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View Full Version : Is Using Throttle To Start Cold Engine On Mech Inj Engines Recommended?



Shaun091382
02-18-2004, 11:58
Hi I was just wondering if it standard to use say 1/4 throttle pedal depressed when starting my cold 6.5TD with mechanical injection..i just had new glow plugs,injectors,fuel filter and injector pump installed and when i try to crank over when cold it kicks like it wants to start but it stalls within 1 to 2 seconds after bucking..when i lightly depress the accelerator problem i have no problem starting the truck thanks for the input.

Kidd
02-18-2004, 17:01
Hmm, never had to do that on my old '93.. is it possible your cold start advance not set right?
What is your cold idle rpm?
K.D.

David Brady
02-18-2004, 17:15
Shaun,
My old 6.2 had a sticker on the visor that said to hold the throttle down I think it was half way when cranking. It didn't seem to hurt it that I could tell.

Shaun091382
02-18-2004, 17:58
After gettin the glow plugs,injectors and IP replaced the truck definitely idles much slower when first started up the idle i dont know exact but i would say for it to be somewhere in the neighbourhood of between 650 and 750rpm and up around 1000 when warmer i noticed along with the lower idle speed when these items were replaces a more profound diesel "rattle" as well..dunno if this is good or bad..its a diesel so i will assume its fine.

john8662
02-18-2004, 20:18
Using the throttle on the first cold start of the day is a must. All it takes is about 1/4 throttle down to engage the fast idle solenoid. The problem with the solenoid is that once energized (by a sensor in the block) it does't have enough of a push to depress the throttle to make the idle higher. Thats why you press down the throttle to help it out. Once the throttle is depressed the plunger on the solenoid extends and will hold the throttle to its extended position until it turns off (warms up). Thats what gives you the higher idle. The MFI 6.5 and the 6.2 are the same when it comes to starting. When starting my 6.2 I depress the throttle (you can almost hear it click into position, or hang), release my foot, crank it up, usually fires first time, if its colder I give it some throttle while cranking it. Some engines are preticular about how they start, I just figured out what works best for mine. The EFI 6.5's don't need any throttle while starting (well mine doesn't).

whatnot
02-18-2004, 22:09
The sticker on the visor on my '93 says to push the pedal down and release it after turning on the key but before starting. (while waiting for the glow plugs)
As stated above, the fast idle solenoid won't engage if you don't.