PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Tuning question? Speed density problems

Old Jun 11, 2010 | 08:20 PM
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Default Tuning question? Speed density problems

Long story short, I have a stock 6.0 with a single turbo in a 71 Nova. Attempting to start the first time I only have spark on #1 cylinder and it is really fast. No spark on other cylinders. Tech 2 shows 3500 RPM key on engine off.

Its a 99 F body computer that has been tuned to speed density, the rev limiter set at 3500 for a base tune, and E85. 95lb injectors.

I plug in a friends 02 Camaro computer and it has normal spark on all cylinders.

Today I get a new PCM and have the shop flash like before, back to the same problem.

What are they doing wrong?? I covered all the bases on my end and it works great with the stock PCM (cant start due to injector sizes-E85-etc)
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Old Jun 11, 2010 | 08:30 PM
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What kind of MAP sensor are you running? 1bar, 2bar, etc? Are you and the shop on the same page on that one?
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Old Jun 11, 2010 | 09:14 PM
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I have the plug and play Cobalt baro sensor and the tuner knows.
It has to be something they are doing but its hard for me to know as Im not a tuner just a gm dealer tech.
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Old Jun 12, 2010 | 08:44 AM
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Rev limit @ 3500, TEC shows 3500 and the engine is not running= shutdown. Did you have the 3500 programmed into the buddy's pcm, when you tested w/ it?
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Old Jun 12, 2010 | 08:58 AM
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Buddies PCM was just a near stock tune with Vats removed. Mine showed 3500, his showed 0 like I expected.

The tuner told me he set the rev limiter to 3500 so I wouldnt boost it until I brought it in for dyno tuning. Is this the problem?

Thanks
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Old Jun 12, 2010 | 03:05 PM
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Reset the limiter, and try it......
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Old Jun 15, 2010 | 06:48 AM
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Well he loaded a stock 99 LS1 tune back in it with the 95lb injectors. Now the car starts so it was something to do with the custom operating system etc. At least it runs now.....
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