94 4.3 died need help!!!

Project"Bag&Drag" · 06-27-2008, 07:42 PM

well my 4.3 just died on me today. and i havent had time to check spark on it, but i think it might be my spiders, b/c it died right when i parked it and aired out then i went to go start it and nothing.

Just cranks and cranks. but i didnt smell fuel and i physically felt under the injectors and they were dry.

I noticed that i poped the 25amp power/ acc. fuse, does this control the PCM at all??
cause i aired it up and it seems that i rubbed though some wires on my passenger side harness. i taped them all up and then tried to start it and nothing.

I also tryed putting some gas in the throttle to get it to pop at least, and nothing. I am going to test the spark on it tommarrow

Anyone have any ideas??

TCossuto · 06-27-2008, 07:57 PM

test the spark and fix the wires.

Yogi · 06-28-2008, 11:44 AM

Quote: Originally Posted by TCossuto

test the spark and fix the wires.

X2

Project"Bag&Drag" · 06-28-2008, 04:56 PM

ok well i checked the spark today, and thires none, and checked the module on the dizzy and it was good, the cap,rotor, and the coil was replaced today.

But what gets me is that i tested to see if theirs power to the coil,and their is, i got power from all of them. all 4, the two red and white wires to the coil and then the red and white ones from the coil to the dizzy, i also noticed when i crank on it the injectors dont spray, and then when i plugged the dizz module back in they sprayed fine, only when i plugged the connection back.

Im soo puzzled right now

Bill Wheats · 06-28-2008, 09:41 PM

The PCM get a signal from the coils, then gives a pulsing neg voltage to the injectors to turn on.

Project"Bag&Drag" · 06-29-2008, 11:32 PM

So my pcm is shot?

Bill Wheats · 06-30-2008, 12:03 AM

Why would you think that the PCM is shot?
If I read what you meant correctly, then when you disconnected the wires going to your dizzy: the injectors didn't fire - they shouldn't.
With the dizzy wires connected then the PCM sees the signal and fires your injectors.
What more could you want?

What circuit blew the fuse?
Did you test and get spark when the dizzy was connected?

Project"Bag&Drag" · 06-30-2008, 11:44 AM

I dont know what circut blew the fuse, it was the #7 fuse a 25amp and on the pannel it says its a power aux/ fuse?? and i didnt get spark anywhere from the coil to the dizzy at all, but i have power to the coil

Bill Wheats · 06-30-2008, 11:47 AM

Did you try to get spark from the coil wire going to the dizzy cap yet?

Project"Bag&Drag" · 06-30-2008, 11:51 AM

no their is no spark any where in the system

Project"Bag&Drag" · 06-30-2008, 11:52 AM

Quote: Originally Posted by Bill Wheats

Did you try to get spark from the coil wire going to the dizzy cap yet?

yes, their is no spark

Bill Wheats · 06-30-2008, 11:54 AM

Double post

Project"Bag&Drag" · 06-30-2008, 12:00 PM

so any ideas bill?

Bill Wheats · 06-30-2008, 12:14 PM

? If you have a MAF sensor disconnect it and try again.
Pull the module and make sure that it isn't shorting out. Have it tested.
Sorry but I'm on the road...

Project"Bag&Drag" · 06-30-2008, 02:15 PM

the module under the dizzy, if thats the case i already had it tested it passed

Bill Wheats · 06-30-2008, 02:39 PM

Some of the modules need to go through the tester 5 or 6 times before they show bad.

Yogi · 06-30-2008, 02:47 PM

I would try taking the ICM to another store to be retested - just to be sure.

Project"Bag&Drag" · 06-30-2008, 05:19 PM

Ok will do, or should I just get a new one

Yogi · 06-30-2008, 07:06 PM

Quote: Originally Posted by Project"Bag&Drag"

Ok will do, or should I just get a new one

No, don't do that. Just get a second opinion and go from there.

Did you replace the blown fuse? If so, is the new fuse OK?

Check your grounds. The ignition system feeds a constant 12 v. pos. to the system whenever the key is on. It makes the coil spark by connecting and disconnecting the ground side of the circuit. So you could have +12v. but no negative to complete the circuit.

