I already did a search but didnt find a complete explanation.What do I adjust to make 30# SVO injectors work?

 

Under ECM constants, the second constant should be Injector Flow Rate. Type in the number for the SVOs lbs/HR flow rate, save, upload the file to the car.

 

Thats the part I already knew. Isn't there another table you're suppose to modify? Also whats the formula to compensate for the lower fuel pressure that SVO's are calibrated for? I know you're suppose to set them around 31.5 lbs but wanted to do it with the formula.

 

The formula is the Ford SVO pound rating times the square root of (GM fuel psi / Ford fuel psi), which I believe is either (43 / 39.5) or (43.5 / 39). So it's either 31.1 or 31.7.

I think someone else knows for sure.

You'll also want to change the injector offsets. Do a search in this forum for a link to a table. The Somewhere between the 24# and 42# table should work well. No one seems to have found Ford's rating for the 30#.

 

Thanks, found the table.
31.7 I believe is correct.

 

I set the high slope on the FR 30# injectors to 31.5 , to start, but remember, the constant is not set in stone. On fords, I set the them for 28 and 31.5, for high and low slope, to give you an idea. Good luck!

jim

 

Try putting these #'s in the "injector offset vs. Battery voltage table" from this site.
http://carprogrammer.com/Z28/PCM/Injector/injectors.htm



Brian

 

Are those offsets correct? They seem to be way off of what the factory settings are. Even the table for GM Multec inj. are way off of what the ecm has set. Also, I dont believe tunercat allows you to factor in a number after the decimal point; it rounds to the nearest whole number.

 

Try mulitpling the oem offsets by 1.4 for 30lb svo's

 

Steve,
Thanks for the input. Those numbers seem alot more logical then the ones on the fi sight. How did you determine to multiply by 1.4? Is there an equation to figure this out?

 

Something I ran across on dyi-efi web site. I had used the offsets from another site and it started great but had some strange blm's. changed to stockX1.4 and it cleaned up the blm issue, I'm still working with vemaster to try and get 128 in all cells, getting closer.

 

So modifying the VE tables in your car is working to bring the blm's in check?
Or are you changing the offsets based on what you see from VEMaster or something?

 

Steve,
How about some input on straightening up the blm's; that was going to be my next project

 

I had time for a 30 minute data log today, a little freeway then over a country road with a 50 mph speed limit , trying to hit all cell/load varibles. Ran it thru vemaster, burned it and another datalog shows 126/130, much better than before. I still get high split blm's on decell I got two short wot runs, both times it hit cell 18 and a blm of 128 It appears VEmaster worked for me. I've just spent the last four hours comparing .lt1 files I have collected on the web kind of interesting how pro tuners change things. I've put together a tune I want to try tomorrow if it's not raining. I've got a dyno day on the 18th, so I would like to have everything ready for that. I'm hoping for a good turnout for the dynoruns, I would like to talk to someone who has played with PE. If anyone needs a copy of vemaster, I have the newest ver, email me and I'll send you a copy (freeware)

 

Dan, as far as I know (not much) the offsets have an affect on starting, (hot or cold) and idle. When I installed my 30lb svo's, I changed the constant (inj size) but not the voltage offsets. It was hard to start, had to crank for five seconds and hold the throttle open. After changing offsets, I can cold start with a one second crank and have good cold idle.