I'm looking at a 1997 F-350 with the 7.3 Powerstroke.

The truck fired right up, a cold start at 0 degrees, no block heater. However, it was surging a little at idle. It would idle normally, then drop down slightly, then come back up. It was doing this consistently.

I let it warm up for about five minutes while we checked it out. When I got in to drive it, it bogged down considerably when I put it in reverse. Then it idled back up. Did it again when I shifted to drive.

On the test drive it actually stalled the truck out twice, both times immediately after shifting to drive. Once it was going down the road it sounded fine, although it did feel kind of like a pig, not how I remember 7.3 PS trucks driving.

Is this something that should concern me as a potential buyer, or was it probably due to the cold and the short warmup time? I'm going to test drive it again before I pull the trigger, is there anything I should check that could give a better indication of what's happening?

 

If you have a way to monitor it, the ICP would be good to monitor. I suspect one of 2 things are happening.

1) The ICP is loosing pressure causing it to stall, usually because of faulty o-rings.

2) The torque convertor is locking up at idle because pump pressure in the transmission is weak.

Both conditions are worse when the trucks are at operating temperature. One sign about the ICP issue is that the truck will also be harder to start when warmed up.

 

How many miles? Could be worn out injectors.

 

I'm guessing the truck has an auto tranny. If so check the oil level in the tranny. I'm not an auto guy, but from what I've read, low oil can cause stalling issues. Somebody will correct me if I'm wrong.

 

The truck only has 130,000 on the clock, I'd be surprised if the injectors are failing already. John, thanks for the tips. I'll double check the hard warm start issue, although this guy has been driving the truck and says there's no issues when warm, just the lugging when cold deal. I'll double check. I'll check the fluid level as well.

I assume a weak pump issue in the transmission is probably pretty expensive, involving dropping the transmission?

 

Weak line pressure will usually cause the torque convertor to lock up in Reverse. I forgot to mention that, sorry. When that happens, it feels like taking off with a manual transmission in a gear that's too fast.

If the truck only has 130,000 miles on it, it could still be injectors, or the o-rings leaking.

What kind of oil are you using?

Also, you said it acts like a pig when warmed up. If you're used to driving a 99-03 7.3, they have a little more power than the 94.5-97 trucks, assuming they're in stock form.

 

I am used to the later 7.3s, so that probably explains the difference in feel.

When I put it in reverse, or drive for that matter, it bogged down then revved back up on its own, but i seem to recall that it did feel kind of the same as launching a manual in too high of a gear.

I don't know what oil it has, I haven't bought it yet. And yes it could be injectors, but I'm sincerely hoping not.

If the transmission fluid pump needs to be replaced, how big/expensive of a project is that?

 

If the tranny line pressure is the issue, there's a lot of possibilities that could cause it. The most likely is internal leaks, which means it would need a rebuild. Costs for a rebuild is in the 2000 to 3000 range. Ford offers a reman E4OD I think if in the 1800 range. The top builders for that tranny want 3500 and up for it. There are others that can do good jobs rebuilding them though. You may have someone local that does a good job. But, it won't be cheap.

 

Well, I found the test procedure for checking line pressure, so I'm going to give that a shot and see what it reveals.

A couple quick questions about it, does that test need to be done warm, cold, or does it not matter? Does the truck have to be moving in gear to give accurate readings, or will it work sitting in the cab holding the brakes?

 

It should be done sitting still since that's where the problem is. Be careful when doing this.

 

10-4. Will a parts store pressure tester (O'Reilly rental) be sufficient, or does it need to be the factory Ford tool?

 

If you know anybody with a decent diagnostic tool you could look for any stored codes and also monitor data durring another test drive. FYI my truck has an idle surge every once in a while but I believe it to be because I remove the cali emissions pulse damper; not that thats what youve got goin on but just fyi.. Good luck with the potential purchase and post pics if you buy it..

 

I do know some people, but I'm fairly isolated and making it happen on short notice probably isn't possible. I'm going to give it a good look over and another, longer, test drive this weekend. I'll have much more to report then.

 

By your name, I'm guessing you're in Alaska?

 

Yes sir, you are correct.