JPL

I recently installed a rebuilt 22re engine and had my shop look it over after I completed the intall.

Problem: It idles great, runs smooth.. but has a major power loss. It struggles to accel over 4K rpm. It feels like the air flap in the throttle body isn't opening all the way and there's some sort of air and/or fuel restriction. My mechanic is stumped but is pretty sure it's the Mass Air Flow Sensor. It sounds like a start but I don't want to pay $200.00 on a new sensor only to find it's not that.

There are no codes or lights on the dash. My 4runner has been down for almost a year now and my goal was to have it ready for my colorado vacation in December. Please help!

Inferno451

I'd start with the simple stuff, you'll likely find your problem there. Start by checking THOROUGHLY for vacuum leaks, then check ignition timing, then valve timing. Do you know how to check those?

JPL

Thanks for the help. The timing is good (ignition and valve).. I had my adjustable valve gear at 5 degrees Before and the shop moved it back to DTC upon request with no change in performance. I replaced the vacuum lines and made sure all the un-used lines were plugged off.

Thanks again, I'm just looking for more ideas before I fork up the money.

combatcarl

Adjustable valve gear at 5 BTDC? Not sure I follow. The ignition timing? That should be at 5 BTDC. Sounds dumb, but was timing set with jumper in place? E1-TE1? And get a vacuum tester, see what you have at idle, opening throttle, idle down, it'll tell you if there's a cam/valve timing issue.

'89 22RE 4x4 longbed DLX
Sent from my LG-P505 using YotaTech

JPL

The ignition timing was set to 5 degrees BTDC and the adjustable cam gear was set to 5 degrees "A" (to the left on the Cam gear.. I was just messing with it). The cam gear is now at TDC (same as stock gear). There was no change.
I did use the jumper on the Diagnostic contacts E1 and TE1.. I got the flashing ck eng light and the ignition timing was set correctly (also confirmed by the shop).

I'll see if the shop can do a leak test. It really seems like an air/fuel issue.. It runs almost like something is blocking the intake or evenly limiting the injector output (fuel volume), almost like air intake and fuel output is around 50% or less. It does sound like something from the ECU.. i.e. bad / no reading from air mass flow sensor.

Is there an easy way to test the air flow sensor? Maybe measure resistance on certain pins like the TPS..?

combatcarl

I'm mobile surfing right now, so I can't tell, but under my post here, there should be a link to FSM 's. Dig around, find the one that fits your year, and go to town. A vacuum tester is cheap, harbor freight is where mine came from.

'89 22RE 4x4 longbed DLX
Sent from my LG-P505 using YotaTech

combatcarl

Looks like this, connect to a good vacuum port that feeds all 4 cylinders, for best results.

Apologies, I messed that up at first.

'89 22RE 4x4 longbed DLX
Sent from my LG-P505 using YotaTech

snobdds

First off there is no Mass Air Flow Sensor on the truck. If the shop thinks that is your problem...find a new shop. There is a VAFM only...

Second, anytime there are power problems...that is a dead giveaway for your ignition timing being off. Remember, you must insert the dizzy at 5* BTDC on the COMPRESSION stoke. I bet your 180* off and you put the dizzy in when the motor was on the Exhaust stroke. Each way looks like it is correct, but the engine needs to be on the COMPRESSION stroke when setting ignition timing. Then you can jump Te1 and E1 and fine tune it, however, if you do it right there should only be a tiny bit of adjustment needed. The hold down bolt should be dead center in the adjustment range. Then you know it's correct.

Unless your good at feeling the engine on compression while rotating it, there is really only one way to make sure it's at TDC on the compression stroke...you must take off the valve cover. As you bring it to TDC, the two valves on the #1 piston will be loose. Once you get it to TDC, then rotate it to 5* and insert the dizzy with the match mark at 12 o’clock and it should rotate back to around 10:30 with the rotor lining up with the #1 spark plug.

Did you get rid of those KB pistons? Did you use a torque plate this time to hone the cylinder walls to account for the deflection the torqueing of the head does to the block?

