Holley TBI 670

[JeffHK5]

Got a mild 454 with the non-digital Holley 2 kit that I just installed with good results. It starts, idles and runs up to 4,500 RPM great but all most will not start when hot!

When it does start, it blows black smoke like it's way rich for 1-2 minutes.

Is it the temp. sensor making the computer think the engine is cold or could it be deeper than that?

It does not matter if its been running for 10 min. or 2 hours!

I have looked through past posts and have had no luck answering this question.


Thanks, Jeff

 

[1-ton]

What is the Holley part number for the TBI you have. Does it happen to be 502-20S?

 

[JeffHK5]

I actually have a 510-502-20S(Jegs) on my rig , which is the digital version of the one that's on my buddies truck. The non-digital one that I just put on my friends rig is the one that's giving me fits! Both our systems run the add-on closed loop oxygen sensor and for the most part work great on low RPM big blocks.

Other than my ECM saying "DIGITAL 2D" on it our EFIs look identical.

I just looked at what I typed , man I hope you can fallow what I was saying........ ...........

Thanks, Jeff

 

[1-ton]

It sounds like your trucks ECM thinks the engine is cold all the time. Make sure the ECM temp input unit is working, and that you wired up the Holley closed-loop kit properly.