Stumped on engine misfire?

Tiny
SWOLL2
  • MEMBER
  • 2 POSTS
The van has the 3.3 V-6.
Thanks,
Steve
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
JASONRAY
  • MECHANIC
  • 213 POSTS
Unplug the coil pack. Find the Dark Blue/Tan wire. Using a normal test light connected to BATT +, probe the terminal. Have someone spin the engine over. Did the test light flash? Make sure to spin it for about 10 seconds or so. If the light does NOT flash, the problem is between the coil pack and the PCM. This wire is the one the PCM uses to fire the #2 and #5 plugs. It should fire each cylinder twice during each revolution. Once on the compression stroke and again on the exhaust stroke. If the test light does not flash during this test, the signal is being lost from the PCM to the COIL. OR, the signal could not even be generated inside the PCM. If it was a crank sensor problem, it wouldn't fire any cylinders. Start there and get back with me.
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+2
Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
PICKUPMAN2386
  • MEMBER
  • 2 POSTS
  • 1996 DODGE CARAVAN
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 166,000 MILES
I Have a 1996 dodge grand caravan it has the codes P0300 and P0303 for random misfire and #3 misfire. Van runs great while driving at idle or during load it starts missing. I have replaced spark plugs, plug wires and cap and rotor, also crank shaft sensor. I have been out of the shop for awhile and I don't wanna keep throwing parts at it. Can anybody help?
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
I would Recheck the tune up and ignition coil
check injector
do a compression test

good luck

need manual CHECK IT @
https://www.2carpros.com/kpages/auto_repair_manuals.htm
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
PICKUPMAN2386
  • MEMBER
  • 2 POSTS
I checked the plugs #3 has a stain from the misfire. Wire is good I checked the injector and also the EGR valve. I haven't done the compression check yet can find my guage. I checked the intake though and throttle body for build up and found none. I Pressure washed engine to remove any extra oil around the plug and replaced #3 plug again. The EGR is good I ran some injector cleaner through it and also reset the codes after that. No check engine light yet but still idles rough, prob just a matter of time. Any other ideas.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
AYORK1293
  • MEMBER
  • 4 POSTS
  • 1996 DODGE CARAVAN
  • 3.3L
  • V6
  • FWD
  • AUTOMATIC
  • 219,000 MILES
I have a 96 dodge caravan se, 3.3l. It has a misfire on 2 cylinders. When it was purchased a week ago the ignition coil had a broken connection for one cylinder, it was just replaced, 4 days ago, by myself, when I started the van up after installing the new coil, it was missing on 2 cylinders, started pulling wires directly off of the coil and the coil wasnt even firing on those 2 so I went back to autozone and warranty swapped the coil for another new the very next day, installed it in their parking lot and it was still missing on the same 2 cylinders with the same result, the coil itself not firing, has a new battery and autolite plugs with duralast wires, im just wondering if it could be the pcm or the bcu or a combination of the 2/
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
If the coil is not firing on 2 cylinders that share a coil circuit, then you have either burned out the driver for that circuit in the PCM or the wire connecting it is bad.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
AYORK1293
  • MEMBER
  • 4 POSTS
To what wire are we referring?
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
The wire that connects that circuit in the coil to the driver in the PCM
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
AYORK1293
  • MEMBER
  • 4 POSTS
Ok, so would that just be disconnecting the pigtail from the coil and using a multimeter to check for resistance
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
No, checking resistance won't tell you if the wire is shorted to ground or another circuit. The wire has to be isolated at both ends and tested multiple ways. You should be using a scope to test for the signal coming out of the PCM
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
LILTIPPIBIRD
  • MEMBER
  • 1 POST
  • 1996 DODGE CARAVAN
  • V8
  • FWD
  • AUTOMATIC
  • 180,000 MILES
I have a dodge gran caravan july96 model. I recently had transmission, crank censor and cam censor replaced. Van ran fine for aprox. 3 more wks. Now from running after stopped, gear change will surge and jump up in rpms. And sometimes will not change to third gear. Stopping and recranking van will sometimes fix problem. Diognosis box gives out a misfire readout still. Where should I start looking next? I am a female adult who knows more than most about cars but I really dont want to get ripped off. Thank you for a responce. Will make a donation when affordable. Just put out approx. $1600.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
BMRFIXIT
  • MECHANIC
  • 19,053 POSTS
Misfiring codes !
Have to start by checking the engine for tune up.

Cycle key on off on off on read P codes in odometer area
or check engine light will flash out the codes
(for example code 12 check engine will blink pause blink twice )
check tranny fluid too
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
AYORK1293
  • MEMBER
  • 4 POSTS
Ok, I dont know what you mean or how to do that.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
You don't have to equipment to do this anyway and if you try to improvise you could destroy the computer if it isn't already. You're going to have to get a pro to track this down for you. If it ends up needing a computer, it has to be programmed anyway.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
JWRKAILUA
  • MEMBER
  • 1 POST
  • 1996 DODGE CARAVAN
I am getting a 96 Dodge Caravan, 3.3L, with 114,000 miles. It has had the transmission replaced a few months ago. The guy is getting rid of it because he is moving and it is only running on 4 cyl. He said the shop told him that the computer needs to be replaced and then the van will run great again. He is not sure which computer module is malfunctioning or where it is. I thought if the computer was faulty, the whole engine would not funtion properly, not just 2 cyl. How can I check this before I buy it? Is there something else I should look at or for (speed sensor, coil packs, ect)? It has had a tune up with the wires and plugs being changed. Any ideas? Thank you
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
MERLIN2021
  • MECHANIC
  • 17,250 POSTS
Well if you have a OBDII scan tool, you can hookm it to the vans DLC and read the codes. There may be a code indicating the PCM not finding ground.
If it is running on 4 out of 6 cylinders, there will be codes present. The MIL should be either lighted or flashing due to the misfire condition, it will also denote the cylinder numbers not fiting. I will say that there is no guarantee express or implied in my answer! You are rolling the dice to buy this van!
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
SLIMDADDY
  • MEMBER
  • 1 POST
  • 1996 DODGE CARAVAN
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 146,000 MILES
There is no spark from the coil pack on cylinders 3 and 4. I replaced the coil pack and still have the same problem.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
BLACKOP555
  • MECHANIC
  • 10,371 POSTS
Since you replaced the coil pack and still no spark you probably have a bad ignition module.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)
Tiny
ALWAYSGREASY
  • MEMBER
  • 2 POSTS
  • 1996 DODGE CARAVAN
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 128,426 MILES
I have a 96 caravan has new plugs timing belt cap and rotor. When driving a while engine miss fires. Will stall 2 I havent been able to get it to act up. My mother drives 60 miles or so and it dies. Are those known for crank sensors? What about fule pumps?Not realy shure witch way to go. Dont want to throw parts at it. Please help.
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Monday, July 27th, 2020 AT 9:53 AM (Merged)

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