Reader Question Hi Austin,
I have a 1994 Caravan with a 3.0 L engine which does not maintain RPMs at slow speed, about 50 km/hr. The pulsing is mild but noticeable. There are no issues at other speeds.
What should I check to correct the problem?
Thank you in advance.
Hey there Jerry,
First thing I would look at would be if your vehicle is equipped with an EGR valve, and if it is….I would disconnect the vacuum hose attached to it and see if that helps the problem. If it does, you most likely need a new EGR valve. You probably have a decal on the underside of the hood which will show you the location of the EGR if you do have one.
I would also look at the tune up parts, spark plugs and spark plug wires. It could be possible that you are having a small engine miss. You can sometimes power brake the engine (with the vehicle in drive and your foot firmly on the brake, slowly increase the engine RPM and see if the surge is there) DON’T do this longer than 20 seconds or so. If the surge is there, I would try a new set of spark plugs and spark plug wires.
Last thing I would look at would be fuel pressure coming from the fuel pump. With a manual screw on gauge you can rent from your local auto parts store I would check the fuel pressure at the engine. You could have a weak fuel pump.