Project"Bag&Drag" · 06-30-2008, 09:08 PM

Quote: Originally Posted by Yogi

No, don't do that. Just get a second opinion and go from there.

Did you replace the blown fuse? If so, is the new fuse OK?

Check your grounds. The ignition system feeds a constant 12 v. pos. to the system whenever the key is on. It makes the coil spark by connecting and disconnecting the ground side of the circuit. So you could have +12v. but no negative to complete the circuit.

So that means the white wire would be the ground in this case on the coil.

And the new fuse is good. I just am wondering what made the fuse blow. And what it runs/protects.

And I appreciate all the help I'm getting with my problem. This is why I love this fourm!

Bill Wheats · 06-30-2008, 11:00 PM

The white wire from the coil is the trip (sensor) wire to the PCM that tells it to send the negitve voltage pulses to the injectors so that they will fire.

Project"Bag&Drag" · 07-01-2008, 02:21 PM

well i went and tested the module again, several times and it show to be good. i havent had time to check to see if the white ground wire has a good ground, but ill get to it tommarrow

Yogi · 07-01-2008, 02:28 PM

Quote: Originally Posted by Project"Bag&Drag"

well i went and tested the module again, several times and it show to be good. i havent had time to check to see if the white ground wire has a good ground, but ill get to it tommarrow

OK, the white wire is not a continuous ground. The pcm only grounds it when it is time to fire the coil. Check the ground strap on the back of the motor and the ground on the pcm.

Project"Bag&Drag" · 07-01-2008, 06:40 PM

Ok will do, what color wire is the PCM ground, and is the power for it a pink w/ black line?

Yogi · 07-01-2008, 07:37 PM

I'll have to see if I can find a wiring diagram. Is it CPI or TBI?

Yogi · 07-01-2008, 09:10 PM

Click here for a wiring diagram of a CPI motor. Go to diagram #6 for the pcm.

sparks383iroc · 07-01-2008, 09:27 PM

Um, possibly the pickup coil in the distributor is bad.

Bill Wheats · 07-01-2008, 11:36 PM

Quote: Originally Posted by sparks383iroc

Um, possibly the pickup coil in the distributor is bad.

That would be my first guess.

Project"Bag&Drag" · 07-02-2008, 10:30 AM

Ok I was told that yesterday also. I heard that its pretty hard to do also. Btw its TBI.

Bill Wheats · 07-02-2008, 10:57 AM

You can test it with a meter. It will open and close as the dizzy turns. It basically is taking the place of points that were used in older ignition systems.

Yogi · 07-02-2008, 11:35 AM

I couldn't get the wiring diagram for the TBI. Sorry.

sparks383iroc · 07-03-2008, 06:08 PM

Quote: Originally Posted by Project"Bag&Drag"

Ok I was told that yesterday also. I heard that its pretty hard to do also. Btw its TBI.

Not a real hard job if you have pulled a distributor before. Haynes has a step by step on how to test it and how to replace. It is usually a wire that has been rubbed bare and grounded out that causes it to go bad. If I can find my pictures (and get them posted) I'll show you the wire.

sparks383iroc · 07-03-2008, 06:38 PM

Ok, let's see if this will work.

Sorry it's so blurry, I did it with an old LowRes camera phone. If you look at the last picture, you can make out where the green wire is worn through. You can do a quick visual check to see if this has happened by pulling the cap, this wire goes from the PU coil to the Ignition Module

Project"Bag&Drag" · 07-10-2008, 11:24 AM

well i fixed it, i went with my gut felling and replaced the PCM, and guess what it started right up!! thanxs for all the help!!

Yogi · 07-10-2008, 11:35 AM

Quote: Originally Posted by Project"Bag&Drag"

well i fixed it, i went with my gut felling and replaced the PCM, and guess what it started right up!! thanxs for all the help!!

Any problems with the install? Where did you get it?

Congrats!!

