Cold start problems-technique?

Issues pertaining to the TGB/C30X series engine and driveline issues
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sixbennetts
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Cold start problems-technique?

Post by sixbennetts »

Okay, truck has a new engine, not even broken in yet. At temps above 10°F it starts every time, no problem. Anything below that is hit or miss, probably depending on my technique. When the truck is warmed up, it purrs like a kitten. Smooth idle, plenty of power, no skips or backfires. Perfect.

Plenty of juice, so it always turns over. Both batts good, starter too.

So, when it's - 10°F, I make sure all accessories are off, pull out the choke fully, push in the clutch fully, turn the key, push the starter button, and it starts, and runs, kinda. It chugs, like it's not firing on all cylinders. Very
rrough. If I try to touch the pedal, I get a possible stall and sometimes a backfire. If I DON'T touch the pedal, it will chug for a few minutes and stall. I've tried letting it chug for a bit, then tapping in the choke a little at a time, thinking maybe it was warm enough to go without it. The tiniest bit less than full choke, and it stalls.

On the times when it's above zero, and I'm able to get it running, it takes about 5 minutes to warm up. It will chug like I said above, at idle, unless I give it a little gas. When I do, it's pretty smooth when cold, but if I try to drive it too early, I'm met with backfires and stalling. Then, there comes a point where it's like a switch is flipped and it immediately runs perfectly. Night and day.

I'm using high octane gas with no ethanol, (lucky enough to have a place in town that sells it), and lead substitute per bottle instructions.

I know this is a technique problem, I'm just not catching on to
the right sequence. Any pointers?
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westernair
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Re: Cold start problems-technique?

Post by westernair »

Sounds like a fuel delivery problem, either your carbs need to be ajusted or if you use EFI you might need to adjust your MAP.
Shawn

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sixbennetts
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Re: Cold start problems-technique?

Post by sixbennetts »

It's stock Zenith Stromberg carburated. I was hoping not to have to touch them. Sounds like real voodoo.
Uli-RT
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Re: Cold start problems-technique?

Post by Uli-RT »

... have you checked the oil in the carbs ?
and try to start with choke not complete pulled out... or push back a little after the engine has started.
mopar
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Re: Cold start problems-technique?

Post by mopar »

Donny
Well I just started mine after its been sitting since Nov(when I got the Pinz) and I had to crank it for some time as I'm pretty sure it needed to prime the fuel systems. I had tried last saturday and gave up after 15-20 minutes(too cold). Well wanted to move some stuff before the storm and so Thursday night I gave it a go again and spent about 10 minutes cranking with the choke on hand throttle on and pumping and finally she started up and was running good. Today I'll clear the 3 feet of snow and and try to get her started for some winter fun and let you know how it goes. My technique is hand throttle 1/3-1/2 and choke full on no pumping. I have seen it flooded from any pumping so this is what I usually(except when it has been sitting). I have the 123 ignition on mine so it may not be the same as yours. Hope that may be a little helpful. Looking to get out in the snow are you?? Hope things are going OK for you.
Sean

1974 712M AKA the Banana
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sixbennetts
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Re: Cold start problems-technique?

Post by sixbennetts »

With the choke at anything but fully pulled out, it won't start. Has to be all the way out. What worked this morning was no throttle for a couple minutes while it chugged, then I could just barely touch it, a tiny bit at a time, bringing the RPMs up slowly over the course of 5 minutes. If I pushed the pedal too far, it wants to stall.

Again, when it warms up to about 60°C on the guage, it all of a sudden smooths out and purrs like a kitten. If I try to drive before that point, choke position, doesn't matter, it'll backfire and stall out. It HAS to be to that magic break point or it will not run with any kind of load.

Above 20°F, none of this matters, it starts and runs fine.
M Wehrman
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Re: Cold start problems-technique?

Post by M Wehrman »

Have you checked to see if the choke cable is adjusted properly,maybe not closing all the way? This is where I'm going out on a limb because mine has none of the original fuel system,does it have a hot air thermostat off the air cleaner box? It is designed to allow warm air from around the exhaust to go to the air cleaner for smoother cold warm-up. Hoses intact? Personally,I would install an electric fuel pump to be sure the carbs are full before cranking. Just some thoughts....
Mark
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Volvo TGB1317, .95% Morphed!



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westernair
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Re: Cold start problems-technique?

Post by westernair »

Actually in cold weather I have been known to put a piece of card board in front of the oil cooler. This will help get the oil warmer when driving in cold weather and dry it out. If you take your filler cap off and see milky oil it is not getting warm enough. Won't help it start sorry but thought I would mention it as these engines run cool. The flap on the air filter as mentioned should help it run better.
Shawn

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61 haffy 4 door

72 710K - Sold
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edzz
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Re: Cold start problems-technique?

Post by edzz »

I know it’s not a Pinzgauer; however this is from the Pinzgauer operator’s manual, generally standard operating procedure for vehicles of the same era. Note the instruction to declutch (depress the clutch pedal) this helps remove drag caused by the gearbox.
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sixbennetts
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Re: Cold start problems-technique?

Post by sixbennetts »

Yup, same thing in the Volvo manual, too. Thanks, Ed. Been doing that all
along, just didn't say so.

I *think* the secret seems to be barely touching the fuel pedal a tiny bit at a time until it warms up to that point where it smooths out. There's no WAY the truck can be driven at all until it's completely warmed, and the choke can be pushed in all the way. If I try to leave early, I get backfires.
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edzz
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Re: Cold start problems-technique?

Post by edzz »

May want to check the timing and insure that the advance mechanism is functioning correctly.
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sixbennetts
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Re: Cold start problems-technique?

Post by sixbennetts »

If the there was a problem with that, wouldn't it affect how it ran all the time? When it's warm, it runs like a brand new car. When it's above °20F or so, it starts like one.

It's just a cold start issue. I need to find somebody locally that can show me how to care for and tune/balance these carbs, I think.
M Wehrman
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Re: Cold start problems-technique?

Post by M Wehrman »

The advance idea is worth a look,perhaps the decades old lube on the advance mech "de-solidifies" upon warm-up,allowing it to work properly. My .02 4 U!
Stock means no imagination!


Volvo TGB1317, .95% Morphed!



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