Fuel pump issue

[BLUNT]

Please see attached photo. On top is my customers original 40 year old pump. On the bottom is the OE BMW pump I supplied to him to replace it Part # 13311265192 He is using the correct push rod. Ive sold 30 of these combos this year with no issues. Note the slight difference in length of the protruding spring. My customer installed it this way and the pump failed in 100 miles. He stated it was difficult to install with the added force needed to compress the added length of spring. Has anyone else run into this?? There are only 2 combos I know of .. the pushrod is #13311255727

Any insight would be appreciated

[jgerock]

Based on the picture, it looks like the spring in the new one is a stronger one - hence needing more pressure to install it on the engine. The pivot mechanism inside the pump body may also be different in the two pumps. There seems to be a wide variety of these pumps for both BMW's and VW's.

[Guest Anonymous]

Good morning

I have a 1971 carbed 02. My fuel pump (the top one, perolux i believe) went out, in the Home Depot p-lo Emeryville). I literally hitched (difficult task in East Bay Area) a ride to Steve Morans BMW in Berkeley (I called him he said he had one left (the one in the top photo, I was so happy).

I then got a ride back, so excited that at the end of the day on a whim I called and he had my part so I thought. Who knew, I didn't that after several attempts to put this darn thing on, I determined that it does not fit. It appears that the water hose that runs through the carb I believe sits to low (going by memory). Man, that was a hurtful situation.

Anyway I have a few 2002's (but I did not want to leave this one over night) so I called my buddy who has access to my 76, 02' I had him pull the perolux (top one from my 76') he brought it over I swiftly put that bad boy on, and boom, my car starts up....away I go..

All that to say the bottom one did not fit on my 71 with the 38/38 weber. I I took that pump back and to this day I still have a store credit of $90.00 bucks. He sold it to me for more than that but I 've been nickel and diming.

ira

[Mike Self]

that has the crimped-on cover--is an OEM pump as fitted to the cars when they were new. Most I've seen were made by Pierburg. It replaced an earlier one--also Pierburg--that uses a different length pushrod and can be taken apart to replace the diaphragm. It was used on the single barrel carb cars, up through mid-1972.

The pump below resembles the early style pump in that it can be dismantled, but with the later style activating mechanism. It also resembles an Italian-made pump that I used on my '69 as a replacement. It doesn't resemble the OEM pump, and I can't read the maker's name on it. I suspect that the difference in protrusion of the mechanism that operates the diaphragm is enough so that the pump doesn't give a full stroke when activated by the pushrod. One suggestion: make a hard plastic (or aluminum) spacer that makes up the difference in protrusion between the old and new pumps, and try that.

I'd suggest grinding down the pushrod a few mm, but it's hardened steel, and you'd grind through the case hardening and it would wear in short order.

And since you tried an old pump and it functioned correctly, it's not the pushrod or spacer.

Let us know what solves the problem; more of us will be facing it eventually as our old pumps wear out.

cheers

mike

[c.d.iesel]

describe the nature of the 'failure'

first blush says there ia no diff between the two to cause

'falure' ???

installation error ??

[roadhog0]

For a fuel pump I get this #13311261622 and this #13311265192. These were looked up from real OEM, maybe they were superseded?

[BLUNT]

describe the nature of the 'failure'

first blush says there ia no diff between the two to cause

'falure' ???

installation error ??

I think it quit pumping fuel. My point is ive sold this combo to many many m10 guys and never had this issue. Its an OE pump with the correct pushrod. So why the difference in length of the protrusion. Unless the old pump pictured on top is receded?? To my knowledge there are not 2 different thickness insulators

[Napes]

Steve, I got a NOS pump about a year ago from Rob Torres at 2002Haus and I had starving-out problems from the get-go. I sent it back to Rob and he replaced it with another one, which worked fine.

Rob said he could not find any problem with the one I returned to him, so maybe it was similiar to what you've encountered.

The one above was on my wife's '76, but two months ago I had to replace the pump on my car. Got a new one from the dealer and am now having all kinds of vapor-lock problems. Didn't have this problem with the old one.

I guess there are some variations in these pumps. Also, I just checked www.bmwfans.info for my car and it says the P/N is 13 31 1 252 506. RealOEM shows the same P/N for my '75.

Bob Napier

[autobon7]

I am having starvation issues with my 75 and pulled my pump last weekend. It looks exactly like the one on top. When I pulled it, it was packed with what appeared to be old molly grease (spring area). I shot carb cleaner on it and cleaned out the old grease, was not dried up but wanted to see if the spring was binding. Did not seem like it was. Pumped in fresh grease, installed....nothing. I have not checked the fuel line yet. Just my 2 cents.

