6.0 Install Question

[JJAB]

What do you think guys? I just finished an complete LQ9 install. Nelson performance custom harness, GM Hot Cam, long tube headers, built 4L60 tranny.I haven't received the custom tune as of yet, the tuner basically went in and did the basics until the custom tune is performed. Heres the question, I am getting a P0300 check engine code(Randon cylinder misfire). Coil packs, wires, 02sensors, spark plugs, 317 cylinder heads, all is brand new. Any thoughts or suggestions? I have sprayed around the intake and sensors with carb spray and have found no air leaks.

P.S. Took her for a test drive today and she really, really runs. Boy Oh Boy!!!!!!!!!

[AJII]

The cam will throw random misfire codes if the misfire detection number is not increased. That's probably it.

If you have an aftermarket converter, that'll cause it to.

I wouldn't worry about it.

[whitels1]

I second that, I have a Hot Cam in my LS1 Z28 and it throws random multiple misfires if idling for long periods.

[Wasted Income]

You need to do a CASE relearn with the new converter if it's a different diameter/mass than the stocker. That could be causing your misfire codes.

[OldCreek]

Have you manually checked each fuel injector? I had to pull and check each injector to find that one was stuck. My ohm meter didn't pick it up. You could try using a stethoscope on each injector, also. If these are the original injectors I would definately check.

[BR3W CITY]

I'm with the guys on the Misfire count number.

Large cam on low lsa means that the cam and crank position sensors will be putting out readings that will be too far "apart" and it will trigger random misfire codes. Also if your throwing misfire codes your converter won't want to lock up, or will unlock randomly if it does lock up.

A tuner should be able to adjust the misfire count in HPT and it won't trigger faults anymore.

[JJAB]

Thanks to everyone who offered their suggestions and advice. The tuner is supposed to do his magic this Wednesday.

[harnalien]

Is your tuner out of Waco? Interested in hearing how it turns out.
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[JJAB]

He actually resides in Bryan, TX. He is making the trip to Waco to do the inperson tune. I will keep you in the loop as to how it turns out. This will be his fourth tune for me. He is pretty knowledgeable.

[JJAB]

Harnalien, this is in response to your interest. The tune of the 1982 Blazer went awesome, aside from one glitch. It's somewhat comical now, at the end of the tune, they were running the truck so hard at times, a rocker arm bolt backed out and had to be retourqued.

Anyways, the tuner is very competent. The very first thing he did was adjust and fix the P0300 code. He also removed speed governing or rev limits. My customer was actually driving the vehicle as the tuner was sitting the passenger seat doing the tune. Long story short, it is definately to anyones advantage to have a pernonal tune done as opposed to a mail order tune. The custom basically marries the computer and it capabilities to your vehicle and its mechanical capabilities.

[harnalien]

Awesome! Thanks for te reply. I'm really looking forward to getting mine tuned correctly! It's definitely got power, but I want it to be "right." thanks again for the update.
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