Guys and gals, I have a 91 f350 7.3 IDI. have had several issues, but here is the latest. even though the less than year old batteries say 12.74 volts, I do not have the power to crank the motor for more than 7 seconds. that is with the charger hooked up. I have replaced the solenoid, the old 1 wasn't bad but it was at least 11 yrs. old. I also just replaced the positive battery cables and connections.
Some things that have changed recently; I replaced the fuel filter bowl with a fram fuel filter with the bowl built in. (mine was on it's 3rd different leak in 6 months.) I replaced the fuel (gas) cap with a spare 1 not specifically for diesels. when I thought I got a wiring issue fixed, I plugged in the ignition wire to the glow plug harness since it had been replaced with a toggle switch. and it was very hot when I got back to it the next morning, maybe frying the controller or relay or whatever.
I tested 2 of the glow plugs so far and they get hot, but do not glow or turn red, like I have read in other posts that they should. All of them got good readings while still in the vehicle, as in voltage. I have read a dozen posts on my issues, and believe my next move is to remove and clean all the grounds. then test the rest of the glow plugs.

Please let me know what else you believe may need to be checked or done.

 

Uh, glow plugs != cranking problems.

Your batteries may be shot, or the cables, or the starter. As it cranks it over at all, I'm inclined to think batteries. Remember that you can have a 'surface charge' on a set of worn batteries; they will appear just fine until you put a load on it.

Also, what's the RC rating of your batteries(reserve capacity)? You can have two batteries which both have a 1000 CCA rating, but one is half the size. The larger one will allow you longer cranking before it starts to droop... though for the first 30s, they can both supply the same rating(That's what CCA and CA ratings are -- how much current the battery can supply for 30s, brand new).

 

I have to agree with this. First thing I would check are the batteries. Dead batteries can still put out 12 volts. That being said, I would get them tested before buying new ones. Next would be the cables (but you already checked those), then the starter.

 

More info. Starter replaced in april and tested last week. I have battery tester that tests load also. It says they are good and both are under a year old. But I believe I will take them and have them tested anyways. I dont remember the cca right now.

 

Did you isolate the batteries from one another for the load test?

 

I believe I tested them separately. 1 test was performed while replacing the positive cables.

 

You said you replaced the solenoid, did you use a new one?*A used one could be corroded. Any contamination could make a bad connection.

How does it sound when you try starting? Inspect the flexplate/flywheel.

This one is more of a long shot, but how is your exhaust? An infestation, or any kind of clogging could create enough back pressure to slow the cranking over the course of 7 seconds.

 

Solenoid is new. Also I guess it will start if I plug in the charger and turn it to 12v 40amps for about 25 minutes. Then it starts maybe after 2 tries. That was the case even before the new solenoid and positive battery cables.

 

Are your battery cables getting hot while cranking? I suspect the starter. You say you had it tested, like, at Autozone? All their machine does is tell you if it will turn or not. You need an amp draw reading while it is cranking your truck, assuming good batteries at the time of test.

 

IT IS A 2 MONTH OLD STARTER, BUT YES, ALL THAT WAS TESTED WAS AT ADVANCED auto.

 

Doesn't mean it wasn't defective from the factory.

Either way, there is only three things that could be wrong: Battery, cable, and starter.


Also, the fact that it starts with charging indicates to me shot batteries.

A video of you attempting to start it would be useful too.

 

Im suspecting starter as well. Mine did the exact same thing. Would spin over great at first, but as soon as it started cranking, it started slowing down. Could crank for maybe 5-6 seconds. Bought batteries, did the exact same thing.... I suggest the NOS start from OReillys. Isnt advance the same as auto zone? If so, stay the hell away from that place. OReillys is alot better than i gave them credit for, and they carry motorcraft.

 

Advance is a competitor to Autozone. All three chains have their cheap house brand of most parts. All three have "national" and OEM brands of _some_ parts. Autozone seems to have the fewest brands other than their hose brand(s). O'Reilly and Advance have more brand options, typically.

....and I think you meant POS....

The key is whether the load test was done with the batteries isolated. "Believe" doesn't count; make SURE they're isolated for the tests. Otherwise you're load testing as if the two are one big battery. I've read threads where members have taken their trucks to the FLAPS for a load test, and the AutoZtoner comes out with the tester and wow, over 1000 CCA! One guy even asked the AutoZtoner, hey, aren't you supposed to disconnect one battery so you're testing them separately? AutoZtoner said no. Oooops.....

 

Okay, issue resolved. cleaned negative cables. both ends of both cables. I replaced the connector bolts on both cables.

 

That's very true actually, that's why I get a chuckle out of when people say to stay away from one or the other, it's all the same no matter where you go. We don't have Advance locally, we have OReilly's, Autozone, and Napa.

You can get Motorcraft at both O Reilly's and Autozone, don't know about Napa, never tried.

You buy a Murray (Oreilly's Brand) radiator cap and take it out of the box and it is a MotorRad. Buy a Duralast (Autozone) and it's a MotorRad. Funny thing is I recently bought an AC Delco radiator cap for my S15 and it was a MotorRad. (Wasn't funny at the time though. )

At least Napa's marketing is smart enough to put their own names on their parts so the suckers...consumers... feel they're getting value for their overpriced econo-parts.

As far as employee intelligence goes that's dependent on the individual, not the chain. My local Napa guy is pretty stupid. I had a helpful guy at Kragen's (no longer in existence, O Reilly's bought them out.) that if he could find the part he pulled out books! Yes, books, with real paper and words and stuff!