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What could cause this?

(1990 Mercury Sable)
in Glenolden, PA on January 13, 2010
I have a 1990 Mercury Sable, 3.0 engine, 40K orig. miles. I bought it a year ago, was running fine. Starting having trouble in the morning starting, had to keep my foot on the gas to keep it running. Then it started to backfire, sputter and lose power over time. Had a diagnostic run, not throwing codes, was told the fuel pump, replaced the fuel filter and pump. Not the problem. The plugs are good, rotor good, have spark, injectors fine. Pressure was fine thru the rails, regulator was fine. Now it wont start at all. Any suggestions?
Displaying 4 answers & 1 comment
Popular Answer
on January 14, 2010
Need to re-check all the basics, Compression, Timing etc. If it was backfiring, you have an Ignition Problem. Fords of this vintage had problems with their Ignition Modules and Distributors, I was Ford Tech and worked at Ford Dealerships in this era. How new are the plugs and wires? Is the DIstributor Cap Arcing Internally? How strong is the coil, do a maximum coil output test, it needs to be 40,000 volts. You can get a coil output tester at parts store for this. You may have spark but it needs to be HOT! I have seen many techs buried by a weak coil, for example.
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on January 15, 2010
Thanks first off for the response. I'll go back and check the wires, plugs, distrib. and coil again. It was tuned up and those parts replaced in the summer (except for the coil) The backfire was soo much raw gas, it shook the whole air intake. The only other thought I had, was maybe the timing or timing sensor? Maybe it's throwing gas and spark at the wrong part of the cycle? Just guessing here... I'll start with plugs, wires, distr, coil. At least the car is older, and the parts are cheaper. I'll post back if it works. Thanks!

Tried everything, no luck. My original mechanic figured it out. It was the "brain" or computer. He pulled another computer from a 93 mercury at the junkyard, popped it in, and after sitting since Christmas Eve, the car started right up. I'm going to take it to a ford service center and have them calibrate it to my car. But for now, i'm up and running fine.
on October 30, 2010
I would recommend spark plugs and check your fuel pump. That was my problem when i had those symptoms. Got them fixed, car runs good.
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on July 15, 2010
EGR valve and check the catyletic converter for being plugged up
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on September 24, 2010
I had the same problem with my '94 Sable. There is a throttle control on the intake plenum, cost me about $300 at the local Ford garage, problem solved, car runs great
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