conducted the compression test reported all valves extremely tight. The said an overhaul was necessary. I was out of the country and gave the go-ahead.

Upon completion of the rebuild, the engine was near-impossible to start and had no power. A check of the fuel injector pump showed it to be 180 degrees out of adjustment, so once that was addressed, the engine developed much better power, and I proceeded with the break-in procedure. It ran rough at idle, and I attempted to adjust this out through minute changes to the idle control setting, all to no avail. I took the car back to the shop, and the technician blamed the injector pump, saying it was "weak" and couldn't be properly adjusted. (I would have thought that this would have been checked and corrected in the course of the engine rebuild, but no.)

So, $5.5K later, I have an engine that is hard-starting, only runs smoothly above about 1,000 RPM, and has poor low-end power. The engine will not start at all below 40F unless the block heater has been plugged in. The engine smokes prodigiously at start-up and has one leaking injector.

"So, $5.5K later, I have an engine that is hard-starting, only runs smoothly above about 1,000 RPM, and has poor low-end power. The engine will not start at all below 40F unless the block heater has been plugged in. The engine smokes prodigiously at start-up and has one leaking injector."

Dude! I'd be really pisssed at this point and gone postal! I can relate though... my folks did the same thing to 1984 190E too... that should never have been rebuilt... It did not even run better after the rebuilt by a non MB specialist... and then the tranny died not too long afterward... I had to souce a junk 190E with good tranny and sold it for a loss.

I never use that mechanic ever again. Back when I live away, my folks use that mechanic... every other month need service... always a couple hundreds or so... pissed me off... I came home and nothing need fixed... little thing here and there but no evidence that it needs that much service for all the cars they brought over to that mechanic.

Since I came home, no car ever went into service shop. Those existing car need just a bit of care but no major expense except for one car... that when I came home, it didn't show any major coolant loss... and the engine died because of no coolant... dummy coolant light never stayed on so we didn't know. This was an old caddy.

So we gradually bought new cars and not once went back to service shop other than required new car maintenance or warranty claims.

Anyway Randall... that shop of yours cannot be trusted. I definitely don't trust them from what you said. I don't even trust their opinions. They messed up. Injectors are my bet... and I'd check or hire other guy to double check the valve adjustment.

I think this shows that if you have a shop that you know from experience does good work and is honest, it's worth a 35 mile tow to get the car there instead of taking it to someone unknown.

Randall, I think the other big mistake here was after spending that much money, you should not have been so patient or accepting of what happened. The fact that they even offered the car back to you when it obviously would not run right shows they are shysters. I would have given them a couple of chances to make it right. Then I would have taken it to the shop you usually use, or a MB dealer to get an opinion and then fix it. Then I would have demanded the rebuild guys pay the new bill and if not, take them to small claims court. Assuming that is that you're somewhere they have that venue.

It wasn't exactly clear to me and I'm sure to others of us here, how exactly you got into the rebuild process, who did what, etc. But clearly this shop undertook the process of rebuilding the engine. At that point any customer expects that the car would start, idle, have power, run normal, etc, ie everything that should go with a rebuilt engine. Even if they eventually figured out it needed work on the injection pump too and that was not included, it should have been a simple and not ball busting extra expense. This isn't rocket science.

I think even now instead of focusing on the injection pump, injectors, etc, your best bet is to take it to a shop you know is good, tell them exactly what happened, let them do some basic testing and have them give you an evaluation of the whole situation. That should be a couple hours of shop time and well worth it.