Avant 6.2 Saga.. The Movie

[Garand Fellow]

The story so far...

Our hero, a Wyoming boy, purchased an Avant 6.2, paying extra for gear-drive timing mechanism, ceramic coated pistons, balanced rotating assembly, complete fuel system and pre-shipment run-in and set-up.

In Episode Two, the motor arrives and is installed. Alas, the flex-plate was not torqued down before shipping and the resulting damage necessitated additional labor for the installation of a new flex-plate.

In Edisode Three, the motor consistently showed very high EGT's. At Avant's suggestion, the fuel metering and pump timing were changed.. with no change to EGT.

In this Episode, the truck has been in the shop for three weeks now. The shop has attempted to time the engine, but is unable to get the timing to advance past dead zero. Word comes from Avant that there is probably an issue with either the fuel pump or the timing gears were improperly assembled when the motor was built.

As we move in closer too the campfire.. the trusy diesel shop is waiting for word to come down from Avant of what to do next.

Watch for future episodes.

[britannic]

Based on your earlier descriptions, it sure smells of a mis-timed camshaft since you aren't able to change things at the pump. :confused: :eek: :rolleyes: I really sympathize, it's got to be very frustrating after all of the money and time you've put into this project and still no real results. :mad:

[Eric Deslauriers]

Yeah, good thing they're going to cover your labor for their FUBAR. Right?

What they're going to do for your downtime & time invested...

You know, it'd be pretty simple to yank a valve cover (with the IP off) to do a basic check for valve timing vs TDC.

Sigh. My sincere condolences. I'm still rooting for you!

[Garand Fellow]

Latest development: Avant called my local shop yesterday, left a message with the bookkeeper that they needed "more information" on the injection pump. When he returned from lunch, the owner called Avant back.. no answer. tried calling today.. no answer.. I tried calling today.. no answer.

I can't figure what "more information" on the pump they would need. After all, THEY installed the pump when they built the motor.

I remain optomistic... I'm not interested in throwing stones.. I simply expect what I paid for.. a good running 6.2 motor. I have to believe that this has all been some sort of comedy of errors so far and that when the sun finally sinks in the West, I'll be happy.

Now.. back to the movie.

[Garand Fellow]

Okay.. the "new information" needed was the identifying information from the injectors.. something about possibly a pressure mismatch between the injection pump and the injectors.

I relayed that to the shop. The injectors are not the problem.

Avant contacted the shop.. they agreed that the timing gears are the next logical place to look. The shop is tearing into the motor and Avant has pledged to cover the costs.

More later

[britannic]

They would have to be very special injectors to cause a pressure mismatch. The mechanical pump can support the pressures needed by the 6.5LTD injectors.

In fact it's the injector's pop pressure that sets the pump's pressure and the pump can handle at least 5500psi plus (good for injectors with a pop pressure of around 2700psi each - 2 injectors fire per cycle) way above the pop pressure of currently available injectors (with the possible exception of marine injectors).

[rumbler1]

Garand Fellow, I was out in the lobby buying popcorn so I missed part of the movie, but I just thought I'd let you know that I bought a used Banks turbo from Jamie at Avant about three years ago. When I installed the parts I discovered that the right side manifold he sent me didn't fit my application. Jamie bought a new, not used, manifold directly from Banks and had it shipped to me. I sent him the other manifold and completed the installation. I'm just mentioning this because Jamie was true to his word with me, and I wouldn't hesitate to deal with him again. I'll be interested to see how the movie ends. Does the guy get the girl? Does he ride off in a cloud of diesel smoke?
Good luck!

[axle-chassis]

I'm watching this saga with interest because I'm waiting to see how it pans out before I buy my engine.
Its hard to believe it is taking so long to get it sorted out.
Three weeks in the shop is too much. I might consider putting that truck on a transport and send it to Georgia for Jamie to sort it out. Whats that cost? Anyway I sure hope it works out for you.

[johnhanging]

Garand Fellow:

Your shop says they cannot get the "timing" past dead zero. What do they mean by that? There is a rather obnoxious effort involved in setting top dead center on these engines. The GMC manual says to balance the 3 and 5 cylinders (presumably with a micrometer) to find top-dead center for the number 1 cylinder. The crank location is then transferred to the front cover, and after the dampener is installed the timing indicator is adjusted to match TDC. This drove me nuts reading it, and I can't imagine dealing with it in a shop. So finding TDC will require pulling the drivers side head.

