When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Well, I am learning so much about my engine and my truck.
Long story made short, I rebuilt a short block at the local mechanics, my engine was feeling weak and underpowered, had some oil leaks and overheating issues. After the re-build, got everything installed broke in for 400 miles or so with good Joe Gibbs oil before I realized my rings had not seated. ~120 PSI per cylinder. Turns out my o2 sensor was shorter to ground via the shielding in the wire, so although I had continuity to the ECU it wasn't getting a signal. So I was (likely) fuel washing the cylinders and the rings never sat.
I pulled the motor, and took it back to the machine shop. Dropped another 700 dollars to have everything redone, re-installed the motor, broke it in again with good Joe Gibbs Break-in oil, had better power after fixing the o2 sensor, but still seemed to be running rich. Fast forward to last week when I found out my AFM has an open short on one of the test connections, so I've probably been running rich still and fuel washed the cylinders again, I just pulled compression numbers and I'm right back at 120 PSI. Well crap.
So, I am seriously considering re-ringing this block one last time, but I need to be damn sure that everything else on the engine is in tip top shape before I do that.
I have replaced the AFM with one that tests as working.
I have installed a 4 wire o2 sensor (LCE header with the extended o2 sensor location) that seems to be sending the appropriate signals.
I have tested the EGR valve and it is closing under vacuum and open without it
I have checked the for intake leaks using carb cleaner and propane
I have replaced ALL the vacuum lines with new OEM tubing
I have replaced the spark plugs and wires with OEM
New rotor and cap
TPS has been tested (both with the intake off and on)
Timing has been set and checked a million times
Valve clearance has been set and checked
Fuel Injectors have been cleaned/rebuilt
Fuel injector wiring harness connections have been replaced
The rich condition happened on multiple ECU's (one of them was tested before the AFM was diagnosed, I will try to swap back to the other and check)
I am taking the truck into the muffler shop to see if maybe all the rich running has fouled the catalytic converter next week. I was going to ask them to do an exhaust gas check and see what else they may be able to find out,
What else could I be missing leading to a high fuel ratio condition? I think I'd just push the truck off a cliff if I re-ring again and still find low compression. Also, a thought has crossed my mind that maybe the machine shop is doing something wrong? I really don't think that's the case, but it did cross my mind.
I am considering trying to hone and re-ring with the engine installed in the truck, would cost me a little more time, but save me several hundred dollars. I haven't honed a cylinder before, but at this point, I think it's worth trying, and if it doesn't seal, I can still take it to the shop...
Thoughts? I'm going crazy hunting down this rich mixture.
I've burnt through a few cats and valves running rich / lean over the years in my carbed 22R. Currently running a PLX AFR gauge, which works with the smartphone. Might be something to consider so you can park it before damage happens. You'd probably have to have a bung added to your exhaust for an additional wideband 02 sensor on the 22RE.
Thanks Millball, I have checked the ECU temp sender as per the FSM, but I honestly don't know how to check if I am in open or closed loop. Just did a little reading to find that the signals from VTA, VS, VTA, and ECT (temp sender) all have to be in spec in order to get closed loop, do I just need to test those voltages to ground while the truck is warmed up and compare to the specs?
I don't know what the hone was, I can call and ask. The first time this happened, the rings were hastings from 22reperformance, the second time we were in covid shortage and the machinist put in something he could get...looks like Topline?
No codes yet, but I have been pulling the EFi fuse for a fair portion of diagnostic work, so maybe I'll have another code in a week or so.
Thanks midnight, I didn't realize that AFR gauge could be acquired at that price point. I'm actually taking the truck in to get some muffler work welded (and check my cat) next week, I'll have them throw the extra bung in there.
I see you're in CO, could the altitude be messing with your compression numbers? I'm around 5k ft (CO as well) and I was getting around 145-150ish PSI on my old 3vze when I first picked the truck up so I doubt it's a cause but it's something to take into account. Are the factory numbers for a 22r around 170 PSI as well?
Yeah, the specs for the 22RE are 142 to 171 PSI. I hadn't ever thought of altitude as a specific contributor to lower compression, but after a quick search it looks like every 1000 ft above see level may only account for a half a PSI , so 2.5 -3 PSI lower at 5000ft, not 45-55 PSI lower. Good thought though. I've driven 22re's at sea level (back in Oregon) and know what it feels like to have that tiny extra power. This engine right now is GUTLESS. (about as would be expected from having way too low compression)
Oh man, I know gutless. I put a 5vz in to replace my 3vz at the end of the summer and the fact that it felt like a massive difference in power shows how bad the 3vz was. Granted it was running on 5/6 cyl but still. Toyota motors are gutless but bullet proof to a point. Curious what you end up coming up with as a solution. Goodluck!
I clearly need some more understanding on how the open/closed circuit works, as well as the CSI?
I pulled the plenum off in preparation to pull the motor (going to re-ring) and found LIQUID fuel (puddles) in the intake. I'm not a wizard, but that seems wrong.
I had driven the truck about 50 ft at this point to pull it into the garage, started it twice (once to re-position for the garage door) I mention that because I'm wondering if the CSI really dumps THAT much fuel when you start it up?
