2.3L ('83-'97) 2.3 runs awful at WOT

[JoeyGoFast]

So I just got my 2nd ranger, a 1993 super cab 2.3 5 speed RWD. The truck starts right up no problem and idles perfect but as soon as you go past 3/4 throttle it looses all power and seems to hit a “rev limiter” or so it seems at about 2000-2100. As long as you keep the throttle about 1/2 or less it will rev all the way to 6500 without issue and it drives fine just as long as you don’t pass that 3/4 threshold where the computer reads it as “WOT.”

The truck likes to toss the 223 code (dual plug inhibit signal lost) out as well as the 122 (tps voltage low out of ranger) followed by the 998 that tags along with them. The codes don’t always appear but the truck continues to just absolutely freak out at WOT. Unplugging the tps doesn’t affect the truck at all which leads me to think that may be the cause of the 122 issue but on the data stream from the scanner it seems to be putting out good values from 1-5v based on pedal position. The truck has good fuel pressure and doesn’t loose fuel pressure when it is WOT so I feel as though a fuel pump isn’t the place to look. The truck was entirely out of gas when I got it so I put about 5 gallons in from a station I trust so I don’t think the problem could be bad gas either as I just filled my other ranger up earlier in the day and it still runs perfect. The MAF also seems to be functioning properly as it outputs reasonable values that follow rpm. Also occasionally when the truck is WOT it will pop out the exhaust other times it sits smoothly at 2100 and upon rare occasion it will rev up to 6 but it is very slow and seems to struggle to get there. Also on the data stream when it is WOT the truck seems to show that it pulls all the timing out and runs on about 2-3 degrees which I’m assuming is how it’s keeping it at such a low rpm.

The truck has me completely stumped as all the sensors and mechanical parts seem to be working correctly but the truck just does not want to be ran WOT. And either way the 2.3 is coming out of the truck to get replaced by a v8 (do I dare say that it’s a sbc?) but I need the motor for my other ranger as I hurt it’s motor while 4wheeling with my friends when I knew it had low oil. I just would like to be able to atleast have ease of mind before I pull the motor to know that it runs good and is healthy so I can fix anything that is needed while it is on the stand. I’m just not sure what could cause it and am just looking for a different perspective of the problem in hopes that maybe someone on here has experienced something similar or knows a truck to look for with these symptoms. Thank you in advanced.

 

[b1pig]

While I'm no expert on the 2.3, generally speaking there could be any number of reasons why the engine is running like this.

Generally speaking though, the engine is just an air pump. If you make sure it is flowing freely into and out of the intake and exhaust, then the problem is certainly internal or electronic.

(not sure what PIDs you can see on that year model)
1- are you you looking at the O2 values as well?
2- What is fuel trim telling you?


I know you said you have "good" fuel pressure, but is it reading the factory spec pressure? My son had a 95 F150 with the I6 that would NOT run unless it had a MINIMUM of 50 PSI. Spec was 50-60 by the shop manual. Fuel pressure and fuel volume are another thing as well, as long as where the fuel pressure reading is coming from (from tank, somewhere in line, or on the fuel rail). If you can read fuel trim, that will help. If the trim is reading more than 30% above normal duty cycle, then the computer is trying to add fuel.... meaning some how it is not getting enough. The O2 value should back that up. If trim is in normal range and O2 is in normal range, then it may be an ignition issue..... which could also back up the code for the dual ignition.

(disclaimer... not ASE.... just had a little experience with fuel delivery issues)

 

[bobbywalter]

The tps is possibly bad unless you log it in situ under load and it doesn't break up......map, maf or plugged filters.


Restricted filter lowers volume under load.....even a bad airfilter. Bad air and fuel filter can do it.

On edit... after re reading there may be a coil pack issue or shorting wire....the vref gnd may be bad...

 

[JoeyGoFast]

Well I gave up fiddling with it and finally pulled out out so I could start with the v8 swap. I’m planning on just using the bare long block when I put it in my 91 because it seems like a lot of little things are different between the too