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holley commander 950 EFI..AGHH!!!!

oneofthefewbmx

oneofthefewbmx

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guys, i swapped out my holley truck avenger carb for a holley projection commander 950 EFI setup trying to get rid of some problems i had with hesitation and stumble....this setup has its own computer software and everything...i have it pretty well tunedi believe except starting the engine while it was been running for ANY amount of time....the thing will start right up when it is dead cold after sitting all night, but after that if it warms up at all it is a mother to try and start agian....is there anyone that lives in central texas that can try to give me a hand tuning this thing?? or do yall know of any shops?? the place that holley reffered me to apperently does nothing but make harmonic balancers so that doesnt help me out....any input is appreciated....thanks!
 
maybe just maybe, maaaaybe its running too lean? First thing that popped into my mind but i dont know much about tuning or engines =(

You know how usually on a truck, when you cold start it it runs pretty rich for a few minutes? But if yours is starting instantly and then its a b*tch to start later... Thats why that came to my mind.

Does this holley commander require a high flow fuel pump???

Kind of talking out my @$$ here but im trying to be helpfull..
 
yea i think it may be running kinda lean afterwards...ill try messin with that....and yea, the kit came with a high flow EFI fuel pump...thanks for your help
 
I run the commander 950 in my K5.

Did you mess with the startup enrichment at all? ...don't mess with it yet.

The 950 allows you to prime before you start, just like a carb, with key "on" (make sure the fuel pump comes on to build pressure" press the gas pedal to the floor once or twice. The ECU will fire the injectors to prime the engine. If this makes it start right up then you know you need more cranking enrichment.

If this doesn't help, post back here and we'll see what else we can figure out:)


Does it only do this after the engine is hot and you try to restart?


__
 
ya it only does it when i try to start it when it is hot...i think im going to change the coolant mods all to 100 and see if it works out...i think it may be dumping too much fuel when the engine is hot....i will try that and get back with you, i appreciate your effort to help me....
 
How old is that kit you're using?

Did you buy it complete originally?


I read an article in one of the rags (Chevy High Performance) about a Holley system that they cobbled together with a throttle body and a newer controller/software. From what I remember, they were having all sorts of problems with it until someone figured out that the one version would only fire half the injectors until full-throttle and the other system fired all 4 injectors all the time.

I can't remember if it created a lean condition, or an over-rich condition. But your description reminded me about that article. Something to check anyway......

The 950 Commander is in my plans, so I'll be subscribing to this thread to see what you find out. Good Luck.
 
Being unfamiliar with this system, can you not identify the temperature the ECM sees that generates the no-start, and then work on that range of temps only?

Making a blanket change would seem to be a bad approach, you may generate problems where they don't exist now.
 
I have a good mechanic I use when I get in over my head, or just plain don't want to do it. :doah: Anyways, part of what I like about him is that he loves to build 4x4s. Right now he's working on a Jeep Comando with TBI350, Sterling rearend, Alcans, Atlas, etc.

He was telling me about installing a Holley FI setup in a Chevy pickup. They had problems getting it to run right. Their problem ended up being a factory installed restrictor in the fuel return line. They took that out and it ran fine.
 
thanks alot for the quick replys guys, yall are awsome...yea the blanket change may be a bad idea BUT i may just save it under a different name so i can always just go back to the old one if this messes it up really bad....also what year was that truck that had a resrictor in the fuel line? i replaced all my fuel line with fuel injection line so its probably alrite, im just curious what year that truck was for future reference...as far as the "complete kit" goes, i bought it from a guy that had it on his tahoe for a long time....it had that harness and ecu and a few sensors...so i had to buy a brand new fuel pump, and while i was at it i bought allll new sensors so i would have no doubt that whole system was working properly....i do believe tho, that the system is pretty friggin old, like 10-12 years or so....but i found on the internet yesterday that a few years back a kid designed a program to "auto-tune" the system. but this is only for the fuel maps, not for my starting problem, but it wouldnt hurt me to at least see if the fuel maps will help my running performance....anyway, thanks again for yalls support
 
Another thing I'm remembering from an article was an interview with some engine specialist shop talking about the most common EFI mistakes.

One of the biggies was making sure that the system was seeing correct voltage (ie. make sure you don't have charging system issues). Apparently, low voltage causes all sorts of bogus sensor readings and the FI system then makes all sorts of bad decisions about how much fuel to add.....

Something else to consider.
 
Not to completely hyjack your thread, but what is the general consensus as to which system is prefered between the Holley Commander and Edelbrock Pro Flow?
 
i have no idea because ive never messed with the pro flo but this system is pretty straight forward if you have any idea what your doin you can adjust everything...but like i said, i dont know what the pro flo has to offer....as far as problems with mine go, i think it was the low voltage so im getting a new alternator tommorrow...thanks for your guys' help!!!
 
Can you post the link to where you found the program for "auto tuning" I'm curious to see how that works.
 
oneofthefewbmx said:
wow that is probably part of my problem! awsome THANKS! im fixin to go take care of that then and see wat happens...thanks again
Click to expand...

If you want to read the whole article find a copy of

Chevy High Performance, August 2006:

Here's the excerpt I'd remembered....

EFI_Top_5.jpg
 
Not sure what year the truck with the restrictor was. I'll have to remember and ask the mechanic about it.
 
Anyone have that "auto tuner"?

I would love to have it myself.
 
i got ahold of the guy that was working on the auto-tuner, and he said he is no longer doing anything like that....he now builds honda civics or the like....kinda sucks....sorry
 
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