Another Injector Pump Question

[Massboy]

Hello,
I have a friend who has a 86' M1009 that is having some issues.

1. Starts pretty darn good cold w/manual push button on glow plugs.
2. Starts pretty good when warm but after long drive and hot, will not start right up.
3. Surges a lot on highway when holding pedal steady
4. Runs steadier when going faster
5. Low on power (slow on takeoff and can't tow anything)
6. Surges or rolls at idle
7. When coming to stop, surges a lot and almost stalls but doesn't
8. Removing oil fill cap when hot or cold shows no blow by
9. No real smoke from either tail pipe
10. Symptoms have gotten worse.

This blazer has little power compared to my own that has lots of power and will tow or plow anything.

I am leaning to the injector pump but this thing starts right up like a new one at least when cold or just warm. Could the high pressure side of the pump be bad or sticking. I have a good used pump that has been turned up slightly. Will it be OK to install in the stock M1009 motor. I noticed that my pump (still on the low compression parts motor I have) is also advanced of the timing mark. Do turned up pumps need to be advanced when installed or do you just adjust a little at a time like any other pump to achieve the "proper" running conditions?

Thanks in Advance

 

[yellowK20]

Check the lift pump and also check the fuel filter make sure its not sucking air.

BUT it does sound like the pump is going out

 

[Massboy]

New lift pump 4-6m, new fuel filter 1wk, and no leaks. Those are the first things I told him to check/change. Previous owner had put an electric pump on it as the lift pump was bad but it's been running with the mechanical pump and the electric pump disconnected for the last 4-6 months. Reconnected the electric pump as a test and no difference.

 

[diesel4me]

I've read that a blocked up fuel return line will stall a 6.2,maybe its got a restriction in the plumbing from the injectors & pump,back to the gas tank??..also supposedly there is some kind of check valve in the return line somewhere that can clog up and give troubles like these...

 

[yellowK20]

I've read that a blocked up fuel return line will stall a 6.2,maybe its got a restriction in the plumbing from the injectors & pump,back to the gas tank??..also supposedly there is some kind of check valve in the return line somewhere that can clog up and give troubles like these...

Restriction in the return line will cause overspeed issues, IE high idle surging should not occur with return line issues.


But that being said it wouldn't hurt to check.

 

[scotto0609]

I've read that a blocked up fuel return line will stall a 6.2,maybe its got a restriction in the plumbing from the injectors & pump,back to the gas tank??..also supposedly there is some kind of check valve in the return line somewhere that can clog up and give troubles like these...

I can verify this as I just put in a new sending unit and pinched the fuel return line. The truck stalls as soon as I switch the tank,but will run fine if I straighten in out. Looks like I will be dropping the tank again this weekend! hope this helps.

 

[Mrpandazz]

I know this is pretty old, but Id like to see if you got it working right. I seem to be having a similar problem with my M1028. I'm learning as I go plus i'm a broke student so id like not to replace the IP if i don't have to. Thanks

 

[Massboy]

