fuel line opinion
- Thread starter jvandyke
- Start date
Dan Sarandrea (Phila)
Waitin' On Parts...
Wait.....what?
REPLACE IMMEDIATELY!!!
What hose did you use?
On the MWB site they say the line from the fuel rail nipple to the injector is 45mm long. That length jams the fuel rail right up into contact with the plenum, IMO adding too much heat to the fuel rail. I'd cut that back to somewhere around 43mm so that the fuel rail has a little bit of space between it and the plenum.
REPLACE IMMEDIATELY!!!
What hose did you use?
On the MWB site they say the line from the fuel rail nipple to the injector is 45mm long. That length jams the fuel rail right up into contact with the plenum, IMO adding too much heat to the fuel rail. I'd cut that back to somewhere around 43mm so that the fuel rail has a little bit of space between it and the plenum.
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jvandyke
True Classic
I replaced them tonight. The rail isn't hitting the plenum. I did the original replacement with the kit from MWB. This time around I just bought hose from autozone and cut my own.
I had been smelling gas and couldn't find it unit the connector hose between the two halves of the fuel hard line let loose enough to drip.
Looks like the lack of the heat shield that would normally be installed on the exhaust manifold heat fatiqued the hose until it gave it up, all the center hoses were baked. All were cracking on the exterior at least, the three center ones were horrible.
Car had been getting hard to start. Tonight after replacing it started, ran like crap and stalled and refused to refire, could be a flooded condition yet, could be unrelated to this failure.
At least it died in my driveway this time. It was a good run I haven't had to wrench on it much in thousands of miles.
Might be time to retire this X.
I should add that my injector cooling fan, which almost never comes on, might be involved, it may not be functioning as it should, heat soaking hoses every time it shuts down.
I had been smelling gas and couldn't find it unit the connector hose between the two halves of the fuel hard line let loose enough to drip.
Looks like the lack of the heat shield that would normally be installed on the exhaust manifold heat fatiqued the hose until it gave it up, all the center hoses were baked. All were cracking on the exterior at least, the three center ones were horrible.
Car had been getting hard to start. Tonight after replacing it started, ran like crap and stalled and refused to refire, could be a flooded condition yet, could be unrelated to this failure.
At least it died in my driveway this time. It was a good run I haven't had to wrench on it much in thousands of miles.
Might be time to retire this X.
I should add that my injector cooling fan, which almost never comes on, might be involved, it may not be functioning as it should, heat soaking hoses every time it shuts down.
Rod Midkiff
True Classic
I am pondering something adding a LOT more heat then normal. even the paint is showing signs. ?? any chance it's running super lean causing the exhaust to get extra hot.
I would be looking into that thought as well.
I would be looking into that thought as well.
Rod Midkiff
True Classic
wow even the aluminum is showing signs of heat (black around where the hose clamp was).....??? ??
lookforjoe
True Classic
Crispy crispy
Particles of the deteriorated hoses maybe in the injectors. The process of removing the hoses may have made that worse. Did you try cleaning the injectorinlets with carb clean or similar while it was apart?
Particles of the deteriorated hoses maybe in the injectors. The process of removing the hoses may have made that worse. Did you try cleaning the injectorinlets with carb clean or similar while it was apart?
jvandyke
True Classic
I just eyeballed the injector tips and passages, everything looked okay, the outer covering of the hoses was trashed but the inner was okay although not for much longer me thinks.
She no wants to start. I will have to pull plugs and have a look. I've flooded this thing a few times in the past and it's a PITA to recover from that. Cranks and spits a bit. Could be an ignition issue too of course.
Never runs hot according to the gauge. We'll see. It's almost time to put her up for the winter anyway and it might not come back out. It's falling apart all over the place, poor little dear.
The red fuel rain is just rattle can so that paint is off due to gas, same on the plenum, silver paint, it just wiped off and the metal is fine.
