"Cold" starting issues.. (ideas?)

[ajrn]

I've got an 84 300SD, that I've been having "cold" starting issues with.. It has never been STELLAR on starting in single F digits.. I've owned the car two years now-- it has 250,000 miles on the odometer.

January was the 8th coldest on record in Ohio-- so I'd kind of "written it off" as, it's just too damn cold..

It was nearly freezing this morning (quite a warmup!), and nearly 40F this afternoon and I still had issues getting her to run.. ONCE RUNNING SHE DOESN'T SMOKE, or anything else to lead me to believe this is more than a starting issue.. There is no loss of power, no increase in oil use (about a quart every 3,000 miles).. Nothing "odd.."

1) This fall I did the "Saab" alternator exchange (115 amp upgrade).. I will ultimately need to have a new 'mount' fabricated, as the bigger alternator body doesn't "slide" in the mount to tighten the belts "enough.." I do have full charging, it just slips a little and makes that horrific noise when the belts are cold.

2) I replaced my battery this week.. I have an Autocraft (Advance Autoparts) 49-1.. I think it's an 850 or 900 cca unit.. It replaced the previous one, for just a smidge over $50, as the previous one had just crossed the 3 year free replacement in September '08.. I have NOT load tested the new battery..

3) When I did the alternator swap, I added a 4 gauge cable from the (-) side to the engine block AT the alternator.. I've read that this can increase "cranking speed.." I also took a 4g cable to from the Alt straight to the battery, and one to the "previous" alternator connection, behind the passenger headlight..

4) I use PowerService in my diesel, at 2x the recommended dose, as I've been told this provides more lubricity for the pump, with ULSD.

5) I haven't pulled the glow plugs, but they appear to be drawing the approprate amperage when I turn the key.. The relay and fuse test okay..

Here's what I'm planning on doing (in the next day or two..)

A) Change oil-- hopefully find some 10w-30 diesel oil.. (making it easier to cold crank)

B) Remove the (+) lug from the starter, and clean that up with a dremmel tool-- hoping that corrosion is making the starter take more amperage, and or turn slower.. It seems like it's not cranking fast enough to "catch"..

C) While I'm under the car, see if the block heater is getting any voltage-- it doesn't appear to be functional..

D) Diesel purge and filter change as shown here ---> http://dieselgiant.com/injectorcleaning.htm

E) Pull check and replace glow plugs as necessary..

I've got a few questions..

Can diesels "FLOOD?" I'm wondering if longer cranking times is causing the engine to be supersaturated with unburned fuel, making it harder to start..

Once the car has run-- even a minute or two, it is NOT difficult to start..

Please, someone tell me they DON'T think this is a compression problem!! Again, it's not smoking past start up, using more oil or anything to make me fear that...

Anyone have any other ideas, hints or thoughts???

Thanks as always in advance..
AJ RN

[kerry]

Bad glowplug(s). Ohm them out. Should be less than 1ohm. Still might be bad even with acceptable resistance but high resistance will tell you a plug is bad.

[tyl604]

Adjust valves.

[Chad300tdt]

I agree with the glow plugs but I think the oil is a big factor too.

I just had an experience where both my diesels wouldn't start. It had been -4˚ F overnight and the following morning only warmed to 4˚ F. I didn't have either plugged in.

I tried starting both cars and they would spin fast at first until the oil pressure built up ... then they would barely turn. I had to push them one at a time into the garage and warm them up with a torpedo heater and they both eventually started.

I switched both vehicles to 5w40 syn and now they turn over like they do in warm weather. The wagon, however, still had trouble starting and I found that I had 4 bad plugs even though the glow plug light came on as normal and didn't do the warning blinks. Once I replaced the plugs and reamed the pre-chambers (which were horribly loaded with carbon) the car started with ease.

[ajrn]

Reamed the pre-chambers??

What's involved in that?? Makes sense to do-- just seems like there'd be no way to do it, without driving the crap further into the engine..

And where did you find 5w 40 Synthetic oil?? (what brand, etc..)

AJ RN

[kerry]

Use a reaming tool with grease on it.
Shell Rotella Synthetic Available at WalMart and PepBoys.

[Chad300tdt]

Originally Posted by ajrn

Reamed the pre-chambers??

What's involved in that?? Makes sense to do-- just seems like there'd be no way to do it, without driving the crap further into the engine..

And where did you find 5w 40 Synthetic oil?? (what brand, etc..)

AJ RN

I bought a reamer online for about $35. Make sure you buy one for your engine because 617 and 606 take different ones. They look like a glow plug with a fluted bit on the end instead of the glow tip. You screw it in like a plug and unscrew it out removing the carbon. Then vac out the pre-chamber and install the new plug.

I bought Rotella 5w40 synthetic oil at WalMart for $19 per gallon.

[ajrn]

Thanks--

I've pm'd a few members here, to see about selling or renting one.. It would be a waste of time to replace the plugs, if they're going to be firing in carbon, right??

I assumed you had to pull the prechambers to do that, and Uh-- I think I'm too whimpy to do that on a currently running engine.. (and I'm not ashamed to admit it!)

I didn't realize the synthetic Rotella was a different weight.. Hmm... Okay.. Walmart isn't usually my first place to look for parts for my girls, but-- I've got to by there on the way home...

I'll let you know what I find-- I'll probably do one thing at a time, so I know when I'm "done.."

If I remove the buss bar from the glow plugs, can I test resistence with them in the engine?? It would let me know how many I need, while I wait for the reamer from somewhere-- although I think I have 5 new Bosch ones at home "as ready reserve.."

Thanks for your time, all..

AJ RN

[compress ignite]

Best test for plugs is to put 12 volts to them (outside the engine) and see if
they GLOW RED...DO NOT GET HANDS ANYWHERE NEAR THE PLUGS WHEN
DOING THIS!

The GP holes can be "Reamed" with the Pre-Chambers still in the head.

[ajrn]

I'd previously "glow" tested them outside the engine, as well.. I've got a 10 amp battery charger that does a LOVELY job of it..

This thread showed the diagnosis of the "rest" of the circuit--

http://dieselgiant.com/glowplugrepair.htm

So-- maybe I should do the quick test (ohm's) at the glow plug relay..

[Diesel911]

Originally Posted by Chad300tdt

I bought a reamer online for about $35. Make sure you buy one for your engine because 617 and 606 take different ones. They look like a glow plug with a fluted bit on the end instead of the glow tip. You screw it in like a plug and unscrew it out removing the carbon. Then vac out the pre-chamber and install the new plug.

I bought Rotella 5w40 synthetic oil at WalMart for $19 per gallon.

It is easy to tell the differance between the Glow Plug Reamer for the longer Glow Plugs like the 606 as the Reamer for it with shipping is around $70 each compared to the $35 for the 617 type Reamer.

[Graplr]

What oil are you currently using? I ask because you state 'hopefully find some diesel oil'. Makes me think you are using regular oil. First use diesel rated oil, then try to find lighter weight (probably synthetic like Rotella or Mobil 1). I buy mine at the local farm supply store. It is called Fleet Farm here but there are many different versions. I'm sure most have diesel oil.

Of course you should check your glowplugs, but many have stated on here that the switch to lightweight synthetic adds 15-20F degrees lower of cold starting. I've always run syn so I have nothing to compare it to but I have done a -4F cold start this winter.

Here is the check list for cold starting problems-

1-Glow Plugs
2-Valves
3-Synthetic Oil
4-Battery/Alternator
5-Starter
6-Fuel
7-Engine (Compression)

It seems you can cross 4 and 6 of your list as you have a new battery, alternator and use Power Service (I don't and have never had a gelling problem even at -22F a few weeks ago).

Since I've owned my car, I've had problems with 1,2,4, and 5. Each gave me problems starting in the cold.

[bgkast]

Have you checked your compression?

Diesels can "flood" if you keep cranking them and they do not fire, poor injectors can make the problem worse. There was a thread on it awhile back: Physics of cold starts

[Putty]

My brother had an 85 SD with the SAME problem...it was compression! Warmer weather made it start better but when that cold came around, it was a pain. After new rings and seals, it popped off at the bump of the starter. Good luck.

[running-snail]

AJ RN -

Just sent pm on reamer. I'm running Rotella T synthetic 5w-40. Starting with a few glow cycles, sitting outside in a campus parking lot, according to my daughter at school.

I have replaced, since owning: glow plugs, replaced glow plug relay with the bosch afterglow variety, adjusted valves, battery, 80A alternator (not quite as big bodied as the 115A).

All seem to be of incremental help