Ok, I had this problem last spring, and took it to the shop. They cleaned something (maybe the maf?) and changed the wires and coil.

The van ran great, for about a week. Then it started again. I was low on $$$, so never bothered taking it back in since then. In the winter, it ran a bit smoother, at least in the deep cold (-20c). When it's warmed up, it lopes badly at a standstill, often stalling.

If I drop into neutral, the loping stops (or is at least imperceptable).

Research on the web has shown me that for other cars/vans with these symptoms, indicated O2 sensors are likely the problem. But here I've seen many say it's likely the MAF.

My question is: Why only when in gear? Why not in neutral too? In park, it will also stall. I've tried disconnecting the MAF, and it doesn't seem to make any difference. I would expect to see a change in performance, either better or worse, if I disconnected this and it was the issue.

I also tried spraying some TB/Carb cleaner into the throttle body and flipped the hose/MAF over and shot a load into the small apeture, then flipped it again and let it drain out. Didn't seem to make any difference.

This van is getting old, and has body/exhaust issues too, and I'm loath to put too much $$$ into it, unless I can figure this out for cheap. Any ideas?

Oh ya, I don't think it's related (maybe? dunno) but the daytime running lights seem 'low' like they aren't getting enough juice. Not sure if it's relevant, but thought I'd mention it.

For those that remember, this is the van I had a coolant leak on the block last winter. Fixed it with a liberal application of JB Weld. Gotta love it. Engine clean and smokeless since then, so it was just the gasket.

Anyway, I'd greatly appreciate any thoughts on this loping/stalling issue.

Cheers,

Garoo.

 

1.
start with cleaning the IAC, I.dle A.ir C.ontrol valve, with some throttle body spray...aluminum housed unit located on 4L on driver side rear of throttle body on plenum...2 bolts and an electrical plug to remove...test first by removing electrical plug at idle-if working-engine will quit....Ford states in service info that IAC not cleanable but many on list have some success

2. pull out MAF sensor from housing by removing electrical plug and 2 security torx screws...soak in throttle body cleaner for 20 minutes...nothing stronger or bye bye MAF....

3. replace oxygen sensor if older than 50k miles

disconnect battery negative lead for 10 minutes after each step to clear KAM memory of stored learned engine parameters in ECU....reconnect and drive for 10-20 miles to relearn adaptive parameters and check for improvement

 

Cool. Thanks for the advice, I'll try the first two. I'll have to check my haynes to see where the o2 sensor(s?) are... and price them out. I take it they can get expensive?

I already tried to remove the IAC plug, but didn't realize there was anything to clean inside... one of the plug/socket retaining clips snapped off when I tried to do it, so I held off. It was a tad cold out, and I couldn't get a good grip on it, so I had tried wedging a key under one side to wiggle it out. Snap!

Will report back, likely tomorrow.

Thanks for the quick reply.

 

Expensive or not, it must be replaced periodically about every 60K miles. It's a maintenance item. Unlike other sensors, it does wear out chemically over time.

 

O2 sensor was about $56 at NAPA last month, for a '95 Aero. Easy to replace, took me about an hour, including 30 minutes disconnecting and connecting the harness in a very tight place. You might have to tap on the wrench to break the sensor loose, and put some WD40 on it a few minutes before. Good luck!

 

I sprayed mine with Liquid Wrench one evening when I got home, then took them out the next morning with a pipe wrench and cheater bar (4 foot iron pipe), easy as pie.

 

I had the same looping issue when idling. I tried cleaning the IAC, but seen only modest improvements. I later replaced the IAC with a OEM and the problem completely dissappeared.

 

Here's a tip I have always done when replacing the 02 sensor in my 3.0 V6 Aerostar van. Pull the Aerostar up on car ramps. After the van has sat for about 10 minutes, disconnect neg. cable on the battery. Spray o2 sensor with WD40. Disconnect wiring harness where the sensor plugs in. With a pipe wrench, gently "break" the seal of the sensor in the exhaust manifold. Usually it will make a high pitched metal "zinngg!" sound. All you want to do is break the seal, by barely loosening. Then spray it liberally with WD-40, PB Blaster, and or/ Liquid Wrench. Go inside, relax, and let the Aerostar fully cool down, overnight. The next day, give it (o2 sensor) a shot of WD 40, and it will come right out. Always make sure you are turning it with a proper gripping socket, and that you are turning it with even torque pressure. Take your time, and it will come out. Also, if you change the sensor once every 5 years, regardless of mileage, and use a light film of anti-seize on the threads, the next time it is changed, they'll come out, and thread in, MUCH easier. Also, I like to insulate the two black and white sensor wires, from the high heat enviornment it lives in. Good luck, and I hope this helps. I was nervous the first time I did this by myself. However, this was the tip a friend told me, and it worked fine. I do not change the 02 sensor, unless I have the time, and can do it in the manner I just described. Ed