Self Timing IP After Long Trip?

[crash-harris]

This is a new one for me!

Edit: I don't see my signature showing up, so I'll put it here. Truck is 1989 F350 7.3L IDI with wastegated Banks Sidewinder.

Backstory;

Made a 400+ miles trip from OH to NC with Thumper. Fresh oil/filter change and new fuel filter the week before leaving. Fuel filter was filled with ATF, ran until the sound changed, then ran hard the next day. I filled both tanks before leaving and added a quart of ATF to the rear and a quart of marine 2-stroke to the front. Ran the rear first, then the front. Had 1 stop to pickup equipment in WV and 1 stop for fuel in VA.

So after finally throttling down in NC after riding the cruise control for about 250+ miles, I noticed a dead/flat spot on the ol' seat-of-the-pants dyno right at 2100 rpm and the idle has self adjusted higher. First it was just the bolt for the high idle solenoid worked itself out, but after seeing it back so it didn't contact the throttle lever, idle was still sitting at about 900, up from 750. Seems like timing is a touch more advanced at idle too. Now it seems to want to idle more at 800-850. Anyone ever experience anytime like this?

Could this be the advance plunger sticking on the lower side off idle, or retarding the timing too quickly? It's consistent right at 2100 rpm. It feels like it's pulling normally and then just falls on its face a bit, but the clatter sounding a little more advanced makes me think it's not a lift pump/supply issue. Running 70-75 most of the time, I never got the "lean fuel, hot cast iron" smell that I used to get with the stock N/A IP before I maxed it out. Still burns pretty clean too, with still only getting black smoke if lugging at all.

On a side note, it attempted to overheat on me on the way back, even though ambient air temps were cooler, but not raining as much. I noticed the factory dummy gauge moving higher than it normally does and looked back down on the same long grade and it was suddenly pegged with the engine light on. When I pulled over and checked it, the rad hadn't boiled, upper hose was as hot as you'd expect, but not scalding or dangerous, got a little gush when attempting to vent the cap and it was fine after idling for a couple of minutes and poking around for a couple of minutes while it was shut down. On restart, the light reset and the gauge dropped back to the N in normal. Thinking I'll be bumping up my timeline for pulling my mechanical gauges off the Enterprise and swapping them over. Still no signs of losing or burning coolant either

 

[crash-harris]

Bump

 

[KansasIDI]

This is a new one for me!

Edit: I don't see my signature showing up, so I'll put it here. Truck is 1989 F350 7.3L IDI with wastegated Banks Sidewinder.

Backstory;

Made a 400+ miles trip from OH to NC with Thumper. Fresh oil/filter change and new fuel filter the week before leaving. Fuel filter was filled with ATF, ran until the sound changed, then ran hard the next day. I filled both tanks before leaving and added a quart of ATF to the rear and a quart of marine 2-stroke to the front. Ran the rear first, then the front. Had 1 stop to pickup equipment in WV and 1 stop for fuel in VA.

Quite the distance. Glad to see I’m not the only one crazy enough to cross many state lines with one of these. But the state lines are a bit farther apart out here…

I know others on here that still do it too, a testament to these trucks’ reliability

So after finally throttling down in NC after riding the cruise control for about 250+ miles, I noticed a dead/flat spot on the ol' seat-of-the-pants dyno right at 2100 rpm and the idle has self adjusted higher. First it was just the bolt for the high idle solenoid worked itself out, but after seeing it back so it didn't contact the throttle lever, idle was still sitting at about 900, up from 750. Seems like timing is a touch more advanced at idle too. Now it seems to want to idle more at 800-850. Anyone ever experience anytime like this?

If you’re talking about the plunger on the cold idle solenoid, those are pretty touchy to adjust, jsyk

Could this be the advance plunger sticking on the lower side off idle, or retarding the timing too quickly? It's consistent right at 2100 rpm. It feels like it's pulling normally and then just falls on its face a bit, but the clatter sounding a little more advanced makes me think it's not a lift pump/supply issue. Running 70-75 most of the time, I never got the "lean fuel, hot cast iron" smell that I used to get with the stock N/A IP before I maxed it out. Still burns pretty clean too, with still only getting black smoke if lugging at all.

How old is the injection pump? It sounds like it’s going out to me.

On a side note, it attempted to overheat on me on the way back, even though ambient air temps were cooler, but not raining as much. I noticed the factory dummy gauge moving higher than it normally does and looked back down on the same long grade and it was suddenly pegged with the engine light on. When I pulled over and checked it, the rad hadn't boiled, upper hose was as hot as you'd expect, but not scalding or dangerous, got a little gush when attempting to vent the cap and it was fine after idling for a couple of minutes and poking around for a couple of minutes while it was shut down. On restart, the light reset and the gauge dropped back to the N in normal. Thinking I'll be bumping up my timeline for pulling my mechanical gauges off the Enterprise and swapping them over. Still no signs of losing or burning coolant either

Good that it’s not losing coolant. The gauges on these trucks aren’t very trustworthy, mechanical gauges is a good idea.

I would recommend carrying a laser thermometer temp gun, if you’re not sure that it’s actually getting hot. If it is, then probably new radiator time.

