changed crank sens. still sputtering/no power

autowriteradam

Registered User
Hey guys, I really need some help on this. My car would spit and sputter on a whim/whenever it felt like it for no apparent reason. It would do it at highway speeds or idling. I try restarting the car on the highway and at stop signs and the problem persists. Sometimes I will just be sitting at a stop sign and the car will just go into this very rough running mode. Its as if the timing is way off or something. So i switched the crank sensor and harmonic dampener. The crank sensor was brand new from ford and the dampener used from a wrecking yard. I used the pulley that was on my engine from the start. It seemed to solve the missing/no power problem for a hundred mile drive and then started doing it sporadically just like before.

I'm really flustered by it and don't know what to do.

One other thing I've noticed. The tachometer reading drops down to almost half of the rpms that the engine is actually spinning at. And when the car sporadically runs normal, the rpms jump back up to normal too?

Should I replace the cam sensor?

Please help.

-Adam
 
It is your DIS module acting up. This happened to me a few months back and would periodicaly start to run bad and would not accelerate and just bog down. I was able to get some cylinder misfires codes from the car while it was acting up which led me to the DIS module. I highly recommend getting the Ford module which was around $330. This will fix your problem.

Nick
 
What codes are you getting? I am having sort of the same problem.
I am getting the code #82 of which the manuel says;
"Supercharger By-pass Solenoid circuit failure"
The only thing is the Supercharger By-pass is vacume operated. What it really is, is the "Idle Air Control Valve" (IAC). Located by the "Thottle Postioning Sensor"
I swapped on off another engine but its still giving me the same code and I replaced the very same unit when I first got the car. It would idle so high, you would have to ride the brake!
The car runs good then it boggs down, starts missing and the tach drops, sometimes it dies.
Anyways I'm going to change my ICM. Exta parts are nice to have!
Will let you know what I find out and any help I can give I will!!!
Cougarxr7
 
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tachometer reading drops down to almost half of the rpms that the engine is actually spinning at.
Classic symptom of cam sensor. The tach recieves its signal from the cam sensor. There was never anything wrong with the crank sensor. When the crank sensor gives trouble the engine flat out dies and the upshift light stays on constantly whenever the key is on.
 
I respectfully dissagree

The cam sensor provides the CID (Cylinder Identification) signal to the DIS/ICM (Integrated Control Module.. aka just the DIS) and secondarily to the EEC. When it goes out, frequently it sends an intermittent CID to the ICM and the result can be: loss of tach, jumpy tach, wavering engine speed (idle), bucking under any load, and hard start or no-start.

Whenever you experience what seems to be a drop in power but the tach still continues, more often the problem is with the DIS itself.

The cam sensor is a relatively cheap part and is subject to failure (I've had 2 of them go out), so replacing it is not a bad idea; its just not necessarily going to fix this problem. In this case, its advisable to pull codes and start shopping for a DIS as the problem is going to get worse.
 
TbirdSCFan said:
The cam sensor provides the CID (Cylinder Identification) signal to the DIS/ICM (Integrated Control Module.. aka just the DIS) and secondarily to the EEC. When it goes out, frequently it sends an intermittent CID to the ICM and the result can be: loss of tach, jumpy tach, wavering engine speed (idle), bucking under any load, and hard start or no-start.

Whenever you experience what seems to be a drop in power but the tach still continues, more often the problem is with the DIS itself.

The cam sensor is a relatively cheap part and is subject to failure (I've had 2 of them go out), so replacing it is not a bad idea; its just not necessarily going to fix this problem. In this case, its advisable to pull codes and start shopping for a DIS as the problem is going to get worse.

Perhaps you are correct, but I'm not convinced. ;) According to the schematic for the involved circuits, the cam sensor sends it's output directly to the EEC which in turn emits a signal which is common between the tach and the DIS. There is another tach signal used by the DIS which comes from the EEC via the shorting plug which I believe is the wire the EEC uses to control ignition timing, although it is a totally different circuit. There is also a connection that goes directly to the DIS from the cam sensor, but that circuit is not common with the tach and instead I believe is used to tell the DIS which cylinder is #1 or some other more obscure function. This is a totally seperate circuit from the ones which involve tach.

