99 electrical/fuel problems

*9Cobra9*

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About 3 years ago I was turning left into my neighborhood and the car dies, starts back up and i get to my driveway and it dies again, wont start. The PCM fuse blew and since then has blown about 3 in the past 2-3 years. For the past 8 months i've been having a moving random misfire with the p050,p060 cylinders then moving to p030,p040 and now back to 5 and 6. Moved the COPs around made no difference, cylinder 4 actually cracked the plastic on the brand new plug. checked injector resistance and they all read the same. Compression test turned out ok for all cylinders. I get lack of s0211? switch cant remember the exact code and right bank lean codes but ive had that one for years. Ive checked all the vacuum lines going to the intake and none indicate leakage.

Then just recently the car started stalling out, hesitating falling on its face when i would turn left. lifting off the gas seemed to help but its been getting worse. the PATS system ------- flatlines and blew the PCM fuse 3 times trying to get out of my neighborhood and back. I'm thinking a short off the PCM fuse which I find out goes through the CCRM and powers all kinds of stuff. I had it on a jack and it would not start just popping the breaker i had in place of the fuse, trying to track down the culprit. All o2 sensors disconnected still popped it. MAF wires look good not too stressed, pulled the trunk apart looked at the fuel pump wires, messed with COP wires untwisted a few. After i dropped it off the jack it started so i've been driving around with the breaker in it. I pulled the ccrm out today but didn't test the relays.

If you didn't get bored and leave here are my questions. the wiring diagram indicates most of the systems powered through the ccrm are fused before it by 2 small 20amp fuses in the central module. The only other power wires go to the coils and the PCM itself. So if those fuses havn't blown the short must be from the coil power wires, correct? It would kinda make sense as turning left and throttle will torque the engine and nearby wires. Could the ccrm be at fault? Could the random moving misfires be related? Any advice would be great, the car has 180,000 miles i'd like to see 200k.
 

BigEag205

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IDK if this helps but on the back of the heads theres a little "resonance plug"? IDR what exactly its called but mine came unplugged and ironically when i went to do a power slide to the left my car cut out and the PATS system light came up and blew the pcm plug. I was stumped and had to leave my car parked there for the day after looking at it for hours. Next day I went back and somehow noticed that the wire had came out of the plug and grounded on the firewall...something to at least check out. Mine was on the driver side head but both heads have them on them (if you've had the motor out it would be easier to know what I'm talking about.
 

006

Slow mustang :(
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IDK if this helps but on the back of the heads theres a little "resonance plug"? IDR what exactly its called but mine came unplugged and ironically when i went to do a power slide to the left my car cut out and the PATS system light came up and blew the pcm plug. I was stumped and had to leave my car parked there for the day after looking at it for hours. Next day I went back and somehow noticed that the wire had came out of the plug and grounded on the firewall...something to at least check out. Mine was on the driver side head but both heads have them on them (if you've had the motor out it would be easier to know what I'm talking about.

Those are for radio interference, but you never know. Check it out OP.

To the OP, in regards to my thread similar to yours when my PCM fuse blew out on the freeway:

http://www.svtperformance.com/forums/new-edge-cobras-51/885550-dead-pcm-ecu.html

Few days after this happened, I was getting on the freeway when the car sputtered and the theft light began to flash. As I pulled over to the side of the frwy, the theft light continued to flash, but the car remained running. The PCM fuse did not blow out though. This got me suspecting that a loose connection somewhere got jarred and caused the system to temporarily lose and regain power super fast, but may have remained in the memory for a few min. I think this flux issue is what's causing the PCM fuse to blow.

When I got to my destination, I popped the hood and inspected the underhood wiring. Next to the fuse box is a black slide/flip up lid. Raise it and inspect the big nut attached to the bronze screw and see if it's loose. Mine was loose and might be from when I installed HIDs a few years ago.

So far, I suspect this to have been my problem because it's been fine since I tightened that nut.

Lemme know what you find. :rockon:

Ken
 

BigEag205

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yes, and when it's out it can cause a cricket like noise through the speakers when the clutch isn't engaged. Creates a fun game to play on passengers that don't know what's going on haha. I just not that cause my PCM fuse to blow when it came in contact with the firewall and the PATS system to come on. 006's problem seems probable as well!
 

*9Cobra9*

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I think i remember those radio resonators are also powered through the coil power wire. Ill take a look at that this afternoon. After going over as much of the wiring as possible and re-taping tucking etc. it hasn't stumbled once no matter how hard I accelerate or turn left. Now it just has the random moving misfire. 2 days ago misfire cylinder 5 came up and i cleared it then yesterday misfire cyl 6 came up. I've moved coils around and doesn't seem to make a difference. compression test ok vacuum test ok. injectors ohmed out the same. what am i missing?
 

01yellercobra

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Check the plugs since moving the coils didn't make a difference.

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