New owner (94 ATX) - Fixed the smoke, now smog failure!

[apanthropy]

Now I'm working on other stuff, see end of thread:


Original post:
Hello

I just picked up a 94 SHO 3.2 in unmolested condition, and it's running rough/very little power. If you don't want to read all the verbose details, my questions are in bold and you can skip the rest.

Occasionally, it will decide to run smoothly and produce tons of power & the CEL will turn off, but not often. I have driven less than 100 miles, almost exclusively as diagnostic/parts run driving - I don't intend to really drive it anywhere until all the newly-acquired-car maintenance has been done and it's running well.

I've been searching and reading here/elsewhere for as much info as I can, and am just confused enough to trouble you guys with a first post & questions:

• Is there a step-by-step for checking the coil pack? I know it's just three transformers, the HV coils are open for the waste spark system and the LV coils appear to have a common ground.. so what impedance am I looking for across each coil?
  [*]what, specifically, takes place inside the DIS module? Is it a computational device (takes input from CPS/other sensors and decides when the spark occurs) or is it an amplifier (takes pulses from engine computer, increases their voltage and current to send to the coil) ? Or something else? This is mostly a curiosity thing, but also may help me in diagnosis.
• Is there a guide for testing the DIS module? [/B]

I have significantly cleaned the engine compartment (upper and lower) and disconnected/greased/reconnected every electrical connector I could find (at least 20, I was at it most of yesterday afternoon), I have removed the DIS and applied Arctic Silver heatsink paste as outlined in a Ford diagram found somewhere on this site, I have added a 4ga ground to the support post of the intake crossover thinger which connects to the batt. negative terminal and a second 4ga ground from there to the strut tower (where other tiny ground cables already connect)

This is an Arizona car so there is no rust, period, and no indication that any wiring is distressed in any way, nor any 'redneck' wiring/work having been done.

KOEO codes are: 111 118 217 181 189 332 and some flashing I was unable to interpret that occurred between the 217 and the 181, I tried several times to count it and it kept looking like gibberish flashing - also the codes don't seem to ever repeat unless I start over from the beginning - aren't they supposed to repeat at some point?

Thanks!

 

[rubydist]

I don't think you are reading them right.

first it will display the koeo (current) codes. 111 would mean all pass, which is what we hope for.

then it will flash a single separater blink.

then it will display the stored codes.

then it will repeat all of the above.

coil pack testing pretty much amounts to measuring resistance in each of the 3 sections.

the DIS is pretty much just an amplifier - the pcm commands spark timing.

with 217 codes, I have had the experience of 50/50 actually being the coil pack or the DIS that was bad.

 

[apanthropy]

I don't think you are reading them right.

first it will display the koeo (current) codes. 111 would mean all pass, which is what we hope for.

then it will flash a single separater blink.

then it will display the stored codes.

then it will repeat all of the above.

You might be right, I have tried several times to read them and it's getting the best of me. Maybe I'll make a video of the flashing and upload to Youtube.. after I get a couple other maintenance issues out of the way.

coil pack testing pretty much amounts to measuring resistance in each of the 3 sections.
.

I'm getting ~13.81 to 13.85 ohms across the three HV coils, not sure what I should be looking for on the LV coils.

Is there a preferred repair manual to buy?

Thanks for the response so far! :thankyou:

 

[b1lk1]

Take a look at that EGR valve too, just caused all kinds of driveability issues in my car until I freed it up.

 

[Shovert]

Flash codes get me also. I had to buy the reader. I always got lost between counting and trying to write them down. Easiest way I found before it, was wife counted them and I wrote them down and later organize them. Maurice

 

[3d914]

Been dealing with DIS & coil pack myself. Here's a link I found with simplified instructions for testing the Ford DIS system coil pack.

You can find additional info on the last page of my project posting.

I down loaded a PDF engine manual, but it's about 40MB. I could try emailing it to you.

Good luck and let us know how it goes.

 

[apanthropy]

Thanks!

I am pretty sure the coil pack is still good, it all seems to test out well. I pulled the cam position sensor off and saw a tiny bit of oil behind it, but not much - replaced it anyway with a new one (but both measure same resistances across any given pair of pins, old and new) - and have a pair of new (used) DIS modules coming in the mail. I am going to inspect the crankshaft position sensor tonight if I have time.. busy week and I am .. uh.. having "fun" learning about these motors. :laugh_ti:


I haven't pulled any of the rear plugs to look at 'em, but I pulled the front 3 - left and center plugs look beautiful & piston tops look clean... right plug shows definite fouling and the top of the piston is crusty No idea how long previous owner has been driving it like this. I hope the cats/O2 aren't all burned up!

I know there's some work to be done beyond this, but I want to get all six consistently firing first, then start putting out the other fires. Then start driving!

Thanks again everybody. Can't wait to start being a contributor (once I've learned things that I can contribute...)

 

[apanthropy]

Is this thing a good idea since I suck at reading flashy lights?

http://www.amazon.com/gp/product/B000EW0KHW/ref=oh_details_o00_s00_i01?ie=UTF8&psc=1

Or, is there a better one (without being significantly costlier) ?

