Cold start injector fuel hose- the 'little perisher'

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Brucey
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Cold start injector fuel hose- the 'little perisher'

Post by Brucey »

Mine failed just today; fuel actually started to wee out of it at high speed!

I was very lucky not to have a 6er-shaped bonfire on my hands....

here's the culprit;

Image

cheers
~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
GWL

Post by GWL »

Yeah, both ends on a E12 based E24. :D
horsetan

Post by horsetan »

:idea:

I seem to recall when I had my 1985 Audi 90CD, it had braided fuel hoses. Is it possible to obtain these for the E24, I wonder :?:
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Post by DC »

I had similar problem with my 628 last week :o
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Drew

Post by Drew »

I replaced my CSV fuel line about a month ago after hearing a similar story to yours. My fuel hose looked original (ie knackered and covered in little splits) and I'm only pleased it didn't pop before I swapped it out. I got some new hose and clampls from BMW. I guess it goes first because it gets a lot more heat than the other fuel lines.

I didn't want mine to pop on a french autoroute so did the job as a pre-emptive strike!!
jrcalvin

Post by jrcalvin »

I was just checking that cold start injector out on my 1987 B10 3.5. Jeez! The L-Jet cars have the cold start right on top on the manifold for easy access! This Motronic one looks crazy/frustrating. So can you really remove the injector with the manifold installed? Oh, you just leave it in place because you are just changing the hose. Nice access to the hose clamp!

If you can remove the cold start injector without removing the manifold...you are far better than I am. The bolts are too close to the injector body for a box end wrench/spanner. I will replace the two bolts with an allen socket head for more clearance in the future using a allen wrench.
Drew

Post by Drew »

I managed to get the CSV out with the pipe attached (to check for leaks). How smug am I??? :lol:

you can just about wield a spanner in the space behind the brake servos
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Post by Brucey »

it is a complete nightmare on any E28 chassis car. Its also one of the few jobs that is worse (I would guess) on a LHD car than a RHD car; the steering box etc must restrict access to the underside of the manifold even more...
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GWL

Post by GWL »

Just to make you E28 based guys feel better, there is a vacuum hose on the bottom of the L Jetronic intake manifolds that goes down to a point on the engine that is a gotcha to get to even with the manifold intake runners off the head. Just did it and was too tired (#@**%) by the time I finished to take any pictures. I am not even sure exactly what it does, but it must have been put on the engine before it is in the car. Mine was over 26 years old and crumbled on human contact.
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Post by bfons »

Drew wrote:I managed to get the CSV out with the pipe attached (to check for leaks). How smug am I??? :lol:

you can just about wield a spanner in the space behind the brake servos
I too am one of the few who has done this without removing the manifold. I think my hands were cramped for 2 days afterwords. Not to mention the scraped up arms.
Brian

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Brucey
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Post by Brucey »

at least in part because I spent about an hour and a half fitting a temporary (1/4" bore, all I could find) hose so I could drive the car a short distance, I had a bruise the size of the palm of my hand on my right forearm, and not much skin left either....

-and then, the following day, when the bruise was ripe and tender, I had to fit the proper hose, which inflicted the same damage all over again...

owwww.....
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86C

Post by 86C »

I could smell petrol on the way home from work tonight. After a quick look by torchlight, you can guess where the problem lies :roll:
86C

Post by 86C »

All done. Took about 25 minutes from start to finish. Used a piece of hose from a fuel injection VW Polo that looks of much higher quality than the BMW pipe that was on the car. :D
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Post by Brucey »

-another 6er-shaped bonfire averted... glad you got it sorted....

cheers
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zeltar

Ok, so now my 6 wants to play this one....

Post by zeltar »

I finally got my 6 back in running order today. It has been sitting idle for 11 months until the wife has released some funds for her. I replaced battrery and cables today, had to fabricate an adapter plate for the three positive feeds from the fuse box since I did not buy BMW replacement cables.

Went to turn her over and no go. Got out and did the typical "shake this hose, wiggle that wire", you know like all good mechanics do. Then noticed a fairly strong fuel smell. Upon closer inspection I noticed a "shiney" liquid in the driverside of the block. I said to myself "that can't be good".

So disconnected the nice new cables from the battery and grabed the Bentley manual, a soda and a smoke (far from the car :)) and found out about this wonderfully placed cold start valve. I am 6'5", 245lbs with giamongous hands and then realized how the frek am I supposed to get in there????

Well after dismantling the air intake and bellows, I proceeded to "hover" on my stomach from the left side to get both hands in there somhow. My original plan was to remove the clamp and rotate it so I could tighten from a "normal" stance, but I became nervous about the fuel that would "spit" as I nudged the loosened fuel line. So, I went to plan B and tightened the tar out of it, at least the best I could muster. Did get it to stop leaking.

