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P1399 After JDM Swap

5K views 25 replies 6 participants last post by  Irish Pilot Mender 
#1 · (Edited)
Hello,

Well, long story short, the timing belt tensioner went out, which caused engine failure so I decided to have a JDM swap done. While my wife was driving home on the freeway she noticed that the check engine light flashed, so she pulled over. I drove to where she was and pulled the codes. The only code was P1399 for multiple cylinder misfire (pending). I did some research and most of those codes are typically present with other misfire codes, however, this one wasn't. I checked the coils and pulled each one and noticed a slight change in RPMs to rule out a bad coil pack. Does anyone else have any idea? Should I go back to the shop that did the swap or does this sound like something other than an issue with installation? I would like to add that prior to the install we did not notice any flashing check engine light.

EDIT: I decided to drive around to see if any other codes were present and now the check engine light came on with the VTM-4 light. The codes present are P0300, P0301, P0304 and P1399 (pending).

Thank you!

Sent from my SM-G960U1 using Tapatalk
 
#2 ·
Did you install new and correct NGK spark plugs that were not sourced from amazon?

Was the EGR valve replaced?
 
#3 ·
The NGK plugs from the JDM engine were kept due to the fact that the mechanic had stated that they looked fine and I used cheap Bosch plugs in the original engine just to see if that was the reason the engine was not starting (prior to swap) so I didn't want to use those. This was a straight swap and the only things that I had him do were swap out the seals and intake manifold.

I did see that the EGR could also be an issue, but considering that he swapped out the intake manifold for ours and we didn't have a code (that we noticed) we didn't think that would be the issue. The light is off and we only knew it was there because it flashed on the freeway. The idle also sounds good and not rough.

Edit: I didn't see any mention of an EGR valve on this motor... only that the EGR ports run along underneath the intake manifold. Unless I'm wrong.

Thanks!

Sent from my SM-G960U1 using Tapatalk
 
#4 ·
I got a similar code on my 2008. I cleared the code, and it hasn't come back since. That was about 3,000 miles ago. I suppose it could need a valve adjustment (that is what people suggested to me when I had 1-6 misfire and a random as well). Everything is working fine so I'll wait until it comes up again before I do anything. :)
 
#5 ·
Ok, an update. I now have P0300, P0301, P0304 and P1399 (pending). I'm leaning towards valve adjustment, but I'm not sure why since the motor should only have 60k miles and the adjustment isn't recommended until 100k.

Ideas welcome.

Thank you!

Sent from my SM-G960U1 using Tapatalk
 
#8 ·
What year is yours? FWD or AWD?
 
#9 ·
Hello,

Well, long story short, the timing belt tensioner went out, which caused engine failure so I decided to have a JDM swap done. While my wife was driving home on the freeway she noticed that the check engine light flashed, so she pulled over. I drove to where she was and pulled the codes. The only code was P1399 for multiple cylinder misfire (pending). I did some research and most of those codes are typically present with other misfire codes, however, this one wasn't. I checked the coils and pulled each one and noticed a slight change in RPMs to rule out a bad coil pack. Does anyone else have any idea? Should I go back to the shop that did the swap or does this sound like something other than an issue with installation? I would like to add that prior to the install we did not notice any flashing check engine light.

EDIT: I decided to drive around to see if any other codes were present and now the check engine light came on with the VTM-4 light. The codes present are P0300, P0301, P0304 and P1399 (pending).

Thank you!

Sent from my SM-G960U1 using Tapatalk
you really can't rule out coil on plug packs like that, you need a in line spark tester to see if you get erratic spark when rpms change.
 
#16 ·
How many days/miles did you put on before you threw a code? I'd think any codes from a ECU mismatch would throw pretty quickly.

On the engine - there are many J35 engines with differences.


The correct ones for the 2003 would be J35A4. Just saying "J35A" is not specific enough. However, the JDM selling company should have been able to cross reference what you needed and make sure you got a compatible engine.

A lot of people say they swap the sensors from the old engine. I'd be inclined to swap a lot of the parts from the old engine, and just keep the JDM parts for spares.
 
#17 ·
My wife drove about 18 miles from the mechanic shop before she noticed the light flash and I'm unsure how many miles the mechanic put on it. I reset the light on the freeway and my wife drove it home around 8/9 miles. The light wasn't on, but I decided to check anyways. There was a code P1399 (Pending) only, but with my research found out that this code was normally with other misfire codes. I wanted to put some more miles on the car to see if there might be other codes present, so I drove it around 2 additional miles and noticed that the check engine light was now on along with the VTM-4 dash light.

