Help getting a 6.2 to start...

[jeeper]

I got a used 6.2 engine and have it mounted in my frame. I wanted to start it before I put all the sheet metal back on. (This is a restoration modification of an old military Jeep pickup).

I placed a 5 gallon diesel can under the front of the truck and stuck the input of the new mechanical fuel pump into it. I cranked the engine over to see if I was pumping fuel. I was not. A few pumps of a brake bleeder later I had the new mechanical pump primed. It pumps fuel when I crank the engine.

Next I loosened the screw on filter at the back of the intake. I cranked it until I saw fuel spraying out of the seal. I stopped and tightened the filter.

Next I loosened the hard injector line at the injector and cranked it until I saw the fitting getting wet. I tightened all the lines back up. I then removed all the glow plugs and cranked the engine over. I could see a mist coming out of the glow plug hole on #8.

I replaced all the glow plugs and tried to start it. It still does not start.

I am not using a glow plug controller. I currently am holding the glow plug wires to the positive side of the battery for about 6 seconds before I try to start the engine.

I know the glow plugs are all good. I have tested each one. I also get a nice spark when I touch the wires to the battery positive.

As far as I can tell the glow plugs are AC Delco 60g's. Should I be firing them longer than 6 seconds?

When I first tried to start it I could see some white smoke coming from the exhaust manifold. I don't see that anymore.

I do hear the IP solenoid click when I power that on.

Is it possible I still have air in the fuel line? What is a better way to bleed the air than what I have tried?

[john8662]

keep bleeding, crack more injector lines open and try again.

[jeeper]

Okay. I've been spinning my wheels on this for a couple evenings now.

I'm wondering if I should have fuel coming out of the return line on the front of the pump? I do not.

I put a brake bleeder on the pump return and created a vacuum on the port. Fuel does inch out but I never lose the suction of my bleeder while I crank the engine.

I'm assuming this means something is blocked. What is it?

The solenoid does click when I power it on.

[Robyn]

Take out all the glow plugs once more and spin the beast until you have a fog of fuel coming out the holes.

Install the plugs and glow it for 10 seconds (make sure the plugs are getting RED hot on the tips)

60G plugs are very forgiving and can take a fairly long glow time.

If you have fuel, and heat at the plugs, it will run.

You might be just a tad short on the glow time.

Are you seeing any white smoke out the exhaust ????

Missy

[jeeper]

I'm not seeing white smoke out the exhaust. I do see it if I pour diesel or spray wd40 into the intake as I crank it over.

I'm thinking I may not be energizing the correct solenoid on the IP. I have three on it.

I know the one on top is the high idle solenoid.

I have one solenoid that blocks the return line in the rear of the IP.

I have one solenoid that appears to be pushing on a rod inside the IP.
http://img521.imageshack.us/img521/3483/79009724.jpg
Am I supposed to energize both solenoids? What is the purpose of the solenoid that actuates that rod?

[DmaxMaverick]

In the order you listed them:

1. High idle, as you stated. Energized via temp switch, same as HPCA. Some systems also incorporate this with the A/C compressor to increase engine speed with A/C engaged (increases A/C efficiency). It's a passive solenoid, meaning when energized, it will not "pull" the throttle, but will hold it at the preset when the skinny pedal is pressed.

2. HPCA (Housing Pressure Cold Advance). The increased housing pressure advances timing for cold starts. This should only be energized via temp switch. The timing can be advanced at any time using this circuit. Very handy for setting pump timing or troubleshooting some fuel system issues.

3. ESS (Engine Stop Solenoid). Stops the fuel flow to the IP when de-energized. No more complicated than it sounds.

[jeeper]

Thanks.

When I look at this setup I am a little confused as to how that j-hook on the solenoid pushes that rod and what pushing the rod actually does.

I'm guessing that the j-hook actually pushes on the rod above the horizontal throttle rod in the picture. I am sliding the cover on from the top of the picture to line the screw holes up.