I know there is an excellent discussion on the subject in the members section....(somewhere....) :D
 
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XR7 Dave said:
According to the schematic for the involved circuits, the cam sensor sends it's output directly to the EEC which in turn emits a signal which is common between the tach and the DIS.
Yup. That's what I see on my diagram also. Mine indicates that the EEC activates the cam sensor (CID signal) and the ICM activates the crank sensor (PIP signal) and both circuits feed both the DIS and EEC. As we know, in normal mode, the EEC needs both the PIP and CID signals to fire the injectors and send the SPOUT to the EEC.
There is another tach signal used by the DIS which comes from the EEC via the shorting plug which I believe is the wire the EEC uses to control ignition timing, although it is a totally different circuit.
Thats should be the SPOUT signal. Its timing and dwell.
There is also a connection that goes directly to the DIS from the cam sensor, but that circuit is not common with the tach and instead I believe is used to tell the DIS which cylinder is #1 or some other more obscure function. This is a totally seperate circuit from the ones which involves tach.
The DIS still needs CID to determine which coil to select. If CID drops out, it just continues to count the PIP pulses and divides by 3 to keep things in sync. The DIS also can continue in the case of a loss of SPOUT. I guess technically, the DIS could do its thing with just the PIP alone if worse came to worse.
I know there is an excellent discussion on the subject in the members section....(somewhere....) :D
Both excellent and confusing. ;) but its a good thing to keep the topic fresh IMO.

One other observation.. when my DIS was dropping coil circuits, the tach would drop by about 30% relative to actual engine speed.. this leads me to believe that the DIS is what drives the actual dashboard tach. If the EEC were driving it, the engine should stumble but the RPMs should read the same.
 
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I've been having a hard starting problem with my car and after replacing the fuel filter, pump and relay and checking pressure, we think the injectors are leaking down. It is harder to start when cold and sometimes easier when warm. The only other symptom it has is doesn't seem to be able to spin the tires as easily as it once could.

If the injectors are leaking down, would this in turn flood the cylinder, thus making it hard to start? When warm, maybe the leaking has been minimal and thus it's easier to start?

I'm getting some injectors cleaned, flow tested and balanced. If this doesn't solve my problem, could it be the cam sensor? The tach works fine.


David
 
autowriteradam said:
Hey guys, I really need some help on this. My car would spit and sputter on a whim/whenever it felt like it for no apparent reason. It would do it at highway speeds or idling. I try restarting the car on the highway and at stop signs and the problem persists. Sometimes I will just be sitting at a stop sign and the car will just go into this very rough running mode. Its as if the timing is way off or something. So i switched the crank sensor and harmonic dampener. The crank sensor was brand new from ford and the dampener used from a wrecking yard. I used the pulley that was on my engine from the start. It seemed to solve the missing/no power problem for a hundred mile drive and then started doing it sporadically just like before.

I'm really flustered by it and don't know what to do.

One other thing I've noticed. The tachometer reading drops down to almost half of the rpms that the engine is actually spinning at. And when the car sporadically runs normal, the rpms jump back up to normal too?

Should I replace the cam sensor?

Please help.

-Adam

I assume when you changed the crank sensor you verified the integrity of the harmonic damper????? Not wobbling with the engine running I hope.
 
TbirdSCFan said:
Yup. That's what I see on my diagram also. Mine indicates that the EEC activates the cam sensor (CID signal) and the ICM activates the crank sensor (PIP signal) and both circuits feed both the DIS and EEC. As we know, in normal mode, the EEC needs both the PIP and CID signals to fire the injectors and send the SPOUT to the EEC. Thats should be the SPOUT signal. Its timing and dwell. The DIS still needs CID to determine which coil to select. If CID drops out, it just continues to count the PIP pulses and divides by 3 to keep things in sync. The DIS also can continue in the case of a loss of SPOUT. I guess technically, the DIS could do its thing with just the PIP alone if worse came to worse. Both excellent and confusing. ;) but its a good thing to keep the topic fresh IMO.