Thanks for your help!

Sent from my SM-G960U1 using Tapatalk
 
#18 ·
You should take it back to who put it, unless you didn’t pay for service, if he is as good as you advertised he should fix your problem with no issue, I don’t recommend trying to remedy yourself cause you don’t wanna open Pandora’s box and end up buying another motor.
 
#19 ·
without a scan tool there is no way to reset the check engine light on the fly something doesn't add up here..check engine light don't flash they stay off or stay on there is no in between.
 
#22 ·
Hello,

Well, long story short, the timing belt tensioner went out, which caused engine failure so I decided to have a JDM swap done. While my wife was driving home on the freeway she noticed that the check engine light flashed, so she pulled over. I drove to where she was and pulled the codes. The only code was P1399 for multiple cylinder misfire (pending). I did some research and most of those codes are typically present with other misfire codes, however, this one wasn't. I checked the coils and pulled each one and noticed a slight change in RPMs to rule out a bad coil pack. Does anyone else have any idea? Should I go back to the shop that did the swap or does this sound like something other than an issue with installation? I would like to add that prior to the install we did not notice any flashing check engine light.

EDIT: I decided to drive around to see if any other codes were present and now the check engine light came on with the VTM-4 light. The codes present are P0300, P0301, P0304 and P1399 (pending).

Thank you!

Sent from my SM-G960U1 using Tapatalk
You can ignore the VTM light. The computer won't activate VTM if the power train is not stable.
Misfires are hard to track. I had misfire codes last summer. Turned out it was not electrical issue. Did a leak down test. My headgasket was blown.
So proceed with the obvious things first.
A friend of mine has an Oddysey,same issue, it was also headgasket.
Hello,

Well, long story short, the timing belt tensioner went out, which caused engine failure so I decided to have a JDM swap done. While my wife was driving home on the freeway she noticed that the check engine light flashed, so she pulled over. I drove to where she was and pulled the codes. The only code was P1399 for multiple cylinder misfire (pending). I did some research and most of those codes are typically present with other misfire codes, however, this one wasn't. I checked the coils and pulled each one and noticed a slight change in RPMs to rule out a bad coil pack. Does anyone else have any idea? Should I go back to the shop that did the swap or does this sound like something other than an issue with installation? I would like to add that prior to the install we did not notice any flashing check engine light.

EDIT: I decided to drive around to see if any other codes were present and now the check engine light came on with the VTM-4 light. The codes present are P0300, P0301, P0304 and P1399 (pending).

Thank you!

Sent from my SM-G960U1 using Tapatalk
Any update?

Ignore VTM as an issue. The VTM is shutting down because the powertrain is unstable due to the misfires. Fix misfires and VTM light will go out.
My misfire codes were a blown headgasket, same as a friend of mine who has an Oddysey.
 
#23 ·
You can ignore the VTM light. The computer won't activate VTM if the power train is not stable.
Misfires are hard to track. I had misfire codes last summer. Turned out it was not electrical issue. Did a leak down test. My headgasket was blown.
So proceed with the obvious things first.
A friend of mine has an Oddysey,same issue, it was also headgasket.

Any update?

Ignore VTM as an issue. The VTM is shutting down because the powertrain is unstable due to the misfires. Fix misfires and VTM light will go out.
My misfire codes were a blown headgasket, same as a friend of mine who has an Oddysey.
misfires are not that hard to track, fouled plugs, wrong plugs, hairline cracks, bad coil/s or boots, not use using plug grease and not dialectic grease, and timing, its really only a handful of things that can cause it especially with coil on plug which makes a lot easier.
 
#25 ·
I’m not saying head gasket is ruled out, I’m saying anything can cause a misfire code, multiple or single whatever have you not only an head gasket is the issue, I’m saying it’s not hard to diagnose a misfire, and I would exhaust all the free options first before I start throwing money and a blown head gasket does not Cause a vehicle to loose heat it does the opposite, heater core will cause air to blow cooler, and of course changing a head gasket will cure an issue cause you replaced everything in between and probably missed the actual problem....
 
#26 ·
Sorry but when the heater core has no coolant in it the vehicle gets cold. Blown headgasket causes engine overheating and cabin cold. The headgasket failure caused coolant to be burned with the combustion process causing misfire. A failed headgasket doesn't always leak into the crankcase.The only thing you replace when you do head gasket is the gasket (and cooloant). It cost me $60, did job myself, 3 months of chasing misfire over.
I agree 100% that a misfire is not hard to find, it's just not in my experience always electrical.
We are both on the same page.
 
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