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Acceleration
1990 Toyota PU. 22RE 5spd 4x4 4:10 rear. 15x10s with 32inch tires. Lifted 3 inches. 190k miles
Problem: Truck starts right up. Drives fantastic. BUT will not get out of its own way. Its good for local driving. It won't accelerate for s***. Forget the expressway . It doesn't like inclines at all. Tranny was rebuilt 6yrs ago. I was resolved to a motor rebuild but after speaking with some friends they think it might be the rear gears. Does anyone have any suggestions. Thanks Lenny |
Might try advancing your timing a few degrees... its been my experience too little timing results in symptoms your having issues with...
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Define slow.
Should go 80 in 4th at least, with your gearing and tire size. 31", but still... performance should be similar. Do a compression test. Adjust valves and timing. New fuel filter (a bitch), new air cleaner. OEM cap and rotor Then buy a 29,99 Voltmeter and start testing sensors. For each sensor, you will find something on the net. TPS (4crawler tps adjustment) Airflow Temp sender (ECU) et cetera |
Originally Posted by ev13wt
(Post 52417094)
Define slow.
Should go 80 in 4th at least, with your gearing and tire size. 31", but still... performance should be similar. https://www.youtube.com/watch?v=vVuPe83NTUg Do a compression test. Adjust valves and timing. New fuel filter (a bitch), new air cleaner. OEM cap and rotor Then buy a 29,99 Voltmeter and start testing sensors. For each sensor, you will find something on the net. TPS (4crawler tps adjustment) Airflow Temp sender (ECU) et cetera I then even had problems stopping the truck. The momentum was too great and I had to bypass the lspv valve , replace booster, upgrade to 1 inch and add manual adjuster just to get it to stop. |
Are you compensating speedo reading for the larger tire? I can't remember what stock tire size is, you can read it off your door jamb, but let's say it is 28", and you've put on 32s. That is a 14% change in tire size, so your speedo will read 14% low. In this example, 75MPH reading is really 87MPH. So check your door for your stock size.
On top of that, yeah a larger wider tire is really going to bog your truck down. Re-gearing puts you back into the stock RPM range, which helps your pep, but re-gearing can get pretty expensive. Toyota OEM 4.88 diffs and I believe 4.30 can be found, and those are probably going to be the most economical, but sometimes those will have lots of mileage. |
Time to got to 4.30 or 4.88 gears
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I had 31s on it prior and the speedo was off by about 12 mph but with the 32s its only off by about 3mph with a side by side test with another car. I found that strange .
Is there a site that I can use to calculate the correct rear gear's? |
I pretty much already described the process, read your door jamb to figure out original tire size, find the relationship to the 32" tire size....as I showed in the example above it was 14%.
With your ratio of new to old in hand, if your tire size goes up 14%, your gear ratio needs to go up 14%. 4.10*1.14 is about equal to 4.67, but to my knowledge there is no 4.67 gear ratio, so your choices are either 4.30 or 4.88. |
Checking it with another car is not 100% accurate as that cars speedo could be off too. Check it with a GPS or a GPS app on a smart phone.
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60 MPH is 1 mile per minute. Get on the interstate with traffic flowing at or above the limit. Have a passenger time your miles while you keep it at 60. Let us know the results.
You seem to have answered your own question though. It was fine before you put the new tires on it. Bigger and heavier tires can and will slow these small motors down quick. |
Thank you for all the insight. It makes sense to change out the gears. I am looking into 4:88s .
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Originally Posted by LIBANKER
(Post 52417111)
I had 31s on it prior and the speedo was off by about 12 mph but with the 32s its only off by about 3mph with a side by side test with another car. I found that strange .
Is there a site that I can use to calculate the correct rear gear's? |
Originally Posted by thefishguy77
(Post 52417140)
.... Have a passenger time your miles while you keep it at 60. . ...
There are some places in the US where there are (were?) signs posted at very accurately measured distances along a stretch of 3 miles or so. I think they were originally intended to help the police calibrate their speedometers. I haven't seen one is a while. Using a GPS seems much easier, though slightly less accurate. |
Mile posts on the freeway/highway.
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I would trust a GPS to be more accurate at a steady speed and compare it to your speedometer right there, than someone clicking a stop watch and doing the math to figure out your speed?
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Thats how we used to do it. You shouldnt be off by more than a 1/2 second. The hardest part was getting a steady 60 on your spedo without cruise. Bow I guess with GPS its easier to get a quick baseline. Dont know if all GPS units are equal. But I have had google maps up running with speed displayed, was over limit to make it show my speed, and another GPS app, Spyglass, that I trust more personally. And spyglass matched my spedo google was close.
Both Iphone run side by side same network |
Originally Posted by thefishguy77
(Post 52417303)
Mile posts on the freeway/highway.
Trucking company I worked for swore up and down that my speedometer was right. I said nope it's off seven mph Sure enough they got off their lazy asses, and finally fixed it, and it was off what I said from the get go. For you guys that have never had an airplane speeding ticket. Ever seen those white hash marks on the highway? They know the distance of those marks, so all they have to do is time you at two marks with a high speed camera. Say hello to the state troopers lined up 20 deep to give you your speeding present. s=d/t speed=distance/time |
Originally Posted by 87-4runner
(Post 52417080)
Might try advancing your timing a few degrees... its been my experience too little timing results in symptoms your having issues with...
Originally Posted by LIBANKER
(Post 52417078)
1990 Toyota PU. 22RE 5spd 4x4 4:10 rear. 15x10s with 32inch tires. Lifted 3 inches. 190k miles
Problem: Truck starts right up. Drives fantastic. BUT will not get out of its own way. Its good for local driving. It won't accelerate for s***. Forget the expressway . It doesn't like inclines at all. Tranny was rebuilt 6yrs ago. I was resolved to a motor rebuild but after speaking with some friends they think it might be the rear gears. Does anyone have any suggestions. Thanks Lenny Advancing timing won’t make that noticeable of a difference but is worth the 5 minutes it takes. I’ve only driven one vehicle in my life slower than a 22re truck and that was a ‘76 Westfalia. 25 MPH in 1st/2nd hear up I-70 West of Denver. Thst thing was dangerously slow. Made the 4Runner feel like a racecar. Unless you bought it specifically to off-road, these trucks are more of a novelty these days. |
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