One other observation.. when my DIS was dropping coil circuits, the tach would drop by about 30% relative to actual engine speed.. this leads me to believe that the DIS is what drives the actual dashboard tach. If the EEC were driving it, the engine should stumble but the RPMs should read the same.

So what you are saying is that a loss of CID will result in no tach whatsoever, and a partial loss in IDM (which is the other half of the circuit via the EEC) can result in partial loss of tach (most likely 1/3 but possibly 2/3). ?? I know that either one results in really crappy running...
 
when my boost selonoid went i dont think i had any boost or very slow boost just as your code described i just bypasssed the seloniod i ran the vacuum hose past itand eliminated it and it ran great the only other time i had no power was damper pully twisted
 
XR7 Dave said:
So what you are saying is that a loss of CID will result in no tach whatsoever, and a partial loss in IDM (which is the other half of the circuit via the EEC) can result in partial loss of tach (most likely 1/3 but possibly 2/3). ?? I know that either one results in really crappy running...
Since you put it that way, yes. Which means a bad cam sensor could cause a drop of IDM hence tach. Since the ICM sends the IDM (acronym soup anyone?) a failure in the ICM can cause it too.

In fact, it turns out that a complete loss of CID is better than a partial loss of CID. Whereas a complete drop of CID can be compensated for, a sporadic (false) CID should wreak havoc on the injector sequence too. This would explain the bucking with even partial throttle which is something I experienced. :(

Moral of the story is pull codes and see if it gives you a lead or just replace the cheap thing first (cam sensor) and then the ICM. But don't assume that the wires aren't a problem either. :rolleyes:
 
finger pointing at the DIS

Thanks for all of the help.

I'm still having the problem. So far i have replaced:
• crank sensor
• harmonic dampener
• cam sensor

After replacing the cam sensor today it is still running rough. I decided to see if all of the cylinders were firing by carefully pulling each of the six plug wires off of the coil seperately to look/listen for spark and how it changed the engine.

looking down at the engine at the coil pack there are the plugs in a 2x3 formation, ok. as seen below.
• • •
• • •
the middle one in each row (the two middle ones across from each other) are not firing at all.

Me thinking it might be the wires, ruled that out by unplugging one that was firing and held the wire over it/put it down it, and got no spark (the engine remained firing on 3 cylinders) I tested it vice-versa by putting what could be the bad plug over the coil pack that was known to be working, and it sparked and ran through it. I know this was not good for the engine so it was only done momentarily to verify the integrity of my plug wires. The wires are good.

Now, sigh... Should I go with replacing the DIS or the Coil Pack?

I'm guessing from all of the recent posts, that i am going to have to go after the DIS.

Any more input is appreciated, thanks.

-Adam
 
when buying from autozone

The DIS... is it...
it is the "control module" part "F136" by WELLS?

right or wrong...
???????????????
an autozone about 20 miles away has one for $80 and they close at 9.

If i could get it tonight i would be ecstatic.

does anyone know?
 
Fixed! :)

FIXED!

First place goes to 935spd
935spd It is your DIS module acting up. This happened to me a few months back and would periodicaly start to run bad and would not accelerate and just bog down. I was able to get some cylinder misfires codes from the car while it was acting up which led me to the DIS module. I highly recommend getting the Ford module which was around $330. This will fix your problem.

However, I did cheap out and get the Autozone Wells Brand for $80. It works... for now.

I had them test my original motorcraft DIS while I was there and it was consistantly failing several of the tests. I think it was failing the "threshold," "PID" and "dwell" tests on their machine.

I came home and put it in its running smooth now. :)

BIG THANKS!

-Adam
 
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