ToyYoda

It's an 85' 22re and I just got a new one of these: http://www2.partstrain.com/v5/produc...+control+valve

and that didn't fix my problem as I suspected with my luck recently. Since my old one wasn't working at all, it's not just money wasted so that's good.

Here's what's going on exactly:
Starts up when cold and sounds / runs great, then after a few seconds it will stumble and attempt to die, usually succeeding.

I just give it gas when it wants to die but sometimes it idles fine or a little high.

Also, sometimes it will idle ok when I get home so I'll turn the truck off and back
on and it won't idle anymore all of a sudden.

I've checked for vacuum leaks over and over again and I just don't think that's the problem.

What else could be the problem? MAF? EGR? Temp. sensor? Would any of those cause poor idling.

This all happened after I swapped my old cylinder head with a brand new one. The MAF has been adjust so maybe with a better functioning cylinder head
might have thrown off the MAF??

ozziesironmanoffroad

maybe, or check your tps. that could have something to do with it.

jcfb

One of the vacuum lines had slipped off my EGR valve, causing a very low idle. Mine would almost die, so I'd gas it. Never actually died, but the EGR valve going bad, or becoming unhooked can cause a very low idle.

MudHippy

Check for codes first off.

If it's a sensor it'll tell you which one.

The EGR is another story(unless you have an EGR temp sensor), you'll have to check it manually.

My first guess is the coolant temp sensor, check the wiring on that. It'd be intermittent, not working one minute working the next. If the wires are starting to go. I just had to replace mine and it made my truck act alot like yours before I fixed it.

Who fiddled with the MAF? And why?

Targetnut

to see if the fuel pump stops at idle. The airflow meter has a switch that keeps the fuel pump running once the engine is started. When you crank the engine it overrides this safety till it is running. If there were something wrong such as a leak in the intake tube or improperly adjusted AFM bypass it might cut the fuel pump.

ToyYoda

I'm not exactly sure how to check for codes. All TPS tests were up to spec. The truck has a long tube header and that's the only reason I could imagine them opening up the MAF to adjust it. I didn't mess with it but noticed the liquid gasket around the top. My old cylinder head was very weak 237k miles so if it was adjusted, then it's probably off. I did clean the coolant temp. sensor when I did the cylinder head swap and the cold start time switch. Is there a test I can do to check the EGR? I need more details on some tests I can do to find this gremlin.

n4ynu1010

Try this link it may help you if you use this type of diagnostics , not sure since I have a '91 , MudHippy will straighten me out if I am wrong :
http://www.off-road.com/toyota/tech/codes/

if not right go here and you can either access the FSM you need online or download the PDF :
http://www.ncttora.com/fsm/index.html

MudHippy

Diagnostic Check Connectors

Short connectors as shown, observe flashing "check engine" light to learn the code. Then see list of codes to determine where to start.

About the EGR,

Pull the hose at the EGR vacuum modulator that runs to the top of the EGR valve(see this link for a pic of which hose I'm talking about http://www.autoshop101.com/forms/h61.pdf). Wipe it off and suck on it while the engine is running at idle speed. If the engine stalls, or at least attempts to, that means it is opening correctly. If not then it needs removed to see why(most likely fouled with carbon build-up/soot). This scenario however wouldn't be likely to effect your engine in the way you describe. If would actually be beneficial to be left clogged shut/not openable, IMO.

To check if it's closing correctly(because this would be the possible cause for your issue if it wasn't)does require removing the EGR valve from the engine and by-passing it by blocking the hole in the intake where it was. If this solves the problem then your EGR valve isn't closing properly and again is probably dirty/needs cleaned. They don't really "break" or "need" replaced much that I've ever heard. Use whatever solvent you prefer to clean it thoroughly if needed.

n4ynu1010

Just remember that some of these solvents you will be using to clean inside of EGR (the valve itself) may have some adverse effects on the vacumn diaphram on the valve (vacumn side)

ToyYoda

Thanks guys! I'll get to testing and post what I find out

ToyYoda

For anyone who digs this post up later on with the same problem and has tried
everything else to get their truck to idle...

...it's the EGR valve.

Block the sucker off, or better yet, get a new one.

n4ynu1010

Hey Hippy , have a question if you are subscribed to this post , even with the FSM I am having a hard time identifying a Emissions peice -maybe you can help me
It is on the same side as EGR yet closer to the firewall , it is vacumn operated and has a large hose attached to it (3/4) going to the air breather (VAFM) via a metal tube under the upper intake , and the control actually hooks up to the exhaust manifold as well like the EGR but in a diff. place , is this the "reed" valve maybe and will it hurt any to remove it as well , does it have any real purpose other than it appears to be feeding the VAFM (exhaust???) and indirectly the intake resonator box

bushinsappony

Bump good question... I'm running into the same thing and I'd really like to pull out/disable as much of the emission system as possible. I mean most of that crap seems to be counter productive to the engine function (EGR etc..) and it's making the engine difficult to tune.

Newbie question (sorry :-), I've seen in pictures of preformance engines(22re) that the pcv valve and vacum lines coming out of the valve cover seem to be removed, instead they put these mini KN looking air filters into the holes instead. What is that all about? And how does it effect MPG if it's removed?