[Matt335]

Hi, I have had my JB4 for quite some time with no issues for the most part...more recently it has caused me the same problem. If I am getting on the throttle aggressively, I will get a check engine and the engine seems to be misfiring and run really rough. I have taken it in and had the injectors replaced as well as a few other items but it continues to happen. I have never run more than map 1 - anyone else experience an issue like this?

Thanks!

[335NJ]

Codes?

It's probably a misfire. Replace plugs, go from there

[Matt335]

I had the fuel pump replaced and I thought plugs too! Yea def a misfire when the JB4 is activated (stage 1) and when putting the car under some speed stress.

Anything that must/should be replaced to even run stage 1?

[ritzzzzzwik]

Originally Posted by Matt335

I had the fuel pump replaced and I thought plugs too! Yea def a misfire when the JB4 is activated (stage 1) and when putting the car under some speed stress.

Anything that must/should be replaced to even run stage 1?

Have you removed the JB4 off and put back in recently? Make sure all all connections are good, especially the power wire.

[335NJ]

Originally Posted by Matt335

I had the fuel pump replaced and I thought plugs too! Yea def a misfire when the JB4 is activated (stage 1) and when putting the car under some speed stress.

Anything that must/should be replaced to even run stage 1?

What codes did you get?

Even on map 1, assuming that's what you mean, you need to replace spark plugs every 15-25k depending on a few conditions, but typically that's the lifespan of them while tuned. Non-OEM plugs like the NGK's get replaced at even shorter intervals.

If you have a misfire code for cylinder X, move the coil from that cylinder to another, and try to repeat the process that causes the misfire. If it happens again and now is on the different cylinder, you have a bad coil.

[Matt335]

Originally Posted by 335NJ

What codes did you get?

Even on map 1, assuming that's what you mean, you need to replace spark plugs every 15-25k depending on a few conditions, but typically that's the lifespan of them while tuned. Non-OEM plugs like the NGK's get replaced at even shorter intervals.

If you have a misfire code for cylinder X, move the coil from that cylinder to another, and try to repeat the process that causes the misfire. If it happens again and now is on the different cylinder, you have a bad coil.

Yea map 1, I think the plugs were changed fairly recently, I drive the car every day but I only have 44,000mi on it!

I actually had all the coils replaced too!

If I open the hood and get in there I am ready to just rip it out and sell it since every time I try and use it I am getting the misfire

[Mike@N54Tuning.com]

Need codes to diagnose properly. If you've been running the JB4 for a while with no issues why do you think all of a sudden its the JB4 causing issues?

Mike

[335NJ]

Originally Posted by Matt335

Yea map 1, I think the plugs were changed fairly recently, I drive the car every day but I only have 44,000mi on it!

I actually had all the coils replaced too!

If I open the hood and get in there I am ready to just rip it out and sell it since every time I try and use it I am getting the misfire

Tuning of any type that applies more demand on components causes these types of issues. Not the fault of the JB4 or any tune out there, strictly cause and effect.

Want a tune to give you 80+ HP? Expect to maintain the components it's using.

[Matt335]

Originally Posted by Mike@N54Tuning.com

Need codes to diagnose properly. If you've been running the JB4 for a while with no issues why do you think all of a sudden its the JB4 causing issues?

Mike

Thanks Mike, I have an email that I haven't finished yet to you guys to see what you know/suggest. After having the fuel pump, plugs, coils, and injectors all recently replaced it is only when I turn to map 1 and drive hard when I have ever experienced the problem. I was driving hard for a few weeks under 0 map after the injectors were just replaced with no problems until last night when I turned to map 1 before leaving work to test it out again and this time I was at low RPMs in 3rd when I could have easily been in 2nd to gun it but wanted to see the low RPM pickup and as soon as the pedal hit the floor it triggered the check engine and started running terrible again. I pulled over, returned it back to 0 map, coasted home and parked it. This AM I fired it up with no check engine and no problems on my way into work even after intentionally driving it a bit hard to see.

[335NJ]

Originally Posted by Matt335

Thanks Mike, I have an email that I haven't finished yet to you guys to see what you know/suggest. After having the fuel pump, plugs, coils, and injectors all recently replaced it is only when I turn to map 1 and drive hard when I have ever experienced the problem. I was driving hard for a few weeks under 0 map after the injectors were just replaced with no problems until last night when I turned to map 1 before leaving work to test it out again and this time I was at low RPMs in 3rd when I could have easily been in 2nd to gun it but wanted to see the low RPM pickup and as soon as the pedal hit the floor it triggered the check engine and started running terrible again. I pulled over, returned it back to 0 map, coasted home and parked it. This AM I fired it up with no check engine and no problems on my way into work even after intentionally driving it a bit hard to see.

Mike, and any other person with experience on this platform will tell you they can't give you a clean cut answer without datalog showing the problem.

Get logs and send them to BMS Support or here.

[Matt335]

Originally Posted by 335NJ

Tuning of any type that applies more demand on components causes these types of issues. Not the fault of the JB4 or any tune out there, strictly cause and effect.

Want a tune to give you 80+ HP? Expect to maintain the components it's using.

Yep totally understand, I am not calling out the JB4 as a faulty product by any means, it's great! Just trying to understand what specific components are put under the most stress so I can look to replace with beefier parts that can handle the additional stress. And if anyone was experiencing the same issue and how they resolved it by either replacing a part or upgrading aftermarket.

[335NJ]

Originally Posted by Matt335

Yep totally understand, I am not calling out the JB4 as a faulty product by any means, it's great! Just trying to understand what specific components are put under the most stress so I can look to replace with beefier parts that can handle the additional stress. And if anyone was experiencing the same issue and how they resolved it by either replacing a part or upgrading aftermarket.

Start by replacing the plugs, that's the cheapest and most common culprit. Logs will give more insight.

[Matt335]

Originally Posted by 335NJ

Start by replacing the plugs, that's the cheapest and most common culprit. Logs will give more insight.

Should have been keeping track of the different codes/logs as I took it in but I don't have them archived at the shop. Plugs were def replaced but looks like coils have not been...how often do those usually fail or contribute to this type of issue?

[335NJ]

Originally Posted by Matt335

Should have been keeping track of the different codes/logs as I took it in but I don't have them archived at the shop. Plugs were def replaced but looks like coils have not been...how often do those usually fail or contribute to this type of issue?

Very often. But to tell for sure, the trick is to move the coil from the missing cylinder (code needed) and see if the misfire follows.

If you want to be preventative now about it, just order 6 coils and see how the car responds.

[Mike@N54Tuning.com]

Originally Posted by 335NJ

Very often. But to tell for sure, the trick is to move the coil from the missing cylinder (code needed) and see if the misfire follows.

If you want to be preventative now about it, just order 6 coils and see how the car responds.

+1

Just scan the car for codes.. Skip the catalogs for now and start with a code. Most likely a fuel / misfire issue but need code.

Mike