We hurt the 496....
11-25-2024 | 09:47 AM
#351
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From: SW Ohio
UnderPSI,
Probably. That's my way. But that's how I've gotten to be the toolmaker I am: asking questions. I'm not trying to find a way to an answer I want. I'm trying to understand how things work.
Thanks. Brad.
Probably. That's my way. But that's how I've gotten to be the toolmaker I am: asking questions. I'm not trying to find a way to an answer I want. I'm trying to understand how things work.
Thanks. Brad.
11-25-2024 | 10:03 AM
#352
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From: SW Ohio
Ryan,
Planning to do just that.
Does this "fuel prime" just run the pump up to pressure or does it open the injectors for a bit beyond just normal cycling?
Thanks. Brad.
Planning to do just that.
That`s person #3 that agrees it`s not an issue yet you`re still going.
If you`re not going to believe the advice you get why bother asking the questions??.. dont be an askhole Brad
Dan,
I don't think asking how things work, instead of just accepting "Trust me, bro", is being an askhole. It's how we learn. Again, I'm not trying to find the answer I want. I'm seeking answers. And, so far, I've just been redirected to not worrying about it. At the end of the day, I will, in fact, "just send it". It obviously worked with the OEM rail after getting the injectors back in order in '22. But it seems odd that, among the expansive knowledge base here on OSO, this information seems to either be some big secret or just not known. And, for the record, there are opposing opinions on how to set all this up. If I were to just "go with it", I still wouldn't know which way to go. Understanding out things ACTUALLY work is how we sift through the good advice and the BS, both of which flow like water on these forums.
So just leave the hose off the fuel rail while you run the fuel pump .. then you only have this so terrible "air" only in the fuel rail.
Holley will "fuel prime" on key start .. it will only do it once untill it sees rpm.
If you`re not going to believe the advice you get why bother asking the questions??.. dont be an askhole Brad
Dan,
I don't think asking how things work, instead of just accepting "Trust me, bro", is being an askhole. It's how we learn. Again, I'm not trying to find the answer I want. I'm seeking answers. And, so far, I've just been redirected to not worrying about it. At the end of the day, I will, in fact, "just send it". It obviously worked with the OEM rail after getting the injectors back in order in '22. But it seems odd that, among the expansive knowledge base here on OSO, this information seems to either be some big secret or just not known. And, for the record, there are opposing opinions on how to set all this up. If I were to just "go with it", I still wouldn't know which way to go. Understanding out things ACTUALLY work is how we sift through the good advice and the BS, both of which flow like water on these forums.
So just leave the hose off the fuel rail while you run the fuel pump .. then you only have this so terrible "air" only in the fuel rail.
Holley will "fuel prime" on key start .. it will only do it once untill it sees rpm.
Thanks. Brad.
11-25-2024 | 10:13 AM
#354
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From: Grand Rapids, MI
11-25-2024 | 10:37 AM
#355
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From: Chicago
You should start learning this stuff ..download the Holley software .. you are going to have to do your own tuning .. Things like cold or hot starts can`t be tuned on the dyno and you only get one chance a day for a cold start ..took me a while to get that dialed in
Description: For MPFI applications, the system will inject a single pulse of fuel, after the first crank pulse is detected. This will only re-occur after an engine starts. Above this value, no fuel will be injected when the engine is cranking/starting. For TBI applications, the system will inject a single pulse of fuel when the key turns on to wet the intake manifold. This will only re-occur, after an engine has started. If you cycle the ignition key multiple times, it will only perform the first prime.
The “Fuel Prime Percent” is a multiplier that works off the “Cranking Fuel” Value in the Startup Enrichment table. The pulse width of the single shot of fuel prime fuel is based off the Cranking Fuel value (which is temperature based) and multiplied by the “Fuel Prime Percent”. A starting value of 200% is usually a good point for MPFI engines and 50% for TBI applications.
11-25-2024 | 11:36 AM
#356
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From: SW Ohio
Oh, HELL no. The whole reason I ended up with this Holley HP ECM is because the previous owner wouldn't STOP fiddling with it. Or, more to the point, wouldn't stop allowing his buddy, who apparently didn't know what the farq he was doing, fiddle with it. The guy I got it from is an acquaintance of my builder. Apparently, the seller kept allowing the OTHER guy to fiddle with the tune, instead of doing what my builder was telling him to do, and he got frustrated with it and went back to carbs. I got the ECM, harness, 3B MAP and FP regulator for $1300, because he wouldn't stop fiddling with the tune, and could never get it to run right. I told my builder that, if anybody was going to be adjusting the tune, it was going to be him. This is not to say he isn't going to educate me on some aspects, such as the startup prime parameters, that I might be able make adjustments to. As I've stated, he already has a base tune that he thinks should be close; this isn't his first rodeo with an HP. And I'm sure there will be a couple three trips to the ramp with a laptop getting it dialed in. I suspect we are going to be doing a fair bit of boating together, at least for a while. I will have capacity for O2 sensors in both banks, so I will be able to at least monitor AFRs.
But knowing that, or at least it appears, the injectors do, in fact, let more than a typical cycle of fuel (or air) through at key-on, is precisely what I was asking.
Thanks. Brad.
Last edited by Brad Christy; 11-25-2024 at 11:42 AM.
11-25-2024 | 11:57 AM
#357
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From: IL
Brad,
my current situation, I personally I like the way they look stock but you do you, by the way you should have a fuel schrader valve on your fuel rail. I owned numerous 496s throughout the years they all had them.
11-25-2024 | 02:49 PM
#358
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From: SW Ohio
That looks cool. I particularly like the Corvette flags badging. How did you paint them, being plastic and all?
Yes, the OEM fuel rail has a Schrader valve. I just figured that a FP gauge anywhere on the high pressure circuit would suffice. I can add one easily enough, and will do so before final assembly.
Thanks. Brad.
11-25-2024 | 03:16 PM
#359
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From: IL
11-25-2024 | 06:44 PM
#360
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From: Murrayville Georgia
when I built my '60 cadillac with the LS I used a corvette filter/regulator unit that is mounted at the tank so it returns in the first foot. from there it has 20 ft of fuel line that is dead headed at the fuel rail so no purge for the air other than the injectors. it only took a couple of cranks and it fired right up. air bleeds out of the injectors real fast so I wouldnt worry too much about it.