I'm also assuming that the vertical rod that the arrow is pointing to is slid down by the solenoid to allow fuel to pump?

I know what happens when I assume though. Am I missing something?

I have cranked the engine over with the glow plugs removed for several minutes. Not all at once. I do not see any spray coming out the glow plug holes. At this point I'm assuming I am not pumping fuel for some reason.

I did see this engine run before it was pulled from the truck.

[Robyn]

There are two electrical connections on top of the IP

Connect power to BOTH
The one thats up near the return line nearest the front of the engine is the shutoff.

The rear most one in the HPCA (cold advance)

The outside solenoid on the linkage is just the fast idle.

Turn the key on and with the IP disconnected, touch the power wire (whatever your using to run the IP) to the front most connector on the IP, there should be an audible CLICK from inside the IP.

The HPCA will normally not make any noise when power is applied.

Once you hear the CLICK, the thing should run when you glow it and then crank it over.

I am suspicious that you have not had power to the shut off solenoid and this is why it will not start.

The HPCA connection and the fast idle solenoid (on the linkage) should have 12V routed through a temp sensor that opens at approx 120F
This can be located in the RH head near the rear (side) or it can be located in the RH side of the water crossover.
As this is a conversion, its your choice as to how to wire it up.

Just be sure to use a temp switch that is closed when the engine is cold and opens at 120F
This only controls the HPCA and the fast idle solenoid for cold start and warm up

The engine will Rattle a lot more with the HPCA powered ON.



Missy

[jeeper]

There are two electrical connections on top of the IP

Connect power to BOTH
The one thats up near the return line nearest the front of the engine is the shutoff.

The HPCA will normally not make any noise when power is applied.

Once you hear the CLICK, the thing should run when you glow it and then crank it over.

I am suspicious that you have not had power to the shut off solenoid and this is why it will not start.

Missy


Thanks for helping me with this.

I do hear a click when I power on the shut off solenoid. I have even taken the cover off and held it against ground (-12 volts) and watched the solenoid pull in. The shut off solenoid is definitely working. I am also definitely powering it on before (and leaving it on) I crank the engine over.

I just went out and bought 2/0 battery cable because I have been told by a friend I may not be spinning the engine fast enough. I have a newer style gear reduction starter installed and it is cranking the engine over plenty fast. It is definitely spinning a little faster with 2/0 compared to th 2 gauge that I had been using.

I have removed all the glow plugs again and am spinning the motor over expecting to see fuel spray out the holes. I do not see fuel coming out at all. I even put my finger over the hole to see if it gets wet from fuel and it does not. My finger stays dry.

It is as if the injector pump is vapor locked. Is this even possible?

I'm afraid I may be missing something terribly basic.

I'm also wondering if it is possible the pump quit between hearing it run in the old truck and dropping it into my truck.

[Robyn]

If the IP is energizing then the issue has to be fuel delivery to the IP.

Once you get fuel to the IP and crank it with the glow plugs out, the fuel should BLOW out the glow plug ports in a misty cloud.

Once the fuel starts coming out, you can't miss it, its is very obvious and you will SMELL IT :eek:

Make sure you have fuel delivery to the IP coming through the filter and the lift pump.

The injection pumps can get full of air, but cranking with the glow plugs out will purge the air from things very quick.

Just make sure you have good fuel delivery to the IP from the lift pump.