06-27-2008, 07:42 PM	#1
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	94 4.3 died need help!!! well my 4.3 just died on me today. and i havent had time to check spark on it, but i think it might be my spiders, b/c it died right when i parked it and aired out then i went to go start it and nothing. Just cranks and cranks. but i didnt smell fuel and i physically felt under the injectors and they were dry. I noticed that i poped the 25amp power/ acc. fuse, does this control the PCM at all?? cause i aired it up and it seems that i rubbed though some wires on my passenger side harness. i taped them all up and then tried to start it and nothing. I also tryed putting some gas in the throttle to get it to pop at least, and nothing. I am going to test the spark on it tommarrow Anyone have any ideas??
	[Reply w/Quote]

06-27-2008, 07:57 PM	#2
TCossuto Registered User Join Date: Aug 2007 Posts: 686 Location: User is: OffLine	Re: 94 4.3 died need help!!! test the spark and fix the wires.
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06-28-2008, 11:44 AM	#3
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by TCossuto test the spark and fix the wires. X2
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06-28-2008, 04:56 PM	#4
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! ok well i checked the spark today, and thires none, and checked the module on the dizzy and it was good, the cap,rotor, and the coil was replaced today. But what gets me is that i tested to see if theirs power to the coil,and their is, i got power from all of them. all 4, the two red and white wires to the coil and then the red and white ones from the coil to the dizzy, i also noticed when i crank on it the injectors dont spray, and then when i plugged the dizz module back in they sprayed fine, only when i plugged the connection back. Im soo puzzled right now
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06-28-2008, 09:41 PM	#5
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! The PCM get a signal from the coils, then gives a pulsing neg voltage to the injectors to turn on.
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06-29-2008, 11:32 PM	#6
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! So my pcm is shot?
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06-30-2008, 12:03 AM	#7
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! Why would you think that the PCM is shot? If I read what you meant correctly, then when you disconnected the wires going to your dizzy: the injectors didn't fire - they shouldn't. With the dizzy wires connected then the PCM sees the signal and fires your injectors. What more could you want? What circuit blew the fuse? Did you test and get spark when the dizzy was connected?
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06-30-2008, 11:44 AM	#8
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! I dont know what circut blew the fuse, it was the #7 fuse a 25amp and on the pannel it says its a power aux/ fuse?? and i didnt get spark anywhere from the coil to the dizzy at all, but i have power to the coil
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06-30-2008, 11:47 AM	#9
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! Did you try to get spark from the coil wire going to the dizzy cap yet?
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06-30-2008, 11:51 AM	#10
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! no their is no spark any where in the system
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06-30-2008, 11:52 AM	#11
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by Bill Wheats Did you try to get spark from the coil wire going to the dizzy cap yet? yes, their is no spark
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06-30-2008, 11:54 AM	#12
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! Double post Last edited by Bill Wheats : 06-30-2008 at 11:55 AM.
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06-30-2008, 12:00 PM	#13
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! so any ideas bill?
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06-30-2008, 12:14 PM	#14
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! ? If you have a MAF sensor disconnect it and try again. Pull the module and make sure that it isn't shorting out. Have it tested. Sorry but I'm on the road...
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06-30-2008, 02:15 PM	#15
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! the module under the dizzy, if thats the case i already had it tested it passed
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06-30-2008, 02:39 PM	#16
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! Some of the modules need to go through the tester 5 or 6 times before they show bad.
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06-30-2008, 02:47 PM	#17
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! I would try taking the ICM to another store to be retested - just to be sure.
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06-30-2008, 05:19 PM	#18
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! Ok will do, or should I just get a new one
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06-30-2008, 07:06 PM	#19
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by Project"Bag&Drag" Ok will do, or should I just get a new one No, don't do that. Just get a second opinion and go from there. Did you replace the blown fuse? If so, is the new fuse OK? Check your grounds. The ignition system feeds a constant 12 v. pos. to the system whenever the key is on. It makes the coil spark by connecting and disconnecting the ground side of the circuit. So you could have +12v. but no negative to complete the circuit. Last edited by Yogi : 06-30-2008 at 07:13 PM.
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06-30-2008, 09:08 PM	#20
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by Yogi No, don't do that. Just get a second opinion and go from there. Did you replace the blown fuse? If so, is the new fuse OK? Check your grounds. The ignition system feeds a constant 12 v. pos. to the system whenever the key is on. It makes the coil spark by connecting and disconnecting the ground side of the circuit. So you could have +12v. but no negative to complete the circuit. So that means the white wire would be the ground in this case on the coil. And the new fuse is good. I just am wondering what made the fuse blow. And what it runs/protects. And I appreciate all the help I'm getting with my problem. This is why I love this fourm!
	[Reply w/Quote]

