As a minimum, plan to replace the rubber seal around the pintel (tip of the injector). When you pull the injector out of the holder that seal will not seal again if it is more than a year or two old. There is a large rubber cushion ring under the metal collar which retains the injector. If that ring is old I would also plan for its replacement. There is a rubber O ring between the base of the injector holder and the head. If you do not disturb the injector holder replacement of that O ring is not necessary.

Have a close look at the bolt which holds the injector holder on the head. If the injector holder is sandwiched between two phenolic washers then the engine has been retrofitted with the kit to improve hot restarts. D jet equipped engines have a problem with hot engine restarts on hot days. If you don't have those washer and you live someplace that gets hot, you might want to consider installing them on all 4 injector holders. When you do this, you need a fatter O ring under the holder. This diagram shows the phenolic washers (#38a) and the revised O ring (#38)

and this shows the part numbers.

I don't know why there are two part numbers for 38. The footnotes have no explanation. A lot of vendors used to sell up date kits with all the correct parts; but, I have not seen those lately. All the parts are available individually, you just need to figure out which part for 38.

If you email HiPerformance Auto Service in Torrance CA they can probably tell you what the correct part number is and can probably supply you with the washers, O rings, pintel seals and the big rubber O ring as a package.

Replacement Bosch injectors are expensive. The Beck Arnley 158-0438 injector is an exact replacement for the Bosch 280 150 036 injector. Rock Auto has them for something over $50 US$. You can send your injectors out for cleaning as an option - RC Injector Service has a good reputation. If original the rubber stub hoses on the injectors will probably be toast and should be replaced.

When reassembling, apply dielectric grease to the pintel seal and the rubber cushion under the retaining ring. This will make things go together easier.

Remember to carefully bleed off fuel before removing the injector. Depending on the condition of the fuel system it may retain pressure and you will end up spraying gas all over the place if you just yank the injector off the fuel rail. Be careful when removing injectors from the fuel rail. The hose stubs tend to stick to the metal tubing and if you are careless you can bend the fuel rail tubing trying to get the injector off. If you kink the tubing you are royally screwed and may have to fabricate a new fuel rail.

 

Thanks 142. I will send all of the injectors to MotorWestPerformance for cleaning, filter. pintle shield. flow test and new hoses. I don't want to pull the cups. This is my first time pulling injectors. After bleeding, do pull all of them with the fuel rail and then remove them from the rail?

 

How do I remove the lock?

 

My 1971 has the earlier rail design with the fuel feed and connection to the fuel pressure regulator at the firewall end of the rail. This provided quite a bit of flexible fuel line to flex which allowed me to carefully pull up the rail without disconnecting the supply and return fuel lines. I would start at #1 to pry a little of the hose off the #1 barb, move to #2 and pry and then move back to #1 and pry it up some more then move back to #2 and then #3 and so on with #4 being the last injector to come off. I ended up with the fuel rail hanging with the supply and return lines still attached.

I think your 1972 may have the center mount fuel regulator? If so, then I might be inclined to disconnect the fuel supply, return and cold start injector lines from the rail and remove the rail and all 4 injectors as a single piece, then carefully pull the injectors off of the rail.

If the pintel seals are original, chances are that the seal will stick in the holder and the injector pintel will stick in the seal which means that the injectors may not come out willingly. Start pulling a bit on injector #1 to get it loose then move to #2 and then #3 and #4 and return to #1 and repeat, the objective being to gradually remove all 4 injectors at the same time with the rail. Reefing really hard on one injector is when you can get a sudden release and a bent fuel rail. Of course, you may find that the pintel seals have completely dried and shrunk in which case the injectors may lift out easily.

 

i figured out the locks and have the injectors out. I really appreciate your help.