Ok guys. My buddy never did anything until it would hardly move. My buddy (actually a young man who is more like one of my kids) is a procrastinator and I kept telling him he should change the pump. My old worn out motor had a good pump and lines on it so I took it off the motor as an assembly w/lines for him. My buddy, again, is a PITA and said his lines were like new and the ones on my pump had a little surface rust on them and he wanted to change them. I told him absolutely not as they are all on, not leaking, and why would you want to screw with $hit you don't need to. (he is much younger than me and not a real good mechanic, thinks he is, but he isn't) Anyway, I downloaded the directions for pump removal/replacement, had him pull it in MY garage and told him to get started. I was going to help him from the start but he got to my house at 3PM, only 5hrs later than he said he would. (I know, I'm a sucker for punishment) He got the plenum off and the lines undone and everything else out of the way other than the pump itself. This ONLY took him until 7pm and when I went into the garage I couldn't believe he wasn't bolting the replacement pump up yet but still removing the bad one. Turns out the pump wouldn't just slide out of the timing gear so I gave it a light tap with a hammer on a drift pin and it came right out.
Now the next project; for the following day because he had to go: leaking valve covers. turns out when it was still in active duty someone in the motor pool went happy with orange RTF. It was smeared all around the valve covers and plenum yet they still leaked. Of course now is the perfect time to re-do them. It was his intention the whole time (finally something smart on his end) so he came prepared or what I thought was prepared. I'm old school and use Indian Head Gasket compound on all my gaskets. I hate RTF as it usually causes more problems than it fixes (yes, I know there is certain areas where it is best, but not on cork valve cover gaskets). My buddy removes all the orange RTF and decides to use gray RTF because "everybody uses it with no problems". I wasn't helping him at this time as I had gotten pretty pissed off at him because he can't even use a ratchet wrench correctly. He works like most younger generation people do these days, SSSSSSLLLLLLLLLLLOOOOOOOOOWWWWWWW motion! Well he puts the valve covers back down, not realizing that you should always tap out any depressions in the gasket area especially where the cover bolts go through. Now once they're down, and again, too much gray RTF around areas, he asked me for my help as he wanted me to check the pump which he thinks he got in correctly. I take a look and he had the timing pin in one of the bolt holes! Can't figure this kid out. I move the pump back, rotate it a little, and it goes right in with the timing pin in the oblong hole.(did he read those damn directions I gave him?????) I put the first bolt in and this time I worked the wrench on the harmonic balancer bolt myself from the top side. It was agony listening to him complain about how hard it was to get the motor to move enough so I could line the bolts up in the pump to take them out when he did it from underneath the truck. With the pump bolts installed, I tightened all the injector lines then went to put all the glow plug wires back on as he had removed them when doing the valve covers. (he isn't smart enough to figure out he could have been doing that while I was putting in the pump) As I'm putting in the #8 GP wire I can see a black wire going under the VALVE COVER! The SOB got a wire under the damn cover and tightened everything back down! Now off come the injector lines from the injectors and out come the valve cover bolts. I lifted the cover enough so that he could pull out the wire with the grounding lug on the end. Back to the finishing of the job now. I'm up under the hood and I put the plenum gaskets in place. I then ask him for the plenum. As you all know there's not much room when you're kneeling on the radiator support and your knees are getting cut up by the sheet metal ridge GM put there just to piss us off. He gives me the plenum and I put it down on the motor. Working on the driver's side I ask him for the piece of cardboard with the bolts in it.(I showed him how to use cardboard to keep track of where each bolt goes. Well, I start to put the bolts in and realize they aren't matching up. By now my patience is gone and I start yelling at him and tell him he must have switched the cardboards from each side. He swears he didn't and turns out this is about the only thing he is right about. I'm frustrated again and tell him to give me the cardboard for the pass. side. Again the bolts aren't right and then the light comes on in my head as I look down at the plenum and see that the # 7 was at the front pass. side. Now I'm really pissed and said to him that he gave me the plenum rotated 180d from what it should be. He replies: " I didn't know there was a difference". You guys need to understand, this kid works for a large commercial truck leasing company, has been a parts manager, and a service manager. Claims he has rebuilt a performance motor in a mustang, etc. Anyway, I jump down from under the hood and tell him I'm done and walk in the house. He leaves three hours later at 1am! I go out to the garage the next morning to find in those three hours he was able to get the plenum turned around and bolted down. Yes, that's it!
Day three: I can't believe a 3-5 hour job has taken this long so I decide I have to work with him to get it done. We put all the wiring back in place in the looms that he had taken out and still not put back in, and I button everything back up including belts etc. I set the pump to just a slightly advanced position because that is the way it was on my old motor and we start the process of purging it of all air. After about 10 minutes of cranking and giving the starter a break, it starts and runs. Once it warmed up it would run but smoked a little and I just moved the pump ever so slightly a little at a time until the smoke disappeared and it ran well. (be sure to adjust pump only when the truck is shut off). Now he and I take it for a ride and it is just like a new truck accelerating perfectly, idling perfectly, if not a little too low and no smoke. He's happy as a pig in **** and so am I as I'm thinking he will now be done and out of my garage. Well, now I go in the house to relax with my wife as he is going to clean up the garage and look for any oil leaks. GUESS WHAT? Huge oil leak from the driver's side valve cover. That fantastic RTF that everybody uses caused the gasket to slip out when he put it in place. Yup, it doesn't happen with the Indian Head that I told him to use as you let it dry overnight. Also, because he never leveled out the bolt areas you couldn't pull the covers down tight enough. This time I let him fix it all.

Sorry for the long post but I thought you guys would get a kick out of a 3-5hr job taking about 3.5 days! I'm sure this kid will tell everyone just how hard it is to change the pump and how he never wants to do it again.LOL He'll probably try and brag to others about the job "he" did.

The problems experienced in my first post were definitely caused by the pump. The truck runs perfectly and an old 6.2 mechanic he took it to after we were done told him to leave it alone (something this kid has a hard time doing) as it sounded and ran perfect to him. If you are getting the same symptoms your pump is on it's way out.

 

[Mrpandazz]

Thanks for the reply, even if it made me a bit nervous about the job

I don't claim to be a mechanic by any means but I tend to follow directions pretty well and have some patience. Plus my uncle is a mechanic with diesel experience so he should be able to help.

 

[Massboy]

First thing look on the internet and download the directions. Get a plenum gaskets set with the injection pump gasket included. If the box says it's included still check as his came without the pump triangular gasket. It's not a hard job at all. It was my first time doing it and to me it was actually easy. If your valve covers are fine then it should go fairly quickly. If you get a pump without any lines attached number the lines in order before you take them off your pump so they go back in the proper locations. Always remove the pump from the motor with the lines attached. It will look like a big spider. I would start at 1 o'clock, numbering that line #1 and then go clockwise looking at the rear of the pump where the lines bolt up. You will need metric sockets and wrenches to do the job. The hardest things usually tend to be the plenum studs that have a nut on them which are used to hold wires like ground lugs. You will try and loosen the nut and the whole stud turns. You will need either a thin 15mm open end wrench (to hold the stud underneath the wire lugs under the nut) or if you have an air hammer, try putting a socket over the nut and lightly vibrating the socket with a blunt air hammer point. This will usually loosen up the nut enough that it will come off the stud. I'm sure your uncle will think nothing of the job. Because the IP is the heart and soul of the motor I think most tend to think it's got to be a big job. I'll do a injector pump over a transmission job any day. Even a starter is more of a PITA than the pump, at least I think so.

 

[Mrpandazz]

Thanks for the info! I'll probably be tackling this in the next week or so, and im pretty pumped to get this thing on the road again.

First ill go through and make sure its not anything more simple since I only got to work on it an hour or so and I live away from home while in school.