[britannic]

How about pulling the glow plugs in #1 and then using a suitable probe to detect when the piston goes over and rocking back and forth once that's established to find TDC? I use a similar method on gas engines.

[ 09-03-2003, 04:02 PM: Message edited by: britannic ]

[grape]

piston stop and a degree wheel is the ONLY way to find TDC, unless you're into guessing.

[britannic]

Originally posted by grape:
piston stop and a degree wheel is the ONLY way to find TDC, unless you're into guessing. Grape, do you have a make or part number for the piston stop? I'm assuming it'll use the glow plug or injector port right?

[Garand Fellow]

Latest update - 9/8/2003

The shop foreman talked with Avant. Timing the pump is impossible, since it is already advanced as far as possible. In other words, even though the timing mark indicates a "dead zero", the pump cannot be advanced... it's already at full stop.

The shop got Avant's approval to pull the timing cover and eveball the installation of the timing gears. No problem there.

They are now thinking the problem is a defective injection pump. Avant said they were going to talk with their pump supplier and get back to the shop here. That was last week.. no return calls yet.

I'm about ready to say enough is enough and file a complaint with the State Attorney General's office.. Consumer Protection. I now have over $6,000 invested in the motor, installation, etc., etc.. and it's not been in a driveable condition at all.

I'm giving it until this coming Friday for some sort of resolution.. if there is no light on the horizon, I start my official complaint. I'll ask for restitution of my actual out-of-pocket costs. If I get it, I'll go down to my local GM dealer and order a brand-new, 6.5 crate motor.. something I now fervently wish I had done six months ago, before all this started.

I hope it doesn't come to that, but I work hard for my money.

[Garand Fellow]

Some movement detected today...

1. Avant says they are having a replacement pump built and will ship it out this week.

2. To eliminate ANY question on the timing gears, I asked the shop to replace the gears with conventional gears and chain. They will then put it back together and try to re-time. If the timing is successful, we'll know that the problem has been with the timing gears. If the problem still exists, we'll replace the injection pump and see what happens next.

[Garand Fellow]

The pump, that was promised to be shipped on 9/9 has still not been shipped as of today, 9/19.

It's now been 3 months since I took delivery of the motor and it's still not running.

[More Power]

Somewhere in the dusty recesses of my memory I seem to recall a situation very much like yours, in that the timing couldn't be advanced enough.

In that case, the injectors were somehow set to too high a pop pressure. This delays the fuel injection timing. This is one reason why I don't recommend using 6.5 injectors with a 6.2 pump or vice/versa.

The 6.5 DB2-4911 operates at slightly higher fuel injection pressures.

MP

[britannic]

As MP says, the injector pop pressure sets the pump pressure, but the DB2 is capable of generating 6700psi, so this shouldn't be a factor. Air leaks, faulty injector pump, malfunctioning lift pump, restricted return lines and mis-timed gears are more suspect.

The timing gears should be easy to check, by pulling the front cover.

[Eric Deslauriers]

I would have expected a Diesel Pages advertiser to take better care of a member. Threads like this being at least one reason, but, hopefully, not the primary one.

Disappointing.

[StorminN]

Garand,

If you paid extra for a pre-shipment run-in and set-up, what has Avant said about that? Have they claimed that the engine ran fine for them?

I'm curious to see how this turns out, as I've got the money for a rebuilt burning a hole in my pocket... and I can't decide whether to go with Avant or the much closer folks at DAS up in Vancouver, BC.

-N.

[cschneider]

If you are in Sequim it is a no-brainer to go to Paul and the rest at DAS. I had a great experience with them back when they were still doing work in Lisa's backyard. They run a fantastic operation and are some of the nicest people you could meet. I like the Avants and think they have a great product but their service sometimes leaves you wondering. Go with DAS, you won't be disspointed.

[dieselbegreat]

You don't think that all 8 fuel lines are installed wrong do you? Would that be way too much retarded to even get close to proper timing? Just a thought...

[britannic]

Originally posted by dieselbegreat:
You don't think that all 8 fuel lines are installed wrong do you? Would that be way too much retarded to even get close to proper timing? Just a thought... i can't see how it would run or even get all of them mis-installed - do you mean each line was attached to the wrong outlet?

