Topic: 22re tune up mystery

[STAGE 2]

Hey all.  I've got a head scratcher here.  Bought my truck back in march with 197k on the clock and had the timing belt, head gasket, and TPS replaced back then.  Just turned over 200k last week, so yesterday I started in on the major service.  The truck was running fine before I started.  I replaced the air filter, fuel filter, O2 sensor, plugs, wires, cap and rotor (all OEM).  Now, while the truck runs smoother under throttle, the idle is rough and lopey.  Adjusting the idle speed doesn't change anything and I've reset the ecu to no avail.  The TPS is only months old so I've ruled that out.  I was thinking possibly a vaccum line, but I didn't disconnnect or move anything in that area so I can't see where anything would have been disturbed. 

Any thoughts?

[jimbo74]

the lines could be cracked, or split, the tps could need to be calibrated, you could just have 200k on the engine...... what is the compression like? maybe you adjusted the timing? what about valve clearances?

and the 22re uses a timing chain, not a belt

[STAGE 2 [OP]]

the lines could be cracked, or split, the tps could need to be calibrated, you could just have 200k on the engine...... what is the compression like? maybe you adjusted the timing? what about valve clearances?

and the 22re uses a timing chain, not a belt

Yes, I did mean chain.  Its late.  As far as the TPS, would changing plugs, wires, rotor or an O2 sensor require it to be recalibrated?  Adjusting the valves are/were next on my list before this came up.  Same with the timing. 

I don't have any compression numbers, but prior to this weekend, the engine was running smooth, getting 23 mpg mixed and had plenty of power (relatively speaking of course).  The idle was very smooth as well.  As far as the lines being cracked, its possible, but A) I didn't disconnect/move/touch anything other than the parts I replaced and B) once it started idling rough this was one of the first things I looked for. 

This is why I'm kind of perplexed.  I was doing this service because 200k rolled around and I didn't know how long these parts had been in service, not because the truck was running poorly.  I suppose a sensor could have gone bad, but the odds of that happening right when I decided to do some maintenance is slim. 

[jimbo74]

you may have not moved anyhting intentionally, but even vibration is enough to split old, brittle rubber tubing.....

what spark plugs are you using?

02 sensor..... has the computer been reset? sometimes they dont like all sorts of stuff being done at once, as the vehicle needs to relearn.....

[STAGE 2 [OP]]

you may have not moved anyhting intentionally, but even vibration is enough to split old, brittle rubber tubing.....

True.  I'm going to recheck this tomorrow, but I've done it twice already and didn't find anything.

what spark plugs are you using?

All my parts are OEM toyota.

02 sensor..... has the computer been reset? sometimes they dont like all sorts of stuff being done at once, as the vehicle needs to relearn.....

I removed the negative cable for a good 20 minutes so the ECU should have reset.

[Rocksurfer]

Did you gap the plugs properly, are they the same plugs or are they hotter or colder plugs? Also are the plug wires the same mm as the old ones. These little things can change the way your truck runs.

[silence007]

See if it does it when you unplug the TPS.  It should default to a higher idle.  If the syptom is gone at that time chances are a recalibration is needed.  As it is adjusted it is condidering all other conditions, if conditions change then it is possible it is not relating well with the rest of the engine.  Smell your exhaust too, just because an O2 sensor is new and OEM doesn't mean it's good, could be bias lean and too rich to run smooth at idle.  spray water on all vaccuum lines while doing it, will determine vaccum leak, if old and weak when you touch them is when they break.  something simple will be the cause, mine missed like crazy after replacing my TPS, simply a dirty pin on harness at the sensor.

[79coyotefrg]

this is a prime example of why you shouldnt fix what isnt broken


its obvious the problem lies in a vacuum line as you have to move a few vacuum lines to change the plug wires.  namely the pwr steering pump vacuum lines.

[STAGE 2 [OP]]

Did you gap the plugs properly, are they the same plugs or are they hotter or colder plugs? Also are the plug wires the same mm as the old ones. These little things can change the way your truck runs.