JPL

I think that's what they called it. I was calling it a Mass air flow sensor because I thought it sounded better than saying that big box on the intake with the connector going to it.

First off the engine was machined at a machine shop with a good reputation.. they measure everything and have all the proper tools for the job.. I'm sure they used a torque plate.

I'm using the same KB pistons as they were still in good condition and not the cause of compression loss.. the machining on the old block was the cause. Everything else was replaced (i.e. rings, bearings, block, gaskets, etc.)

Ignitino timing being off would make sense but it was checked multiple times by my performance shop as I was off one tooth on the cam gear when I brought them my truck to look at.
The engine runs great if you keep it in low RPM range.. after 4K RPM is seems to struggle as if it's not getting engough fuel/air.. but I'll have them check the dizzy to make sure the mark is at 12 O'clock when at TDC and the rotor points to Ignition wire going to spark plug #1 at 10:30 O'clock.

Inferno451

^This. Also, when you have the valve cover off, check to make sure your cam isn't a tooth off. That would do it. With cylinder #1 at top dead center on the compression stroke, the little dimple on the cam sprocket should be right at about 11:30.

JPL

Update: I asked the shop to check for vacuum leaks and his response was.. if it had a vacuum leak it would idle high and/or run rough. I thought well he seems pretty certain about that so I asked him about the timing.. he insured me that the timing is correct and was checked over more than once.

So I picked up a VAFM.. My shop installed it and found no change, no improvement, nothing. The shop is telling me that I need to take it to a shop that specializes in Toyota.. I'm considering the Toyota dealership at this point but wanted to check back with you guys on this mystery issue.

I have 2 weeks to get this thing running and it's really stressing me out. The more and more I think about it the more I think it has to be the ignition timing or distributor.. I would love to find the dizzy off a tooth or so and fix the problem on the spot. I have lost all faith in my Performance 4X4 shop when it comes to engine work. As for exhaust and suspension they're the best up here.

I'm picking up the truck tomorrow and bringing it back to my garage for a couple days to look it over.. make sure the timing is 100%, there are no vacuum leaks, all vacuum lines are routed correctly and connected, etc. I'll even try uploading video of it to see if it might help me fix this headache.

JPL

UPDATE:I have since picked up my 4runner from the shop and checked compression in each cylinder, readings are as followed:
Cyl#1. 149 psi
Cyl#2. 151 psi
Cyl#3. 140 psi
Cyl#4. 139 psi

All cylinders seem to hold pressure (no major lead down noticed). I was hoping to see 150 to 160 + psi on each cylinder.. is there a problem with my compression? This is a new rebuild with KB pistons, this rebuild has only 5 miles as the issue was noticed immediately. This is driving me crazy and I really need to get this issue resolved.

As I stated earlier in the thread, the engine has a noticable lack of power at the bottom end and around 4K RPM it seems to struggle even on flat roads (no hill climbing). Yet it starts up every time no problem, idles smooth, and sounds good (no clicking, high pitch vacuum noise, etc.) I don't want to make the issue worse by driving it but I'm worried I might need to pull the engine again.

I plan on pulling the valve cover tonight and documenting the timing mark locations. Tomorrow I plan on calling the machine shop.. I really don't want to resort to taking it to the Toyota dealership.

Thanks for all the support and help.

Update for my last update: I looked at the compression readings from the original motor and I was getting 130,130,130,and 90.. I realized that I was getting much more power from that motor with worse compression at lower elevation. My semi conclusion is that it's not a "compression" issue. I'm not exactly sure how (if at all) elevation plays a role in compression but I am currently testing at 6,300 feet elevation.

I checked the timing marks and it seems to be on mark.. The crank at TDC (notch at 12 O'clock), Cam gear at TDC (notch at 12 O'clock), and dizzy at 10:30 O'clock (rotor pointing to the number 1 spark plug location: 10:30 O'clock). That sounds correct to me...

Am I missing something obvious? Is it mechanical, electrical, fuel...? I don't feel like I'm getting anywhere. I wish I had a spare 22re 4runner to swap parts with because it seems like the most logical thing to do at this point (considering I'm completely lost here). Just a little venting. Thanks again.