Looking back at the pictures you can see the rail is on the plenum, I agree with Dan, the hoses there are a bit long as kitted, I did make them just a tad shorter and there was a gap now but I'll look again to be sure it's still there.
She no wants to start. I will have to pull plugs and have a look. I've flooded this thing a few times in the past and it's a PITA to recover from that. Cranks and spits a bit. Could be an ignition issue too of course.
Never runs hot according to the gauge. We'll see. It's almost time to put her up for the winter anyway and it might not come back out. It's falling apart all over the place, poor little dear.
The red fuel rain is just rattle can so that paint is off due to gas, same on the plenum, silver paint, it just wiped off and the metal is fine.
Looking back at the pictures you can see the rail is on the plenum, I agree with Dan, the hoses there are a bit long as kitted, I did make them just a tad shorter and there was a gap now but I'll look again to be sure it's still there.
Dan Sarandrea (Phila)
Waitin' On Parts...
If you have a stock manifold, then I would definitely agree that you should keep an eye out on the usual vendor sites and/or put out a wanted in the FSW section for a stock heat shield.
If you have a header, IIRC you have to make a heat shield as most of the available headers don't provision for a heat shield.
I suppose it revolves around whether you are going to keep this car going or move to another one....
If you have a header, IIRC you have to make a heat shield as most of the available headers don't provision for a heat shield.
I suppose it revolves around whether you are going to keep this car going or move to another one....
phillips82
True Classic
The only time I have seen hose destroyed that quickly, regardless of engine bay heat, was when it wasn't rated to the right pressure. Very few cars that have come through our shop over the years still had their heat shields. And as for functional cooling fans... Ha!
Be sure the new hose you got is really good hose rated for high pressure. The last I saw from Autozone was trash. Low quality and only rated to 50 psi. I recommend Gates or ACDelco.
Be sure the new hose you got is really good hose rated for high pressure. The last I saw from Autozone was trash. Low quality and only rated to 50 psi. I recommend Gates or ACDelco.
myronx19
True Classic
Wow! sorry to see
Umm, I don't think you have a fuel line issue - you had a very very very very hot "thermal event" there..
Yikes!! I'd bet that MWB's lines are quite good and not what caused the failure. The outside lines look "better".. but the melted paint?!?!
As others pointed out, your lines are pushing the rail into the plenum which isn't good. You'll sort it out, but keep in mind - FI hose that's not metric is actually 7.9mm. This isn't really that bad for the injectors, but it is on the hard lines that exit the filter. I always had a leak there, had to double clamp it.
Next hose replacement will be 7.5mm FI line.
Glad you dealt with it before a fire!
Umm, I don't think you have a fuel line issue - you had a very very very very hot "thermal event" there..
Yikes!! I'd bet that MWB's lines are quite good and not what caused the failure. The outside lines look "better".. but the melted paint?!?!
As others pointed out, your lines are pushing the rail into the plenum which isn't good. You'll sort it out, but keep in mind - FI hose that's not metric is actually 7.9mm. This isn't really that bad for the injectors, but it is on the hard lines that exit the filter. I always had a leak there, had to double clamp it.
Next hose replacement will be 7.5mm FI line.
Glad you dealt with it before a fire!
Rupunzell
Bernice Loui
Not a thermal hose failure. That is hose material not compatible with fluid (fuel?) being used. SAE spec fuel hose is not red jacketed, looks like an unknown hose that was not deigned for fuel or the coating contacted with a non-compatabile liquid.
Regardless, proper hose for fuel injection is SAE 30R9 spec. This must be printed on the hose. If not the hose used must be made of a material proven and certified to be used with the fuels or liquids involved.
7.5mm ID hose is not common today, 8mm-5/16" ID hose works with proper full band clamps.
Bernice
Regardless, proper hose for fuel injection is SAE 30R9 spec. This must be printed on the hose. If not the hose used must be made of a material proven and certified to be used with the fuels or liquids involved.
