Engine tune-up schedule

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Mike6158

Mike6158

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10 Year
Joined
Jun 1, 2014
Threads
65
Messages
987
Location
Weimar, TX
Website
wildlightimagingstudio.com
I finally took the TLC on a road trip with my grandson. We drove down to Big Bend for the weekend. It's about 10 hours each way. I couldn't ask for a better ride. We didn't do any wheeling unless you count a mud puddle going into the Hot Springs area. Other than what I think is an excessively long crank cycle (more than 3s) everything was great. Fuel mileage was about 16. 18 in the park but the speed limit is 45.

I hooked a scanner up a few minutes ago and everything that I understood looked fine. The O2 sensors weren't very balanced but I'm only familiar with AF control on large industrial engines (I used to write programs for AFR control on 3000 HP natural gas engines).

So the point of all of the above is that I'm not seeing anything that leads me to believe that the plugs, coils, or wires are bad. The fuel system seems fine. Yet the car has a long crank cycle. Longer when it's hot but not by a lot.

At 150k, what should I consider changing if anything? Plugs? Spark Plug Wires? Coils? The last time I worked on a vehicle it was a 30 over 396 in a '69 Camaro and it was carbureted. Once they went electronic I stopped messing with them. The TLC seems to be something that I can work on again.

I wish i had bought one of these a long time ago...
 
I think it needs plugs around 100k. It doesn't have "wires" like the old distributor style ignition engines, it has coils. I wouldn't replace them, unless you just want to do it while you are doing the plugs.

The o2 sensors will get lazy when they get older, it's best to do both sides at the same time in my opinion. Others can speak to if they've only done the first set, second set, or all of the o2's.

There are a bunch of threads on here relating to preventative maintenance, probably some links in the FAQ sticky thread.

They are great vehicles, just did 2500 miles in a week in mine (trouble free) and I felt fine when I got home.
 
Thanks. I have a lot to learn... :) but that's ok...

I should probably read the maintenance records that the last owner left me too.

Is there an operating voltage difference spec for O2 sensors? I suppose the difference could be mixture related.

I read the FAQ sticky but I didn't see anything about pertinent. I'll take another look.
 
Plugs were changed at 107k along with a bunch of other stuff like the water pump, timing belt, etc. I guess I shouldn't try to fix anything that isn't broken
 
By crank cycle, are you referring to the engine starting? Mine was a little slow and was fixed by cleaning corrosion from the battery terminals.
 
No, it spins over fine. From the time the starter motor engages to the time the engine starts is 3 seconds or so. It has a long crank cycle compared to other vehicles that I drive.
 
BTw- Concerning the FAQ and O2 sensor voltage troubleshooting- the link was bad. I let the mod know...
 
Mike, what are your long term fuel trims? I run somewhere in the +\- 3% region, varies. If you're running with less than 5% from nominal and you haven't thrown an O2 code you're doing fine. I'm still running all original O2s at 135k miles and, using TechStream, I can monitor output voltages, run sensor health checks etc and nothing has faulted or failed yet. In your OP you are getting 16 to 18s mpg, that's a good indicator you don't have issues IMV. Starting does seem to take a while, maybe why mr T built in the crank till start hold cct?


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My long term fuel trims were 0 when I checked the first time this morning. I had disconnected the battery so that I could change the headlight bulbs a few days ago. Maybe that is why. I went for a drive of about 5 miles and checked

LTFRM1(%) -0.8 (with an up arrow beside it)
LTFRM1(%) -1.6 (no arrow)

Bank one O2 sensor voltage was toggling between .020 and .740 every second or so. Bank two slowly changes between .035 and .040 with an occasional spike as high as .085

When I program start sequences for industrial engines the routine goes something like this: engage the starter, RPM check for at least 75% crank speed, ignition on for 1 second, open the fuel valve, confirm running RPM after 2 seconds. There is other stuff related to result confirmation and ignoring things until it comes up to operating temperature but the basic sequence is always the same. Maybe that's what's going on with the TLC :)

I had two ABS codes that didn't come back when I cleared them. C1246 and C1223. One is the master cylinder pressure sensor and the other is an ABS malfunction. I know these aren't related to the start cycle. I think they are old codes that were never cleared when the previous owner had the brakes serviced.
 
