Been chasing other issues, now is my injection pump dead?

vagabond0351

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I know a million questions have been answered on the topic, but I'd greatly appreciate an analysis of my specific situation.

My last thread in this forum details some of whats below, and I thank you all again for the help thus far.

I posted this in the facespace group but I'm not seeing any replies.

Bought a 86 6.9 f250 a few years ago, now at 153k miles, had a number of problems I fixed one by one unrelated to the fuel system/running. One day the glow plug controller apparently stuck open and burned all the plugs, took me a while to figure out that whole thing[was completely new to diesels]. Got it seeming to work, truck was starting great for a while, running well enough, seemed kinda weak sometimes but figured "thats an old idi". After a summer ago driving it often, it started hard starting again even with the correct motorcraft plugs testing good. Its mostly just sat with a camper on it for about a year since. Today I went for a little drive and after warming up and filling up at a gas station, it stalled immediately after start. Started right up again, drove a ways down the road, felt maybe less power, stalled again when I let off throttle and on clutch. Start again while rolling, pulled into a parking lot where it kept stalling on me, and eventually wouldnt start again at all. As far as I can tell it has the original injection pump. It still has fuel pressure at the Schrader(holley red lift pump). Injectors themselves are freshly rebuilt from RussRepair. Return system has also been rebuilt with russ repair o-rings and r&d rails. No leaks detectable.

I've thrown a ton of money at this truck now, (plenty more than the above mentioned upgrades) please tell me I'm probably just due for the injection pump...
I didnt know to try pouring water on the IP, I'll be filling the filter with atf or something and trying it cool in the morning too.
Thanks

Ps... whats the best/most economical way to have one of these rebuilt anymore? I dont see the options on r&d or russ...


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WrenchWhore

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First of all. Nice truck! I rocked a big ol Lance on my old bullnose for years. Such a great adventure rig. I'm sure others will mention it's not recommended to put new injectors on a old IP. If the IP is worn it has to work extra hard to pop those new injector pressures like it's suppose to. They're recommended to replace together. With that being said I've done just what you did and had no issues. Doesn't mean I won't have issues later...You say the engine feels weak and has new glow plugs? Have you done a compression test? Do you still have the fuel selector valve? What exactly on the fuel system have you replaced? How much fuel is in your tanks? Do you still have the factory water separator? (mounted next to brake booster) All of these questions will help to narrow down the list.
 

vagabond0351

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You say the engine feels weak and has new glow plugs?
-yes, long story, took it to apparently the only shop in town that would touch it, they did a compression test and replaced the plugs, and immediately "ran the plugs on the manual switch for 20 seconds" in conjunction with an operational auto controller[rx diesel, installed before me]. For the past 2500miles, weak as in I'm not doing more than about 65mph with the camper, and need all of 1st gear to get moving. The day it died it felt weaker still like really not wanting to accelerate.
I drove it around the other summer without anything on the back and it was ok. It would get up to 85mph more or less fine(i have 35" tires). If i was towing a car up-hill on a dolly, it would eventually slow down no matter what gear until i was doing about 35mph

Have you done a compression test?
-Yes, sorta. Aforementioned shop said "all cylinders were equal just above 300" but couldn't give me a sheet of paper saying the numbers. This was 2 summers ago

Do you still have the fuel selector valve?
-yes, and I'm -pretty sure- it still works properly

What exactly on the fuel system have you replaced?
-most of the hoses, holley red lift pump just after selector, fuel filter, return bypass delete, return orings, return rails, injectors.

How much fuel is in your tanks?
-Was running on rear which was ⅞ full, then filled it all the way right before the stall. while it was doing its stalling I switched to front which was ½ full til the fill-up. Fuel was a little old(maybe 9 months) when this happened, but I run power service in both tanks, and had recently added heet as well.
Also again, had fuel pressure at Schrader.

Do you still have the factory water separator?
I actually bypassed it last summer(I know, bad, but I've barely run the truck since. If this thing is fixable I'll either put the 7.3 filter/separator on or a racor.)


Thank you
 
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The_Josh_Bear

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You're saying that you bypassed the factory filter, and now have no filter? I ask because: 1. That will ruin your IP over time and 2. Based on your symptoms this sounds like a clogged fuel filter, at least that's where I'd check. Do you have a pre-filter on or before the Holley? I had a little one on a cube pump years ago and it clogged up, took me 2 days to remember it was even there and delete it. -Flame Thr

I agree with @WrenchWhore that using new injectors and an old IP isn't ideal, but I've also done it and there weren't any major issues, they just wear down the already worn IP a little faster. That said...stranger things have happened, and if you're on the original pump 38 years and 150K later it's probably time to get a good one.

