Tuning 87 4Runner Turbo with CT26 tips

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thetoyotaman

thetoyotaman

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Just filled up and the 4Runner got 9mpg. Granted she's SAS with 35's but looking for tips as previous owner had the distributor off a tooth, timing mark so far advanced the mark was basically pointing at the passenger frame and the AFR messed with. I've never heard it knock so I'm guessing I'm going deaf or the computer is retarding. But for those with this setup, what was your sweet spot on the AFR wheel? My understanding is timing should be set at 5% degrees with the jumper wire. I have a standard timing light and vacuum gauge. I've replaced plugs, air, and fuel filters. Thanks in advance!
 
I am running two of these turbo engines. One has a Garrett, the other has an original CT20 with a CT26 compressor. I use an independent wide band O2 sensor with a digital read out in the cab to get AFRs. With these ratios you can turn the AFR wheel. The numbers @EngEngr posted are good.
 
Thanks for the info. I have a new problem. It stalled the other day and will barely start. If you feather the throttle you can get it above 3000 rpm but anything below that it runs real rough and dies.
 
You have spark. Air Fuel Ratio?
 
We need an AFR for sure it looks like. Also plan to check codes.
 
One of the problems I was aware of prior to it stalling is that if you turn the key to on without starting the fuel pump runs continually. I thought they were supposed to prime for several seconds and turn off.

Ok, tried to check codes but it doesn't seem to matter if the diagnostic connector is jumped or not with the key on (engine not running) check engine light just stays on. There's no blinking. Wondering if the ECU failed.
 
No telling what the previous owners installed or changed. The truck is nearly 40 years old and some parts may be broken. Get the Factory Service Manual out and follow the repair instructions. My procedure for "project vehicles" is pull the engine and transmission, rebuild both with quality parts, test wiring and sensors, replace what's broken, reinstall all parts according to the FSM, and break in the engine. This is how I've found success with "project vehicles."
 
Just wanted to give an update. Recently, when the 4Runner stalled out in the middle of an intersection and would not restart I towed it home and tried to check codes on the computer. Everything it was doing told me that ECU had failed. Replaced all the caps and reinstalled tonight and she’s running better than ever. Planning on going back to retune everything and eventually get an AFR meter to dial it in.
 
Rebuilt ECU threw codes 3, 11, 14. AFM was bad and TPS out of adjustment it appears so far. Fixed computer is helping sort it all out. TPS connector and forward fuel injector connector broke. Found a TPS housing replacement but have to figure out a fuel injector connector replacement. The TPS I found on eBay but hasn't worked as good as others I've done in the past swapping the housing as this one is slightly different. Found a previous owner splice that was loose and just fell apart like it wasn't even crimped. Replaced it with a marine crimp connector installed with the correct tool.
 
Forgot to mention the front fuel injector has a brown wire and a brown/red wire. Anyone know what the orientation is for the wires or a part number for the connector housing?
 
I think 1987 was a weird year with fuel injectors. I've seen 2 connectors. Replacements for the square connectors are easily available. As far a orientation, it's DC running a switch. I don't think it matters
 
Latest drama was it stalled out again. Turned out now the hose off the turbo blew a hole in it. Replaced and throttle response is now smoother but it’s missing and popping below 2500 rpm. This things keeping me on my toes. Since last post, we adjusted the TPS, replaced broken connectors and replaced the AFM.
 
What are do the spark plugs look like and what is the gap setting? While I've never messed with turbo Toyotas, when adding a turbo to Honda's we had to set the gap tighter or they would run like garbage.
 
I replaced them about 1400 miles ago but ordered a colder set to use. How much tighter did you go? .031 stock iirc.
 
I cannot remember specifics, I just remember going several step colder (Taking a 160 HP engine to 300) and setting gap tighter. Hopefully a 22rte owner can chime in. I think it's one step colder for every 50 hp but don't hold me to it. This has been 20 years ago.


Eyeballing the plugs can tell you a lot. Running rich when 50 miles can foul a plug causing a misfire. A faulty o2 sensor in an FI application can cause pinging. Colder plugs can help reduce the chances for the pinging.


Without a wideband o2 sensor you'll have to read plugs. Reading plugs is...fun.
 
Interestingly no difference in spark plug between the 22r, 22re, or 22rte.
 
thetoyotaman said:
Interestingly no difference in spark plug between the 22r, 22re, or 22rte.
Click to expand...
I was surprised when I saw that in the FSM too. are you running a factory 22rte ECU or did you go standalone?
 
Here’s a good site with a bunch of info that relates to the 22RTE including AFM adjustments and some ways to get basic O2 readings from the stock ECU.

 
I have 3 solid 22RTEs running with forced induction. All 3 were worn out when I got them. They all had bearings in rough shape, elliptical cylinders, cracked exhaust manifolds, cracked turbo turbine housings, and that was just the beginning. IMHO, engines in rough shape are frustrating. I spent more time fixing them than driving. This is why I started my engine and turbo building hobby.

AFR adjustments are simple with a wide band O2 sensor and digital readout. Modern O2 sensors can detect the air density change between a cool morning and warm afternoon.

The 22RTE is worth the effort. The forced induction options make this engine a true "Legos for adults" project. I really enjoy all 3 of mine. It is fun to pass modern vehicles at will with no concern for elevation or incline.
 
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