I've had my tunes for nearly 6 months now and for the last 2 months I've started to get a misfire on multiple cylinders under load (i.e. rapid acceleration, hills, etc.). DTC reads P0300 (misfire on multiple cylinders). I switched from the 93 Perf tune to the 87 octane tune and very little difference. Same problem and if I really pushed the acceleration I could get the Emission Control Light to come on on the dash display.

I called Troyer and they said definitely NOT the tunes so I took it to the dealer where they tested plugs, coils, and fuel injectors and couldn't find the problem. $200 later they said it was probably in the programming (which I think was just an easy cop-out for them). They told me to put the stock programming back on and bring the truck back in to them.

Earlier this week I reprogrammed back to stock (after paying $150 for the 3 inch AF1 tube so I didn't have to put the whole stock air intake back on in place of my 3.5in AF1 tube) and now the truck runs no problem (except it's SLOW). I can't get it to misfire at all and no DTC's come up. I've run it up hills with the pedal on the floor with AC on up to 100mph and still nothing.

So the question is: Is it the tunes or is it that the stock tune just doesn't put enough stress on the motor to reproduce the problems? Any help would be GREATLY appreciated because I'm at a loss as to what to do next. Thanks.

Sean

 

try tuning it again but just leave the 3" AF1 on and see what happenes. You probably have 87-octane in it since you're back to stock so give the 87 custom tune a try

 

Change the plugs

 

"Change the plugs." That's what I thought and that's what one of the mechanics at Troyer told me. I already spent $200+ on new plugs (including installation) right before I put the tunes on 6 months ago before all this happened. The new plugs only have 6-8K miles on them. And supposedly when the dealer checked everything out last month they took one brand new OEM plug and put it in the cylinders that were misfiring and it didn't change anything (I'm skeptical). Also, if it was the plugs wouldn't I be having the same problem with the stock tunes?

jpdadeo: If I put the Troyer tunes back in with the 3inch air intake tube, won't that mess up the air:fuel ratio since it was tuned for the 3.5in tube?

Thanks again for the help. I only know just enough about this stuff to be dangerous and I'm really banging my head against the wall trying to figure out what to do.

Sean

 

its the coil/ coils or plugs, a tune is not going to cause a misfire. I would check each coil pack even though the dealer said they checked them make sure they are all tight and pull the boot off and look at the coil wires. I had this issue 2 times both times it was plugs the first set had 13K the other had 6K both were autolite plug.

 

A tune can cause a misfire if not tuned properly. However, in this case, it sounds like something is wrong with the truck mechanically.

 

Which plugs would you guys recommend?

 

Brisk.

 

X2

 

Alright, I'm revealing my ignorance, but I've never heard of Brisk or X2 if those are types of plugs. Who makes them and where can I buy them? Thanks.

Sean

 

Bowman I haven't heard of them either but the X2 means he has the same opinion (opinion times 2)

 

Brisk USA

http://www.briskusa.com/

do they even make a plug for the 3-valve? what's the stock number if ya know?

 

I'm positive that they make a plug for the 3V but I don't have the PN.

 

i found this # but i don't think they are for the 3-valve

Brisk Premium LGS - GOR14LGS

i don't know? but i'm in the market for plugs soon

 

briskracing.com just listed a plug for the mustang. F-150 didn't even pop-up. Any other plug suggestions?