Pagoda SL Group

W113 Pagoda SL Group => General Discussion => Topic started by: mauro12 on May 28, 2019, 11:00:02

Title: Injection pump and fuel injectors
Post by: mauro12 on May 28, 2019, 11:00:02
Hello guys, I wanted to ask you a question regarding fuel injection pump and fuel injectors. How do you know if the car needs an injection pump overhaul rather than new fuel injectors? My car has a rich mixture and a poor gas mileage ( about 14mpg) . Im thinking to buy 6 brand new injectors in the hope to solve the problem but at the same time I’m scared that my injection pump has to be calibrated . I would like to spend the right money for the right think.
Any suggestion ? Thank you
Title: Re: Injection pump and fuel injectors
Post by: ja17 on May 28, 2019, 15:33:06
Hello Mauro,

 It's difficult to guess what issues you have without analyzing the whole situation. Does the oil level in your IP continue to rise? Have you done the "linkage tour". You can have your injectors tested and possibly cleaned. Have you checked the fuel mixture with a meter or the "split linkage test"?
Title: Re: Injection pump and fuel injectors
Post by: MikeSimon on May 28, 2019, 16:19:40
I am not sure that your problem can be blamed on the injectors. These are not "unit injectors", they are just nozzles. They can be plugged or they can drizzle, and can cause poor performance and response but I don't think they would be the cause of poor fuel mileage or a rich-running condition.
Title: Re: Injection pump and fuel injectors
Post by: mauro12 on May 28, 2019, 17:14:44
My fuel injection pump is the r22 model with no oil reservoir ( probably installed from the previous owner). Has always worked fine with normal fuel consumption and emission within the limits. Some years ago i started to have some rich mixture conditions with black smoke in acceleration and a slow increase of rpm. This problem was partially solved with a full cleaning of the injectors, power of the car now is ok with good acceleration . The only thing i cannot figure out is the high fuel consumption but im convinced that is a mix between wrong calibration of the pump ( probably worn out parts) and a not perfect spray pattern of the injectors. What's the average cost of a complete service on our inj pump?
The ignition of the car is ok as the linkages and i recently had a full service of the throttle body.
Title: Re: Injection pump and fuel injectors
Post by: Shvegel on June 07, 2019, 11:20:50
Last number I heard from Hans at H and R was $1750 for the pump, check injectors and cold start injector.  Speaking of that start the car and remove the tiny hex bolt from the side of the cold start injector.  If fuel leaks out it needs repair or replacement.
Title: Re: Injection pump and fuel injectors
Post by: Cees Klumper on June 07, 2019, 11:44:48
I also think it might be something relatively simple, such as a worn barometric compensator or the cold start valve leaking. I just recall experiences of members who had their pump overhauled, only to find the actual problem was elsewhere. So it's worthwhile to check the other possibilities first. There are of course reputable rebuilders in Europe, probably referenced in other threads here.
Title: Re: Injection pump and fuel injectors
Post by: Shvegel on June 07, 2019, 14:51:33
I didn’t spend a ton of time around Hans but I did hear him on the phone telling a number of people they didn’t need him. Having rebuilt my own pump I can tell you the way they are built it is nearly impossible for it to slip out of calibration. 
Title: Re: Injection pump and fuel injectors
Post by: Benz Dr. on June 07, 2019, 15:23:48
I find that pumps tend to go rich over a long period of use. This might be fuel injectors or leaking cold start valve or the pump. So, it may not go out of calibration, but small amounts of wear can affect how they work seeing how they're very sensitive to any kind of adjustments.
Title: Re: Injection pump and fuel injectors
Post by: mauro12 on June 09, 2019, 11:50:06
My CO at idle is around 9%, so is by far too high. Consumption about 14mpg. The csv is ok and linkage too. I don’t know if to buy 6 new injectors and maybe solve the problem or send the pump  and injectors to a specialist and have them cleaned and calibrated. Would be a pity to buy new injectors and instead I could gain the same result with a good ultrasonic cleaning process.
Title: Re: Injection pump and fuel injectors
Post by: Derm Cain on July 01, 2019, 05:08:54
Had issues with my pump last year.  I have been around at lot of, mostly fuel injection, test benches and experienced people over the years.  H&R (Hans) has a great facility and knowledge.  Excellent service and reasonable pricing. 
Title: Re: Injection pump and fuel injectors
Post by: lowpad on July 01, 2019, 22:05:36
I don’t believe that Hans is involved with H&R anymore. I’ve dealt with Marty Neubauer there.  He has extensive testing equipment and helped me with my cold start injector.  He’s all set up to test injectors.  You can reach him via FB. 
Title: Re: Injection pump and fuel injectors
Post by: Benz Dr. on July 01, 2019, 22:52:56
I don’t believe that Hans is involved with H&R anymore. I’ve dealt with Marty Neubauer there.  He has extensive testing equipment and helped me with my cold start injector.  He’s all set up to test injectors.  You can reach him via FB.