[dieselbegreat]

Yes, I mean that they are in the correct order, but one cylinder behind where they should be. That would put the timing 45 pump degrees retarded = 90 crank degrees retarded for each cylinder. So, you'd have to rotate/advance the pump almost 45 degrees just to bring it back to time, if the pump and fuel lines will twist and stretch that far. Just an idea. You could visually check which output is supposed to be Cyl #1 against a properly running motor. I don't have mine with me right now so I can't help with that. I believe it is one of the two outputs at the top side.

[britannic]

Originally posted by dieselbegreat:
Yes, I mean that they are in the correct order, but one cylinder behind where they should be. That would put the timing 45 pump degrees retarded = 90 crank degrees retarded for each cylinder. So, you'd have to rotate/advance the pump almost 45 degrees just to bring it back to time, if the pump and fuel lines will twist and stretch that far. Just an idea. You could visually check which output is supposed to be Cyl #1 against a properly running motor. I don't have mine with me right now so I can't help with that. I believe it is one of the two outputs at the top side. Very interesting idea, but at 90 degrees out, I just can't see how it would start; the compression would have dissipated and the air temperature would drop below fuel flashpoint.

Is there enough adjustment in the IP to get it close enough if this actually happened? Also, The IP lines would have to bent and some probably wouldn't fit anymore. YMMV, but I found that if you keep the inj. line pairs clamped together, there is only one way they'll actually fit.

[Garand Fellow]

The wrap-up.

Avant sent a replacement injection pump. That was the problem. The pump they installed was setup for a turbocharheg 6.2 running at sea lever. My truck is non-turbo and I live at 6,500 feet elevation.

With the new pump:

First 2 tanks of fuel (60 mph) get 11.5 mpg.

I start adding Red Line Oil 85 Plus diesel fuel additive.

On a 700 mile run.. I average 16.5 mpg. That's 75 mph interstate speed.

EGT never climbs above 600.. even pulling 7% grade.

I'm happy

[rumbler1]

Garand Fellow, I just came back from intermission, just in time for the exciting conclusion. Glad to hear your truck is running well again. Curious to know how the antelope hunting is out your way. My wife and I were in Cheyenne a couple years ago and loved it. Saw lots of antelope while out there. Someday I'd love to go back and collect one or two.

[mhagie]

Ahh the hero wins in the end.
BUT WAIT, his lowly sidekick with a new avant 6.5TD has developed a knock on maiden voyage (made it about 50yd)
The plot thickens,is it an injector? or is it deeper?
The good Dr Jamie says to try and locate noise to one cyl and switch that inj w/one from other bank and see if knock follows.
But this cowboy is reluctant to play the switcherooo game, me thinks that be too much work involved, Injectors aren't that hard to remove but why play musical injectors.
This humble backwoods boy thinks that one should have a new injector in hand and change out w/new and see if noise go away.
Will the Dr agree? Will cowboy get his way? Will injector even fix the knock? Will cowboy get this resolved before he goes on social security?
Stay tuned, :D the saga continues.

[Ratau]

Garand,
I live in Pretoria at the same elevation (2000 meters) than you. My 1982 Blazer 6.2 is running at 11 mpg. at 75 mph and no power on hills. My wife outruns me with a 2.8 DT Isuzu pickup. Jim Bigley wrote in his article

[britannic]

Ratau: at your elevation a turbo will help immensely in ensuring your engine gets enough oxygen, keeps the timing from getting too retarded (timing will retard as combustion slows down with less atmospheric pressure) and allows you to turn up the fuel.

Meantime, get your engine timing checked at the same elevation you drive and see if it's too retarded and costing you power.

[Ratau]

Britannic
The pump is set according to the Stanadine spec. sheet (DB2829-4267J). Is there a different setting for sea level and at 6,500 feet elevation or is it just timing and turn up the fuel a bit. If the engine was running over fueling for some time could it be possible that carbon build up around the valves preventing the valves from seating properly and not sealing? Is there a product that will loosen carbon out the system?
Thanks for your help!
Danie

[britannic]

Ratau: ;) I'm really asking how is the timing set on the physical engine, as this is where it will make the most difference.

What improvements you have made to the exhaust and air intake?

Does SA run a hotter cetane diesel?

Do you get a lot of black smoke?

The valves in the 6.2L-6.5L are designed to rotate incrementally with each opening and this will keep them clean.