 

[SHOdded]

Works well for me. I got the extension cable too since I felt lazy

 

[apanthropy]

Update:

I bought (via email-paypal-express mail) a pair of used DIS modules from a new Turbo Thunderbird friend I found selling some on a Turbo Coupe forum (yay google!) and stuffed one in, pulled all six plugs and gave them a cursory cleaning, then reinstalled them and fired it up... SO SMOOTH!

So, that problem is solved... check engine light is still on and off, but the tach now reads correctly and it runs much better! I'm sure it's still not right, I haven't touched the o2 sensors or any of that jazz and I haven't got around to reading codes yet - or even resetting the ECU from whatever current stored codes are in there.

After it warmed up, I noticed a LOT of smoke under the hood. Looks like the cats are getting a lot hotter now than they have in a while and the crud has started burning off them - did I mention the engine has a few oil leaks? Also, I'm getting the idea that the previous owner had been driving around on 4 cylinders for quite some time

The cats were NOT glowing, but smoking a lot, so I shut off the engine and misted them with a water spray bottle to avoid potential for an actual fire - don't need that.

After everything had cooled, I took off the pass. tire and whipped out my tired, leaky miserable old pressure washer and called upon its services "one last time, again"..

Even with a mighty dose of Scrubbing Bubbles Bathroom (and engine!) cleaner, the cats are still well coated but a whole... WHOLE lot less crud all around them. I hadn't cleaned the engine from this angle when I cleaned it before, so there was a lot more crust and junk down there. After I finished, I started it up and held the throttle open with a penny to warm the engine back up, still a bit of smoke but far less. The sun's down so I can't check for where my specific leaks are, but I'm guessing it's time for me to do the mythical "60k" I've been reading about on here and will get the front crank seal and hopefully as many other leaks taken care of as possible at that time.

So, that's the update.

Thanks for the help guys, we'll see if I can keep this old bull on the road for a while. I hope to get it on the highway this weekend and give it some burn time, after I've had the opportunity to recheck codes and assess its updated operating status.

 

[SHOdded]

For the amount of work you are doing, you should be taking pics of your journey You may find the need to replace your O2 sensors if the misfires have been happening for a while. And don't wash the engine from up above, getting water in the plug wells is not good (though various means exist to take care of that problem as well).

Looking forward to see what codes you get.

 

[rubydist]

good news.

now reset the codes, drive a couple days and then tell us what the current codes are.

 

[apanthropy]

For the amount of work you are doing, you should be taking pics of your journey You may find the need to replace your O2 sensors if the misfires have been happening for a while. And don't wash the engine from up above, getting water in the plug wells is not good (though various means exist to take care of that problem as well).

Looking forward to see what codes you get.

Thanks for the tips - I'm already budgeting for new o2 sensors but harboring a hope that they somehow have been preserved and just need a half hour of highway driving (with all 6 sparks firing) to burn clean...

They aren't much but here are a couple photos I took last night to show my mother what I had bought. Feel free to poke fun at my messy garage

 

[Shovert]

Looks good. Don't look in mine, 2 cars, motorcycle, engine on stand, workbench, tools and parts. 20x24 garage. Wonder why my project is outside.Maurice

 

[rubydist]

yeah, that is a clean garage by most of our standards...

 

[apanthropy]

Time for an update: I had a busy weekend and didn't work on the car until last night.

I cleared the codes with my recently acquired code reader, then went for a drive, CEL illuminated within 2 miles. Would sometimes shut off, then come back on. Returned home and checked KOEO codes - 189 and 332.

I removed the spark plugs that had previously been fouled and found them a much healthier dusty tan color.. woo!

To address the 332, I removed the DPFE sensor and the vacuum hoses between the EGR valve and its actuator. The one to the EGR diaphragm was cracked, so I replaced it with a new length of hard emissions tubing. The rubber end booties still feel in excellent condition, not too soft or brittle or any of that.

The DPFE sensor is crusty on both inlets. Not fully obstructed, but crusty - after googling, it looks like these sensors tend to fail a lot. I sprayed electronic parts cleaner into each hole for lack of a good reason not to, and sprayed some B12 Chemtool down the hoses into the EGR tube. The smaller diameter tube backed up quickly... is that the one on the intake side of the EGR orifice? - it DID drain pretty rapidly as well, just that it would fill rapidly when I applied spray to it.

I put a small length of hose on the nozzle of the EGR valve's vacuum actuator and sucked with my mouth, then kinked the tube to hold vacuum. The EGR had opened significantly and easily. I sprayed some more B12 Chemtool in there, which didn't seem to affect the crust in any way whatsoever, nor was the pour-out liquid resulting from it very dirty looking I also cleaned the screeny gasket thing. I did not know how to remove the whole EGR tube - anyone got any tips for how to remove the whole egr tube?

I found instructions online for testing operation of the DPFE sensor using a voltmeter and will begin that tonight. I could just shotgun parts at the car, but I'm not a wealthy man (if I was, I'd probably buy a newer car ) - so I'd rather be sure before throwing parts at the car.

