22re Won't turn over after long, hot drive

[DouglasVB]

Short version: Long story short, I drove from Colorado to California on Sunday only stopping for gas in my 1988 4runner DLX (22re, 156k miles). The starter became progressively more sluggish until on my last two fuel stops, I had to push-start the truck. The next morning after the truck cooled down, it fired right up multiple times and had no problems. Even while the starter was barely turning the engine over, the truck drove fine. Should I be replacing the starter (replaced with a remanufactured unit a month ago and no problems until now) or is something else possible?

I originally posted over on my awesome local Toyota 4x4 forum and it was suggested I replace my starter with a genuine from the Toyota dealer remanufactured unit as insurance against further problems. I'm posting here to see if you all have any other ideas that I should try before or at the same time as I replace the starter. Original post here: http://www.risingsun4x4club.org/forum2/showpost.php?p=269438&postcount=134

Longer version: I started from Denver at about 4:30am. The truck started up fine. I stopped near Vail to use a toilet (okay, I lied before. I stopped once for non-gas reasons). The truck started up fine. I stopped in Thompson, UT for gas. The outside temp was probably about 80F at this point. The starter was slugish but the truck started up and ran fine. Next stop was St. George, UT. I pulled into an AutoZone to get my battery tested (thinking maybe it's not holding a charge). The battery was fine. The truck wouldn't turn over but was barely trying with my foot pushing in the clutch. I was able to get it to barely to turn over and run by using the clutch cancel start switch (lower left below the steering wheel on the dash). I pulled across the street, got gas, and was able to use that clutch cancel switch to get it started again. Outside temp was 112F. Still not using AC at this point because I was trying to conserve fuel and also all of the hills needed the full power of my 22re.

Across Arizona and Nevada, I saw outside temps up to 117-120F in a few places. It was damn hot. I broke down and used the AC sparingly when the steering wheel became too hot to touch.

In Barstow, CA I stopped for fuel again. Outside temp was around 105-110F. Found a gas station with a bit of a hill on one side. Got gas. Went to start up but it didn't want to turn over. I roll-started and it fired right up and away I went.

In Fresno, CA I stopped for fuel yet again. Now the outside temp was around 85-90F. Again it would barely try to turn over. Luckily there was yet another hill. One roll start later and away I went.

The next morning after sitting in the cool air for nine hours (60F outside) the starter cranked strong and fast, the truck started up, and away I went no problem. I stopped and started several times and the starter functioned as it should.

I haven't driven the truck in such hot weather or for such a long distance before (just got it a month and a half ago). The starter was replaced about a month ago with a remanufactured unit from O'Reilly. At the time I didn't know that I could get parts to rebuild my own. Everything else with the truck is working well (good compression in all four cylinders, all fluids except for power steering an coolant have been changed in the last month, good voltage according to my voltmeter I put in the dash, etc...)

I was looking through Roger Brown's guide to starter troubles ( http://www.4crawler.com/4x4/CheapTricks/Starter.shtml ) and thought maybe I could be having troubles with a flaky ground or something else along those lines. While I was driving across the desert, I didn't feel like trying to get to the starter in the engine bay to try and jumper between the solenoid and a positive voltage source.

Any thoughts on what I should be trying to chase down aside from replacing the starter again? I'm okay with push starting the truck but I figure it would be nice for the drive back to have it start normally.

 

[snobdds]

Short Version
Check your grounds. Check your starter relay. Check the connections going to the starter. Check your Fuel pressure regulator and the VSV on top of the valve cover that goes to the fuel pressure regulator (If you have to, bypass the VSV and run manifold vacuum directly to the fuel pressure regulator to remove that variable).

 

[DouglasVB]

Check your grounds. Check your starter relay. Check the connections going to the starter.

Will do. I think I'll install a bypass for all of the wiring in the truck (so I can directly run the starter without all of the wiring in the cab) as well.

Check your Fuel pressure regulator and the VSV on top of the valve cover that goes to the fuel pressure regulator (If you have to, bypass the VSV and run manifold vacuum directly to the fuel pressure regulator to remove that variable).

Excuse my n00bness, but what would the VSV and fuel pressure regulator have to do with the starter turning the engine over? Since the engine starts as soon as I feather in the clutch while roll starting, wouldn't that verify that the vacuum switching valve and fuel pressure regulator are both good?

 

[snobdds]

Your fuel pressure regulator increases the pressure in the fuel rail when hot to prevent the fuel from boiling and help with hot starts. Vapor lock in the fuel rail. The truck will be hard to start without the increased pressure from the fuel pressure regulator.

It really doesn't make sense that your starter is not working when the engine is hot. Most cases it the opposite. I think you have a fuel delivery problem when the engine is hot. The fuel pressure VSV is controlled by the computer to allow manifold vacuum to travel to the fuel pressure regulator when the coolant is hot.

Check your wiring first though...need to eliminate that variable.

 

[DouglasVB]

I just picked up the parts I needed to test the electrical side. Will test that this afternoon. I'm able to replicate the very slow starter when the engine is hot.

 

[vegasfj40]

Any more info on this? I'm wondering if its not the starter.

 

[DouglasVB]

I haven't had any troubles since putting in a bypass relay and starer switch; adding a bunch of extra ground points to the engine block, frame, and body; and cleaning the battery terminals really well. However, I also haven't driven it across the desert for 12 hours straight again either. The hottest and longest drive it's seen is about 90 degrees and about an hour. No trouble starting after that.

Next Monday I'll have another long cross-desert drive and should be able to tell pretty quickly if it was all the wiring between the ignition switch and the starter or not. With that information, then I will proceed forward.

 

[vegasfj40]

So how was the drive across the desert? Any problems?

 

[DouglasVB]

Hey sorry for the slow updates. Work has been busy, yada yada.

The drive back across the desert was uneventful. The starter was slugish most of the day but temperatures never really went above 90F where we were driving.

I have since tested the ability of the starter to make the truck "crawl" in 1st gear low range on flat ground. It barely can make it crawl when the truck is cold and the air is cold but as soon as the truck is up to operating temperature and it's above about 50F, the starter won't make the truck crawl. (this is using the clutch start cancel switch, etc)

All signs point to something in the starter binding up when the truck gets too hot. Based on the current draw from the starter when it refuses to start the truck, I think the plunger assembly is good. Same with the contacts. That leads me to believe that either the bearings or something else involved with the motor spinning swells when the truck is hot.

I won't have time until mid to late August to address the problem (hashtag too much work). At that point, I think one of the members of the Rising Sun 4x4 Club has a spare original Nippon Denso starter that needs a rebuild. I'll get that starter, do a rebuild myself, and install it. Then I'll carry my gimp starter as an emergency backup part.

 

[rrodscott]

I had a similar problem with intermittent starter operation and when I took the starter apart the main contacts were almost burned out. I got lucky because a friend owns a alternator and generator rebuild shop. You can test the starter motor by connecting the main wire to the positive terminal with the coil disconnected or the dist cap removed which takes the solenoid part out of the circuit. If the solenoid snaps forward to extend the starter pinion but the contacts are worn you can jumper the terminals with a old can solenoid just to troubleshoot.