Sluggish acceleration, stops when foot is off accelerator

I have a 2007 Mazda 5 and over the past few days, I notice the acceleration seems slightly sluggish, especially on inclines. Then last night I had a problem where I was driving and whenever I took my foot off the accelerator, the car would stop (rather than gradually slowing). And when I put my foot back on the accelerator, the car jerked forward before finding the right speed. I parked and after work, it drove just fine. Drove fine this morning also. The shop says I need a new solenoid purge valve, but after reading about that valve, I don’t understand how it could cause my problem. Any opinions? The car didn’t stall whom it stopped, it just stopped moving forward.

You may well have a bad purge valve solenoid, but…based on the description of the symptoms, it sounds to me more like a transmission problem.

The first step is to check the transmission dipstick, and report back to us on the level, color, and odor of the fluid. It should be at the “full-hot” mark when the engine is fully warmed-up, and it should have a reddish color and should NOT have a burnt odor. If you see a low fluid level and/or a brownish color and/or it smells burnt, then this confirms some transmission issues.

Make sure that you check the fluid level by using the methodology mentioned in your Owner’s Manual, as the procedure differs somewhat from one make to another.

Also…is the Check Engine Light lit up?
If so, find out what trouble codes have been stored by the vehicle’s OBD system, and then come back to this thread to report those codes. Auto parts stores will usually read trouble codes for you, gratis.

Hmmm…I was hoping that…4 days later…the OP would return with answers to the questions that I posed, but it appears that she is not coming back to this thread…

When this happens, stop the car; walk to each wheel; and with your finger lightly touch that wheel (be careful one may be really hot). You might be able to tell just by smell. If you find one or more that is hot, have a mechanic check the brake on that wheel and/or the entire brake system.

Hope to help.

A faulty purge valve might cause a drivability problem, but this doesn’t sound exactly that. Maybe you’ve got more than one problem. The purge valve and something else. With a 2007, it could be among a host of things that could go on the fritz. 8 years old and all. The above ideas about testing/confirming the brakes and transmission are spot on. If this were my car, the first thing I’d do is bring al the routine maintenance up to date, then proceed from there. Often just doing that will fix, or at least will aid in the discovery of whatever’s not quite working.