Darn...2002 F350, about 190K. 6 speed. Only mods are 4" exhaust, Ford performance intake. I have a tuner, but haven't had it on for months.

Sometimes it doesn't wanna start, with no way to predict when it will happen. Never overheats, never surges, no smoke, no hesitation...when it starts, it runs well.

My first guess was to put the tuner on to see if it popped a trouble code. On the first and second try, the tuner wouldn't even power up (but everything else did). On the third try no trouble codes found. After waiting about 10 minutes, it fired up like normal. Cranks normal, still gets great fuel mileage and normal power. I powerwashed it while up on a rack, thinking it might be a bad CPS and I wanted to clean the underside anyway. Pretty sure it's not a fuel issue, but I changed the filter anyway.

Whilst I was under there...aha...I noticed a loose grounding strap. The strap is on the passenger side of the motor, maybe a foot or more behind the turbo. It hangs down far enough to easily grab it. I can't see where it was originally attached, but finding a new spot is not an issue.

So, I had the wife crawl in and try to start it with me (hopefully) keeping the grounding strap from contacting ground, thinking that if it failed, then worked when I grounded it that I would be a genius.

It started all three ties she turned the key, although I couldn't see for sure where the grounding strap was coming from, and I may have contacted ground anyway. I have yet to fix the grounding strap issue.

My gut tells me it is either the loose grounding strap or some other mysterious problem...likely the same one that made me forget my original log on name.

Anyway, does anyone have any thoughts on what would cause the starting problems? I have a couple of spare CPS in the glove box. Could that be it?

thanks

 

Starting and cranking are two different issues. It cranks? Does it smoke while cranking? What's your battery voltage while cranking? Did you by any chance make sure your battery cables were all tight? What's your oil level? When was your last oil change? If you suspect CPS, it's a couple of minutes to swap.

 

Cranks normally with no smoke and fuel bowl fills. Batteries are working fine and all cables tight and corrosion free. Yea, I've changed a CPS by the side of the road. Flat tipped, long handled screwdriver and a 10mm socket if I recall. Fresh oil not a problem.

 

Pay attention to what lights are on the dash when you get the no start. I have a similar issue with or without my tuner on. When it does not start, the WTS light never comes on and the SES stays on. I also do not hear the usual relays click under the dash. It is really easy to not notice any of this stuff and crank away. A couple of key cycles later I get the WTS and it fires right up.

 

I have had something like this happen to me, I didn't know something was up until the truck threw an ses light. Normally the truck takes 2-3 cranks then fires up. I thought this is normal and that's all the thought I put into it. One day for some reason it threw an ses light. When I jumped in about a half a dozen times with the light still on it took half a crank and was running... I pulled the codes... There was nothing but default codes. So I deleted them all and fired the truck up... I've been back to 2-3 cranks before she starts since then.