The plugs I installed were gapped correctly at .031.  I dont think the plugs that I pulled out were correct for the truck as they were not either of the two listed in the FSM and they were a bear to get out as they required the smaller of the two plug socket sizes (3/8" I think)

[STAGE 2 [OP]]

See if it does it when you unplug the TPS.  It should default to a higher idle.  If the syptom is gone at that time chances are a recalibration is needed.  As it is adjusted it is condidering all other conditions, if conditions change then it is possible it is not relating well with the rest of the engine.  Smell your exhaust too, just because an O2 sensor is new and OEM doesn't mean it's good, could be bias lean and too rich to run smooth at idle.  spray water on all vaccuum lines while doing it, will determine vaccum leak, if old and weak when you touch them is when they break.  something simple will be the cause, mine missed like crazy after replacing my TPS, simply a dirty pin on harness at the sensor.

Gonna check the TPS today.  As far as the 02 sensor, I didn't think it regulated idle, only when under throttle.

[STAGE 2 [OP]]

this is a prime example of why you shouldnt fix what isnt broken


its obvious the problem lies in a vacuum line as you have to move a few vacuum lines to change the plug wires.  namely the pwr steering pump vacuum lines.

Well, if you're right, then I may have a bigger problem since I didn't have to move anything.  The garage that the PO used was some tiny independent joint, and my opinion of them wasn't to favorable when I discovered that they installed the fuel filter backwards, and as stated above, used the wrong size spark plugs.  I'm wondering if they farked with the vaccum system as this was where he got his smog checks done as well.  I'm gonna check what I have with the pic in the FSM to see that nothings been removed, capped, etc.

[STAGE 2 [OP]]

Just a thought for the peanut gallery while I go hunting today.  The one sensor that I did come into contact with and move a bunch was the AFM (didn't whack it with a hammer or anything, but took it off the truck and dusted the inside of the air box with a dry clean shop cloth).  Could this potentially be the issue?  Also, it appears my AFM has been opened before (the same crappy garage) since the oem silicone seal is gone and has been re glued back into place.

Again, the truck ran just fine before this, and does run smooth now when uder throttle.  I'm just wondering if something was messed with to compensate for the incorrect plugs or (if I find it) a missing vaccum line and my changing things back to proper specs has thrown the balance out of whack. 

Thanks guys.  Appreciate the help. 

[silence007]

Gonna check the TPS today.  As far as the 02 sensor, I didn't think it regulated idle, only when under throttle.

O2 sensors are always working.  In CL operation they have less than 200ms to change from rich to lean or lean to rich.  If the sensor is bias lean, meaning not seeing the rich input at the PCM it will try to increase the pulse width of the injector, which in turn could cause it to stumble a little at idle, and earlier I ment AFM when i talked about the dirty terminal, That sensor is very important to any and correct opperation.  Celica GT one from 83ish works best.

[STAGE 2 [OP]]

Update: ran the engine with the TPS unplugged and the idle rose but was still rough.  Also checked the vaccum lines again both visually and with misting water.  Nothing. 

[silence007]

did you save everything you replaced?  If so back one at a time.

[STAGE 2 [OP]]

did you save everything you replaced?  If so back one at a time.

I have the old O2 sensor.  The rest I tossed.  I cant imagine new factory parts would cause this.

[silence007]

I am just saying new parts are not always good, even toyota, maybe just replace with other parts, just brainstorming possibilities.  Troublshooting older vehicles is harder than new ones, will fall back on what you replaced or what is affected by what you replaced that could cause this symptom, then there is always the coincidence and it isn't related at all. If I hear of a possibility I will post, I am hoping and sure when you figure it out you will share, I am curiouse to know.

[silence007]

try just tapping the AFM, the tap test is valid diagnosis in the industry.

[STAGE 2 [OP]]

I am just saying new parts are not always good, even toyota, maybe just replace with other parts, just brainstorming possibilities.

Here's a question for you then.  The cap and rotor that were originally on the car were the reddish brown variety.  The replacement cap and rotor that I got from toyota were both black.  I know that earlier 22re's came with the brown caps and later ones with the black, but is there any difference between the two other than color?

