JB4 help

[hachicho]

I have bought a JB4 and i got it installed i have been running it on map1 it was working fine for the past two weeks. the other day i was driving and i down shifted the car to accelerate and service engine soon light comes on and the car starts to vibrate and acts wierd. so i turned off the car and the light went away. therefore, everytime i push the gas pedal all the way i get the same problem. but if i turn off the JB4 and push the gas pedal i get no problem.please help if any one has encounter this problem before.thanks

[RaihaX]

Sounds like a prelude to a misfire - check your code.

[hachicho]

Originally Posted by RaihaX

Sounds like a prelude to a misfire - check your code.

I checked it. It is a misfire on cylinder 6 I also checked my spark plug it was a little dirty but I cleaned it and tested the car it worked fine but after 2 hours I got the same problem don't know if it is from the JB4 or something else

[RaihaX]

try swapping your coil pack.

It could also be your injectors.

[hachicho]

I have did that and I had my car at The dealership they changed my high pressure gas pump and the injectors. I don't know what exactly is the problem because sometime it works fine and sometime it does not. They have told me that I might need an update for the JB4 I was wondering if this is the problem.

[RaihaX]

Might help to email terry?

[Dackelone]

Why not just read the code thrown>? I thought the JB4 can read codes by itself?

[Beemw335]

First thing is spark plugs, use another cylinder's plug and see if the prob stays in cylinder 6. I so then swap coils and see if it once again stays in cyl 6. If it still does than its either an injectors or you need to clean your intake valves

[rathissolid]

Originally Posted by Beemw335

First thing is spark plugs, use another cylinder's plug and see if the prob stays in cylinder 6. I so then swap coils and see if it once again stays in cyl 6. If it still does than its either an injectors or you need to clean your intake valves

+1 check the spark plugs

[Dackelone]

Originally Posted by Beemw335

First thing is spark plugs, use another cylinder's plug and see if the prob stays in cylinder 6. I so then swap coils and see if it once again stays in cyl 6. If it still does than its either an injectors or you need to clean your intake valves

How would intake valves via carbon buildup cause a misfire? Carbon buildup would create poor(decreased) power but not a misfire.

[hachicho]

I found what was the problem. It is the spark plugs I had the one prone head on it but it suppose to be the three prone head. I have to change them on Monday and will see that will happen.

[Mike@N54Tuning.com]

plugs are usually the cause of misfires so definitely check those.. and make sure to change them every 15-20K if tuned.

Mike

[Dackelone]

Originally Posted by hachicho

I found what was the problem. It is the spark plugs I had the one prone head on it but it suppose to be the three prone head. I have to change them on Monday and will see that will happen.

I would also reccomend you only to use/buy spark plugs bought from a BMW dealer. Some people have had issues with aftermarket Bosch plugs with the same specs as the BMW-Bosch plugs. I don't know why that is... but to be on the safe side I would just buy your replacement plugs from a BMW dealer.

Maybe my DIY might help you out...

135i Spark Plug replacement DIY...

http://www.1addicts.com/forums/showthread.php?t=602804