06-30-2008, 11:00 PM	#21
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! The white wire from the coil is the trip (sensor) wire to the PCM that tells it to send the negitve voltage pulses to the injectors so that they will fire.
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07-01-2008, 02:21 PM	#22
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! well i went and tested the module again, several times and it show to be good. i havent had time to check to see if the white ground wire has a good ground, but ill get to it tommarrow
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07-01-2008, 02:28 PM	#23
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by Project"Bag&Drag" well i went and tested the module again, several times and it show to be good. i havent had time to check to see if the white ground wire has a good ground, but ill get to it tommarrow OK, the white wire is not a continuous ground. The pcm only grounds it when it is time to fire the coil. Check the ground strap on the back of the motor and the ground on the pcm.
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07-01-2008, 06:40 PM	#24
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! Ok will do, what color wire is the PCM ground, and is the power for it a pink w/ black line?
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07-01-2008, 07:37 PM	#25
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! I'll have to see if I can find a wiring diagram. Is it CPI or TBI?
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07-01-2008, 09:10 PM	#26
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! Click here for a wiring diagram of a CPI motor. Go to diagram #6 for the pcm.
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07-01-2008, 09:27 PM	#27
sparks383iroc Registered User Age: 42 Join Date: Feb 2006 Posts: 192 Location: Under this ****in' Truck in INDY User is: OffLine	Re: 94 4.3 died need help!!! Um, possibly the pickup coil in the distributor is bad.
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07-01-2008, 11:36 PM	#28
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by sparks383iroc Um, possibly the pickup coil in the distributor is bad. That would be my first guess.
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07-02-2008, 10:30 AM	#29
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! Ok I was told that yesterday also. I heard that its pretty hard to do also. Btw its TBI.
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07-02-2008, 10:57 AM	#30
Bill Wheats Registered User Join Date: Apr 2008 Posts: 1,192 Location: Maine User is: OffLine	Re: 94 4.3 died need help!!! You can test it with a meter. It will open and close as the dizzy turns. It basically is taking the place of points that were used in older ignition systems.
	[Reply w/Quote]

07-02-2008, 11:35 AM	#31
Yogi Registered (Ab) User Join Date: Feb 2008 Posts: 3,192 Location: League City, TX (Houston) User is: OffLine	Re: 94 4.3 died need help!!! I couldn't get the wiring diagram for the TBI. Sorry.
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07-03-2008, 06:08 PM	#32
sparks383iroc Registered User Age: 42 Join Date: Feb 2006 Posts: 192 Location: Under this ****in' Truck in INDY User is: OffLine	Re: 94 4.3 died need help!!! Quote: Originally Posted by Project"Bag&Drag" Ok I was told that yesterday also. I heard that its pretty hard to do also. Btw its TBI. Not a real hard job if you have pulled a distributor before. Haynes has a step by step on how to test it and how to replace. It is usually a wire that has been rubbed bare and grounded out that causes it to go bad. If I can find my pictures (and get them posted) I'll show you the wire.
	[Reply w/Quote]

07-03-2008, 06:38 PM	#33
sparks383iroc Registered User Age: 42 Join Date: Feb 2006 Posts: 192 Location: Under this ****in' Truck in INDY User is: OffLine	Re: 94 4.3 died need help!!! Ok, let's see if this will work. Sorry it's so blurry, I did it with an old LowRes camera phone. If you look at the last picture, you can make out where the green wire is worn through. You can do a quick visual check to see if this has happened by pulling the cap, this wire goes from the PU coil to the Ignition Module Last edited by sparks383iroc : 07-03-2008 at 06:46 PM.
	[Reply w/Quote]

07-10-2008, 11:24 AM	#34
Project"Bag&Drag" < EST 1989....> Age: 19 Join Date: Aug 2007 Posts: 490 Location: Merritt Island FL User is: OffLine	Re: 94 4.3 died need help!!! well i fixed it, i went with my gut felling and replaced the PCM, and guess what it started right up!! thanxs for all the help!!
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