The other code, 189, could be present because I dumped a couple gallons of E85 into the tank along with gasoline, to accelerate the cleaning of the two formerly dead cylinders. I am going to top off with gasoline to dilute that out.

So... that's the status. Improvement is good! I can't wait to get this car emissions tested, it needs a road trip!

 

[rubydist]

the egr tube threads into the exhaust manifold, so that is how to get that off.

typically, it is not the egr valve that is at issue, it is the sensor tube. there is an orifice in the tube to the intake, and the two little hoses connect above and below it. the dpfe sensor looks at the difference in pressure across the orifice to "know" if the egr is working right. usually, the egr is working just fine, but the dpfe sensor cannot tell because the little lines are filled with crud.

 

[apanthropy]

the egr tube threads into the exhaust manifold, so that is how to get that off.

typically, it is not the egr valve that is at issue, it is the sensor tube. there is an orifice in the tube to the intake, and the two little hoses connect above and below it. the dpfe sensor looks at the difference in pressure across the orifice to "know" if the egr is working right. usually, the egr is working just fine, but the dpfe sensor cannot tell because the little lines are filled with crud.

Thanks again! :thankyou:

I had time today to dig into this again, the EGR tube on my vehicle connects to the exhaust with a two-bolt ****** (two 12mm bolts) and a gasket. I had to consult with my inner sailor to invent a few new curse words while trying to figure out how to access them (buncha extensions through the tire well? nope. Up from the bottom? maybe if my hands were smaller.....) - finally I got to them by kneeling on the battery and holding myself up with my right hand on the driver-side strut tower and my left hand reaching behind the engine and feeling around for the bolts. Fun with warm engine on a sunny Phoenix day

So - EGR tube came off, and I filled it with oven cleaner, waited a while, then dumped black gloop out of it into my waste bucket. Then again. And again. When the oven cleaner stopped producing black goo, I shot the garden hose through the EGR tube and verified that there was significant flow through the opposite end AND the nearest-to-hose DPFE tube. Either direction, there was a lot of flow from the opposite end and from the DPFE tube nearest the water source (since there's an orifice between those tubes) and if I blocked off the open end of the EGR tube, water would shoot out of both DPFE tubes equally. that seems pretty much like the behavior I'd expect from a clean tube, and it looks shiny and clean inside too.

After reinstalling the EGR tube I also put a new DPFE sensor from autozone on - though now I think that might have been a bad move since it has a metal chassis and seems like the old style, not the newer type plastic one with both hoses on the same side of the unit.

In any case, I still have the 332 code. If I reset, it takes just a mile or two for it to come back.

So, I removed the throttle body from the intake manifold. After unbolting the TPS I gave the throttle body a good bath in oven cleaner too. I did the best job I could with carb cleaner into the open end of the intake manifold and the two vacuum ports on the (vehicle) front of it.

Reassembled, still have 332 code.

If I manually apply vacuum to the EGR diaphragm while at idle, the vehicle stumbles a bit... doesn't try to die or anything, but it clearly stumbles. Should it almost die?

All of the wiring on this car appears in excellent condition for its age and I've seen no indications of a likely fault in the wiring.. but this 332 is running out of excuses.

The EGR enters the (vehicle) rear half of the upper intake manifold and appears to follow a cast-in channel under the main intake are passage, but I'm not sure where it goes from there or what the best way is to clean it. Should I remove the entire intake manifold? Is there a link to a how-to for that? Is there a diagram somewhere showing where the EGR passages go in the manifold (so I can be sure I'm cleaning them correctly)

And.. short of buying the very cool but out of my price range TWEECER thing, is there a way to spoof the DPFE to shut its darn mouth for a bit so I can try to pass the emissions test? I really need to get this car operable soon - Arizona's DMV office won't let me title it independent of registering it, and I can't register it independent of emissions test, and I can't insure it independent of titling it... so that means I have no legal way of owning the vehicle, nor no responsible way of driving it until it's able to pass an emissions test - illuminated CEL is an automatic fail.

 

[SHOdded]

Search on "nostril" and you will see a pageful of helpful threads. Make sure they are CLEAN. A good one is here:

http://www.shoforum.com/showthread.php?t=7907

Maybe pulling the SPOUT connector will help you pass your emissions test? Do you have any readouts handy?

So how the heck do you drive it to a testing center, if all those 3 are tied together in a merry-go-round? Flatbed it? Crazy they won't let you title & register independent of emissions. In Maryland, you get that, and a notice to test emissions shortly thereafter. Does AZ have a "classic vehicle" law under which your car might be exempt?

If code is still there, might want to replace under warranty, or get another DPFE (plastic) sensor from elsewhere like RCM Automotive or RockAuto, SHOsource seems to have original design.

http://www.rockauto.com/catalog/x,carcode,1138968,parttype,5088
http://www.rcmautomotive.com/id15.html
http://www.shosource.com/catalog/product_info.php?products_id=387

 

[rubydist]

is the check engine light being on an automatic fail of emissions testing in AZ?

what if you remove the light bulb? there is no computer connection to the tester on the obd1 cars, so the emissions test lab would not know that the ce light is trying to illuminate...