My 94 7.3 IDI turbo diesel has been acting up lately. A few weeks ago I noticed that the engine would turn over slow and take longer to start esp. when cold. I thought it was just the batteries since they are four years old. I kept checking the voltage in them and it was always at 12.8 volts even after sitting. I talked to a few people who said the batteries may not hold up when a load is placed on them (when starting). I tried new batteries and it didn't help. It still does the same thing.
I'm assuming the starter is to blame. If you have any ideas let me know.

 

Sounds very similar to mine. When I acquired the truck, it would not start by itself without the heater plugged in, just would not crank much over 5 to 10 seconds without sounding like the batteries were completely run down. I pulled the starter and had it checked out, nothing wrong there. The battery cables looked pretty ragged, so I replaced them all. Bingo!! Starts fine ever since.

 

How fast did yours turn over? Mine starts fine once it turns over fast enough. Did yours turn turn over slow and then pick up?
Mine turns over slow for about five seconds and then picks up and turns over at normal speed and the truck starts. (when cold)
When its warm it turns over slow, but starts right up.

 

Sounds like a bad connection to me.
To be safe, I would check the batteries first though.
Go down to an auto supply place that can load test the batteries, before they test the batteries you must remove one of the grounds on either battery.
You can not load test two batteries at once.
Most of those guys are not up on a twin battery system.

If they test OK, then start inspecting every connection for corrosion or loose connectors. When you are doing this, unhook the grounds on both batteries, a wrench that shorts out on something can burn holes in things real fast with that much juice running through it.

If you could have someone else crank the truck, I bet you have a connection that is getting hot when you are cranking it, when it gets hot the expansion of the connector is making a better connection after a few seconds of cranking. The reason I said have the batteries load tested, that connection may be inside the battery. When they test it, if the voltage jumps up after 5 or 10 seconds at load, replace that battery before it lets you set somewhere.

 

Turning over slow then speeding up as it cranks was the same thing I had when mine had a bad starter. It would drag till it warmed up a bit then it was fine, it always cranked fine when it was warm though.

 

I have load tested both batteries (disconnected) and they both tested fine. I will check the connections when I get off of work today to make sure they are all good.
If they all check out good, I'll assume that the starter is going bad.
Thanks for yalls info!

 

I checked all the battery cables (cleaned and tightened them up). Now I'm guessing that the starter is to blame. Does anyone know how much a starter for a 7.3 runs and where to get a good one?

 

Do a Voltage drop test on the starting system.

http://www.fluke.com/application_not...AGID=1&SID=103

 

The last one I got was a Mitsubishi gear reduction starter, as I remember it was a little over 220 dollars.

 

The starter is going bad (load test proved it). I have found the following starters/prices at different stores. Any input on these would be appreciated.
(all reman starters)
Carquest--Delco--$152--3yr warranty
Autozone--Duralast--$170--lifetime
Oreilly--Ultima--$170--lifetime
Napa--?????--$186--2yr warranty

 

If you can afford it the mitubishi starter is much better in my opinion.my truck came with the delco and when it went bad , I replaced it with a delco.When that one went bad I switched to the mitubishi and although noticably smaller and lighter in weight my cranking rpms are much faster than the delco.

 

Mitsubishi Gear reduction starter is the way to go.

 

Where can you get the Mitsubishi reduction gear starter? Who sells them?
Thanks.

 

Almost every place that sells starters sell both.
The Mitsubishi starter is small compaired to the Delco one, but the Mitsubishi starter cranks it over way faster.

Just ask if it is the Delco direct drive or Missubishi gear reduction starter.
I get mine at NAPA, they stock both kinds.

 

I just bought a starter for my 85 6.9 last weekend and it cost me $179 with a lifetime warranty. I bought it from carquest auto.

Just a hint when taking it off. Use a normal 1/2 inch socket to take off the screws. Start with the bottom one closes to the pasenger wheel and then the top one. For the top screw use the normal socket and 3 4'' extensions and a socket wrench at the end. When you use the 3 extensions it is able to move slightly and you are able to get the screw off quicker. Once u get the top one go for the last one on the bottom this is the easiest way i found and the quickest since it only took me and 1.5 to take the old one off and insert a new one.