 

[crash-harris]

I was referring to the advance plunger on the IP itself (that actually retards timing as fuel/throttle is increased). I have no idea how old the injection pump is. It came off the Enterprise and looked like it was pulled off a van before that, but the nicer looking rebuilt IP that was on Thumper when I purchased it behaved like it had a hot start issue. Although, wit turned out that a lot of my hard starting was due to a failing starter at that time, but the truck still just would not fire after a 15-20 minute trip and only a 5-10 minute cooldown. The pump from the Enterprise has given no problems since I swapped it over, until this trip. It also behaved this same way all weekend in NC and all the way back to OH, but it really felt like if I say, shifted to 3rd and just laid into it (like on a on-ramp), there was no noticeable flat spot in the curve at all.

 

[IDIBRONCO]

Glad to see I’m not the only one crazy enough to cross many state lines with one of these. But the state lines are a bit farther apart out here…

Hey now. I've gone to Texas several times with mine. Going clear to San Antonio is almost like crossing another state line.

 

[crash-harris]

Tried to get a short video showing the amount of throttle shaft rotate in this "dead spot", but of course the servers still can't handle processing a 30 second clip I thought that maybe the allen screw at the end of the timing arm had backed out or something. It just seems like the IP is retarding the timing too early in the throttle shaft's rotation now, but the cam that controls that advance lever hasn't slipped on the shaft or anything.

 

[FrozenMerc]

Definitely sounds like something is worn out or loose. Your best bet may be to swap injection pumps and see if that cures it.


KansasIDI - Many of us are just wacky enough to cross state lines with these old rigs. I am planning a 900 mile haul at the end of September to go get my next IDI project. It will be fun to see how the old girl tows this big parachute.... Hoping for a strong northerly wind to push me all the way down I-29.

You must be registered for see images attach

 

[KansasIDI]

Has that been A series IH swapped (6.9/7.3) or is it an IDI CAT 1100 series?

 

[crash-harris]

Definitely sounds like something is worn out or loose. Your best bet may be to swap injection pumps and see if that cures it.

I've been contemplating that and will probably do so when time allows (hard to come by with produce harvest and festival season approaching). The problem is, I'm fairly certain the other pump I have has a hot start issue, and I have no other pumps and need to replace the roof on the house before a new IP is even something I can think about. I could go on a whole side tangent on that and needing farm equipment first, etc.

But I did toss the Tach & Time on t this evening and had 8°, so I bumped it back up to about 8.6°. I could still feel the flat spot in the curve from working the throttle under hood, but timing retarded at a steady rate when moving the throttle. Could just enough wear on the mechanical lift dropping a little fuel pressure at that given rpm cause a small plateau in the curve without really affecting timing at all?

Also checked the Schrader valve while the engine was running, but the fuel wasn't coming out in a steady stream, more like the "spurt, spurt, spurt" in time with the engine like you would expect with a mechanical fuel pump on a single piston Kohler engine.

 

[IDIBRONCO]

Also checked the Schrader valve while the engine was running, but the fuel wasn't coming out in a steady stream, more like the "spurt, spurt, spurt" in time with the engine like you would expect with a mechanical fuel pump on a single piston Kohler engine.

That may be a sign.

 

[The_Josh_Bear]

If you have questions about the fuel pressure/supply, it's time to get a gauge on it, preferably while driving. I used an old-timey vac-pressure gauge for mine and used a magnet to stick it to the wiper arm for testing a few years ago.
That's how I confirmed my suspicion that my Facet pump wasn't keeping up with WOT and I was right! 4-5psi cruising and 0-1psi WOT.

That said, I doubt you have a phantom fuel supply issue at that RPM. I agree that it sounds more like the IP itself-- that's a pretty lame spot to have a dead zone. You'll know right away with a gauge on it under load.

It's hard to say what I would do next...you said the advance cam didn't spin, the engine runs good besides the hiccup, and WOT she pulls just fine without the issue. So WOT fuel supply is fine, clearly.

Other than more ATF soaking I suppose you can pull the cover on the IP. Check for crud. I doubt it's the issue but it's worth a shot.

I agree with the IP swap, since it's what you can do. For hot starts, pour room temp water over the back(towards the cab) of the IP. Should fire right up after that.

 

[crash-harris]

I have a fuel pressure gauge in the Enterprise, but haven't been able to get around to swapping it over yet either, and it's been a number of years. I think gauges are getting bumped up the priority list though.

Water across the old IP is how I diagnosed the hot start issue with that one. Both tanks are rocking a quart of ATF and half a large bottle of MMO since I discovered this.

On the note of the Duralift pumps, I had installed a 40222 on the Enterprise and had 5-7psi at idle and about 1 psi at WOT. I have another 40222 under hood and bolted up on this truck as well, just not connected to any hoses or wiring yet. I ran out of time to finish the install when I did the return lines and eliminated all the other olives after the filter head.

 

[IDIBRONCO]

I have a fuel pressure gauge in the Enterprise,

On a side note, I always thought that you should have run personalized plates on that truck that read "NCC1701". That would have been the topping on the cake.

 

[crash-harris]

That's was my plan But the driver's side of the can was resting on the frame and it was going to cost $3K to repair, so I picked up Thumper for $4K

 

[FrozenMerc]

My wife would say that is prime example of Boy Math.