Hans went to the great injection pump in the sky a while back. I believe Marty is his step son.
Title: Re: Injection pump and fuel injectors
Post by: lowpad on July 02, 2019, 23:13:42
When I was there a few months ago, he was busy as heck, which is encouraging for such a specialized business.  Apparently Hans left him an attic full of pumps ...
Title: Re: Injection pump and fuel injectors
Post by: perry113 on July 06, 2019, 15:12:43
I just had my injection pump rebuilt on my barnfind 1966 230SL 4 speed. I sent it to Robert Fairchield. He fully serviced the pump and checked the injectors and cold start valve and solenoid.
I also had him rebuild my 1965 230SL automatic and 1963 220SEB coupe's injection pumps. No issues whatsoever.
His work and pricing are very good but at the expense of a somewhat long turnaround time.
I would say his pricing is half of what the handful of other other specialists are.
Title: Re: Injection pump and fuel injectors
Post by: Shvegel on July 08, 2019, 01:55:36
After I rebuilt my pump I had Hans run it on the dyno and set it up for me.  Once I showed him how interested I was in the pumps the gates opened and he took me on a tour of the shop.  Besides the average everyday stuff he had quite a valuable array of pumps on the shelf for sale.  Early 911's, BMW 2002 pumps and even 2 300SL pumps.  Even at his advanced age and frail condition he was very excited about sharing what he knew. 
Title: Re: Injection pump and fuel injectors
Post by: mauro12 on August 01, 2020, 14:31:22
Hello guys, probably this September I will convince myself and get my injection pump to overhaul . The car is running great but I want to get rid of this rich running condition and poor fuel mileage. My doubts are regarding the expression : never fix something that isn’t broken and my pump seems to work. I’m pretty sure the wrd is not working well. Probably the injection pump thermostat is still the original one and maybe is broken. I read that to fit the new thermostat you have to drill some holes is it right? The new thermostat is slightly bigger than the old one.
What do you think is an onest price to have a calibration and overhaul of the pump? Thank you
Title: Re: Injection pump and fuel injectors
Post by: Peter h on August 01, 2020, 15:41:06
I would not look at the price first, but whether the result is perfect.

From 1500 euros upwards you have to calculate.

Peter
Title: Re: Injection pump and fuel injectors
Post by: mauro12 on August 01, 2020, 16:01:37
Yes of course , I just wanted to have an idea. Have you gone trough this process ?
Title: Re: Injection pump and fuel injectors
Post by: Taleb on August 01, 2020, 20:26:26
don't waist your time , send it to marty from  H&R for complete restoration will cost you 1700$ I just did my two pumps R20 and R14 ,,,, good luck
Title: Re: Injection pump and fuel injectors
Post by: mauro12 on August 01, 2020, 20:34:40
I found here a local bosch service that has the right equipment to overhaul the pump .i think the difference must be amazing with the pump perfectly calibrated right ?