Cadillac Repair: 1993 Cadillac DeVille, exhaust gas recirculation valve, exhaust gas recirculation

Question
I believe Tom Joy helped me w/ my no heat problem. Replaced heater core AND backflushed system...now, it's blazing hot! YAY!! And thanx. New problem...Caddi just cuts off while driving...it'll start right back up but it's cutting off 2, 3 times a day...this just started. My Bonneville had same problem & fixed it by replacing ignition module. I'm wondering if this could be same problem w/ Caddi? On-line, there's a few suggestions...Oxygen sensor & MAP sensor being two of them. Do you have any suggestion? I'm a woman who distrusts mechanics & I like to be armed w/ info before I take it in. Thanx and Happy Holidays!!

Answer
Hi Susan,

Well you sound like a smart woman to me!

It could be a couple of items, so keep these under consideration prior to investing in expensive ignition parts.

1) Fuel filter:  A clogged fuel filter (just like a coffee filter) will begin to deliver fuel slower and slower as it gets gunked up.  You may want to make sure that as you drive, it is not getting enough 'coffee to the pot' as you accelerate, thus demanding more fuel.

2) Also, some of the DeVille's have a fuel strainer (like a filter) in the tank, which can get clogged as well.

3) An air filter that is clogged, or a PCV module, will cause this problem as well.

4) Finally -- the ulitimate issue:  You may have water in your fuel.  Go to the auto store and buy three containers of 'dry gas' (about 2.00 each).  Add this to a fresh tank of high-test gas and let it run for a little while.

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If all that fails, and the car seems to stall only if you accelerate quickly and suddenly let go of the gas, that could be an EGR (Exhaust Gas Recirculation) valve.  That is worth having inspected.

Finally, now it would be time to have your ignition system looked at (I'm assuming the car has newer plugs, etc.)  The oxygen sensor usually tends to cause a) The check engine light to come on b) rough engine operation.  Although possible, the O2 sensor usually doesn't cause the vehicle to come to a complete stop, and than start up again.

The MAP (Manifold Absolute Pressure Sensor) - again, it is possible, but you would probably have trouble starting your car when it is cold before it would cut off your engine completely, again, it could be possible, but it is unlikely.

So, in a nutshell..this sounds like a small problem.  Start with the simple, inexpensive things and work from there.

Best of Luck and Happy New Year.

Ron