If you get a new battery, then the length of time it takes to start the engine will probably decrease.
 
The battery is less than 3 months old. Crank speed seems fine. It's crank time that is long
 
Forgive me for asking a stupid question, but do you know what kind of plugs were installed at 107k?

I have seen 2uz-fe's that didn't have iridium plugs take what seemed to take longer than "normal" crank times.
 
Mike6158 said:
No, it spins over fine. From the time the starter motor engages to the time the engine starts is 3 seconds or so. It has a long crank cycle compared to other vehicles that I drive.
Click to expand...

Yes, that's what I meant. Mine was like that when the terminals were corroded. It cranked fine, just took a while to start. With the terminals cleaned it was cut by 2/3 or 3/4.
 
Mike6158 said:
Crank speed seems fine. It's crank time that is long
Click to expand...

I also thought this to be the case with mine; it seemed like it was turning over fine, and just taking a long time to start.
When I replaced the battery (and cleaned the terminals) the crank time decreased by about half (from about 2 seconds to about 1 second).

I hear what you are saying. If it runs fine after starting, and you are getting normal fuel economy, then I would check the battery and associated connections. In my case, replacing the battery fixed the crank time problem, even though the crank speed seemed fine before battery replacement.

Hope this helps.
 
LockedNLoaded said:
Forgive me for asking a stupid question, but do you know what kind of plugs were installed at 107k?

I have seen 2uz-fe's that didn't have iridium plugs take what seemed to take longer than "normal" crank times.
Click to expand...

@ 97,137 miles he put Toyota Part Number 90080-91180 plugs in. There's a hand written note that also says 60 plugs NGK and something that I can't read that looks like found. That's the best I can come up with. 150k plus now.

I think I have a new yellow top Optima that I could drop in. It makes sense that a weak battery could turn the engine over fine but not deliver peak voltage to the coils. I was thinking plug wire and single coils from the old days. It's not like the engine is a big bore beast with high compression so current draw shouldn't be too bad for the starter. But... if the battery is weak... or has low CCA then that might be the problem. I'll give it a look and see what comes out of it.
 
I swapped the battery and I can't tell any difference in the crank cycle. Using my precision clock source (I counted) it's about 2 seconds so maybe I'm just used to the more modern EFI engjne crank cycles. The Optima doesn't fit with the factory battery hold down. The battery is about 1-3/4" lower than the hold down. I'd like to keep the Optima though. Is the Slee battery box for the stock location a good solution for this?
 
That makes sense. Just a random thought but every time I do something to the land cruiser I am impressed by how well it's made.
 
Mike6158 said:
I swapped the battery and I can't tell any difference in the crank cycle. Using my precision clock source (I counted) it's about 2 seconds so maybe I'm just used to the more modern EFI engjne crank cycles. The Optima doesn't fit with the factory battery hold down. The battery is about 1-3/4" lower than the hold down. I'd like to keep the Optima though. Is the Slee battery box for the stock location a good solution for this?
Click to expand...
In toyota's 2UZ engine group functional description they discuss their hold crank cycle and indicate its in the 2 - 25 second range and that the engine is considered running when rpm>500. Coolant temp and fuel pressure are two inputs to the crank hold cct, maybe a fresh fuel filter wouldn't be wasted effort?


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I thought that previous owner had recently replaced the fuel filter but when I looked at the invoice again is says- Owner requests fuel filter change and then in the notes it says No fuel filter. Price - $0.00 so I'm going to guess that they didn't change it. Thanks for asking that. I thought it was already done.
 
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