No start after IP. Shocking.

Alright, so, I got this old 1986 6.9 with a four speed abandoned at my shop. The guy finally sells it to me, and we fiddle around with it, do an ignition, all the fluids, a couple of burned out glow plugs a fuel injector line kit, and got it running really nicely. I was starting it and idling it for a couple hours every couple days while i was working on getting it all legal. The day i went to take it home, checked everything one last time, it fired right up, idled fine for 20 seconds and died. A bit of cranking and away we went.

Got it home, started checking it all over and found out that my truck made about 2 quarts of oil in that 45 mile drive home. Now, I'm but a humble toyota technician, but thanks to this site, I gleaned enough information to deduce that when i started it to bring it home, the diaphram inside the lift pump let go, causing it to die, and subsequently hard start, as well as dump some fuel into my crankcase on the drive home. Did the lift pump, changed the oil, again, and test drove. Still making oil. Again thanks to some good info here, i found that the injection pump can leak around the shaft and down the little oil fill riser deal. Bummer.

A guy i work with has had a couple of these trucks and thus, had an IP laying around which he donated to my cause. Doing the IP seemed pretty straight forward, nothing moved, and I have working cutoff solenoid. Lined the marks up on the IP and cover. It is maybe, MAYBE, if that much, a dimes width to the drivers side if viewed from straight on.put everything back together and snugged down. But it will not start, and i have cranked on this ******* a ton.

I have fuel at the schrader valve and noticed that the threads on the hard line at the number 1 injector are leaking, probably because i bunged them up, but there is fuel that far. I am going to pick up an injector tomorrow and hoping napa can make me a line. With all of that said, would that leaky injector keep it from starting all together? I know these are sensitive to air intrusion, but i wouldnt think that much so. Would the slight advancement from static keep it from starting all together? OR did the dickbutt at work just give me a bunged up IP? I'm at my limit and would like to get this nonsense wrapped up quickly. Thanks in advance.

-Josh

My opinion, not likely. These are mechanical so they have to hit a certain psi to get the injectors to fire. Any air bubbles will lower the psi since they can compress.

Will 1 keep it from not running? No, it would keep that cylinder from running so it should run but rough.

I am guessing you still have air in the lines. Took a solid 30 minutes of crank for 10 sec, rest for 2 min, and repeat until the air was out for me.

Oh, and you'll know you're close because you will start to get white smoke out the tail pipe. If you're not getting smoke yet, your injectors are not firing yet.

I wouldn’t think one injector would keep it from running. We check them by cracking the line one at a time and it barely interrupts the idle. You said the IP is lined up slightly to the drivers side and used? Used pumps retard timing and to the drivers side retards the timing. I’d turn it to the passenger side, then try to bleed the system. After that, I’d suspect a bad pump. I’m no expert, but that’s where I’d start


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Thanks! Well, I had that much backwards. I will loosen it up and roll it back a hair and see what happens. I thought the same thing about the injector but was unsure and wanted to ask those who know more, before yanking this pump out, just to put the old one in, before locating a new one just to...you get the idea.

Btw, the IP leaking should *not* put fuel into the crankcase. There are three seals on that shaft to keep fuel and oil apart, and a drain hole right at the bottom of the IP. If you get fuel (or oil for that matter) leaking past the seals, it will drain out the weep hole at the bottom-front of the IP.

The earlier models of the Injection Pump did NOT have a weep hole.

Rob I gotta disagree there, I’ve had plenty of leaking pumps come in that were dry at the weep hole, a lot of times the hole could be plugged but usually they don’t leak from there.

When changing the IP, did you pull the top gear cover completely off? I have never done it before, but I have heard that is a no-no with the chance of the gear getting a tooth or so off. To check it and line it back up is a real pain because it's hard to see the marks on the other gears below.

Thewespaul said:

Rob I gotta disagree there, I’ve had plenty of leaking pumps come in that were dry at the weep hole, a lot of times the hole could be plugged but usually they don’t leak from there.

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I agree that they don't leak from there usually - but you are telling me that those pumps leaked past that hole, into the crankcase, without leaking from there?

Usually, in my experience, they leak from the light load advance plunger seal. But that leaks out onto the valley pan, not into the crankcase.

I took nothing apart and marked everything. I removed the three 12 points under the oil fill neck, the three on the back, throttle linkage, and three electrical conectors. I Swapped the lines on a bench.

As far as the fuel in the oil, if its anything other than the IP at this point, its a project that is sadly beyond me. I don't have the time or inclination to yank out and rebuild a motor when I already have a dedicated project. It ran far too good to have some kind of base engine problem imo, but ive been fooled before. I'm about to get some lunch and start in on it again. Update soon. Also, when i pulled the IP out, the snout seemed pretty wet, but that could just be me wanting it to be that.

Did you say you replaced the lift pump? I seem to recall the lever goes under the thing it rides on in the engine. If it went above I'm not sure what would happen. Would it tear the new diaphragm? I'm not sure. Everything you've said would seem to indicate a torn lift pump diaphragm. You might want tp pull out that new lift pump and check.

I did put a new lift pump on it, and it started fairly quickly and drove nicely on a test drive and started it fine a few times to move around the shop. I am not overly skeptical of the lift pump because the old one didn't seem to do anything different than the new one, when air was applied (sucking/blowing into it). I even almost put the old one back in after "testing" it compared to the new one, but for the amount of effort that thing takes to R&R and not knowing the age of the old one, i put the new one in anyway. It seems like it would be pretty hard to get that arm over the cam, unless you were trying to.

I rolled the ip back a little, got fuel to the schrader valve, and then the batteries started getting weak. Ive yet to see this thing cheech any smoke at all.

Nothing. Not a single huff of smoke of any kind. Bad IP? I dont see how i couldve crossed any of the lines or anything stupid like that.

*Edit* There seems to be a healthy amount of fuel at the return line on top of the I.P. as well, if thats helpful.