Mercury Repair Questions? Ask a Mechanic for Answers ASAP
Hi this is MATT CAREY. One of the most common problems of hesitation can be the MAF ( Mass Air Flow Sensor). It will most times not even set the check engine light. The MAF is best diagnosed with a scanner that can read fuel trim data. You can remove the MAF and see if the tiny hot wires are dirty, then clean them with brake clean spray to see if that helps. If you do, be careful because they are very delicate.
Of course this is just one scenario. Could be something else, but worth looking into. Do you have a Check Engine light on, any codes? How many miles? And when is the last time you have had a tune-up? Thanks, MATT
Thanks Matt, I will check out the MAF or have it checked. I have a check engine light on but have had it checked out and the only thing that comes up is a heat sensor that has been broken for years. The spark plugs were checked just recently and they were okay. The car has about 95,000 miles on it. I did not specifically have the air filter checked and assumed that it was part of the diagnostics but perhaps I should have it checked. A few years back I had trouble with the accelerator plate and had to have it cleaned. Could that be a problem again? The symptoms were similar but not the same.
A dirty throttle plate can cause problems, usually it causes stalling when coming to a stop. Not a hesistation. As far a engine light, do you mean a O2 sensor heater code? if so, probably not related. But you never now if you have a new code in addition to that one.
Check the MAF, and Throttle plate, can't hurt. let me know. MATT
Okay, thanks. When I hit the accept button, will I still be able to follow up and let you know if the problem was anything you recommended looking at?
I'll be here to help you either way. You can accept now or wait, whichever you are more comfortable with.
Also try this. Put your Emergency brake on, and with the van running in drive, put your left foot on the brake and then give it gas with other foot. We call it a power brake test, basically as you rev the motor, you are putting a load on it. And you are looking to see if it misses, or cutts out. Just don't burn up your trans.. Do it for a few seconds at a time.
Let me know what it does. MATT
Okay, thanks I will check that out too.
I'm here when your ready. Has it been running rough more , (like you said it did in the rain)? Just wondering if the problem seems to be getting worse/ or more often? MATT
I checked out the emergency brake as you told me but that was not the problem. I took it to my mechanic and gave your info. They kept it all day and finally found that it was the transmission sensor. I probably don't have the exact name of the part but am sure you know what I am talking about. The cost to repair it is about $800.00. Does that sound about right?
There are a handfull of different sensors on the transmission. See if you can find out the exact name, and I can try to give you an idea of price. MATT
It is the transmission control module and the speed sensor (the odometer has not been working correctly) for an estimate of $781.00 including labor
Yes that sounds reasonable. At least you will have a warranty. MATT
Thanks for your help