Did you fill the tank with gasoline on accident? ;Poke You did call it a "gas station"...rather than "fuel station".

Those tires/wheels look nice on your rig! Do they match our bolt pattern or do you have hub adaptors? Axle swap?
 
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WrenchWhore

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Your compression numbers aren't my favorite. If it was taken care of and only has 150K+ i'd expect compression numbers near the 400's but thats just me. When the glow plugs cooked when the controller stuck open did they all come out in one piece? Any broken ones? You can really kill a cylinders potential if it ingests metal. Scoring occurs and compression is down. An NA 6.9 won't be a powerhouse especially with a camper on its back and no turbo. With that said have you ever checked the timing? It only takes a few degrees to make one of these engines feel weak. Lastly if none of what I just said is the culprit and you believe the IP is your issue i'd take a friend in another car and replicate the issue. If it dies and the cool water brings the IP back to life I think it's safe to say the IP is weak. I'm cheap so i'd probably do a few hot soaks in ATF or Liqui-moly diesel purge to make sure it's weak. Personally I'd go with R&D for a IP but there are others as well.
 
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vagabond0351

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You're saying that you bypassed the factory filter, and now have no filter? I ask because: 1. That will ruin your IP over time and 2. Based on your symptoms this sounds like a clogged fuel filter, at least that's where I'd check. Do you have a pre-filter on or before the Holley? I had a little one on a cube pump years ago and it clogged up, took me 2 days to remember it was even there and delete it. -Flame Thr

I agree with @WrenchWhore that using new injectors and an old IP isn't ideal, but I've also done it and there weren't any major issues, they just wear down the already worn IP a little faster. That said...stranger things have happened, and if you're on the original pump 38 years and 150K later it's probably time to get a good one.

Did you fill the tank with gasoline on accident? ;Poke You did call it a "gas station"...rather than "fuel station".

Those tires/wheels look nice on your rig! Do they match our bolt pattern or do you have hub adaptors? Axle swap?
The water separator was bypassed, not the fuel filter. I'm running a new(less than 4000 miles) motorcraft fuel filter. None before the lift pump, and once more, I do have a couple psi of fuel consistently spraying out of the Schrader.
I am thankfully certain I put diesel in the tanks.
It did "feel like it was running out of fuel". But as I keep repeating, I at least had good fuel coming out of the Schrader on the filter.
I'll take that as at least a partial vote for 'replace IP'
 

vagabond0351

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You compression numbers aren't my favorite. If it was taken care of and only has 150K+ i'd expect compression numbers near the 400's but thats just me. When the glow plugs cooked when the controller stuck open did they all come out in one piece? Any broken ones? You can really kill a cylinders potential if it ingests metal. Scoring occurs and compression is down. An NA 6.9 won't be a powerhouse especially with a camper on it's back and no turbo. With that said have you ever checked the timing? It only takes a few degrees to make one of these engines feel weak. Lastly if none of what I just said is the culprit and you believe the IP is your issue i'd take a friend in another car and replicate the issue. If it dies and the cool water brings the IP back to life I think it's safe to say the IP is weak. I'm cheap so i'd probably do a few hot soaks in ATF or Liqui-moly diesel purge to make sure it's weak. Personally I'd go with R&D for a IP but there are others as well.
Yeah my understanding is they should be higher, but the shop wouldnt even give me a specific number, and I dont have proof they actually checked. In short, I dont have anything good to say about them. Dont really want to buy a tester that fits this if i dont have to, and as I mentioned despite being near a "city" with dozens of diesel shops, the shops around here dont want to even look at idis.

Shop didn't say any plugs were broken or hard to remove (they probably would have billed me even more if they were) but they said "they all tested bad".

Oh I forgot to mention I actually have a timing adapter for this, and was able to check it. Shortly after the glow plug situation, I turned it up about the max advance within spec[dont remember off hand what that equated to]
I still need to get around to testing if it runs again now cool, and yeah testing the water trick sounds like a good plan. Didnt get around to any of it today, too many other chores...
 
