stall, extreme intermittent start, out of ideas

[94Suburban]

I'll preface this by saying I have been mixing WVO and diesel on and off for about 20k now. Had to change injectors and inj pump most likely from inadequate water removal and filtering Oct 2007. Have learned since then, been doing good for about 10k until about three weeks ago. Just before the trip I dropped the tank and cleaned the heavily clogged sock and floated the rest of the silver looking tank coating out of the tank. I then ran the lift pump with a gallon of fresh diesel to flush the lines.

Was on way home from long weekend trip in mountains(about 600miles on odometer now). Just stopped to put a few gallons of diesel in as I didn't want to run it less than 1/4 tank in case screen in tank had got clogged again. About 3 miles down the road, came to a stop light. Started rolling up windows, when I pushed the AC switch---- she died. Coasted to side of road, pulled and looked at filter, good . Cracked several inj lines, pumping good fuel. Hooked up spare FSD, still nothing. That was the extent of my roadside troubleshooting. Had her towed to the house.

Over the next three days until I had time to work on it, it would crank and start right up but only intermittently ( say 1 out of five tries). Starting to think its electrical now. Checked ops, good. I went through all the inj pump connections and the grounds, including the one on the pass side head (had blown head changed over Christmas 2007). All looked good. Put clear hose on inj pump to check for air, looked good and no leak down by next day. Pulled #1 injector and hooked to the fuel line, no spray even after bleeding again. I figured my mix might have clogged the inj again.

Pulled and cleaned all injectors, didn't want to spend $ on new ones just yet. Had them all hanging from the inj lines after cleaning. Watched all inj spray nice pattern. That was my test since I don't have pop tester yet. Reinstalled and still same story.

I recalled my timing chain appeared pretty slack when I changed the inj pump the first time. So... I had one on hand (not too confident this was the culpret) I did it anyway. I triple checked all my alignment marks and 100% confident I'm not off by any. Placed the inj pump about 1/16 to the pass side of alignment mark on engine. Still no start.


Just finished swapping the ECM from my '95 Sub, same 'F' code engine. No start. Until now she had not throw a single code. After changing back to old ECM, I'm now getting a 62 which I haven't found the meaning of yet.

I don't have a compression gage but both 94 and 95 seem pretty similar with my calibrated finger over the #1 glow plug hole. I'm heading off to Autozone now to pickup a glowplug controller and 2 new batteries. She seemed a bite slower cranking than my '95. I already tested my controller and the plugs, everything appears good and all the ones I pulled glowed red hot. Batteries show a good 12+ volts, but they are about 5 years old now.


Been searching the forums the last couple of weeks,
I'm out of ideas if the cranking speed doesn't help.

Any thought would be appreciated.

[More Power]

It's been almost 24 hours since you posted this, and no one has answered. Probably because this is a tough one to answer with any hope of actually solving the problem.

You're not going to like what I have to say, but I'll say it anyway..... :o

I think people who run WVO in their electronic 6.5 are doing their 6.5 and themselves a disservice. The DS4 is a challenge for some to see decent reliability anyway, and adding WVO just piles on a whole lot of uncertainty along with proven problems. Your post above illustrates that pretty well. I could relate others.

My advice is that if you must run WVO, you don't run it in the DS4. Converting to a DB2-4911 mechanical fuel injection pump would cut in half the problems associated with WVO (but still significant). Personally, I wouldn't consider WVO unless diesel fuel were $10/gal or if it were an emergency situation. The cost of replacement fuel injection components and my time are worth more than any cost savings realized when running WVO.

Why not invest in a processor to create genuine bio-diesel? The cost of a couple of DS4 replacements will pay for a processor.

Jim

[94Suburban]

Jim

thanks for giving me your honest opnion. I was slowly coming to the same conclusion, about the elelctronics in the DS4. I thought I would have gotten slammed a little harder, thanks for being so polite about it.

She was running this morning and sounded alot stronger, probably the new timing chain.(I know I got that back in right at least) Will hook a couple of injectors from the wifes '95 tomorrow to see how they are spraying in comparison to the ones I cleaned.

In the mean time I like your idea about the mechanical pump. I will be researching this great resource for info on that tonight.:o

In answer to your question on wvo compared to making bio. I researched the bio about a year an a half ago. It was just too much hassle to get a hold of methanol in significant quantities, thus the wvo approach. Cost is the bottom line in the long run. When I finally get her running right it will be saving me about $200 plus a week at the current fuel prices. But for now the wife doesn't want me getting near her '95 with any wvo, I wonder why?

thanks for your responce