94 3.0L Aerostar xl plus extended

I recently replaced the MAF, wires, plugs, rotor, air filter, and fuel filter. The van starts up fine when cold. It idles fine when running or driving.

After driving 10-15 miles with temp gauge in normal range the rpms seem to rise. This is when things start to change. When I came to a stop and then stepped on the gas to drive off the motor felt like it was going to stall.

If I turned off the motor it would not restart unless I pumped the gas pedal 3 or 4 times and it would start and sputter but return to a good idle. If I turn it off and let it sit for an hour it will start right up.


After several start cycles things got worse to the point that after 15-20 miles driven and the temp in normal range, the van stalled when I stopped at a red light and tried to drive off. I finally got it to start with a lot of smoke out the exhaust and it idled/drove fine until I had to stop and drive off again. As long as I don’t have to stop and go it runs fine.


I can not get any codes out of it. I was able to retreive codes back in june but now none show up not even 111. I am getting a blinking airbag light code of 32. My horn and cruise work. Could there be a short in the clock spring that would affect the ability to pull the codes? (Although I had the airbag light on when I read the codes the first time)

Since I cant read the codes would it be reasonable to assume the stalling and increased rpms on a warm engine might be caused by the ect or tps?

Thanks for any HELP…

 

Probably the Idle Air Control Valve (IAC).

 

Could your cat's possibly be clogged, or a messed up o2 sensor again?

 

does your PCM go thru the self test and ok when key is turned on?
CEL should light for approx 5 secs when key is first turned on, then go out

 

I too would suspect an IAC. They tend to suddenly start going out, causing the symptoms you describe. Chances are it's an original part, which should be changed, and it's very easy to do. A 10 minute job, diconnect neg. (-) battery cable before changing.

If you sometimes notice a minor backfire or lugging coming from the throttle plate / boot area, it's 99.9% the IAC. usually, the slight backfire occurs when fully warmed up, under acceleraltion, and the van feels like it has a lack of normal power. I've been told the 3.oV6 is basically being starved for air, when this occurs.

Just something to consider, Good luck. Ed and Happy Thanksgiving/.

 

Thanks for your input,

I went here: http://fordfuelinjection.com/?p=39 and did the IAB Testing.

Let the engine run til normal temp range and pulled the plug. The rpms dropped to a normal speed and the engine continued to run at a smooth idle.

If I am interpreting the instructions properly it must be the IAC.

I have one on hold at pep boys for 44.99 with 1 year warranty made by borg warner.
Anyone have any trouble with borg warner parts?

thanks

 

I would doubt the clogged cat idea. A clogged cat will become increasingly restrictive as engine load and rpms increase, and would show up within seconds of startup at the longest unless it is a rattleing chunk issue, which you would be able to clearly hear. I would agree, go for a new IAC valve. It is cheap enough that if it doesn't work it is ok. They tend to go out a lot anyway, so replacing it counts as part of a complete tune up.

 

What is the torque spec. on the air bypass valve mounting bolts on my 3.0L ?

My haynes only lists 4 cylinder (@ 71-102 in-lbs) and 4.0 V6 (@ 72-96 in-lbs)

I am going to assume it is safe to torque between 71-102 in-lbs

thanks

 

90 in-lb or 7.5 ft-lb. You'll need a very small torque wrench.

 

Thanks for the info copper.

Things not going good here. I changed out the IAC and it didnt help.

Im afraid to take it out on the road and blow it out because of the stalling.

Same symtoms as before.
I let it idle to normal water temp and stepped on the pedal and it hesitated, burped and felt like it wanted to stall. I shut it off and tried to start up with no start.

Got any more suggestions guys?

thanks

 

Pull the vacuum line on the Fuel Pressure Regulator and see if there is any gas in the line. Also, put a vacuum gage on the line to see if it gets any vacuum at all.

I'm really surprised. If the car is running that badly, there has got to be a code stored in there somewhere,

Since you replaced the MAF, wires, plugs, rotor, air filter, and fuel filter lately, check the MAF again to make sure you didn't forget to plug it back in. Also, check the wires and make sure they are seated correctly both on the distributor and on the spark plugs, and that they are not crossed-wired. That's the most common mistake when you change the wires.

Also, how did the van run before you change all those things? If it used to run better, than you definitely made a mistake somewhere along the line.

 

It ran bad before thats why I did the wires etc.
Why would it start right up and idle evenly if it wasnt getting fuel or there was an issue with the wires or plugs you would think it would run really rough. This only happens after the engine/water temp warms up to normal range. I do have to replace my flex pipe on the exhaust. But I would think that would cause rough idle also rather than a stall on initial acceleration or hard to start when warm?
When you said cross wire do you mean wrong wire on plug or just crossing a wire over another?

 

I meant wires on the wrong plugs, e.g. distributor wire # j on # k plug. I lost count of the number of times I made that same mistake, so that's why I think it should be checked.

Also, you have a '94 3.0L, that means Sequential Fuel Injection, so you should be able to do a cylinder balance test. But before that, I still think you should try reading the code once more. If everything passes and you get a 111 code then I'd suspect the problem lies in a system not monitored by the PCM and we'll try looking at those one by one.

 

thanks copper.
Im not a mechanic. Im fine changing oil, brakes, plugs etc. I've changed injectors, fuel pumps, heater cores and the timing belt on my contour but Im not too keen when it comes to testing for electrical or major fuel delivery issues.
I hate to give up on this thing so I will give it a little more of a try before I throw in the towel...
There are knowlegable and helpful folks on this site but Im sure they will eventually get tired of dealing with a novice.
I will go over the wires etc. probably tomorrow and will get back to you.
thanks

btw: every time I see those blinking eyes I get a good chuckle

 

I will also double check on the post by 96_4wdr:

"does your PCM go thru the self test and ok when key is turned on?
CEL should light for approx 5 secs when key is first turned on, then go out"