DTC 36 when cold, Why?

[curmudge1]

My 94 Blazer w/ 6.5TD got a NEW DS4 injection pump a little over a year ago, & a new chip, all for only $2200 (<sigh>). Has been running fine ever since; recently replaced the lift pump & OPS, FWIW. Just yesterday & last Sunday, when the engine was still pretty cold (mid-20s degF), the SES light flashed on briefly, once or twice, then did not come back on that day. I just checked the stored DTC (paperclip method), & all that I saw was a DTC 36. I don't push it too hard when it's cold, & usually let it warm up for several minutes, but not those two times.

Does anyone have any thoughts about if this might be just a "cold thing"? Maybe have something to do with the fuel? I've bought some fuel lately from a different station than usual, this place didn't use to sell diesel, but it does now & it's as cheap or cheaper than the places I used to buy from, & it's more covenient.

TIA.

[moondoggie]

Good Day!

Since DTC 36 & DTC 35 are closely related, you might want to look at DTC 35 - Help! (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=004386#000000). I got most of my info from a search I did on this forum, about two weeks before all that data went away. It's kinda long, but might be worth a read.

If you read it carefully, you'll find that I was pretty sure I had a temperature-related problem until cleaning the grounds actually fixed it.

Blessings!

Brian Johnson, #5044

[GARY PAGE]

I don't know exactly why but I can tell you when I added the cold start mod to my 95 the code 36 went away. maybe someone can comment on this.

[tom.mcinerney]

The Fel-Pro div of Federal Mogul's web site has discussion of advantage of aluminum heads over cast iron for sealing because thermal expansion of aluminum forces a good gasket seal. A local mechanic remarked that a common service procedure on GM V-8s (gassers) is R&R of aluminum intake manifold with new gaskets, as the old gaskets 'dry' out, shrink, lose seal. He commented its very common for the engine grounding studs to loosen as gaskets shrink. So not unreasonable for low voltage cold from poor grounding, resolves with warmup.

[moondoggie]

Good Day!

tom mac 95: Thanks, that probably explains it. Makes you wonder if moving grounds right to the block might eliminate this potential problem