Pictures I just took when checking the timing and compression.




The spark plugs all look like this.. seems a little too lean. Maybe It's a fuel delivery problem. Could the fuel pump slowly go bad and cause issues like this? Almost like it's in limp mode?

annoyingrob

What's your fuel pressure like with the vacuum line disconnected from the regulator? IIRC, it should be about 38psi.

How's the TPS?

JPL

I was thinking about checking the fuel pressure next. I need to borrow or buy a fuel pressure guage.. What could cause low fuel pressure? It seems pretty even so maybe I have a clogged fuel filter or bad regulator.. The fuel filter was new a year ago but my 4 runner did sit without running for about 6 months. Thanks for the tip.

I was curious about the TPS but my crappy mechanic was saying no way it could be that. I'll look into that too. I think I still have the link on how to test it using a volt meter. Thanks again!

annoyingrob

low fuel pressure could be caused by a bad regulator, a plugged filter, a pinched line, or a failing pump. It's probably NOT the problem, but it's worth checking just to rule it out. I would still test the AFM and TPS signals at the ECU. take a look at the factory service manual, it will tell you what the signals should be. A vacuum leak MIGHT still be a possibility. A very small leak might not manifest itself as a rough idle, especially if it was something between the AFM and the throttle boy. Less throttle = less affect that a leak there would have on the motor.

Out of curiosity, are you running new fuel injectors? If so, did you ever have them flow tested? Are they the same size as stock?

JPL

That all makes sense and I plan on ruling out everything if possible. I need a good service manual.. every link I try requires a membership or registration for the pdf file. Anyway, I did try a new AFM and it didn't make a difference so I returned it. I do have another throttle body off my doner engine so I might try the TPS off it..

The fuel injectors are the same (OEM) injectors I had before and had no issues.. I have not had them flow tested and I did notice the O rings were a little worn out and seemed a little loose but I'm not seeing any leaks. I sort of ruled out the injectors early becaue the engine was running smooth and all the spark plugs looked the same.. I really should have them flow tested though.. Where can I do that? Would it be worth it to run some seafoam or injector cleaner through my fuel system?

I appreciate the help.

annoyingrob

Just because the AFM isn't the problem doesn't mean that it's working. Although unlikely, one of the wires could have been pinched going to the ECU. Or, one of the wires could have been iffy, and broken loose when un-plugging/plugging.

Don't worry about testing the injectors. I only brought it up IF you had new injectors. Your old ones are known working. Don't run seafoam or injector cleaner for the time being.

JPL

Sounds good. I'll search for an ECU pin out and see if I can tone out the wires and check continuity. I would expect something like this to throw a code or error message.. I guess they're very simple setups. Thanks for the ideas.. I plan on going over everything tomorrow. Checking connectors, wires, fuel pressure, TPS, etc.

JPL

Good Update! I put everything back together today with a plan to go over some key parts as talked about last night: Fuel pressure, TPS, AFM, etc.

I looked up the link to adjust my TPS and was messing around with the connector looking for the pins and making sure there was no damage. So I got everything back together and decided to start it up.. I left off the TPS plug on the side of the throttle body on accident but it idles fine but with the check engine light on.. I decided to take it around the block thinking I can cancel out the TPS this way.

With the TPS unplugged I seem to have all my power back and it runs great! Past 4K rpm no problem, up hills, etc. So it looks like I found my problem!

So does this mean the sensor is bad? Should I just replace it and adjust the new sensor? I guess it could be an issue past the connector to the ECU.. I plan on swapping the TPS off the donor motor and seeing if it makes a difference first. Thanks so much everyone. Looks like I'll make my Colorado trip next week after all.

annoyingrob

The sensor might not be bad, it might just mis-adjusted.The TPS sends a throttle position AND an "idle" signal to the ECU. If it's not properly aligned, the idle can stick on too late, or the position can be off, which gives you all sorts of strange results. Take a look for the adjustment steps. It involves a feeler gauge and a multimeter.


Good you found the problem!