spout in--ping. spout out--no ping.

Here's the starting circuit for a '94 Bronco from the EVTM. The Anti-theft module is in the circuit for starting the motor (in the solenoid circuit). The pencil notes are corrections I found regarding the pins on the Anti-Theft module:

http://www.supermotors.net/getfile/874093/fullsize/94-bronco-evtm--pg.-201.jpg





http://www.supermotors.net/getfile/874092/fullsize/94-bronco-evtm--pg.-202.jpg

Miesk5, BroncoJoe, Mikey350, and all you other seasoned rocket-scientists, I really appreciate your help and diligence in diagnosing this matter. I think we're getting to the end of the road for this problem, and I hope you'll help me out in my next ventures on this remarkable machine. Today, I went to O'reilly to get the new EVR solenoid, and installed it in the parking lot of the store (in the rain). After getting it installed, I got back out on the street and the pinging was just as much there as it's ever been. ENRAGED, at the fact that i had bought, yet another part that didn't solve the problem, I got back out on the highway and had it running like a scalded dog. It was pinging and bucking like a.... well, i guess like a bucking bronc. From the store to my house is about thirty miles, and I had my foot in it pretty much the whole way. I goosed it every now and then and noticed the ping was starting to "dissipate". I was trying not to give myself false hope, however I was running theories through my head as to what could be happening. By the time I got back to my house, it was still pinging like it always did. I did some checks on it; watching the EGR diaphragm, checking/tweaking my plug wire arrangement to ensure that i didn't have crossfire (i was really out of ideas). I took it back out on the highway a couple more times, then played around with some more stuff; performed some "percussive maintenance" on the EGR valve, checked some vacuum lines for leaks with some B12 Chemtool. Then I took it back out on the highway again, and noticed the ping was gone AGAIN!... I knew it was only a matter of time then. I made a U-turn in the highway and headed back towards my house... and it hasn't pinged since. That was about 10-15 miles ago. The only logic I can muster up is; the EGR valve has been not moving for who knows how long, and now that the EVR solenoid is directing it to move, it's getting some exercise. Not knowing EXACTLY how the egr functions; does that make any sense? I haven't attempted another KOER test, as of yet. However, after I drive to work and back tomorrow, I'm going to see if somehow the spout code has disappeared.

on a side note, ever since I've been playing around with the EGR system my MIL has came on a few minutes after I get on the road. However, it clears every time i turn off the key, then turn it back on. Does that make sense? Once again guys, I appreciate your expertise.


Matt :beer

yo Congrats!

I really am perplexed as to da absence of any EGR related Codes in the beginning of this hunt.

Guess what I saw this morning?
It was in ref to EGR Eliminator, MIL, DTC 332 & EVP/DTFE confusion! by sydude...

This is just a clue...
"The EEC-IV logic will not allow the operation of the EGR system once the EVP 33 and 34 are registered. There by, no timing advance is added by the system, since the EGR function is bypassed"

Warm Cruise
We have come to a point where we are happy with our speed and want to just cruise into the sunset. What sounds easy turns out to be one of the most in-depth strategies we use. It is assumed that we citizens spend most of our time at cruise (yeah right), so we need the lowest emissions, highest economy, and moderate power at this time. The only good thing of warm cruise is that engine conditions are stable and need the least amount of safety nets. We still have the throttle air bypass at 100% in preparation for future braking. Fuel is stabilized with the switching of the HEGO; it cycles about 10-20 times a second. To do this the fuel ratio is leaned and enriched slightly each time the HEGO switches from lean to rich. Its like a high wire act, balancing fuel for maximum economy. EGR is operational allowing more timing with less fear of detonation. EGR also lowers the amount of oxygen in the mixture by about 15%; this means we dont need as much fuel. The canister purge valve is opened to ingest fuel vapors, this allows us to cut back on fuel metering slightly more and prevents fuel vapors from escaping to the atmosphere. Timing can be advanced to increase engine temperature and counteract EGR influence upon igniting combustion gasses. Timing is used to control engine temps, hotter engines burn fuel more completely..." http://fordfuelinjection.com/?p=3

so that got me to;
"Further research shows that this is a very common problem as the sensors get old. If anyone is still running EGR and are having odd timing/bucking issues at low loads then look into this. In my case my timing would shoot up to over 40 degrees as soon as I came off idle and until my load got higher, and there was no timing table combo that would add up to that. The EMI was introducing this issue. http://www.eectuning.org/forums/viewtopic.php?f=2&t=15355&st=0&sk=t&sd=a&start=60


The EGR is used to reduce NOX emissions by recirulating exhaust gases into the intake and mixing them with the intake charge. The EGR only works when the engine is warm and at part throttle. It does not function at WOT. If you remove it you will get no performance benefit at all. You will increase your chances of getting part throttle ping. What happens is the EEC expects a certain percentage of the mixture to be inert gases, so it adds more timing to compensate. If the inert gas is not there, or worse yet, you have allowed it to let oxygen into the intake system, there is simply too much timing added by the EEC. Some people don't have a problem with ping. Others do. You will also get a CE light, but it will not go into 'limp' mode. Hope this helps.
Don http://fullsizebronco.com/forum/showthread.php?t=193312&page=8

I'll get into it further when I have more time.
Sleep is not an option right now...lol

yo,

Use MIKEY's Diagram to check for "SERVICE open or short to ground in VPWR circuit between PCM and EEC power relay."

*update*

for some reason, this wasn't found in the TSB that miesk5 posted--nor the "pull test" i did on the wires. However the stars aligned, and as i was reading my timing i watched the computer advance the timing--then watched it drop back to "base" timing (10*). My father in law was helping me and I yelled "QUICK, start touching stuff (meaning for him to start moving stuff around). He bounced the EEC around a bit, and I saw it happen again. So, I went over to the EEC and started pushing and pulling and working wires around in circles to to try to find the intermittent connection again. Amazingly, i found the SIG RTN wire was dropping its connection every once in a while, causing stuff to go nuts. So, I pulled the harness off and went to the corresponding pin (46), and crimped it together a bit tighter than it was. After that, I put it back together and tried my damnedest to get it to happen again and it never did. Also, I've had the absence of a particular code 213--ever since. There's a faint ping SOMETIMES, still. Also, I'm pretty sure that my engine stumble is being caused by cylinders 3 & 4 misfiring intermittently. To find my misfiring cylinder(s), I took my timing light and put it on my passenger side bank starting at number 1. I watched the light blink and off to a steady pattern on cylinder 1 and 2. Then when i got to 3 i saw it stay off every so often. So, i pulled the plug wire off (pulled the end off of it as well), then pulled the plug and noticed it to be very black. I'm not that good at reading plugs but i think that means unburned fuel (?). Absently-mindedly, I decided to pull plug #4 as well to compare it to (keep in mind i didn't use the timing light on this cylinder. :duh ). #4 looked to be "normal" it was a light whitish (i jacked up the plug wire on that one as well). SO, i swapped the plugs between 3 & 4, "repaired" the plug wires temporarily til i can get some new ones (and a plug wire puller), and put it all back together. Now, 3 & 4 are both misfiring. Silly part is, idk if #4 was misfiring to begin with, due to the fact that I didn't check it in the beginning. I pretty much effed myself on that experiment. Regardless, the code is gone. The ping is less prominent. Progress was made. :rockon

After I get some replies on this post (since i don't wanna take up a whole page), I'll put up some more questions I have about misfire and adjacent cylinders.