93 missing intermittently

[1615]

I have a 1993 RT/10 all stock (except exhaust) that has been missing intermittently. It seems to run strong at higher RPM's, but at idle and at constant speed it will hesitate as if a cylinder is missing. The key on / key off codes are 12, 33, 55 - so none of those are applicable (standard battery disconnected recently / AC clutch / end code). I put new spark plugs and new wires on it, no change. I'm now suspecting fuel? But since it runs strong under acceleration not sure it's a fuel flow issue? Any ideas or suggestions would be greatly appreciated. Thanks.

[dave6666]

Check your fuel pressure while driving. You have to tape the gauge to the windshield. Yes it works. Yes I've done it. During the day when people are like WTF is this person doing. Or do it at night and carry a flashlight to read the gauge. If pressure is lower at idle then at speed it could be the pump or filter.

[GTS Dean]

How is the battery condition? There are a number of chassis and engine grounds which can become oxidized and inhibit full current flow.

[Viper Red]

Check your MAP sensor. Mine did that and when I replaced it, different car completely.

[horsepower junkie 2]

My 97 did the same thing the Wizzard said to replace ox sensors did and it solved the problem.

[Steve-Indy]

All good suggestions above. That said, if you can find a dealer or shop in your area that still has a functioning DRB III ( or possibly the older DRB II)and the proper OBD I "Y" cable, you can analyze many of the above mentioned areas (amongst others) and possibly save some time, money, and frustration.

[Viper Red]

I purchased this on Amazon and it worked perfectly identifying the problem with the MAP sensor.

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[1615]

Thanks for all the advice. I went with replacing the MAP sensor and so far so good, that appears to have solved the issue.