1993 Explorer Stalls at Idle

[MadExplorer93]

No longer needed thks

 

[Turdle]

Bump to the top of new posts-
Welcome to the site--

 

[JDraper]

Moved to proper forum..

 

[Turdle]

Moved to proper forum..

I was right behind you

 

[JDraper]

Nah..s'alright here...the only forum that the rules are followed to the letter on is the Technician corner. The rest are flexible.

 

[dogfriend]

Cool.... i love my X and want to improve it.. i getting motorcraft plugs and wires and coil for it.

The coil resistance is 14.0, 13.8, 14.0 and on primary is 1.4, 1.4, .08 this is to high as normally they should be around 11.5 max on the secondary.

The plug wires resistance is 15 ohms, 10, 9.8, on driverside and i did not check the passenger side as they are original wires and COIL too and i will replace them.

Now one thing i need to know for 100% does the MAF have 2 wires in it or only one as i think maybe it is an issue for the startup stalling.

The RPM ides at 1000rpm and out of no where slowly drops and stalls, but like i noted in my original post when it warms up like 2-3 min it OK.

Your coil resistance is too high as you noted. When mine was 12.5K, I had misfire problems under load (like trying to pull my trailer uphill) so you will probably want to replace the coil pack. I don't think that explains the stalling though.

When it is running and starts to drop rpm, try to crack the throttle open just a little bit and see if the idle improves or not. If it improves, I think you have a sticking IAC valve. Mine failed this way once, although mine would idle in P, but stall if you shifted to R or D.

You should have either 3 or 4 wires coming from the MAF, two wires should be Tan with a light blue stripe, these wires go back to the PCM (term 14 & 15) you should have a Red wire (VPWR) and a Black wire (GND)

 

[mawrazen]

I had the same problem after upgrading my wires.Do u hear a sucking sound under hood?

If you can hear a sucking sound under the hood, you have a loose, disconnected ar bad vacuum line.

Listen at the rear of the engine at the vacuum tree. Then feel around and try to cover up the the spot in question. If the sucking noise stops, you have found the missing line. There should also be 1 or 2 branches of the tree that have a cover on then to block them off.

Hope this help!

 

[wood1]

http://www.explorerforum.com/forums/showthread.php?t=154711

Yes the MAF has two wires inside it. To clean it you really have to take it out of the housing. If you continue having trouble check your TPS.

Chris.

Oh, and have a look at GLACIER's thread on the MAF, very nice with pics as always, thanks GLACIER.

 

[dogfriend]

Dogfriend:

The IAC is about 3-4 months last year. The Vehicle sat for about 8 months (started a little here and there in that time frame) then i purchased it about a few months ago.

I understand, but its possible to get a defective part. I'm not saying you should replace it, I'm saying that you run a simple test next time you have the problem to try to verify that its not the IAC. Because the symptoms you are describing (can't maintain idle speed as the load on the engine changes after startup) really points to the IAC.

There are also other possibilities; vacuum leaks as posted above. You may not have any obvious hoses leaking, but its possible to have a leaking intake manifold which is also a vacuum leak.....

 

[dogfriend]

Now as for TPS i did check the Volts and it is .96 from stock, not sure how to test it for failure though????

If you have an analog voltmeter (with a needle instead of digital readout) you can test to make sure that the voltage change is steady as you move the TPS through its range. If you have dropouts (voltage drops suddenly) then it means the TPS is bad.

 

[dogfriend]

All i have is a digital voltmeter and when you say through its range.. is this when the engine is running in idle then turn the throttle while testing the .96 volts.

I also probed the other wire on the TPS and it is 4.99v

My wire colors are:

Red, Grey/black, Grey

By touching Red and the middle wire engine off (Key turned On) and back probing the wires while plugged into the TPS still = .96v and then still back probing the red wire i back probed the third wire farthest to the right = 4.99v

When I said through its range, I'm talking about moving from idle setting all the way to WOT (wide open throttle). The voltage should increase smoothly as the TPS moves through its range. You really need an analog meter to do this type of test.

I believe the red wire is VPWR which should be steady at 5V (you measured 4.99). VPWR is the circuit that supplies power to all of the engine sensors.

 

[quicklook2]

iac could go bad for no reason.

could be 10 years or one month.

i bought a set of security everything fastener tools (100 pieces) for under 8 dollars at harbor frieght tools. get a set.

replace the iac.

replace the plugs and wires with motorcraft and then reset the computer.

i never read if you got the codes.

 

[wood1]

I wonder how long it's been since the fuel filter was changed? Do you have a pressure gauge to check what the fuel pressure is doing when it's acting up?

Also, you can check the TPS by hooking it to an analog multimeter and slowly moving the throttle, or in you have it off, turn the piece inside while watching the hand of the meter. It should move smoothly with the movement of the sensor.

I'd clean the throttle body with carb cleaner and reset the idle as well.

There is a MOD to the TPS whereby you check the output voltage with the key on, not running. I did it on my 5.0 Mustang years ago, seemed to inprove the idle quality before I changed the cam... here's a link. The standard back in the day was .98 V. I think it had something to do with the computer throwing in a bunch of timing when it read 1.V but don't quote me.
http://www.explorerforum.com/forums/showthread.php?t=79362&highlight=TPS

Chris.

 

[wood1]

Sorry dude, I had read the previous posts but only scanned them that time.

As far as setting the idle use this link, it is the same as the '93.

http://www.mysporttrac.com/mysporttrac/projects/IdleAdjust/IdleAdjust.htm

To be honest you're doing everything I would, other than the fuel filter, check for codes, compression and fuel pressure check, check for codes, oh and did you check for codes? I see you haven't had a chance to replace the plugs and wires. You already know that if you are trying to troubleshoot a miss/stall, the first thing you should do is to make sure you have your tune-up parts covered.

Keep us posted, I'd like to know what you come up with.

Good luck and congrads on the purchase. I love my ex too.

Chris
ps did you check for codes?:
edit: I was doing some reading and I forgot to mention that you should check the lower intake manifold to make sure the bolts are torqued to proper spec, they get loose (mine were), also you may have dirty injectors

 

[awood]

The computer will need several miles of driving to re-learn itself, like you said.

I'm curious...have you tried to pull codes? This is usually the first step. I experienced a faulty TPS that showed up on the KOER test, but never set a CEL light.

 

[quicklook2]

Cool i will check the idle once i done all wires etc...

Also what is a good scan tool for this vehicle?

Is this a good one,

From Autozone

Actron / Ford Code Scanner

Now remember i live in CANADA

I will keep all posted once i get all this done.

go on ebay and do a search for :equis innova 3145 code reader.

it is electornic and way better than that actron.

 

[quicklook2]

here is the guy i bought from.

http://cgi.ebay.com/ebaymotors/Equu...ryZ43989QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

you may find it for a few dollars less.

and of course ask about canadian shipping.

this does koeo, koer and cyl balance tests.

has a memory and no lights to count it does it for you.