1993 Regency hesitation on acceleration

217555 miles
3.8L

Ok..here it goes.....
Acceleration is fine when car is cold, but after warming up under moderate acceleration car stumbles and surges then under hard acceleration condition improves slightly, but more noticable when it stumbles. So I am ruling out ignition parts and focusing on sensors since I've read the computer is in a default mode until the temps come up and that is when the gremlines go to work.

Another symptom is when attempting to shift out of overdrive the car jerks a few times before in gets out of OD. BUT if I accelerate quickly the transition is smooth out of OD. I'm thinking this may be caused by the stumbling acceleration and not trany problems since the issue is hit or miss.

Initially thought it was bad gas, but the situation has not improved after a few tankfulls. I recently replaced the MAF after cleaing the old one seemed to help, but still stumbles with new MAF.

Now after searching the internet I found another 3800 owner that replaced the Air Intake Temp Sensor. I checked autozone and found 2 different parts avaialble.

1. Air Temperature Sensor - installs in the airbox behind the filter.
http://www.autozone.com/images/products/edm/edm3578003.jpg
I disconnected this sensor tonight on my 51mi drive home from work and there was no change in the problem.

2. The air intake temperature sensor - I have NO idea where this sensor lives on the engine.
http://www.autozone.com/images/products/msd/msd2320003.jpg
Will try to disconnect and drive if someone can tell me where to find this rascal.

Any assitance would be very helpful. Gas milage is down from 26mpg to 22mpg. Have not replaced fuel filter, wonder if that may also cause the issue, BUT the big fly in the ointment is that the car runs GREAT until it warms up. Another odd thing with the way it is running I have never had a code trip the CEL...wierd!

Hope I have described my issues in enough detail for a fellow member to assist. Thanks for this great resource and I will be a member till the car is no longer with me.

Welcome to AF. A full scan will see if any of these sensors are at fault, so far all you have done is based on hearsay, I would do the scan and check fuel pressure also.

Welcome to AF. A full scan will see if any of these sensors are at fault, so far all you have done is based on hearsay, I would do the scan and check fuel pressure also.

Will a scan show anything since the check engine light has not come on? Thanks for a quick reply to my woes.

Yes you can read the temp sensor inputs, the pcm relys on these and does not know if the coolant temp sensor is " lying"

Stupid question, but do you know if my car is OBD1 or 2 or do I need the old fashioned jumper wires?

Never stupid to ask what you do not understand , obd1. The jumper will only allow you to access codes, you need a full scan to look at the sensor inputs.

:biggrin: Problem solved!!!!!!!

Stopped in to my local Advance to get a scan and described the problem. They suggested a new set of wires and BAM!!! Hesitation eliminated! Lovin my ride again:grinno: Hope this post will help someone in the future with this issue. Thanks for a great forum. I will continue lurking.....:licka: