Surging/Bucking and Engine Dying.

A few of you know, I've had problems with this before. I've replace DIS, Cam Sensor, Cam Sensor harness, checked over 90% of the harness for shorts, etc etc etc.
Then one day, it goes away completely. However tonight, go to start the car, and it falls on its face. I was finally able to get a video of it right after starting it. First video is one of the engine from before. (same symptons once again.)

I thought before, it seemed to do it when it was hot. Ruled that out. Then it seemed like it did it when it was wet outside. Holds partially true, as it did it when I cleaned the engine bay. I'm lost. So if anyone is able to help me, I'd GREATLY appreciate it.
<div align="center">
<object type="application/x-shockwave-flash" data="http://feat.putfile.com/flow/putfile.swf?videoFile=Engine-problems" height="349" width="420" align="middle">
<param name="movie" value="http://feat.putfile.com/flow/putfile.swf?videoFile=Engine-problems" />
<param name="quality" value="high" />
<param name="allowFullScreen" value="true" />
<param name="allowScriptAccess" value="always" />
<embed src="http://feat.putfile.com/flow/putfile.swf?videoFile=Engine-problems" allowFullScreen="true" allowScriptAccess="always" height="349" width="420"></embed>
</object><br><a href="http://media.putfile.com/Engine-problems?utm_source=embed1&utm_medium=embed">Engine-problems</a> - <a href="http://media.putfile.com/code.php?n=Engine-problems?utm_source=embed1&utm_medium=embed">Get Video Code</a></div>

<div align="center">
<object type="application/x-shockwave-flash" data="http://feat.putfile.com/flow/putfile.swf?videoFile=Surging" height="349" width="420" align="middle">
<param name="movie" value="http://feat.putfile.com/flow/putfile.swf?videoFile=Surging" />
<param name="quality" value="high" />
<param name="allowFullScreen" value="true" />
<param name="allowScriptAccess" value="always" />
<embed src="http://feat.putfile.com/flow/putfile.swf?videoFile=Surging" allowFullScreen="true" allowScriptAccess="always" height="349" width="420"></embed>
</object><br><a href="http://media.putfile.com/Surging?utm_source=embed1&utm_medium=embed">Surging</a> - <a href="http://media.putfile.com/code.php?n=Surging?utm_source=embed1&utm_medium=embed">Get Video Code</a></div>
Where it smooths out at around 13 seconds. I was barely giving the car gas and holding it steady. After that, I slowly started pushing it in just a bit farther.

i'd check the balancer/crank pos. sensor... sounds like it's intermittently loosing spark and/or spark signal. just my .02

Also maybe clean the MAF and IAC just for good measure.

I appreciate the reply. I've checked the Crank sensor harness, that is fine. As far as crank sensor itself, haven't changed it. From what I can see underneath the car, the balancer looks fine. No wobble in the pulleys at all either.

The MAF has been cleaned as of lost week, as well as new fuel filter finally, etc.
I have a new MAF I may throw on there, but it was tuned with the early style MAF, and the extra I have is from a 94-95. From what I've heard, that'll throw the A/F ratio off.

Last time I had the upper portion of the intake apart, the IAC looked fine, but cleaning it couldn't hurt.

I just don't get how it can be so intermittent. Sometimes it'll follow a pattern, and then boom, it changes.

ok then, lol. How bout plug wires? Still seems like an ignition problem, just from how it's acting. Maybe spray your wires w/ a fine mist of water from a spray bottle while its running, if you have spark "leaking" from the wires, it'll show up like that, helps if it's right around dusk outside too.(low light will make it easier to see the arcing) only other thing i can think of is a broken plug ceramic or a finicky ECM...

Plug wires are brand new. Taylor wires with ~1,000 miles on them.

As far as the ECM...I've went as far as to disconnect all the connections...clean the contacts, put some dielectric grease on there, and make sure they are connected nice and tight. Even cleaned the contacts to the chip. I'm really hoping it's not the ECM.

From what I've gathered, and according to the EVTM's I'm looking at, the IRCM supplies power to the ECM?
I just had problems with the IRCM fuse burning itself up. (literally...burning.)
Previous owner also had problems with it, so he wired the fans to run constantly.

And I agree 100%. Spark related somehow. While driving, the surging reminds me of a stupid push mower when it's flooded.

you are correct about the CCRM. here's a wiring diagram, if it'd help any

Haha, exact one I was looking at. The Ford CD, and Alldata come in handy sometimes.

In your opinion, what do you think the correct course of action should be? I personally don't think the IRCM could cause it to be that intermittent..but then again..it's an SC so who knows.

I honestly dont know man. I cant really think of much else. Do you get any codes? prolly not, that'd make it easier, lol. bout the only other thing i can think of at the moment is a problem w/ the connection b/w the plug wires and plugs or coils. It just acts so much like its arcing somewhere... maybe check to make sure none of the wires have fallen against the manifold... Keep in mind, i dont even have an SC, but i've been a mechanic for about 7 years, and all cars are essentially the same, right? If your car were in my shop id be looking for spark leak somewhere...

Coil pack is good. No arcing from any of the wires. I have a spare coil pack I may slap on there anyways.

I'm gonna try to locate an IRCM, and then if I must, ECM.

Im not really shure but I think SC's play a big part on FUEL

Make shure you GAS TANK is FULL!!

190LPH fuel pump, new fuel filter, new lines. No worries there.
It has done it leaving the gas station after filling up before.

i had a similar problem

one mechanic told me to clean the injectors, they were clogged straving my car of the right amount of fuel... i ran some redline injector cleaner it helped but not by much.

i changed to plugs and wires, and problem went away. sold the car to my brother, and he is now having the same problem, but the plugs are fine. i hope you figure it out so i might be able to help him figure it out.

i thought vaccum leak when i heard stalling, and surging, you might want to check your vaccum on your boost guage.

Merlon said:

one mechanic told me to clean the injectors, they were clogged straving my car of the right amount of fuel... i ran some redline injector cleaner it helped but not by much.

i changed to plugs and wires, and problem went away. sold the car to my brother, and he is now having the same problem, but the plugs are fine. i hope you figure it out so i might be able to help him figure it out.

i thought vaccum leak when i heard stalling, and surging, you might want to check your vaccum on your boost guage.

Click to expand...

Injectors are fine. Cleaned them, and problem still there. It's also too intermittent to be injectors doing it I'd think.
Vac is at 18-20 and always has been, except once when I forgot to tighten something..it was like 13?
Vac stays strong except when the engine starts to stumble...you can see it moving slightly in the second video.

If your brother finds out what it is, care to post in here for me?

Crawled underneath the car tonight...in the rain.
I noticed I have a small antifreeze leak that runs down the front of the engine right by the crankpulley/balancer and sensor.
I'm beginning to wonder if the crank sensor can't cause this, but I'm going to investigate further.

I'm debating on just ordering an IRCM, Crank Sensor, BHJ Balancer, some underdrives, and all that fun stuff next pay check. Maybe even get a used wiring harness and re-do it.

Anyways, anyone else think the crank sensor could cause it?

My vote is for an intake gasket leak......

Take a length of vacuum hose.....

Put one end in your ear and probe around the TB area and down both sides of the intake/head connections.....

Pay close attention to the rear seal area.....

Swap your Fog Light relay and your EEC relay.

ED

’94 SC Red Auto: 110,000 Miles, Headers, No Cats, Pro Torque 2500 Stall Converter, TRANSGO Shift Kit, 10,000 Lbs Auxiliary Tranny Cooler, Tranny Fluid Temp Gauge, 3.73 Gears, 70mm BK Throttle Body, 76mm C&L MAF with Gold Tube, A/F Ratio Gauge, Raised SC Top, Teflon IC Seals, ’90 XR7 SC Pulley, ARP Head-Rod-Main Studs, Scorpion 1.73 Rockers, Solid Motor Mounts, Iridium Plugs, Live Wire Plug Wires, Screamin’ Demon Coil, 36# Accel FIs, Custom Air intake, K&N 9” Cone, Royal Purple Synthetic Lubricants and Optima Yellow Top.

Really? Swap the Relays?
Although I never thought of that, for some reason that seems genius in so many ways. Now, now I have a few things to do when it isn't 10*.

In the first video it sounded like the alternator was working hard (wining) low voltages will cause misses like that then the alt brings up the voltage and things smooth out. Have you checked your voltages during the problem? I also had an issue like yours that turned out to be a loose engine to body ground. The car would run fine most of the time but would go through "Fits" where it would miss and sputter. I added an additional ground wire from the negative bat cable to an intake manifold bolt which solved that problem. one third thing make sure your DIS connectors are tight and corrosion free I was having an issue where the car would run fine but when I nailed it from a stop it would begin to go spinning the tires about 2 feet then fall flat on its face (Boy was that embarrassing) I found it by wiggling wires around while the car was running when I hit the DIS connector the car died. Unplugging and re-plugging the DIS connectors a few times fixed that problem

Hey, did you ever get this resolved? I've been chasing the same/similar problem for months now - started when I replaced the alt., then the car kept throwing coil errors. Replaced ign. coil, DIS, cam sensor, fuel filter, and it's got new Autolite plugs and Motorcraft wires - no more CEL and runs fine at low throttle, but bucks/stumbles at WOT or under boost (this happens at any time, temp, or gear, but seems to happen more when in 3rd or above). I've read a whole bunch of threads on this, and yours seems to be the most recent. Any luck?

KTris said:

Hey, did you ever get this resolved? I've been chasing the same/similar problem for months now - started when I replaced the alt., then the car kept throwing coil errors. Replaced ign. coil, DIS, cam sensor, fuel filter, and it's got new Autolite plugs and Motorcraft wires - no more CEL and runs fine at low throttle, but bucks/stumbles at WOT or under boost (this happens at any time, temp, or gear, but seems to happen more when in 3rd or above). I've read a whole bunch of threads on this, and yours seems to be the most recent. Any luck?

Click to expand...

Nah. It's still doing it. Granted, ours are a bit different. My only does it between 1,000 - 2,200RPM's. Right now I am rebuilding a complete engine harness to rule out any wiring problems.