02 hard start

[loudtruckguy]

02 7.3 has 2 new 1000/850cca batteries...voltage in the morning is 12.6 when key is turned and glows come on drops to 11.4. Sounds like low voltage at first. after cranking for 15 sec a few times the speed of cranking coomes up. after 2 minutes of this it goes and runs fine. if you turn it off it will start right up and ussally will for next 8 hours after that we start all over. any thoughts?

[NoRalPh]

First, 11.4 sounds great to me Nothing low about that with the heavy draw of the GP system.

Second, I'm not sure what you're saying in your post though,,,, The speed that the engine turns over on the starter Increases ????? The more your crank it (15sec) the FASTER it cranks????

Try the block heater one morning, could the oil be really thick?

[loudtruckguy]

sorry i'll clarify when i turn it over i usally crank for 15 secs wait 10 and repeat when you turn it over it sounds like it has a low battery...it barlely cranks. as you keep doing this it gets better and better and 2 minutes later it starts. Temp is only like 45 at night shouldn't be oil at that high of a temp. my 96 fired right up(with one 4 year old battery) so oil is out.

[Ford Feller]

I am so having a similar problem. My problem occurrs when I haven't driven or cranked my truck in several days. The motor is turning over slowly and after several minutes and attempts the engine finally cranks. It has two brand new batteries and the temperature is not a factor seeing as I live in the Houston, Texas area...anyone have any advice?!

[NoRalPh]

Because of the way the injection system is designed, our trucks need to crank at a normal speed (I think it's around 200rpm) in order to start well. In fact, if the PCM sees anything lower than 100rpm it won't even send the signal to the IDM to even try to start.

A good, initial, cranking speed is very important. I would next wonder about the starter. If you're sure your batteries are OK and all the related connections are also good, could be a tired starter.....

[loudtruckguy]

starter would make more sense if it got weaker the more it cranked...something with the oil pressure makes sense. i've been told that the oil pressure has to reach ......before the injectors inject.

[NoRalPh]

That's why I thought of viscosity first BUT if you're not using the wrong oil then you're thinking that there is some, internal, "pressure load" of some sort that lessens as you crank for awhile? Not sure that can happen......

More likely on the oil side would be the "thickness load" lessens as things warm-up from the friction of spinning. Just for the heck of it, I would at least try plugging it in once

I'm also not sure you can expect a tired starter to loose it's ability to crank with time and just get slower & slower. I don't think it has to work that way.

My thinking was, (and without being there to hear what it sounds like I'm just spit-ballin here) that if the starter were marginal the initial cranking might not be building enough pressure for the injectors but with some time it could cross that threshold and the engine itself could add to the cranking speed as an injector or two fired a cylinder.

I don't know how "slow" your "slow" cranking is,,,, but, as I said, if it's too slow you're just wasting your time and batteries because it won't even attempt to start without being over 100rpm.

[loudtruckguy]

new sympton ...ok same sequence now when it does start it burns blue for a few seconds then a little white and then ok. I've had gassers with bad valve seal do this could i have oil seaping down into cylinders while it sits then when i fire it i'm compressing oil? i'm going to start checking oil to see if it is droping ...i don't use the truck everyday so its hard to notice....any other ideas

[NoRalPh]

More likely than guide seals, would be leaking injector O-Rings allowing engine oil into the cylinders...

How many miles on the engine?

[loudtruckguy]

96k miles i've only owned it since 90k...i'm going to try plug in just to see what happens