My '91 Ranger 3.0 runs great since rebuilt engine and trans, but it surges during accelleration. The surging is barely noticeable when at less than half throttle, but it surges more if I get on it harder. It does not seem to surge if accellerating downhill. It's most noticeable when there's a load, like when I'm pulling a boat.

Truck has fuel injectors from a '96 Taurus, but the stock fuel rails from '91. Trans is rebuilt A4LD.

Any ideas what may be causing this? Mike

 

I would check for stored codes first. You don't even need a scanner to do it.

http://www.thorssell.net/hbook/eectest.html

Have you tried cleaning the MAF sensor?

 

Thanks, Rockledge,

Have not tried cleaning maf sensor. Where is it on this truck? Is it a wire that reads airflow somewhere in the air intake? How do I clean it?

Thanks for the link to code reading. Have not gone there yet but will if the sensor cleaning doesn't do it. Mike

 

I'm not quite sure exactly what it looks like on your '91, but the MAF sensor/housing is in the air intake duct down by the air filter box.

https://www.ford-trucks.com/forums/1...-cleaning.html

 

Thanks. Get back to you with results later. mike