well ever since its gotten cold (especially 35* and below) my 98 12v starts like crap. the wait to start light comes on for the usual amount of time. but then it cranks a lot before it will actually start and stay running. the truck hazes for probably 15 minutes after starting ( a good amount of hazing)

the only thing fueling wise that is different from last winter is i put in some used 215 injectors and a #0 plate (adjusted gov arm). other than that the fueling/ timing is the same as last winter.

last winter it would start first crank and stay running with a little bit of throttle (always starts faster with some throttle).

i know my idle is fine at 850rpms (not idling too low).

it has a fresh fuel filter

lift pump and overflow have about 20k on them so they should be all set.

return fuel line is new so no leaks letting air in there, it doesnt seem to be an air in the fuel issue.


could it be the grid heaters? or more than likely the grid heater relays? where are the relays located and how common is it for them to fail??

any other ideas?

 

Does the volt meter cycle and lights dim?

The relays are down on the drivers side fender.

My 12V doesnt like the cold either.

 

i'm pretty sure the volt meter cylces and the lights dim, it used to anyways


my 12v used to start awesome in the cold, started fine at -10 last winter....

 

Oh come on Doc....LOL...

I would suspect the heaters not cycling fully. I would check the fuseable links from the battery to the relays and clean up the connections to the relays on the signal wires (those ridiculous rubber boot style connectors).

Apart from that its ohm-testing the heater grids, but they do not fail very often at all.

On and aside.. The DDP injectors don't care for the cold much, very lopey at idle until it gets a little warm. But still starts good..

 

Mine hazes like crazy now in the cold too since Ive put in the 0 plate.But then again my grid heaters are run through a switch and I dont use them unless I dont have it plugged in

 

What outside temp do you guys start plugging them in?

 

i never plugged mine in last winter (cause i'm at school) and it started fine down to -10 * F

 

You may have only one grid working.

On a cold morning, have someone start it. You can check for voltage at each post on the intake horn.

 

mainer,

i just replaced my head gasket, and at the same time installed 215 injectors, 191 DVs (you should have 181s from the factory..probably not much difference) and a #0 plate.

My truck exhibits the same symptoms as yours.

It hazes for a good while before it stops.

I lowered my idle speed when I did all the work, which makes it a little harder to start. I've always had to push the gas pedal while cranking, (due to GSK washer mod I was told) but i have to push it a little harder not to make her "fire right up" after installing the injectors, new plate, and DVs.

I don't think we have a problem with the heater grid or anything.

Mine starts great. It just takes a little more throttle pressure to get it to fire, and I can't immediately let off the gas after it starts (first 2-3 seconds) or it will die. I'm thinking the extra fuel is making mine haze.

I think it just goes with the territory.

 

Conn,
Did you put back in a stock head gasket or a thicker one? If it is thicker, you lowered your compression which will make it start worse.

Fuel plates should not have an effect on cold starting since the fuel arm won't be contacting it.

If Mainer's truck is hazing for 15 minutes, it doesn't sound like the grid heaters either. They cycle for a few minutes but after that the engine is warm enough that they don't make any difference.

I wish I had a better suggestion. I suppose that your timing could have slipped or you could have an injector sticking open.

 

Dartmouth,

I installed a .020 thick marine gasket. With .010 off the head, I wouldn't think an additional .010 of clearance would effect much compression wise, but who knows. I installed new injector washers as well, which could have changed the spray pattern a bit too I guess.

I'm chalking my "harder-to-start" problem up as a signifigantly lowered idle speed. I had to lower it becuase the dang thing almost didn't have the brakes to hold it idling at a light.

As far as the hazing goes, I'd say my injectors and DVs have everythign to do with it.

We did check the timing right before I went back together with it. 16° according to the dial.

I'm just goign to live with it for now. The truck runs good, it's just a little tricky to start and not rev the engine past 1000 RPMS with no oil pressure built up yet.

Of course, I could upgrade the rear wheel cylinders to help with the walking problem and bump the idle speed back up.

 

Extra .010 will equal around half a point of compression. With a .020 gasket and no material removed, you'd be looking at around a full point, in the 15.3:1 neighbourhood.

 

It sounds like the fuel heater is not working check the fuseable link in the PDM.

 

ok update everyone.....

so i checked the relays the one red wire with 90* snap connecter was completely off the one relay. so i put it back on (it was loose, didnt snap like it should) and it started awesome (like it used to), then the next day i made sure it was on and it started like crap again, and has done so since.

so today i spliced on an eyelet and got a nut and put it on that way, still same starting issue, got out the multimeter and it appears that at the grid heater i'm only getting power to 1 of the 2 wires (while the "wait to start" light is on)

so would this mean i have a bad relay? where else to check?