Keep us posted

Missy

[DmaxMaverick]

You need to verify the lift pump is actually pumping fuel. The mechanical pumps have a weep hole on the pod, and if there is ANY fuel at that hole, the pump is shot. Even if it will pump enough to fill a container, it won't develop any pressure. Remove the IP inlet and install a gage. Crank the engine for 5-10 seconds. The pump should be providing 4-9 PSI. A "vapor lock" is possible, but only if the LP isn't working. The IP has an internal transfer pump, but will rarely "self prime" (especially on a worn IP). If you've pushed air through the IP, it can take a LOT of cranking to push enough air out to actually "pop" the injectors. If you loosen the injector lines and get fuel weeping while cranking but no fuel into the cylinder, air lock is more likely (and a bad IP is less likely). Verify fuel supply, then purge the system downstream. Once you confirm you have air-free fuel supplied to the IP, loosen all the injector line nuts and crank until all of them are wet with fuel (20-30 second intervals, with at least 2 minutes between, to prevent overheating the starter). Once all the injector lines are showing fuel, tighten them and continue cranking until the glow plug holes are misting fuel. Install the GP's and it should start. AC60G plugs can take twice the glow cycle time as previous plugs to get hot enough to fire off. 15-20 seconds should be a good starting point. More or less later, after you have a running engine. If you use quick heat plugs, no more than 8 seconds will get them as hot as they can.

[jeeper]

Thank you thank you thank you all.

It finally roared to life this afternoon.

I guess I just wasn't cranking the thing over long enough. It took waaaay longer to get fuel to the injectors than I was expecting.


Again, thanks for helping me.

[Robyn]

Normally, when I have done an overhaul on one of these, it takes about 20-30 seconds of continuous cranking with the glow plugs out to get fuel out the plug holes.

This is after first making sure I have fuel flow to the IP without air in it.

Once that happens its roll it over until the fuel mist comes out the holes.

This is very easy on the starter with no compression in the engine, plus the engine will spin a LOT faster too.

Cranking one of these on compression with dry lines all the way is a bloody career and really heats up the starter and your "Patience" :rolleyes:

Glad to hear that things went well.

Missy

[jeeper]

Just to tie this up with a bow I thought I'd share this for anyone who stumbles upon this in the future.

I discovered what was causing the lines to take so long to prime was a small leak on my fuel line coming from my tank. I had a rubber hose connected to a short piece of steel line that was just sticking into the top of an open 5 gallon gas (diesel) can. I had a hose clamp on it but didn't have it tightened tight enough.

The lift pump was able to draw fuel from the tank but was sucking air at the same time. I was not getting enough fuel to the injection pump therefore it took a long time to prime the lines.

I have since got my fuel lines run back to the truck fuel tank and installed an electric lift pump near the tank to prime the line up to the mechanical fuel pump on the engine. The electric fuel pump is only used to re-prime the line if I run out of fuel or change a filter or whatever.

[Robyn]

Glad you got it sorted out.

Diesels do not like air AIR , not even :eek:

Just a tiny bit will cause issues, especially if the system is dry.

Keep us posted on the progress, and do post some piccy's of your project.


Missy

[jeeper]

Here is a short clip of the first start. (http://www.youtube.com/watch?v=C2HOCvWE0qk&lr=1&feature=results_video)

Thanks for all the help.

I do have another question now though.

When I start the engine from cold it starts great and idles fine. As soon as it gets warm it starts "missing" and quickly shuts down. When I feel the crossover it is pretty warm but not hot enough to burn me. The thermostat may or may not be opening. I will put a new one in to be sure. The upper rubber line is barely warm to the touch at the point it dies.
When I try to restart the engine immediately after it dies it just cranks and cranks. If I let it "cool off" for a few minutes it starts fine again.

What may cause this?

[jeeper]

I am guessing at this point because I haven't pulled the pan but I think I may have a spun bearing.

I have read a lot of old threads around the Internet and many of them say just get another engine because they are so cheap.

Around here that isn't as easy as it may be in other parts of the country. Salvage yards around here don't have any vehicles that old to choose an engine from.

I don't know what the oil pressure is/was because I haven't got any gauges connected yet.

At this point my symptoms are the engine will turn over very slowly.
It makes a squeaking noise like metal grinding. (I haven't spun it any more since that started happening.)

Is it possible to put new rod/main bearings in the engine from below the truck or is another engine pull required?

I guess I get to drain my 7 quarts of new oil and pull the pan to investigate.