No that I have read this post for the second time now with personal expierence, I should probably replace that farging line, huh?

If that is the case where does the other end go to? I see from Brucey's picture above that it goes to #4 &#5 inlet. That doesnt mean much to me :oops: I see that it goes towards the firewall but I am afraid to hear what unreachable destination the other end is at.

Sorry for the dissertation but I feel I should kick this back up in the listings so others might be able to catch this one early.
Thanks in advance.
--Eric
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Post by Brucey »

the other end is attached to the fuel rail; there is a spigot on the underside, just between the #4, #5 inlet runners.

-you will be pleased to hear that this end is a bit easier (well, a lot then) than the other end...

I have a picture of this somewhere, I'll post it later if I get the chance

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Post by Brucey »

found it...
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zeltar

Great, thanks.

Post by zeltar »

Next question, does that line stay perssurized if so then for how long? I am trying to figure out how much fuel should come out vs. a big scary mess.

Thanks again.
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Post by Brucey »

typically for a few minutes there will be some pressure; it depends how good your check valves are.

The good news is that the amount of fuel that will come out is quite small; I'd suggest to break the connection at the back of the fuel rail first (the feed hose nearest the firewall) and catch what comes out witha shop towel.

Next, disconnect the cold start hose; this will liberate more fuel (the fuel rail will drain) so a small jar to catch this is a good idea.

Oh, and try to work on a cold engine, with the battery disconnected, and an extinguisher to hand; we don't want to hear about any impromptu barbeques....

cheers
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My turn for the pain

Post by songzunhuang »

Well after a lot of reading, I am about 99% sure I have this issue. It's gonna be a long Saturday.
-----
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Pipes

Post by Pipes »

Wow! just about to post on this - i've been smelling fuel on start up for weeks and had no idea what was happening - thorough investigation tomorrow but already seen fuel leaking out of the end of the hose onto the rail.
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Post by songzunhuang »

Pipes wrote:Wow! just about to post on this - i've been smelling fuel on start up for weeks and had no idea what was happening - thorough investigation tomorrow but already seen fuel leaking out of the end of the hose onto the rail.
Hey, wanted to let you know that I changed out that hose yesterday and it took all of 30 minutes. I'm not sure what's different about my car, but I didn't have nearly the trouble that I was expecting after reading the posts. I posted some pictures in my projects page at viewtopic.php?t=25858&postdays=0&postorder=asc&start=60. It's in the middle of page 5.

I bought a meter of the OEM BMW fuel injection hose. Only needed about 8 inches. So when I have time, I'll change out the other hoses as well.

The hose clamps have 6mm screws. I was able to get a socket on the clamp under the intake manifold. I was even able to get a long screw driver on the screw. I used the screwdriver for most of the operation and then used the socket to tighten it up. I did have to do this by "feel", but I was also able to get a tiny peek of the clamp by looking past the rubber intake boot.

In any case best of luck to you. My hose was in terrible shape!
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383
Pipes

Post by Pipes »

went into a mild panic when I discovered several small leaks - it's Sunday and wasn't sure I'd get the hose and clamps for replacement (reluctantly went to Halfords) etc...

Anyhow I found it really fiddly and had to enlist another pair of hands but we got there in the end - all sorted and improved!

ABS brake sensor and new exhaust middle section to get this week before MOT.
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Post by songzunhuang »

Pipes wrote:went into a mild panic when I discovered several small leaks - it's Sunday and wasn't sure I'd get the hose and clamps for replacement (reluctantly went to Halfords) etc...

Anyhow I found it really fiddly and had to enlist another pair of hands but we got there in the end - all sorted and improved!

ABS brake sensor and new exhaust middle section to get this week before MOT.
Oh that picture you posted is all too familiar. I stared at it for a long time wondering how I was going to do the job. The anticipation was worse than reality for me.

Feels good to have it done though. Hopefully we won't have to worry about it for another 15-20 years@
-----
Song Huang
1984 633CSi
Last 7 of VIN: 6997383
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Re: Cold start injector fuel hose- the 'little perisher'

Post by Brucey »

I just reviewed this thread and it occurs to me that some folk do this job relatively quickly and easily (it would take five or ten minutes with good access but 25-30mins tells its own story...) but others struggle more. I think I was in the latter camp.

Obviously access varies with model and if you have forearms like tree-trunks that isn't going to help any either.

But the other factor may be a simple one; temperature. Fuel hose is stiff and unyielding when it is cold, whereas when it is warm it is much more malleable. This can make all the difference to fitting the hose over the CSI spigot.

When I was working on mine it was about 2 degrees centigrade and I was working outdoors. This is not a good arrangement! If you have a choice about when you do this job, choose a nice warm day, work indoors or something!

cheers
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