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The_Josh_Bear

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The water separator was bypassed, not the fuel filter. I'm running a new(less than 4000 miles) motorcraft fuel filter. None before the lift pump, and once more, I do have a couple psi of fuel consistently spraying out of the Schrader.
I am thankfully certain I put diesel in the tanks.
It did "feel like it was running out of fuel". But as I keep repeating, I at least had good fuel coming out of the Schrader on the filter.
I'll take that as at least a partial vote for 'replace IP'
Glad to hear it!

+1 on timing the engine, though I don't know why it would change so drastically. But it helps a lot, especially with N/A and low performance.

In my experience with a dying IP and heat soak, it never started and then stalled from heat soak. It was nearly impossible to start again after sitting for 20-60 mins. (the cool water trick worked wonders for that, years after it all started...:idiot:)

There's also the outside possibility that you are building return pressure somehow, which will kill the IP dead. I don't remember how much, something like 5psi and it's undrivable/dies. How that would happen is up to your return routing I suppose, I don't have any guesses. But if you unhook it at the back of the engine and blow LOW pressure shop air(10psi) through the line you'll hear bubbles in the tank, or not.

Another test is to skip the fuel system altogether and rig up a supply line from a diesel can on the ground and a return line straight from the IP return to same can or different. If it runs, you have a supply or return issue. Easy enough to hook one back up and see which, then start the real troubleshooting.
If it doesn't run, IP time.
 
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vagabond0351

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Glad to hear it!

+1 on timing the engine, though I don't know why it would change so drastically. But it helps a lot, especially with N/A and low performance.

In my experience with a dying IP and heat soak, it never started and then stalled from heat soak. It was nearly impossible to start again after sitting for 20-60 mins. (the cool water trick worked wonders for that, years after it all started...:idiot:)

There's also the outside possibility that you are building return pressure somehow, which will kill the IP dead. I don't remember how much, something like 5psi and it's undrivable/dies. How that would happen is up to your return routing I suppose, I don't have any guesses. But if you unhook it at the back of the engine and blow LOW pressure shop air(10psi) through the line you'll hear bubbles in the tank, or not.

Another test is to skip the fuel system alltogher and rig up a supply line from a diesel can on the ground and a return line straight from the IP return to same can or different. If it runs, you have a supply or return issue. Easy enough to hook one back up and see which, then start the real troubleshooting.
If it doesn't run, IP time.
Updated my other reply, forgot to mention I have timed it.
Havent heard about the return line pressure situation. I do have a modified system for the r&d rails, so I'll have to check on that...
 

IDIBRONCO

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Ps... whats the best/most economical way to have one of these rebuilt anymore? I dont see the options on r&d or russ...
Since nobody's mentioned it yet, Russ is no longer with us. He passed suddenly a few months back. Someone is running his web site and plans to do doing most of the stuff there. He did stop rebuilding IPs, what, a year or so back? You can still use R&D, Classic Diesel Designs, or Moose Diesel for fuel parts. I have to agree with Josh. This just doesn't sound like a dying IP to me either. I'd do some more checking before labeling it as RIP.
 

vagabond0351

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Since nobody's mentioned it yet, Russ is no longer with us. He passed suddenly a few months back. Someone is running his web site and plans to do doing most of the stuff there. He did stop rebuilding IPs, what, a year or so back? You can still use R&D, Classic Diesel Designs, or Moose Diesel for fuel parts. I have to agree with Josh. This just doesn't sound like a dying IP to me either. I'd do some more checking before labeling it as RIP.
Oh dang. Sorry to hear that. His sticker is on the back of my camper.

Small update. When otherwise cold, but after leaving the block heater plugged in for a couple hours to generally guarantee a quick start, it did fire off immediately, but then quickly died. Didnt really want to start despite being mildly warm. It would stay running with the accelerator half way down. I still have a clear line between the return rail and IP, and noticed a considerable bubble/gap forming there as it ran [no fuel flowing thru it]. Need to get a new strap wrench to pull my fuel filter apparently, but still had strong flow from the Schrader. Dont think I'm going to be able to run it enough to test the water trick
 

IDIBRONCO

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Oh dang. Sorry to hear that. His sticker is on the back of my camper.

