Advice on 2.2L engine surging & transmission slipping

[1987dodgearies]

I have a 2.2L engine with about 32,000 miles on it in my 1987 Dodge Aries sedan. It has a strange habit of surging. The problem really only occurs when braking, especially hard braking, when I brake abruptly and then come to a full stop. The surge come on as soon as I'm not moving and only lasts about a second or two.

The engine will surge like I gave it gas and the car tries to lunge forward as I hold the brake pedal down. It only does it once, then doesn't repeat the problem until the next time I abruptly apply the brakes, in order to come to a complete stop.

I wondered if it was due to cracked vacuum hoses, but besides my PCV valve rubber hose elbow looking kinda rough, all the other vac hoses seem soft, tight and without cracks. The funny thing is, I replaced my PCV valve elbow only about 9 months ago and its already full of cracks. (poor quality rubber I guess) I doubt this is the problem, but wanted to mention it.

Any ideas of what might be causing this to happen? Thanks in advance for any ideas.

The second thing.....I also noticed that every so often, I'll be at a complete stop and when I press on the gas pedal it acts like the car is in neutral. It then quickly "pops" back into gear and it fine again. This only happens every so often, so its not like the automatic transmission fluid is low. That one stumps me because it only does it every so often. I wondered if the bands might need adjustment or some sort of other transmission service.

[RichG]

Hey. I have a similar surge issue. My mopar mechanic thinks it's the throttle position sensor, or throttle position motor, or a combo of both. I sometimes idle at 2800 rpm, and can do 30 mph without my foot on the pedal. I am going to remove and clean both, soon as I feel ambitious.....

[1987dodgearies]

I was also wondering if it has something to do with the throttle position sensor, only its odd because at least in my case, it only seems to do it when I do some hard braking. Maybe it does it at other times, but I just only notice it when braking.

[89ARIES]

Hello there 87Aries. Can you email me some pictures of your car, and maybe a running and driving video? I could upload it to this site.
My email is aries89@chryslerkcar.com. Also, have you done the key dance?

Sincerely,
Guy V.Coulombe
The Chrysler K-Car Club
CKCC President and founder
818-219-2587

[1987dodgearies]

Well, my cars not a whole lot to look at. It sat for years in a yard over in New Jersey and had all sort of bad rust on it when I bought it back in the winter of 2013. But I'll save that for another post.

The key dance?

I just might have..if you are referring to the terrible aftermath of accidentally inserting the key upside down into the ignition.
It's funny because whenever I go to a garage for service, I "school the guy" at the counter on not putting the key into the door locks or ignition upside down. They look at me like I'm an idiot but unless you have done it, you really don't understand how much doing so stinks. Is that the key dance your referring to?

[K-CAR_WAGON]

..

[1987dodgearies]

Ahhh... not the key dance I was thinking of.
I had performed a flashing light code check like that on a Blazer I used to own, so I'm somewhat familiar with what your talking about. I'll check out that link today.

UPDATE : I checked the codes tonight and see my Aries is showing the code 15 and 23.
15 is for "No speed/distance sensor signal "
23 is for " Throttle body temperature sensor signal out of range "

I'll have to take a look under the hood tomorrow. I'm hoping its a matter of a few corroded or dirty connections.

[1987dodgearies]

I ended up taking the throttle position/speed sensor off the throttle body. There are two screws that hold it in place. The lower screw acted like it was epoxied in place. I couldn't believe how tight it was.
When I got it off, the sensor seemed completely clean inside and outside. The spring in it seemed to function properly when I rotated it. I expected to find some sort of crud buildup in there, but there wasn't any crud at all. I reinstalled it for now. I wonder if the switch itself just went bad. They are only about $7 so I might just replace it with a new one. I'm just not a big fan of part swapping as a means of trouble shooting.

The one thing I did find is the 90 degree elbow that attaches to the PCV valve is completely full of cracks and leaking again. It irritates me because I just replaced it last August with an elbow made by Dorman, so it didn't even last 3/4 of a year. I just ordered one online from NAPA, which is supposed to be their brand.

I'm hoping its a different brand and a better quality of rubber, not just the same part with some other companies name on it. As soon as the new PCV hose elbow is replaced, I'll continue the trouble shooting.

[K-CAR_WAGON]

..

[1987dodgearies]

Thank you for pointing out those links for the speed sensor.

I was just driving the car this evening, and its still surging quite a bit. I figured the sensor on the throttle body (that I just visually inspected) might not be working properly, I just wanted to see if it still snapped back like it was supposed to.

I appreciate the info on the speed sensor. I'll read this over right now and see about testing it or replacing it. Then onto the Throttle body temp sensor too.

I just went outside and took a look at my speed sensor. It looks like my 1987 Aries has the old style (pre-'87) sensor with cable based on the photo.

My sensor has two wires going to it, but the sensor doesn't have the plug style connector sticking up from it..so based on the photo comparisons, its the pre87 sensor as seen on the far left of the photos.

So according to the link... "When replacing the old style (pre 1987) speed sensor with a new unit, you will receive the new style 2-pin version. In order to install it, you have to remove the old style sensor's base from the transmission housing by removing the 10mm bolt. It will also come with a short adapter cable."

Is that really all that there is to swapping over the new style 2-pin version? That shaft that extends down into the trans looks so much longer..(like twice as long) on the older version, compared to the newer one.
------------------------------------------------------------------------------------------------------------------------------------
Seems the second problem I'm experiencing is also likely being caused by a bad speed/distance sensor

Here is something I just read of a similar problem " the transaxle acting (in my mom's words) 'as if the transmission was 'slipping' on the highway. This is the other common symptom of a bad speed/distance sensor. The sensor gives the computer the speed info, and the computer uses it to lock and unlock the torque converter. When the sensor is bad, the transmission will often go into and out of lock as the erratic sensor 'says' the car is above or below the lockup speed (about 38 mph)." quoted from the following link http://www.allpar.com/eek/dx-sensor.html