Bumped the timing and turned down the fuel today...

[kas83]

Seems kind of a backwards move, but ever since I got this truck, I've been able to black out a city block with no problem. It was simply too much. So I decided to turn the fuel screw back about 1/4 turn. I took it for a spin, and hooked up the 24 ft camper. I was glad to see the pyro stay at or under 950*, boost at about 7 psi, and held 65 mph no problem. Before turning the pump down, it wouldve been around 1150*, 11 psi, and smoking like a freight train at 65.

When I got back, I decided to twist the pump a little to try and get it to start better. It was roughly a nickel's width to the drivers side of the hash mark, so I put it straight up with the hash mark. Holy cow, this thing really woke up. Numbers were roughly the same with the camper behind me, but it seemed a little snappier taking off and out on the highway. Overall, I'm glad to have less smoke, less boost and EGT's, but roughly the same power as before.

Also, these injectors must be leaking like crazy, the exhaust has always been enough to burn your eyes, and hazes blue while idling, although not quite as much anymore.

Anyways, when it comes time to freshen up the engine, I think Mel and Russ will be getting calls from me to facilitate the injection system refresh.

 

[Diesel JD]

Sounds like a good move, you should be able to get the same boost without all that smoke if it were timed to spec with good injectors, but for now the move you made is good, too bad you don't know where your timing really is, but especially with a potentially tired pump and bad injector a nickel's width retarded from the hash mark probably wasn't anywhere close to 8.5*BTDC or 1.5ATDC let alone the newer specs we discuss here.

 

[david85]

Keep an eye on how it perfroms for cold starting for the next little while. Generally these engines will start eating glow plugs before they start to perform poorly from over advanced timing. Mine wasn't even that much advanced and it started munching on the plugs shorty after the moose pump went in. Had to back it off.

 

[zacky6661]

Keep an eye on how it perfroms for cold starting for the next little while. Generally these engines will start eating glow plugs before they start to perform poorly from over advanced timing. Mine wasn't even that much advanced and it started munching on the plugs shorty after the moose pump went in. Had to back it off.

new to IDIs, how would i know if my truck were "eating" the glowplugs? mine fires up with absolutely no problem, cold weather or warm, but id like to know what to look for in case they ever were to do this.

 

[Diesel JD]

They'll just burn out more frequently and when you pull them out you tend to see a lot of erosion or pitting on the GP compared to one that just died from it's lifespan being up. It's a good warning but n most cases you won't be chewing GPs unless you're advanced beyond 0.5ATDC or 10.5 BTDC, IOW within book specs. As it sat previously your timing was probably very retarded. No way to know for sure though without getting a meter on it. I don't know how far you are from the Chicago MKE area but a bunch of the guys are there at this years IDI rally as we speak,a nd would probably love to see you and put that timing spot on for free.

 

[david85]

In my case there was no visible damage to the glow plugs. They simply stopped working. After putting new ones in I retarted the timing slightly and never had a problem since.

 

[dyoung14]

I have burned tips complety off

 

[david85]

As crazy as you are, I decided to save the dead plugs and am thinking of making them into dummy plugs for a future hypermiling experiment based in part on your experience. Having to plug the truck in just to get it to fire off isn't very practical, but I am wondering if having the plugs removed and timing curve advanced beyond their normal tolerance will result in a noticable gain for power or MPGs. Doesn't cost me anything to keep them in a drawer until then.

 

[dyoung14]

As crazy as you are, I decided to save the dead plugs and am thinking of making them into dummy plugs for a future hypermiling experiment based in part on your experience. Having to plug the truck in just to get it to fire off isn't very practical, but I am wondering if having the plugs removed and timing curve advanced beyond their normal tolerance will result in a noticable gain for power or MPGs. Doesn't cost me anything to keep them in a drawer until then.

If your results are like mine then you should notice a big differnce at the seat of the pants

 

[david85]

You mean my wallet? (cue the canned laughter)

I can't help but wonder if the higher fueling rates of the moose pump require more advance though. Thinking out loud, more fuel = longer injector open duration, so more advance would be needed to get the majority of the fuel burning by TDC. It sure ran like a ***** ape before I turned it down.

The other thing that has me wondering about removing the glow plug tips is the prechamber would effectively be opened by a small amount and MAYBE allow for a better fuel/air swirl. I have no idea if this would be noticable but considering how little it takes to drop the compression of the engine it makes me wonder. Bigger prechamber can't be all bad right? Maybe some of the gurus could chime in on that.

 

[dyoung14]

You mean my wallet? (cue the canned laughter)

I can't help but wonder if the higher fueling rates of the moose pump require more advance though. Thinking out loud, more fuel = longer injector open duration, so more advance would be needed to get the majority of the fuel burning by TDC. It sure ran like a ***** ape before I turned it down.

The other thing that has me wondering about removing the glow plug tips is the prechamber would effectively be opened by a small amount and MAYBE allow for a better fuel/air swirl. I have no idea if this would be noticable but considering how little it takes to drop the compression of the engine it makes me wonder. Bigger prechamber can't be all bad right? Maybe some of the gurus could chime in on that.

I say chop you some tips off some burnt ones install them start playing with the timing till you find the most power then start cranking the fuel up till you run into egt trouble then i bet your going to see much higher boost/power numbers and we know you motor will take it, its decompressd and studded

 

[david85]

Have to invest in a new pyro first since mine has been dead for a few months now. Work is slow at the moment so I'm holding off on spendy items though.

Until then I'm staying out of the smoke

 

[Diesel JD]

The first thing you need is to get that engine timed David...until then you are just guessing about where the timing is and where it needs to be. You know your stuff and you have a good ear, but it seems the consensus is that that's only good for being in the acceptable zone or roughly spot on +- 2 degrees.

 

[david85]

Agreed, which is one more reason I won't be messing with it anytime soon. I'm hoping for a timing meter to show up on Ebay eventually but I'm in no hurry to mess with what seems to work so well. I'm overjoyed that I somehow found time to replace the left hand leaf stack a few days ago. Also did a front end alignment, shot some undercoating on the frame and bare patches under the cab, and oiled up the body with some gear oil. It wreaks right now but I know it won't be rusting in the spots I intend to salvage.

Right now I'm satisfied with the truck and it gets great fuel economy and isn't falling apart.

 

[Diesel JD]

True. I got lucky, really lucky with my timing meter, unfortunately it was because of another member's bad luck. He bought a really nice MT1480 off of ebay but it came with a missing or broken(and NLA) luminosity probe, and he was nice enough to pass the meter along to me at his cost. It works for mebecause I had a new old stock snapon lumy probe together with a poorly functioning MT254 which is a lumy/inductive setup. I know Gary doesn't like pulling the #1 glow plug but to me it's easier than falling off a log. If I ran into another member's truck that didn't want to let go of the gowplug I'd try another hole with the right offset dialed in or tell him/her, sorry but it's a no go. I'm not anxious to do another head gasket job, but so far I haven't had the slightest problem with pulling any of my glow plugs(knock on wood) not even the burnt out ones, but then they're always berus an always on the 87 and up system.