I did install an aftermarket AFR meter, and so far I'm enjoying collecting data, but I don't really know what I'm looking for. I'll discuss what I think is supposed to happen (please correct me) and also what I'm observing on my truck.
I THINK when the truck is cold (according to the ECU temp sender) the truck should not be allowed to go into closed loop, which means it is basing all fuel decisions off of the TPS and the fuel map in the ECU alone. This generally leads to slightly richer conditions than the stoich ratio. (still above 14?)
Once the truck is warm according to the ECU sender (I don't know if this is a limit or a gradual change?) it uses information from AFM, air temp, TPS, O2, and RPM sensor to decide if it should stay in open loop (slightly rich conditions) or go into closed loop (cycling itself to maintain 14.6-14.7 AFR). At some point threshold of RPM and TPS, I think there is a Wide Open Throttle which just dumps fuel and has full open air, bit I am not certain. (AFR around 12 at this point?)
My understanding is that the open/closed loop should cycle quickly, even under heavy load acceleration to try and maintain the 14.6 AFR. I'm assuming that should be 1-2 seconds of open loop before it "corrects" into closed loop. Is that right? If I lay on the throttle, will it just stay in open loop forever?
Current Behavior of the truck:
When I first start the truck (cold) I can't see the first 30 seconds of the AFR, due to the warm-up time of the sensor, but then after 30 seconds, I am running at about 12.5-13 AFR. Way rich. Driving for about 30 seconds is usually enough to bring this back to around 14.6 (it fluctuates a lot between 14.3 and 14.8, hard to see). The truck doesn't start on the first crank, usually takes 3 seconds or so before it fires up. "Cruising" down the road (flat, no acceleration) keeps the AFR close to stoich. When I get on the pedal, it goes way rich, down to 12.0 - 12.5 and stays there. This isn't pedal to the floor necessarily, just trying to get the truck to go up a mild hill will do it. Seems to happen more in gears 3-5 than 1 and 2, even though I give about as much gas there, and rev close to 4K RPM.
I know the last two times I rebuilt, fuel washing was the likely culprit for unseated rings. Seeing liquid fuel in the intake makes me think I have not yet fixed the "running rich" problem. I've checked the AFM, the O2 sensor, and vacuum leaks. The only known issue right now is lack of compression (which I assume is causing the rough idle and occasional miss. I was thinking that maybe because of the loss of power, it's forcing me to be heavier on the gas pedal, which could be contributing to the fuel wash/ rich condition, but if that's the case I don't know how anyone would ever break in an engine..
(I did check the CSI for leaking by pulling it out of the plenum and jumpering the Fuel Pump. I can hear the pump working and no drops from the CSI... I also tested the ECU temp sender and Cold Start time switch for proper resistance at temp, and those are correct, still need to ohm out possible wiring harness issues between those senders and the ECU.)
I'm really at a loss, but anxious to get this engine running right. Thoughts?
Couple of pics attached showing the puddles of fuel in the intake (brown nasty, but it's definitely fuel) as well as the state of the CSI when I pulled it out and some patterns on the plenum body that make it look like I have positive pressure pushing liquid (fuel???) out of the gasket mating surface. Is something blowing OUT of the intake plenum where I should have vaccuum? The dirty side is the UPHILL side of the plenum mounting surface... Fuel Puddles in intake manifold CSI, Dirty and kinda wet looking? But doesn't leak when the Fuel Pump is engaged
Thanks, I'm picking up a fuel pressure gauge tester tomorrow and will look for leaking that way. I feel like I would see leaky injectors much more in the AFR gauge/performance of the truck but I don't know what else can put liquid fuel in there...
Not the CSI, as far as I know. It's attached to the Throttle Body, not the intake manifold. The injectors are feeding directly into the intake manifold, so...
Bear in mind the leakdown test for the fuel pressure only specifies that the system hold pressure for 5 minutes. Don't let that fool you into thinking something else is responsible. I would guess, though, that leaky injectors would bleed down the pressure starting as soon as the engine is off. Or the fuel pump is off, if you're just using the jumper to run it. If the fuel pump check valve is bad, it would be a slower leak, I think.
that’s a normal amount of fuel in the runners. looks the same as my ‘87 #1 that i’ve put over 100k miles on since 2013. gas mileage has been pretty consistent between 22 and 17 mpg over that time. ‘87 #2 that i rebuilt the 22re gets better mpg, but i haven’t had to take apart the intake/plenum since rebuilding to see how much fuel sits in the lower runners. mpg runs around 23 to 18 for that one.
also, i happen to believe that most of that raw fuel is from the csi, rather than the injectors, but i don’t have proof of this. fwiw, the csi injector is only “on” when the key is in the “start” position. it doesn’t do anything when the key is at “on/run”.
This is great news, thanks Wallytoo. I just got done doing the fuel pressure checks and everything is normal ( a couple PSI under spec, but I'm not terribly worried about that). I really needed someone to tell me what I was seeing was normal, hah.
Anyone have any ideas on what AFR values I should see and for how long? I don't want to re-ring just to have to rip it all apart again....
11-10-2021, 01:26 PM
