fuel injection pump seized up

[Cees Klumper]

Taking the pump off is really not that big a deal so don't be afraid to 'go there'. Just make sure on re-installation you line up the markiings as explained on this forum. Good luck, almost there!

[travellerdogs]

Thanks Joe, am going to take your advice. Your opinion and advice is much appreciated. Will post the results on the outcome. Carey

[travellerdogs]

Thank you Cees, didn't look at the name. Am gonna take the pump off. Just seems too much hassle trying to work around all that equipment and I would like to get a better look at the inside where the plungers and rack is and how it operates. I'm assuming I can make a gasket for the side cover. I have all types of material for that. The local MB dealer is a distance from me and usually slow as most parts have to come out of Toronto or Germany. Thanks. Carey

[ja17]

The gasket is a rubber o-ring type material. It can be re-used bu,t as usual, best when new. The two support brackets on the rear of the IP are a can be a bit of a challenge to dis-connect.  Removing the main  fuel filter canister will help access the lower IP flange nut.

[travellerdogs]

Hi Joe, finally got IP off. Took me more than a couple hours and I have a hoist. Had trouble getting the valve cover off as it was not clearing the hood latch on the firewall.  Had to loosen off the trans mount bolt and jack the trans up to get the cover to clear the latch.  I had the car up and cleaned the marks on the harmonic balancer and marked them with white paint TDC and 20 ATC and then watched the #1 intake and exhaust cam lobes. They were up off the valves for compression and the #6 lobes were down on the valves for intake along with the distributor rotor at #1 on cap. . When I finally got the IP off it looks like the gear is off one spline on the IP cam gear. Not sure how critical that is but will try to turn engine back a degree to make them match.  After watching the hoist lifting the car I see the motor and whole drive train dropping with the suspension.  I learned that earlier last week  when I had problems with the linkage on the trans jamming on the skid plate when I put a new bushing on the shifter shaft on the trans. When I let the car down on its four wheels everything then worked with lots of clearance for the linkage as well as giving me lots of clearance for the removal of the valve cover.  I'm learning a lot as I go along. Now on to the pump. I have it on the bench, the pins are in place as they are pinned in place with a fine punch on the edge of the hole so they cannot come out. I pulled #2 cylinder out with a magnet, took a look at the cylinder and looked down the bore, I observed the pin protuding into the bore. I dropped the cylinder down and got it to drop over the piston. When I move the rack it is  not spinning but it wants to push up. I figure when the check valve is installed and the fitting torqued down it will be unable to lift, am I right? #6 also wants to lift and rotate but I got it seated also. I am going to tap the pins in a bit and pin them with a punch on the two that are lifting. I think I got this thing figured out so far. Everything looks good and moving freely. Pistons rotating and pumping up and down freely.  I am going to make a new gasket for the end of the IP at the block just for insurance. The rubber gasket looks usable on the side plate, would like a new one if it were available. Gonna wash everything out with varsol and alcohol and clean it all up and reinstall the side cover. Hope it works.  I'm going to check the solenoids by putting 12 volts to them and go over the CSV solenoid and take the fitting off as advised and check the screen and valve for movement. I damaged a trans cooler line at the radiator when I left a wrench on the power steering pump used to turning the engine over manually. Then hit the starter later and forgot the wrench on the pump, it jammed on the rubber cloth line to the bottom of the rad. Tomorrow I will look at this all with fresh mind and see where I got from here. Till then, will keep you guys posted, Carey

[ja17]

Hello Carey,

Yes, when the check valves are in place the cylinders on the IP will stay put. You may want to tap all the pins a bit. If everything is moving and free, you should be good to go. The injection timing is not super critical, just line up  the marks on the pump and return the engine to 20 ATDC. Best to always turn engine in normal rotation, so you may have to turn it two revolutions if you are past 20 ATDC now.

The transmission oil cooler lines are low pressure. In a pinch, you can skin the metal crimps off the old line and re-use the fitting with new stock fuel line hose clamped to the fittings. This is a good emergency or temporary fix. Do not use stock water hose.