Small update. When otherwise cold, but after leaving the block heater plugged in for a couple hours to generally guarantee a quick start, it did fire off immediately, but then quickly died. Didnt really want to start despite being mildly warm. It would stay running with the accelerator half way down. I still have a clear line between the return rail and IP, and noticed a considerable bubble/gap forming there as it ran [no fuel flowing thru it]. Need to get a new strap wrench to pull my fuel filter apparently, but still had strong flow from the Schrader. Dont think I'm going to be able to run it enough to test the water trick
This sounds like you don't have to worry about the water trick. You're getting fuel drain back for some reason. That's where the fuel drains back to the tank after the engine is shut off. In case you haven't yet, you may need to check the flow of your Holley pump. I know that it has some pressure at the Schrader valve, but how much? It would also be good if you had a way to test the flow rate, or at least had a fuel pressure gauge. There is a possibility that your Holley is getting partially plugged. I believe that it was in Hot Rod Magazine a long time ago. I read that you should have a filter before your electric pump to keep crud from the tank out of the pump and another one before the carb, to keep possible debris from the pump out. Fuel tanks will get deposits built up in them after several years. Even if you keep everything clean, it still happens from fuel sitting for long periods of time. There may even be debris from a pump or it's rubber hose that goes the the nozzle.
 

Rocknit4x4

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Another thing worth considering - I was having the stalling when pushing the clutch in on my truck - turns out there’s a TSB on this subject and ford found the problem to be USLD can be “dryer” or something - basically buy and use the stanadyne fuel additives. If you look into it there’s been a lot of guys that confirmed it makes a difference for some aspects of performance - it worked for my truck. With your other issues this may not be right on the target but worth keeping in mind. I seem to have the issue every year in the fall 2 years in a row - new pump, new injectors, new returns, new tanks, new shower heads, still had the issue - was thinking about another pump when I found the TSB, $10 worth of additive fixed it up.
 

vagabond0351

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This sounds like you don't have to worry about the water trick. You're getting fuel drain back for some reason. That's where the fuel drains back to the tank after the engine is shut off. In case you haven't yet, you may need to check the flow of your Holley pump. I know that it has some pressure at the Schrader valve, but how much? It would also be good if you had a way to test the flow rate, or at least had a fuel pressure gauge. There is a possibility that your Holley is getting partially plugged. I believe that it was in Hot Rod Magazine a long time ago. I read that you should have a filter before your electric pump to keep crud from the tank out of the pump and another one before the carb, to keep possible debris from the pump out. Fuel tanks will get deposits built up in them after several years. Even if you keep everything clean, it still happens from fuel sitting for long periods of time. There may even be debris from a pump or it's rubber hose that goes the the nozzle.
I greatly appreciate your experience and advice, but I just want to confirm, are you saying that the drainback issue would cause it to stop running while driving? Or are we thinking that's secondary to a somehow clogged fuel pump despite the flow at the schrader? I'll put a gauge on it here soon and update this post. Unfortunately my gauge is a standard gasoline type with a higher range than the couple psi this system runs, but the needle still comes up a tic.
I was suspecting the gap in the lines now was from the IP not putting enough fuel out for there to be 'excess' sent to the return line system, but I am still pretty ignorant of the details there, I've only replaced the parts to prevent air intrusion. Maybe my clear lines are hardening and no longer sealing well enough... I just feel like I'm chasing my tail here with -possibly- related or the same or completely different problems 2 years later on the same old engine

rocknit, thanks, that seems a bit absurd that the truck would completely die and be unable to run simply due to additive, and I do run additive, although the stuff in the tank was a little older until I just refilled it...

oh Josh if youre still reading: the wheels are matched to the hub, no adapters. theyre black rhino brand. P/O worked at a tire shop and thats the only thing he seemed to have done semi-right. the lift is decent I guess just taller than I would have done.
 

IDIBRONCO

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are you saying that the drainback issue would cause it to stop running while driving?
It can. It can make it so the engine starts up normally and then dies when the air gets into the injector pump. Air will replace the fuel as it drains back to the tank. Then it's a major B-word to get the air bled back out so that the engine has fuel again. This only happens on start up.
Or are we thinking that's secondary to a somehow clogged fuel pump despite the flow at the schrader?
It is possible that they are related. On my first 1985 F250, I had a universal inline filter before my cheap electric pump. The truck would have air in the fuel system. Once it got started, then it would run fine. It finally got to the point where the engine would starve of fuel at higher RPM. I finally had a light bulb click on and checked that inline fuel filter. It was pretty clogged. Once I replace it, I no longer had the problems. The only thing that I can think of is that the restricted filter held a little bit of a vacuum on the fuel after it went through the filter. That would be enough to make the fuel start draining back to the tank.
I'm not saying that this is your problem, just that it's a possibility.
 

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