Brandon13

So I have searched for this many times and haven't really found anything like my problem.
To start out i have a 1993 Pickup 22re 4wd w/ a v6 radiator. An i just replaced to Head Gasket somewhere between the lines of 4000-10,000 miles ago.
Well ever since i finished it my truck hasn't idled the same. It runs perfectly fine when driving or cold but once it warms up it idles around 400-500 rpm and rough. So to compensate I adjusted my idle up to about 800rpm but even now sometimes it will go back down to 500rpm and i have to tap on the gas so it will go back to 800rpm.
Also i started to work 1.5 hrs away so i started to drive that about 3 times a week and i would check to oil and coolant frequently and i started to notice about once a week I would have to add about .5 liter, maybe a tiny bit less.
Truck never heats up past 1/4 except on hills, it goes to about 1/3. No white smoke no oil in water or water in oil.
So I did a little research and checked for coolant leaks replaced my radiator cap and thermostat and then I pulled my spark plugs hoping not to find a clean shiny one, and all i found was that cylinder #3 had and good amount of white corrosion on ground electrode.

So my questions are:
Where is my water going?
Was that water that caused to corrosion on the spark plug? If so could that be the issue to my idle?
What could cause a rough idle?

Thanks

scope103

I don't have enough to be definite, but if "tapping" the throttle brings the idle up I would suspect something wrong around the throttle body; the dash pot, throttle opener, TPS, or even the air valve. http://www.ncttora.com/fsm/1990-1995...e/throttle.pdf Run through those diagnostics to rule them out.

Brandon13

I'll try that. Thanks

Brandon13

So i tried to check my AFM with a ohmmeter and i could not get any readings. not sure if I used it correctly or not but came up with nothing. I dont have any check engine light on but i jumped E1 and Te1 and got the codes 24 and 31

ksti

Maybe this can help you good luck

[IMG] Code 24 INTAKE AIR TEMPERATURE SENSOR SIGNAL--OPEN OR SHORT IN INTAKE AIR TEMP. SIGNAL --INTAKE AIR TEMPERATURE CIRCUIT --INTAKE AIR TEMPERATURE SENSOR --ECU[/IMG]

[IMG]Code 31 MANIFOLD AND/OR AIRFLOW METER SENSOR SIGNAL CIRCUIT --AIRFLOW METER/CIRCUIT --MANIFOLD PRESSURE SENSOR/CIRCUIT --ECU[/IMG]

Brandon13

so when i was checking my MAF i accidentally tried to start it when it wasnt plugged in, and thats why the codes showed up. So I cleared them and they didnt come back but still a choppy idle.

James Woods

iTrader: (1)

Typically white on the spark plugs indicates that you are running lean, or too hot. You say you have the opposite going on. I would get an infrared thermometer and check your engine temps and do a pressure test on the cooling system.

Brandon13

How do you check/ fix if you are running to lean

ksti

I'ts possible those codes were stored before you rebuilt motor or happened right after fresh install. As for choppy idle, could be a number of things TPS, throttle body dirty, ( you probably cleaned it i'm assuming ) I would say alot of the time it's a vacuum leak. I would re-check all vacuum lines for leaking (Map Gas). I was chasing an erratic idle for about a year now and found my charcoal canister had a crack in it. It's been okay since repair. The FSM is your friend, it will tell you the different diagnostic checks to do. As for possible having trouble with olm meter there is a section on http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml It will also show you how to use a volt/olm meter for testing check your TPS also. Good luck

Brandon13

Yes I did clean the throttle body and intake. I did a little investigating for leaks but I need to spend some good time on it, and the PO of the truck broke the canister and just siliconed so I'll check that. I have an original FSM and that's my main source. And thanks for the ohmmeter link I was looking for that but couldn't find it

James Woods

iTrader: (1)

^ I would suspect after doing major engine work that there would be a vacuum leak that would explain why you would be running lean, also misadjusted timing can cause it to run lean. If you have the wrong spark plugs (step to hot) can cause white on the plugs and many more things. To start I would do as I stated above just to make sure that your temp gauge is correct and that you don't have a coolant leak somewhere.

ksti

Another thing I just remembered, check idle air screw. I know my 3vze has an o-ring on it if your 22re does then it probably is worn out and will cause idle issues also. Any hardware or AP store has one just match it up.

vital22re

iTrader: (2)

are you sure your head isn't cracked? you wouldn't have a pic of this plug would you?

Brandon13

no pic of the plug. But when I did my HG I had the head resurfaced and pressure checked and it passed. And since then i have never over heated.

ksti

So Brandon, Just curious, what's the verdict on your rig?

TylerH

My truck does the same exact thing. Also when mine is hot and i go to start it it will just die untill i tap the gas a few times. Really annoying. I have some bad water leaks so i think thats it. Im going to fix all the water leaks soon and see what happens.

Brandon13

So I feel really stupid. I fixed the coolant leak, it happened to be the radiator cap. I drove 2 hrs away then let the truck sit for a little more than 2 days and the coolant was still topped off.
But my idle still sucks and i found one hose that melted from the inside so I fixed that and still sucky idle. So I am going to try SEAFOAM and changing the fuel filter <---- looks like it has been on there for all of the 260,000 miles

ksti

You may get a little better throttle response from seafoaming and FF change, but I still think your idle issue is something else. I hope I'm wrong, did you check TPS and o-ring on the idle air screw?

Brandon13

Haven't checked the TPS but I'm hesitant to check the o ring because I don't want to mess with the air a fuel ratio. I'm just try to do all this before I got to smog my truck.


What could make my truck run lean? Cuse my spark plugs were white

abecedarian

Issues with the TPS adjustment can cause the ECU to look at sensors it shouldn't be paying attention to. For instance, at idle the response time from the O2 sensor is too slow for the ECU to use it correctly so it should ignore it, but if the TPS doesn't tell the ECU the trottle is closed idle issues will occur.