[DmaxMaverick]

If it's cranking at all, even a little or very slow, it's probably not a spun bearing. More likely a broken flexplate, flywheel/clutch issue (whichever applies), bad starter, bound up tranny, or an accessory at the front end (to begin with, in no specific order). Also check battery health, wiring/connections, and starter alignment and engagement (make sure the front support bracket is in place, and a bolt or block isn't broken). It helps during this exercise to pull all the glow plugs, which takes away compression until you can get it worked out (batteries last a lot longer and it won't kill a good starter)

You can do an in-frame overhaul, but it's a lot less inconvenient to just pull it out.

[jeeper]

Well I've pulled the pan to inspect. I think I do have a spun bearing.

http://img821.imageshack.us/img821/9446/dry1a.jpg


The top arrow is pointing at where I rubbed a drop of shiny gray (read metal flakes) oil from the crank. The other arrow is pointing to a bone dry rod end. All the other rod ends are covered with clean oil.

The oil pan itself is very clean. Almost no sludge. No metal shavings anywhere.

What are the chances the damage is minimal enough to put a new bearing on that rod and run it?

[jeeper]

It is definitely a spun bearing. Where do I go from here?

http://img11.imageshack.us/img11/5650/spun2.jpg

http://img688.imageshack.us/img688/1001/spun1.jpg

[DmaxMaverick]

2 options:



Start over. Get a new engine and toss the old.
Determine the cause, THEN repair yours.


Just repairing the crank/rod, etc. will likely have you revisiting this if you don't find out why. They don't do this all by themselves. They are very forgiving, and don't self-destruct. 6.2/5 engines rarely ever spin a bearing, and when they do, there's always an outlying cause. Oil pump drive, oil cooler line rupture, or some other oil system failure. Could also be a broken crank, which does happen from time to time. Some of these have ran thousands (and tens of thousands) of miles with a broken crank before they let go completely.

[jeeper]

Well I pulled the engine a while ago and thought I'd share my embarrassment with everyone.

I realized why my rod bearing was dry when I started attaching the chain to the back loop to pull the engine.

I had replaced all my accessories on this engine. I also replaced the egr manifold with a j code. I couldn't get the back bolts off or on with the vacuum pump in the way. I forgot to bolt it back in place after I had the intake on. When I went to attach the chain to the loop I noticed the vacuum pump sitting up out of the hole.

[john8662]

ran with no oil, ouch.

I'd do a complete disassembly, have the crank turned .010/.010 have the rods resized on the big ends.

have the block vatted, cleaned, checked, put it all back together with new cam, rods, and mains.

I've done simularly bad things to engines, sorry man.

[Liftgate]

Don't feel bad dude. I almost did the same thing. Removed the intake plenum and the vacuum pump at the back. Was doing some work at the steel injection lines to stop leaks. Tried to start the thing and thank God it wouldn't. Then I remembered about the vacuum pump and oil pump drive. :eek: The next thing I did was get my electric drill and hook up a bunch of hex sockets and prime the oil system by running the drill to turn the oil pump drive gear way down in the engine. I havn't had it running yet because I replaced the injection pump so I hope I don't have any spun bearings. Good luck to you and your jeep. :)

[IUPAC]

After 6 years of sitting, I finally took the first step of restoring my 87 V2500 GMC. The truck is almost stripped (only the cab and hood remain) to the chassis. I have most of the parts to put it back together. Before going any further, I wanted to make sure the engine ran as well as did when I parked it. (Mouse damage to the wiring under the dash caused a draw on the batteries, leak in the fuel tank and brake lines needed replaced.) Following the advice posted in this thread, it fired up the first time I attempted it.
1. removed glow plugs
2. removed fuel supply and return lines and placed new hose from lift pump into a fuel can
3. primed fuel filter
4. cranked until fuel came out of the glow plug holes
5. re-installed glow plugs
6. fired it up
Thanks for the great thread! Very helpful!