7.5mm ID hose is not common today, 8mm-5/16" ID hose works with proper full band clamps.
Bernice
jvandyke
True Classic
the hose that failed was from MWB kit so I'm sure it was proper
this engine has not run hot since the head gasket issues a few years ago, I think I did the lines at the same time so am pretty sure the hose post dates those thermal events but I could be wrong, even so those never got "super hot" just a mild overheat (according to the temp gauge) and that was 10s of thousands of miles ago.
I believe the lines from the rail to the injectors as kitted by MWB are indeed too long, I had fitment issues when I installed it then and have shortened them up a tad more this time around (perhaps not enough)
I used 5/56" ID modern fuel rated injector hose this time around, although I don't think this car will see too many more miles to be honest. I hope to make it run again and drive it through the fall but we'll see.
The paint isn't melted it simply met some gas and sloughed off. It was just cheap rattle spray paint I did at the time to amuse myself
Maybe the fact that lines were too long and pushed the rail into the plenum is all it took for the whole works to overheat?
I suppose the intake would get pretty hot so maybe?
(oh, and just between you and me, a fire would have helped me make my decision as to what to do with the car) :mad4::devil:
this engine has not run hot since the head gasket issues a few years ago, I think I did the lines at the same time so am pretty sure the hose post dates those thermal events but I could be wrong, even so those never got "super hot" just a mild overheat (according to the temp gauge) and that was 10s of thousands of miles ago.
I believe the lines from the rail to the injectors as kitted by MWB are indeed too long, I had fitment issues when I installed it then and have shortened them up a tad more this time around (perhaps not enough)
I used 5/56" ID modern fuel rated injector hose this time around, although I don't think this car will see too many more miles to be honest. I hope to make it run again and drive it through the fall but we'll see.
The paint isn't melted it simply met some gas and sloughed off. It was just cheap rattle spray paint I did at the time to amuse myself
Maybe the fact that lines were too long and pushed the rail into the plenum is all it took for the whole works to overheat?
I suppose the intake would get pretty hot so maybe?
(oh, and just between you and me, a fire would have helped me make my decision as to what to do with the car) :mad4::devil:
jvandyke
True Classic
around 15,000 mile on this hose, I will say the line to the cold start injector has had to be replaced twice since then because the outer coating was quite badly crazed and cracked. Maybe it just a bad run of hose in the kit I got.
myronx19
True Classic
The red part in the picture is the fuel rail, not the hose of course.
BTW: 7.5mm hose is quite common (DIN spec), just need to know where to buy it
Trust me, the band clamp cannot squeeze the 7.9 hose around the intermediate pipe between the filter and rail - it will leak eventually. On the barbs, no problem. But the 7.5mm is correct, and technically does not need a clamp. Reuse the collar (easy to remove) and away you go. Paul Valente switched me on to a supplier in the US that sells fuel injection hose in 7.5mm made by Continental (and tons of other metric stuff), but out of respect for the vendors who sell the hose kits - I won't post the link.
sdlsaginaw
Steven Lawson
Blocked return line from the regulator causing excessive fuel pressure?
jvandyke
True Classic
I think it was flooded, tried again just now, was trying to fire, held pedal to floor, no luck then I started to pump it like crazy, I don't know what difference that would make on an FI car but it caught and ran.
No leaks.
Interesting.
Maybe if you've had this MWB kit you should check your hoses.
No leaks.
Interesting.
Maybe if you've had this MWB kit you should check your hoses.
Matt Brannon - Midwest Bayless
Mad.Matt
Wow...
Jeff, I've never, ever seen hoses look like this, even on the worst basket case cars we salvage, and I've seen a lot of FI hose replacements, good and bad.
Am I correct to say that the cold start injector hose appears in OK shape?
Any chance that you've sprayed down the plenum with brake parts cleaner, or other solvent, chasing leaks, cleaning, etc.? Multiple times?