[jimk]

Looks to me that by the time the pump is pulled in place, the mechanism is over stroked and soon over stressed the diaphram. Like Mike said, either more spacer (and longer studs) or shorter rod might be needed with this pump.

[tbrduc]

what is the 'pumping' object? Is it a diaphragm that might fail due to longer rod or heavier spring rate?

I had one fail en route on a '72. I'm not certain exactly what happened, but I did a road-side repair buy road-grinding the phenolic (bakelite?) spacer enough to allow actuation to get me moving ..and order a replacement from Mesa Perf...when I lived out there.

[1453aalapapa]

easy explanation. but one has to go back to the white books to see PARTIALLY why, and then have insight on what bmw AND the direct importers are doing. first, the white books. we all know there were 3 pumps for the carb engines. the early one that was rebuildable, then the brass top one, up to 74, and then from 74 on. if you dont believe me, check the white books, i always do. so we are looking at the non rebuildable ones. for up to, but not including usa 74 my, the pn is 13 31 1 265 193. still available from bmw. then, from 74 my on, 13 31 1 265 192. also still available. however, checking bmw etk, 8/2011, there is a 3rd pump, 13 31 1 261 622, which etk says fits 9/75-7/76. there is no reference to that part number in the white books. further checking with bmwna, the 193 and 622 both have stock in germany, ONLY the 192 has stock in the us. which generally means the 192 number is still popular. i suspect the difference in the 193 and the 192 is how the inlet/outlet is clocked, but i dont quite remember. i have NO idea how bmw came up with the 622, but it ONLY fits usa cars. the pump rod is correct for all 3 pumps, since the early one is nla.

now we go to the direct importers. since only 2 of them carry this pump, and both carry the same one, i suspect this pump actually is for a vw, but the supplier says it can be used for bmw. suppliers dont know everything. and it is easier to carry 1 part that fits a bunch of cars, instead of the exact part.

lastly, do NOT confuse OE with OEM. these 2 acronyms are widely misused and generally misunderstood in the parts business. this pump is oem, but it is NOT oe.

[BLUNT]

easy explanation. but one has to go back to the white books to see PARTIALLY why, and then have insight on what bmw AND the direct importers are doing. first, the white books. we all know there were 3 pumps for the carb engines. the early one that was rebuildable, then the brass top one, up to 74, and then from 74 on. if you dont believe me, check the white books, i always do. so we are looking at the non rebuildable ones. for up to, but not including usa 74 my, the pn is 13 31 1 265 193. still available from bmw. then, from 74 my on, 13 31 1 265 192. also still available. however, checking bmw etk, 8/2011, there is a 3rd pump, 13 31 1 261 622, which etk says fits 9/75-7/76. there is no reference to that part number in the white books. further checking with bmwna, the 193 and 622 both have stock in germany, ONLY the 192 has stock in the us. which generally means the 192 number is still popular. i suspect the difference in the 193 and the 192 is how the inlet/outlet is clocked, but i dont quite remember. i have NO idea how bmw came up with the 622, but it ONLY fits usa cars. the pump rod is correct for all 3 pumps, since the early one is nla.

now we go to the direct importers. since only 2 of them carry this pump, and both carry the same one, i suspect this pump actually is for a vw, but the supplier says it can be used for bmw. suppliers dont know everything. and it is easier to carry 1 part that fits a bunch of cars, instead of the exact part.

lastly, do NOT confuse OE with OEM. these 2 acronyms are widely misused and generally misunderstood in the parts business. this pump is oem, but it is NOT oe.

I know the difference between OE and OEM and that pump pictured came direct from BMW.

[Todd21]

Steve,

Since I'm rebuilding a motor I just went through this my self appearently the plunger style pumps "may" have a differnent length push rod. While the lever style pumps would use a longer push rod.

The Plunger Style Pump (PSP) you show in your photo has the rod connected to the diaphragm that protrudes beyond the body of the pump.

The Lever Style Pump (LSP) has a lever that the push rod contacts. The lever does not extend beyond the body of the pump.

Given that there is only one insulating block, I would think there are two different push rod lengths to compensate for the different style of pumps.

The 13311252506 LSP calls for push rod 13311250398, while the 13311265192 PSP calls for a 13311255727 push rod. While I have not yet confirmed that the push rods are different lengths, it would only make sense with the design of the pumps.

Todd

[jgerry2002]

There are multiple lengths of the pump pushrod.

I have bunch of them in my parts of varying lengths.

Not sure which year is which however...