Well the infamous code 1399 hit my car three weeks ago, and my brother has been periodically been looking at it. So far he has
Replaced the fuel injectors and rails
Checked the timing (all good)
Checked the compression (all good)
Checked the coils and plugs (all good)
Changed the EGR
Cleaned the EGR channels

I guess we will be looking at the crankshaft and camshaft position sensors this week. Does anyone have any other ideas on what this issue may be? If so, please post them, even if you think it is far fetched.

 

Odds are its just a coil pack causing the issue (where disconnecting them one at a time while running wont show the culprit). Unless you replace one with a known good one, drive until the light comes on and then swap that to the next cyl etc.. until the light doesnt come on, "checking" them really does nothing, not to mention how did he check them?

 

What is 1399?

 

1399 = random misfire

As Fsttyms1 previously stated......oftentimes a faulty coil pack is the culprit.
But other things can cause this code as well, try searching and you'll be enlightened.

 

Look for this on the boot of the coil pack

If you see that replace the coil.

 

P1399 is most likely a coil, or coils. How are you/your brother checking them?

 

When I had a couple of bad coils, I measured them for resistance every which way, but could not find a difference between good ones and bad.....?

 

Resistance measurments will do nothing when you get the coil out. It's usually under a load that whatever coil is misfiring.....is going to fail.

The only way you can properly check the coils at once is with a lab scope and a low amp probe. It's expensive, and not for a DIYer. But as a certified tech...i'm able to do it.

First and formost...are the spark plugs OEM brand, or are the some cheap bullshit Bosch or Autolite? Denso is the OEM brand you want, and they're $12 a pop.

Next, what quality of fuel are you putting in the tank? I'm guessing it's 85 ocatane. These cars demand 93 ocatane for optimum performance.

Also, it may be the EGR valve is hung up or the passages are carboned up. My first step would be to remove the coils and carfelly inspect every square inch of it. Maybe one of them has a hair-line crack, or is arcing outside the boot. More than likely is a failed secondary winding in the coil it's self, causing a misfire under load.

Let us know what you find. At best, you could replace 3 coils on the front bank, celar the code, and see if the light comes back on. If it does, then swap the new 3 coils to the back, and repeat. Only problem is....if you have 2 coils that are bad on seperate banks...well, it's a musical coil game from then on, until you replace the correct coil.

Hope that helps...

 

Thank you very much for your help, the issue was either the spark plugs or the ignition coils. We replaced them all, and the car is running great. My wife even things it has a little more power than before. I have not driven the car, since being fixed. I can't wait to see how the car drives now.

 

How did the old plugs look when ya pulled them out ?
Did ya replace all of the coil packs ?

 

I did not remove the plugs. Someone worked on my car. I think he mentioned the coils were arching. I replaced all six coils and all six spark plugs.