Q: 1984 ranger revving high before shifting into gear. Automatic Transmission

asked by on July 19, 2017

Whenever I put my foot on the gas, the engine revs pretty high before shifting into gear. Seems to be a delayed response. Transmission fluid is full, and no other problems. Is this going to require a new transmission or is this potentially symptomatic of something else?

My car has 86000 miles.
My car has an automatic transmission.

This may be a sign of a faulty MAP sensor as the vehicle responds adversely to a load put on the motor (i.e. putting it in gear, making turns (which makes use of the power steering pressure switch) turning on AC or engaging the brakes). The Manifold Absolute Pressure (MAP) sensor senses engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The engine computer then uses this information to adjust ignition timing and fuel enrichment. When the engine is working hard, intake vacuum drops as the throttle opens wide. The engine takes in more air, which requires more fuel to keep the air/fuel ratio in balance. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation that can damage the engine and decrease performance. This may also be caused by other closely related components such as a dirty or failing mass air-flow sensor, a faulty throttle position sensor or potentially a vacuum leak. I would recommend having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $65/hr

What others are asking

Car showing various fault codes Ford (Transit?)

Hello - the P1631, if this is for a Ford Transit van as it appears, is most often a byproduct of a poor battery condition, with multiple cranking events before a successful start. I would check first for low starting...

How much does it cost roughly to have a new transmission pit in on a 2008 Ford Explorer XLT with 131,500 miles on it?

The cost of an off-the-shelf re-built transmission for this vehicle is in the range of $2,000 to $3,000 or more if you buy a Ford certified unit from the new car dealer. Rebuilding the transmission might be somewhat less costly....

Brake lights still work, though tail lights and dashboard lights do not.

It could be that the dash and taillights share a common fuse. This could be determined by looking at the fuse information in your owner's manual. One important thing to remember is that fuses don't blow for no reason -...

Where and how should children be seated?

While adults can sit in any position in your car, that’s not true for children. Children must be properly seated at all times, but the type of seating will vary depending on your child’s age, weight and more. Here’s a...

Reservoir keeps being empty no visible leaks and oil looks good color

The reservoir is going empty due to a blown head gasket most likely. You will need to have the system pressure tested first to make sure the radiator and coolant reservoir is not leaking under pressure. I suggest having a...

Left rear power window not working

I would first look at the window regulator to ensure the linkage isn't tied up or tangled or broken in some way. Also, check for the correct power and ground at the switches and the motor. This will show if...

Where to get back up camera repair?

Claimed by Kevin Gainer

alternator went out,after changing it the check transmission light comes on,it idles fine but go to give it some gas and it boggsD

The vehicle sounds like it has a lot of different issues and safety concerns. The fact that two major electrical components failed around the same tame, and now shows Transmission Warning Light leads me to believe that there may be...

My truck won't start on the key but will start straight up on a jump start I have changed the glow plugs and the deisel pipes

Hello. If your car will not start on its own, but will with a jump start, then the first thing I would check is the battery. If the battery is old or worn it may no longer have enough cranking...

Related articles

The Best Used Cars to Buy to Maximize Resale Value
A A car is not an investment. An investment, by definition, increases in value. A car is a necessary purchase, and it will never appreciate in value, with the possible exception of classics and antiques. So, as a used car...
A Buyer’s Guide to the 2011 Ford Ranger
The The 2011 Ford Ranger offers affordable pricing with excellent styling. It is a compact pickup that is both inexpensive to operate and own. The vehicle is capable of going off-road while still being able to tow 1,600 to 3,100...
A Buyer’s Guide to the 2012 Ford Expedition
The The 2012 Ford Expedition has ample room for passengers and cargo, while still being able to tow anywhere from 8,900 to 9,200 pounds. The Expedition has two-tone exterior packages making it stand out against its competitors. Along with that,...