The Sub-frame mounts are most likely bad on your car, allowing the front suspension to drop too far when the car is lifted with the suspension dangling. This is a project for another day.

Good luck, keep us posted.

[travellerdogs]

Hi Joe, will try to fix that trans cooler line, got lots of fuel line here in stock. Several of the  cylinders in the IP seem to have a bit of sideways slop in them, is that normal? This pump has been off the car previously as I noticed a few things that were not just right, looks like homemade gasket on pump end and other things. My experience on working on cars I usually can tell if something has been removed previously. The BBB says the car must be resting on all for wheels before doing any linkage adjustments so there is probably some movement of the drive train when  you lift the car. When I did the linkage I dropped the car on 4 big aluminum car rims and then climbed under the car and hooked up the linkage and also checked to make sure I could shift into all the gears. Subframe bushings are probably bad as the car has just over a 100K on the odometer. I have other later SL's so am familiar with the bushings. Thanks for the input, Carey

[ja17]

Yes, a bit loose is ok, since the fit of the cylinders in the outer IP housing is not that precise.  The fit of the IP pistons (plungers), in the IP cylinders, is very precise and is measured in millionths of an inch! It is so precise that no seal or piston ring is used on the IP pistons (plungers). The seal is made by engine oil which is fed into a circle groove in the cylinder wall. The metal oil line attached to the back of the IP delivers the oil to the IP cylinders from the engine block. 

[w113dude]

Yes, a bit loose is ok, since the fit of the cylinders in the outer IP housing is not that precise.  The fit of the IP pistons (plungers), in the IP cylinders, is very precise and is measured in millionths of an inch! It is so precise that no seal or piston ring is used on the IP pistons (plungers). The seal is made by engine oil which is fed into a circle groove in the cylinder wall. The metal oil line attached to the back of the IP delivers the oil to the IP cylinders from the engine block. 

I would have loved to be present at the time of designing and engineering this pump in Germany, what a precise piece of equipment.

[travellerdogs]

I got a couple questions. First, how critical is the torque specs on the IP fittings that hold the check valves down. My torque wrench is a half inch drive Snap On but it is an older unit and could be out of calibration. I have a new inch pound one but it only goes up to  200 inch pounds and converted that is just over 16 lbs. Tech article says 21.7 foot lbs. It has to hold the check valves down and seal them. Sounds like I read here that the line fittings then are torqued less that the check valve fittings. Makes sense as the check valve fittings would not have to be held when tightening the fuel lines. Next: How much oil do I put in the side cover before buttoning it up.   Also if the engine turns CCW then that would make the IP pump turm CW as it runs off the cam that also turns the Distributor. Just want to make sure for when I install the IP for timing purposes. Appreciate some input on these issues. Thanks. Carey

[Benz Dr.]

I guess you need a 3/8 torque wrench.

 The pipe fittings should have small blocks on them that prevent the fittings from turning loose. If they're not on your pump, someone probably removed them. I'm thinking the specs are important for this job. IP's are sensitive to things being done right.

Don't worry too much about filling the pump with oil because it will fill from the engine as it runs. The pump turns in the same direction as the engine, which is clock wise. Always turn the engine in this direction while doing any timing related precedure.

[ja17]

Hello Carey,

If you torque the fittings too much, you can crack the IP housing. Too loose and it may not pump at all.

The pump turns the same direction as the engine.

[travellerdogs]

Thanks Dan, got a proper torque wrench coming tomorrow. Also I marked the gear in the block where the IP mounts and watched it move. It goes CCW with the engine. I'm working alone here so I have to climb up a ladder to the engine when car is on hoist. Lots of up and down ladder. I saw the litle blocks on another blow up of an IP. Wondered about them. Everything is coming along pretty good, got the injectors soaking. Still lots of things to check. Going to torque the fittings and install the pump. My timing chain is loose and the top shoe is worn. Should the chain tensioner tighten it up when the engine is fired up. Gotta look in manual to see how the setup is. I got the engine exactly on 20 degrees ATC. Thanks, Carey

[travellerdogs]

Just wanted to clarify a point. I am looking to front of car when under the hood and that is why I say the engine is turning CCW. I should be standing in front of the car and then the engine is turning CW. All depend where you're standing. My mistake. Carey. Not used to working on cars with the hood hinged from the front.

[Benz Dr.]

When ordering parts you should always state which side of the car you are talking about from the seated postion inside the car. When working on the engine you generally refer to things from the front of the block.

[travellerdogs]

Thanks Dan, I usually am sitting in car when ordering parts for cars. Drivers side is Left, Passenger side is right. I screwed up on the rotation looking from the car seat. I got the IP check valve fittings torqued to 20 ft lbs, I,m used to working on old bikes so I don't strip to many threads. I understand that overtightening could crack the housing. So for ordering engine parts you're saying the opposite applies? Carey. 

[Benz Dr.]

No, not really. If you were to order a motor mount it could be LT or RT as seen from driving position.

When it comes to the engine, you would still be ordering LT or RT valve cover gaskets on a 450SL as seen from seated position. This is where it becomes a bit different because number one piston is always at the front of the engine and on the right bank on a V8. Because you might be turning the engine over by hand, and you would be standing in front of the engine while doing this,  it's stated as clock wise. So I think that for the most part, we are really only talking about engine rotation while mostly everything else is stated from driving position.



 

[travellerdogs]

That's where I find it a bit confusing. All the years working with chevy small blocks that is how I did things. Guess I should continue doing that. Thanks, Carey

[travellerdogs]

Hello Joe, I got the car running. Put everything back together. Followed your instructions,got the fuel up at the pump, then got it at the injectors. Went over all the solenoids, CSV, Soaked injectors in Carb cleaner then alcohol for a few days. It fired up on the first turn of the engine and ran and idled. Now for fine tuning. Thanks, Carey

[ja17]

Congratulations Carey!

Keep us in the loop while your doing the tuning.  Learn what the split linkage CO test is all about. That will help you along.

Joe Alexander (ja17)
Blacklick, Ohio

[71Blue280SL]

This thread was great.  My SL had, due to my own neglect, been sitting for years, and the injection pump gummed up.

Drained the tank, followed the directions on this thread to "tap" the cylinders/pistons free, soak with alcohol and Liquid Wrench, and it fired up last night!  Took several days of soaking and tapping, but I was so excited I did not have to take the pump off the engine. 

Other than to say thank you, I wanted to pass the tip that I used a quick release air nipple (like you have on the end of an air-ratchet) to screw down on the check valves as a removal tool.  Threads on easily and provides plenty of bite to pull out the valves.

Now I am back to working on the car for the reason I parked it - the IP is gushing oil from, I believe, the lower rear corner of the inspection plate.  I hope it is just tightening down the plate or replacing the gasket, and not from between the IP piston housing and the back half.

[Garry]

Now you just need to do the Split Linkage Tour and you are away.  

Join as a Full Member and you can access that area in the Tech Manual.

[Shvegel]

450SL,
I usually store injection pumps by pumping automatic transmission fluid through them then capping the inlets and outlets. They actually make a storage fluid to do this as well.

[71Blue280SL]

Well the car runs great, but oil is indeed leaking from the bottom corners of the inspection plate.  I pulled it off, put gasket seal on both sides, and reinstalled.  I let the gasket sit for a day, and it did not leak on the next run.  However, it has started leaking again from the front lower corner of the plate.

My engine has less than 1000 miles on it since being rebuilt (and the pump replaced) and it started leaking about 500 miles after the rebuild.  Is the IP getting too much oil pressure?  The leak is big enough that you can see the flow of oil dripping off the IP.

The car runs great, and the leaked oil does not smell like gas.

Thanks.

[garymand]

I think I noticed early on you said the cover plate was leaking.  It really shouldn't.  take a look at the picture: http://www.sl113.org/wiki/Fuel/Injection
The pumps have an oil input under pressure, but no visible outlet.  The outlet is at the gear drive flange of the pump.  There is a spillway hole where the oil overflows the spill way and flows into the chain gallery and down into the sump.  That hole has to be open.  The hole is shown clearly in a pic.  If the gasket is rotated, the hole would be blocked.