fuel injection pump

[n/a]

Hi Guys, I just had my injection pump replaced. My car was dumping fuel into the oil, hence the replacment..

Before the pump was replaced the car would start on the first crank and would run great. The car would run wonderful in town and under 3000 rpm.. The car sounded like it was working very hard at 3000 rpm....

Now the car runs awful under 3000 rpm and runs beyond my expectations above 3000rpm  the car purrs at 4000rpm. some times when you are trying to speed up it spitters and sputters a little then clears up.

the car will not start without a lot of cranking and several tries when cold.

any thoughts on what to do next... I like some of the new things but would rather have it the way it ways...



Rick Payton
1968 280SL

[Douglas]

replaced the injection pump? that must have cost a pretty penny. why didn't you rebuild yours?

Douglas Kim
New York, NY
#11304410018260

[rwmastel]

Rick,
I'll bet that you will have to troubleshoot from the beginning because your old FI Pump may have been tuned to compensate for some other problem or poorly adjusted component.  See Tom Sargeant's excellent writeup on checking your linkages at http://index.php?topic=160 as this should be step one.

Rodd
1966 230SL Euro
1994 E420

[Cees Klumper]

On FI pumps in general - common opinion seems to be that the FI pumps used on the W113 rarely fail and will go for many moons. So before you buy a new FI pump (very expensive) or go through the expense of having it rebuilt (generally also very expensive), it may be worthwile to get a properly stored used one that is correct for the engine, and trying it out.

Also, check out the Technical Articles on the FI pump and related troubleshooting - there is a great deal of relevant information already there.

[Tom]

It sounds like something other than the FI pump-I think Rodd is correct-you may have had adjustments made to the old FI pump or linkages to compensate for the FI pump issues.

Best,

Tom

[ja17]

Hello rick,
Can you give more details on the replacement. Was it a factory new, factory rebuilt, good used, aftermarket rebuilt injection pump?


Joe Alexander
Blacklick, Ohio

[n/a]

Hi Guys,

The shop replaced the FI Pump with a good used pump.  This seems to be working fine. I had the cars timing advanced a little....This made a BIG difference. The car runs much much better. I still have a little problem with it cold starting but not that bad.  The next thing I am going to do is have the ignition system replaced to one of the Crane systems...  I will keep you all posted on the cars progress...

PS I have my original pump... Who would you have rebuild it? I would like to some day have it put back on for originality sake.

Rick Payton
1968 280SL

[Tom]

Rick,

Hans at H&R Fuel Injection in Bohemia, NY (Long Island) rebuilt mine and did a nice job.  You are right to want to re-install the original once rebuilt, as you will know that the correct one is installed.  Also, Hans will be able to tell you if that pump had been rebuilt in the past.  It is a common practice for the rebuilder to etch a code into the metal denoting where the pump was rebuilt.

Hans is at H & R Fuel Injection Ltd (631) 589-1600

Best,

Tom

[n/a]

Tom,

Thanks for the info... I called Hans what a wealth of info.... I am going to take my pump to him.... His shop is about a half mile from my Cousins house..... What a small world.....  Thanks again

This site is so helpful

Rick Payton
1968 280SL

[Cees Klumper]

As far as cold starting problems, this could be due to improper tuning/operation of the cold start thermostat on your new FI pump. If you look in the technical articles, you will find a lot of information on that particular topic.

[n/a]

re the cold start:- It might be worth looking at the proper functioning of the ignition intake manifold valve (made by Bosch) it might not be working properly.