Misfire after driving home on a REALLY rainy day

[Sixxshot87]

Car is misfiring like the spark plug wires are wet one week after they actually did get wet. Checked terminals on both the coil pack and plugs and everything is bone dry. The car started doing this as i was driving and hit a few massive puddles. Ive had cars get wires wet and you just let dry out and problem goes away but not this time. again its just like a misfire like when the plug wires get wet, the difference is drying out didn't help. coil pack? crank position sensor? injectors? Anyone ever have this before? The car does crank and run but with no trouble codes.

 

[TurboBuRick]

Fouled spark plug?

 

[Sixxshot87]

anyone anyone?

 

[Sixxshot87]

Update: unscrewed all 6 plugs and tested them with each corresponding wire and all 6 are sparking. So then I was like ok maybe this is head gasket # 10 million even though this time I have zero reason to believe that anything I have done this time has blown anything (but how many times have we all said that to ourselves). So i do a compression test and all 6 cylinders are within 3% of each other at better than acceptable numbers. radiator is not draining or foaming, no steam in exhaust. oil is clean. no pressure coming out either valve cover. only thing odd to me on the scanmaster is voltage seems to park around 13.9-14 volts (it has never done that from what I remember, usually 12.8-13.4 ish engine on. Are injectors last on the list or what? Again it is a consistent miss like a dead cylinder. I'm clueless. help.

 

[Clark6]

cam sensor?
crank sensor?
reset your computer?
Maf sensor?
ignition module?

 

[garyk1970]

Wiped cam lobe? A laser temp gun would narrow down the cylinder

 

[TRYMYSIX]

This EXACT same thing happened to me several times and I chased it for weeks. Heres where to look FIRST! Pull out the ECM from the kick panel and check it for water. Mine was full of water on the top harness plugs. Dried them off, cleaned them denatured alcohol and coverd them with dielectric grease. After words I found a leak at the bottom corner of my windshield that was letting water dripn onto the ECM. Fixed the leak, now no more water in the ECM!

 

[Sixxshot87]

I'll hope to hell I didn't wipe the cam. its a roller cam with only about 1500 miles on it. Using ZDDP and 20-50 valvoline racing. I have a laser temp gun so Ill check each header as well as if the computer some how got wet. Neither would surprise me at this point as it is always some thing dumb. Would anything cause this that has to do with the fuel injector harness and its grounding, causing an injector to stay open or closed (some thing like that). I'll repost later today after i do the first two tests

 

[87gnguy]

Here's another long shot but it actually happened to me.

While driving in the rain, my car developed a misfire. I checked EVERYTHING I thought it could be. I had just put brand new plugs and wires on the car but I checked those again. I checked the ECM, the coilpack, crank sensor, everything. What I found was when I had installed my new plug wires, one had inadvertantly gotten looped high up on the firewall behind the coilpack and had gotten pinched in the windshield wiper arm as it moved. While it was being pinched, it almost chopped my wire in half as the wipers moved (it was raining hard that day so I had my wipers on hi). It was so high up on the firewall I couldn't see it when checking all the other stuff.

 

[Sixxshot87]

Update; the cylinder closest to the firewall (#6 I believe) is not firing according to my temp gun. Other cylinders hit over 300 degrees while this one was at 140 ish. It has compression and spark. I unplugged the injector and no change. It is NOT dumping gas so this leads me to believe the injector is stuck shut. can a wiped cam still be potentially it given the info or can that be ruled out? I tapped on the injector fairly hard and its still isn't spraying fuel so now what?

 

[Sixxshot87]

also, from what I'm reading, injectors open by grounding out. so if that is the case , does each individual injector have an individual ground and if so where is it OR does the entire injector harness ground off one point? remember, all other injectors work so I'm all ears

 

[aminga]

There is one constant 12 V feed applied to all injectors through one of the Injector harness pins. The other 6 connections are ground that the ECM completes to fire an individual injector. The injector plug harness is under the coil pack.