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Injector and pump flow

  
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Injector and pump flow

 
chevyheart chevyheart
New User | Posts: 5 | Joined: 11/12
Posted: 11/12/12
09:31 AM

Hi to everyone. Lately I've been having a lot of problems with my stock Q-Jet. For this reason and with the need of saving fuel I would like to convert to EFI.

However there's a world of options out there and I would like to build my own MPFI setup. Discarded the TBI route 'cause there isn't much difference since it's a wet flow system (as far as I've read).

With all info out there I'm getting a little confused about the size of the injector and fuel pump to use. Some say there's a way to determine that by means of a formula.

Can anybody clarify this for me plase?

Thank you very much your help will be appreciated.  

waynep71222 waynep71222
Enthusiast | Posts: 448 | Joined: 03/12
Posted: 11/12/12
10:51 AM

welcome to the forums...


before we get into discussion about injector sizing and fuel pump flow rates..

you should know.. that if you have other issues with your motor that seem to be carb related but are really not... then you are going to have serious issues with your fuel injection conversion...

there are a bunch of us here who can talk you through most issues if you can do the greasy work on your end..

you might want to describe your exact issues with us.. then run a few diagnostic tests.. and examine some of your components..     your issues could be really really easy to fix...

start with year.. make model..  engine type and size.. ignition system type.. carb number.. cam specs if other than stock..
an idle manifold vacuum reading would also help...  

chevyheart chevyheart
New User | Posts: 5 | Joined: 11/12
Posted: 11/25/12
02:45 PM

Well you're right there could be ton of possibilities other than the carb, and went the easy route swapping my carb for a frind's carb and the problems went away.

Tested fuel pressure and is constant at 5psi, so it seems it's the carb. It bogs off-idle, hard starting when hot and sometimes in cold starts (like if choke isn't working).

'82 Chevy C10 350ci HEI 16in-hg with stock cam, compression, heads, etc.

No longer want the Q-jet, I know there are some pretty good Q-jet tuners out there but in my opinion is a losing battle. When this carb ran ok, everytime conditions changed, like altitude and temperature, so did performance.

I had the chance to drive a couple of old cars converted to EFI and they drive like new cars, so I think EFI is in the truck future.

Thank you! your help will be appreciated.  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 11/25/12
03:18 PM

A Holley TBI is one of the best going right now. That could change next week. The Cup guys converted to them. They still get the same mileage. But the performance is better. That set-up from what it was a decade ago is so much better hands down.
  Like you said they drive and perform like New Cars...They run the same hot or cold. Is your 82C10 used as a cruising truck, or a daily driver? Let us know I'm sure someone will have had some experience with one type ot another.

Bob  

chevyheart chevyheart
New User | Posts: 5 | Joined: 11/12
Posted: 11/27/12
11:37 AM

It's a daily driver and a vacation flagship, that is 10-14 hours of driving, so I need it to be reliable and find spare parts even on 7 Elevens (kidding), I don't know if going MPFI is really going to make much of a difference in the mileage.

Your input will be greatly appreciated.  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 11/27/12
12:52 PM

chevyheart

When we did our winter vacation to Florida for the Daytona 500. I would only stop to get gas. We lived in New Jersey at the time. I did a lot of driving for my job. So my bladder cotrol was a lot mere the (2) and (2) boys and myself...LOL...

Just back 10 years ago you needed a Lap top to calibrate the Fuel Curves and timing curves. Today it's on a touch key pad. You choose what you want. So a 10 to 14 hour run you can change the calibration by changing the settings on the Touch Pad. Nice set-up.

Bob  

chevyheart chevyheart
New User | Posts: 5 | Joined: 11/12
Posted: 12/17/12
12:13 PM

All right Bob thanks, was a little busy but I'm back and yeah you're right about current offerings, in fact I'm drooling with Holley's Dominator EFI ECU. Also found some nice tools (talking about hi-tech) and want to share with you:

EFI Math

https://play.google.com/store/apps/details?id=com.mexicanchevyshotmail.com.mexicanchevys.efimathandroid

https://itunes.apple.com/us/app/efi-math-ipad-version/id573605062?ls=1&mt=8

https://itunes.apple.com/us/app/efi-math/id571695726?mt=8&uo=4

Thank you!!  

pepsi1 pepsi1
Guru | Posts: 1718 | Joined: 09/11
Posted: 12/17/12
06:36 PM

chevyheart

Many thanks. Merry Christmas.

Bob  

chevyheart chevyheart
New User | Posts: 5 | Joined: 11/12
Posted: 12/26/12
10:56 AM

You welcome, thank you too and Merry Christmas and happy New Year!!