 

The reason there are two part numbers for 38 above is this: There is a retrofit for the Item 35 Injectory housing mounting scheme due to hot start issues. Early cars(no idea how early) used Item 38, a thinner P/n 960218 O'Ring. Later cars and those that want to try taming down the hot start issue add 2 ea Item 38a (Pertinax/phenolic/fiber) washers as shown, one now goes between the item 35 housing and the block, the other on top of the housing to help keep the heat from the injectors due to the combo exhaust ports directly below on the head. Item 38 thicker P/N 960168 is now used as there is a gap that has to be sealed due to the washer (about .015") thickness. The washers and correct O'ring can be ordered from VP Autoparts among other sources, I had very good response from Terri there, he USPS mailed them to me in Alaska. I have suggested VP create some kits for this as the problem was widespread in all the engines that intake and exhaust ports on the same side. There are 10 or more Volvo models alone. I've heard it's not a cure all but when I replaced my injectors with aftermarket Beck Arnley units I figured it was a good idea to at least try the retrofit. Turned out I think I had a vacuum leak on the center two injectors from the condition of the 53 YO original orings! See the 4 orings below. Everything points to these two center (2 & 3) being a huge problem for heat. As a proof of concept test I mounted a 12V 4" "muffin" fan aimed right at the center two injectors, used a 120 deg thermostat to control it and hooked it to the battery via a fuse. See the other picture. The hot start issue is tamed way, way down if not gone entirely. Some luck may also be had putting a metal heat shield over that combo exhaust port to at least slow down the heat flux. Places like Arizona may have to employ all the "fixes", Alaska may skate by a little easier.
Note: The pressure gauge in the second picture is for troubleshooting and keeping track of system health, ie pressure should come up rapidly to 30 psi and stay there while the engine is running. Various check valve "healths" can be monitored; ie after shutdown a perfect system will hold pressure for quite a while. It's not a cause to go changing expensive and difficult parts in pursuit of this; the fuel pump brings the system pressure up very rapidly even from zero.

 

I am not sure that Volvo ever fitted the insulating washers from the factory. The 1979 version of the parts manual that covers up to the 1972 model year does not provide a chassis number for the application of the insulating washers or the matching fat O ring. In fact the section of the parts manual covering the B20F specific details (revised fuel rail, fuel pump and cold start timer) shows both the thin and fat O ring being used on the B20F versions. The manual seems to imply that the washers are an alternative fitting option. My 1971 142 E did not have the washers and I have talked to owners with 1972 B20Fs who were adamant that their engines were not equipped with the insulating washers - and suffered the hot start problem. For 1970, 1971 and 1972 cars I think fitment might have occurred if you complained enough to your dealer.

The 1973 and 74 D jet cars might have received the washers from the factory. If you had access to the later 1973 and 74 parts manual a diagram indicating that the washers were the only option would indicate that they were factory fitted.

 

Update: Test drive was spectacularly successful! Idle is much smoother, part throttle surge is gone and so far I cannot provoke the hot start problem! Granted, it was only 60 deg out today but still. Will have to dial the idle down a bit, it now is 1100 at start and 950 warmed up. Odd thing now with the engine - under solid throttle, when the revs hit about 4300 there is a real surge in the rate of rpm increase. Got to be a bit careful passing the 5000 rpm point, it's going for redline pretty fast by then.


142 guy -very good points again. The second Volvo I had was a late '60s, 144 '69 or thereabouts, very solid vehicle, it had the Zenith-Stromberg 175 CD-2 carbs as I recall.
My third Volvo is an early build '72ES; it did not have the washers when I did the above rebuild. The records I got from the first owner showed a LOT of FI related work, in retrospect all the indications of mechanics that had no idea how the DJetronic worked. In fact, they had the fuel pressure set at 46 psi! I ran it that way for a lot of years, only finding out when I put a pressure gage in to check the pressure after failing a smog test. I dialed the pressure down to 30 psi which made the car much more problematic to drive but improved the fuel mileage. There was at least one probable "repair" to the injector system - the #4 injector was a -024 instead of the normal -036 as found on the other three cylinders. Bosch specs are identical for the two part numbers FWIW. What I get from the Volvo parts illustration on the thin/fat o'ring parts is this: The first entry is the original configuration, the second entry a part of a retrofit in conjunction with the Pertinax insulating washer. Volvo should have listed the retrofit parts as a kit; perhaps it is in some obscure internal publication.