This appears to be something attacking the outside of the hoses.
We are extremely cognizant that 7.5mm FI hose is the only stuff to apply to a Bosch L-jet system, so I am perplexed as to what
the issue could be.
Jeff, I've never, ever seen hoses look like this, even on the worst basket case cars we salvage, and I've seen a lot of FI hose replacements, good and bad.
Am I correct to say that the cold start injector hose appears in OK shape?
Any chance that you've sprayed down the plenum with brake parts cleaner, or other solvent, chasing leaks, cleaning, etc.? Multiple times?
This appears to be something attacking the outside of the hoses.
We are extremely cognizant that 7.5mm FI hose is the only stuff to apply to a Bosch L-jet system, so I am perplexed as to what
the issue could be.
myronx19
True Classic
I agree with Matt, at first I thought the paint bubbled from heat - but now it looks like it was some sort of fluid (fuel!?!?!) I think his plenum is painted as well, which explains the bubbling of paint (if there was a fuel leak or other chemical).
Easy fix - glad you caught it quickly - BTW: it really does appear that the rail and those two screws are jamming into the plenum. Mine is separated there.
I still had the original center and cold start fuel line from 34 years ago on my car.. I split it open, and it still looked pretty good!
Easy fix - glad you caught it quickly - BTW: it really does appear that the rail and those two screws are jamming into the plenum. Mine is separated there.
I still had the original center and cold start fuel line from 34 years ago on my car.. I split it open, and it still looked pretty good!
jvandyke
True Classic
Cold start injector hose had a little outside crazing and cracking, not severe but I have replaced this hose at least once since putting the kit on because it was looking ratty so that hose isn't an original to the kit (honestly it might have been a section of hose from the kit I didn't use before but I can't say for sure).
The line to the pressure regulator looked fine but I had replaced that one before too as it had started to look questionable. This hose still looks fine.
I have only degreased this engine a couple times and that was a long time ago. Nothing else has been sprayed on it as far cleaners go.
Pretty weird. Potential fire hazard though no doubt, it was dripping straight down onto the injector cooling duct then onto the exhaust manifold. I'm pretty lucky it didn't light off going down the road. Although it would have been pretty cool looking for a minute or two.:excited:
Karl (member here) was over tonight to pick his X up from storage at my place and we looked at his original hoses on his '85, they look pristine.
I ran it to work today. All good (well, honestly it isn't idling like it should, even stalled once but who knows what's up with that). I checked my hoses several times and all secure.
Pretty weird. My next one might get pretty stainless.
Maybe some sort of contamination or heat cycling. I don't know. I will try to examine the old ones for identification of some sort. I'm a little surprised no one else has has seen something like this before. I agree with Matt that it appears to be exterior damage. What about the fact that the rail was hard up against the plenum? Could that have transferred enough heat to do this over time? It now has some gap.
The line to the pressure regulator looked fine but I had replaced that one before too as it had started to look questionable. This hose still looks fine.
I have only degreased this engine a couple times and that was a long time ago. Nothing else has been sprayed on it as far cleaners go.
Pretty weird. Potential fire hazard though no doubt, it was dripping straight down onto the injector cooling duct then onto the exhaust manifold. I'm pretty lucky it didn't light off going down the road. Although it would have been pretty cool looking for a minute or two.:excited:
Karl (member here) was over tonight to pick his X up from storage at my place and we looked at his original hoses on his '85, they look pristine.
I ran it to work today. All good (well, honestly it isn't idling like it should, even stalled once but who knows what's up with that). I checked my hoses several times and all secure.
Pretty weird. My next one might get pretty stainless.
Maybe some sort of contamination or heat cycling. I don't know. I will try to examine the old ones for identification of some sort. I'm a little surprised no one else has has seen something like this before. I agree with Matt that it appears to be exterior damage. What about the fact that the rail was hard up against the plenum? Could that have transferred enough heat to do this over time? It now has some gap.