[silence007]

I have never heard any difference.  Yours could have been original, or old enough to still be original.  I have seen color variations on other manufacturers and it meant nothing.  One way to answer that would be to find out if you get a different cap and rotor based on those ages when purchasing a new one or ask toyota dealer.

[STAGE 2 [OP]]

Ok, I spent last night scouring the interwebs and going through the FSM and I found something that may be an issue.  I've looked at a couple of pics of 22re's to compare to mine and all of them have this sensor on the valve cover...




...the problem is that mine doesn't.  What is this and what does it do?  For reference my rig has a build date of 11/84 (1985 model year) and is a california model. 

[madhunt]

is the afm sticking look for a wear spot on the trap door. not all 22re came with the same vacuum soliniods some had none some had two or one depends on what yous truck is soposed to have.

[STAGE 2 [OP]]

Disregard the pic.  I did some additional checking and that solenoid is for AC equipped trucks which mine is not.  Going to check on the AFM tonight.

[WHITE_TRASH]

Ok, I spent last night scouring the interwebs and going through the FSM and I found something that may be an issue.  I've looked at a couple of pics of 22re's to compare to mine and all of them have this sensor on the valve cover...







...the problem is that mine doesn't.  What is this and what does it do?  For reference my rig has a build date of 11/84 (1985 model year) and is a california model.  

That's the switch that raises the idle when the a/c is turned on.  I'm guessing yours doesn't have a/c?

It does sound like a vacuum line is causing the issue.  Check the lines on the throttle body all the way to their sources closely they are "ported" vacuum so they are only active with the throttle closed at idle.

I yank all that vacuum crap off other than the a/c idle up on all the rigs I work on and I have yet to have a rig not run better when done.  So making sure all that crap is at least on correctly will certainly help.

[STAGE 2 [OP]]

I yank all that vacuum crap off other than the a/c idle up on all the rigs I work on and I have yet to have a rig not run better when done.  So making sure all that crap is at least on correctly will certainly help.

I need to pass CA smog, so its going to have to stay.  Ironically, one of the next things on my list was to ditch my old rubber lines for new silcone ones.  I might as well go ahead wth that so I can rule out the vacuum lines.

[STAGE 2 [OP]]

I'm about to order a vacuum hose kit.  Can someone confirm the ID for the smallest hose (3 or 3.5).  I know that the med is 6mm and large is 10mm.  We'll see if this fixes things.  Thanks.

[STAGE 2 [OP]]

Anyone?

[Cheesemaker]

Make sure the parts you got are for the right month/year of manufacture.  A buddy had issues with his motor, and it came down to the fact that he was getting parts that were for rigs that was made after 3/89.  And his rig was manufactured 2/89.  Just one month off caused us some headaches.

[STAGE 2 [OP]]

I always order by giving the part guy my VIN.  Of course, thats no guarantee, but I know the plugs and wires are legit as the part numbers match whats in the FSM.

[STAGE 2 [OP]]

Update:  Went through everything I could think of and the problem didn't go away.  The truck sat for a couple days as I was busy with work.  I finally had some free time yesterday so I took it to my buddy who is a toyota mechanic.  Of course, when I started it up in the morning it idled fine.  Got on the freeway and it was nice and smooth.  About halfway there it was running so well I was wondering if the problem fixed itself so I got off the freeway and came to a stop on an inclined off ramp and thats when it started again.  Very loopy rough idle.  Light turned green, I got back onto the freeway and continued on to his shop with the truck running nice and smooth while under throttle.  There were a couple of more lights before his shop but the truck idled fine. 

Of course, once I got there, the truck ran smooth.  We let it idle for a while, drove it around but no dice.  He checked the timing which was perfect, checked the vacuum system which was perfect, and the TPS, which was perfect.  His diagnosis was that it had to be something electrical since the mechanics were all fine and it was running great while at the shop. 

So here are my new questions.  First, could a cracked knock sensor cause this.  Second, it seems like being on an incline makes this problem more likely.  What electrical issues would be affected by an incline?