my engines rans bad after washing it

[da89cup]

I washed my engine when it was (too) cold outside (-15C/+5F) and now it runs very poorly. It backfires - if that's what it is. I hear loud pops from the exhaust at idle & while driving. It's completely gutless.

I installed a new distributor cap & rotor and I found that the wire from the coil to the cap was shorting out to the frame so I put in a new one. All the other wires are good. The spark plugs were changed about six weeks ago. I checked to see if there was any moisture in the cap & there was a little, so I dried & sprayed it with electric dry. I don't know what else could be the problem.

Please help. I don't even want to drive the thing now!

[fiveohpatrol]

you coulda soaked your TFI module or your coil as well. Since you had a problem around your coil with the wire, i'd bet your coil is going south.

There's a number of things you shouldn't get wet and you really need to be careful when spraying your engine down to avoid getting virtually any electronics wet.


good luck, sorry i couldnt help more

[Mr 5 0]

The TFI and the coil are clear suspects and need to be checked. If you have a buddy with a similar 'Stang you can check the coil by switching it with him for a test drive.
A used (junkyard) coil would also work for minor expense. If the problem is solved, buy a new coil.

TFI modules usually just crap out entirely and disable the engine but dampness could be a factor, too. Engine heat should have dried it out quickly but corrosion is a factor in anything electronic. Once a contact is compromised by corrosion the part usually malfunctions.

It's also possible you got some moisture into the Mass Air meter, especially if you didn't protect it, as it sits right on top, easily sprayed. Common mistake when washing an engine.

Try disassembling the meter (2 screws) and check for moisture inside, using a Q-tip to dry it, if necessary. Be very careful about touching the hot-wire with anything other than a Q-tip.

One of these parts is probably the culprit. I vote for the Mass Air meter - but no bets.
It could also be a shorted wire lurking somewhere or some other electronic part was dampened. Check all the spark plugs and plug wires for cracks. Replace what's needed.

Good luck and let us know if and when you find the problem - or if it just 'goes away' as the part in question dries out from engine heat.

[da89cup]

I swapped the TFI (black module behind the intake on the firewall right?), & it didn't help. I swapped coils & nothing either. I cleaned the MAF with electronic cleaner & a q-tip & it ran better for a little while but after about 2 blocks it ran bad as before. I think I'm just going to replace all the plug wires & see what happens, I'm running out of ideas. Thanks for the advice though.

[fiveohpatrol]

the TFI module is on the distributor.

I don't know what you are referring to thats behind the intake.

Sounds like your mass air sensor is bad, because you said you cleaned it and it ran better for a few minutes then got better right?

Time for an aftermarket one

[FoxBuilder]

I think the sensor you replaced behind the intake was probably the MAP/BP sensor (3 wire connector, 1 vacuum port). I also think the MAF maybe going out. Try rotating the MAF clockwise (as if you are standing in front of the bumper), if it seems to improve the MAF is bad.

[95mustanggt]

Does the power ever surge? When my MAF went south I had huge problems with power and detonation before I replaced it. it limped along fooling the computer diagnosics for 3 or 4 months too.

[Brad]

I did the same thing, I could barley drive the car.. I replaced wires, cap, rotor ect.. It ended up being the TPS.. The TPS is sealed but you can get just a touch of water in were the wires go, that's all it took... I replaced it in 5 minutes, I was back to smok'in the tires..... It's worth a shot, Good Luck..

Brad..