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Rupunzell
Bernice Loui
5/16" SAE spec 30R9 clamps down easily past 0.250" using ABA small band clamp. 5/16" hose ID about 0.312". For a 7.5mm hose ID about 0.295" which is about 0.017" smaller. ID hose tolerances are going to be more than 0.xxx". Given that the 5/16" ID SAE 30R9 hose easily clamps down to 0.250" with a ABA clamp and the hose barb fitting is going to be large than 0.295" (7.5mm), it will seal.
https://goo.gl/photos/2HaVuo6pFEA1GHmB8
ABA clamps produces a round clamped hose ID.
https://goo.gl/photos/AKs9WHHQSVWtyaoA7
If the common perforated band worm drive clamp is used, there is no possible way to achieve a know good clamp on a hose this small and those perforated band clamps will extrude the hose material damaging the hose and significantly increase the possibility for hose failure where it has been clamped.
These barbed fittings and hoses are similar to the Parker "Push-Loc" system where the hose is made with a special angle inner braid that compresses the hose ID as pressure is applied. This is why hose clamps are not needed in the OEM design.
http://www.arvihitech.com/parkerfluidconnectors_1.php
ABA small band clamps can be purchased on line at Hose Clamp King.
http://www.hoseclampkings.com/cat-44-1-52/304-ss-screw.htm
The difficult and expense way would be to use Stratoflex (now owned by parker) 156-5 hose with ABA clamps. Done this once, not easy but do-able.
http://www.aircraftspruce.com/catalog/appages/strato156.php
The -5 hose has an spec ID of 0.281" which make pushing this hose over a slightly larger 0.295" (7.5mm) barb not easy.
Service pressure of 1500psi, service temp -65 to +300 degrees F.
http://www.aero-hose.com/_docs/156 catalog.pdf
Quick Google search yields 7.5mm DIN spec hose.
https://www.belmetric.com/braided-metric-hose-oem-c-14_138/rh75-braided-hose-75mm-p-8316.html
The other possibility for the peeling hose is heat from an exhaust leak spraying hot exhaust gas at the hoses. Still, this does appear to be a fluid non-comparability with the hose material meeting the exterior.
Bernice
https://goo.gl/photos/2HaVuo6pFEA1GHmB8
ABA clamps produces a round clamped hose ID.
https://goo.gl/photos/AKs9WHHQSVWtyaoA7
If the common perforated band worm drive clamp is used, there is no possible way to achieve a know good clamp on a hose this small and those perforated band clamps will extrude the hose material damaging the hose and significantly increase the possibility for hose failure where it has been clamped.
These barbed fittings and hoses are similar to the Parker "Push-Loc" system where the hose is made with a special angle inner braid that compresses the hose ID as pressure is applied. This is why hose clamps are not needed in the OEM design.
http://www.arvihitech.com/parkerfluidconnectors_1.php
ABA small band clamps can be purchased on line at Hose Clamp King.
http://www.hoseclampkings.com/cat-44-1-52/304-ss-screw.htm
The difficult and expense way would be to use Stratoflex (now owned by parker) 156-5 hose with ABA clamps. Done this once, not easy but do-able.
http://www.aircraftspruce.com/catalog/appages/strato156.php
The -5 hose has an spec ID of 0.281" which make pushing this hose over a slightly larger 0.295" (7.5mm) barb not easy.
Service pressure of 1500psi, service temp -65 to +300 degrees F.
http://www.aero-hose.com/_docs/156 catalog.pdf
Quick Google search yields 7.5mm DIN spec hose.
https://www.belmetric.com/braided-metric-hose-oem-c-14_138/rh75-braided-hose-75mm-p-8316.html
The other possibility for the peeling hose is heat from an exhaust leak spraying hot exhaust gas at the hoses. Still, this does appear to be a fluid non-comparability with the hose material meeting the exterior.
Bernice