parish8

iTrader: (6)

i started out with 21.8lb@58psi stock injectors or 2.74gm/sec
then i went to 41lb@58psi injectors and used 5.16gm/sec for a flow rate. it ran good but i was still over 100%duty cycle.
yesterday i bolted in some 50's 58lb@58psi, i used 7.20gm/sec to start with for my flow rate and the truck was way lean

after spending a good part of my evening programing and loging it seems in order to keep my ltrims anywhere near 0 i have to richen it up all the way to 5.2gm/sec. thats where i was before <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> once i got my ltrims near 0 i did some wot runs and guess what, my numbers are prety much identical to what i had before with the smaller injectors.

50lb/min maf, close to 6000rpm and 22ms pulse width with the old and the new injectors <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" /> WTF is going on here, the truck runs good, ltrims are between -5 and +5, o2's are falling off just a little right at the top. did i get the bait and switch scheem pulled on me? this are the injectors that i got http://www.racetronix.com/Racetronix...ctor_Sale.html

JAS

Does your fuel pressure drop?

parish8

iTrader: (6)

yes, i need a pump but it doesn't drop till about 5000rpm, that shouldn't effect the requested pulse width should it?

JAS

What's your fuel pressure at:

idle?
tip in?
50%+ throttle?
WOT?

parish8

iTrader: (6)

the fuel presure on the trucks are vacume/boost regulated

idle 50psi
tip in 55psi or so
50% throttle 58psi
wot 62ps1
than at the very upper rpms the fuel presure dropes hard, makes a quick dip to 45psi or so.

BigTex

iTrader: (16)

That doesn't look good to me. When I made the same move to the SVO 30s, my tuning was within 5% of the 36# calculation @ 59 psi.

I think you need to contact the seller. Their site has "all sales final", but if you didn't get the part you paid for, that needs to be corrected.

JAS

Those 50's in the picture on their website look exactly like the 50's I have from PTE.

What is your fuel pressure at idle with the vacuum hose disconnected to the FPR?

You injector table is flat correct?

parish8

iTrader: (6)

table is flat, about 59psi with vacume line unhooked.

could i have them hooked up backwards? i had to wire in diferent pigtails. all the pigtails had a grey wire with some other wire, all my injectors had a pink wire with some other wire, i matched all the greys to all the pinks.

JAS

7.13 g/s

Fix your fuel supply issue first.

If you dropping fuel pressure after 5K then don't rev it to or past 5K until you can feed the injector. The injectors aren't going to give you more fuel majically if the pump isn't suppling the volume.

Do you have pic's of you blower setup, etc?

<small>[ December 07, 2002, 05:40 PM: Message edited by: JAS ]</small>

parish8

iTrader: (6)

i realize the injectors are not going to give me the fuel without a pump also. i am working on a pump and it isn't an issue under 5000rpm.

this is a diferent problem, i enterend 7.2gm/sec, and was +25%lean, so i started droping by .5gm/sec untill my ltrims were around 0, ended up at 5.2gm/sec befrore the ltrims came in line. those injectors seem to flow the same amount as my old ones

Camaroholic

iTrader: (1)

I can't help here, but I can tell you a real story...

Friend of mine bought some "30# Ford injectors", lightly used, for his LT1 car. They had a different part number on them than the 30# injectors that I had in my LT1 car. He stuck them in his car, set his injector constant to 32, and his LTRIMS went to 160 (that's off the scale lean in the LT1 world). He started doing exactly what you did - set his injector constant down a #/hr at a time, until his LTRIMS settled to 128 (0%). He ended up at 22.5. I talked with a couple other guys who had issues like this with some used injectors, and it turns out that they were all running this same part number - everyone in the Ford world thought they were 30#, but stick 'em in an LT1, and they are not.

Moral of the story is, what works in one car may or may not work in another. My SVO 30# injectors work great in my LT1 car, and I run a constant of 32-ish. So, you may be experiencing something similar. But I don't know. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

FWIW. So, you may not be crazy after all. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Andrew

JAS

Did you do any mods from the time you switch from stock injectors to the 42's/50's?

MAF?

PCV mods?

Intake?

Spill the beans...

JAS

BTW, your previous injectors were 36lb @ 43.51psi ? Who's and part #'?

parish8

iTrader: (6)

well, seems like i am always doing something, when i put the 41's in i just set the injector flow rate to 5.16gm/sec since that is what the math said they should flow. i check my ltrims and they were something like +2% to -8%, not too bad i didn't think, certainly not worth messing with.

i have a stock maf and stock TB, i havn't touched any of the tables in ls1 edit that might effect my maf reading. now with injectors that are suppose to be 40% larger than before. i shuld have to increase the injector flow rate to get the ltrims close. it really seems like the injectors are alot smaller than advertized.

since i checked my ltrims with the 41lb injectors i have put in a diferent tranny, welded in a h pipe in the exhaust, removed the egr. nothing major. i am about ready to pull one of those injectors and run a flow test on it.

JAS

Why are you chasing your tail?

Do you still have the so called 41's?

Put them back in and use the old # and check ltrims.

I can't help you if you don't answer questions directly. I asked you for the part # of these so called 41's.

Not to be abrupt, but ANY mod can screw things up. YES, even EGR removal, exhaust work, etc.

You say you got rid of your EGR system in between. Did you check the egr seal? Do you realize what the PCM program is looking for in oxgen content change during EGR activation at certain RPM levels?

Hate to say it, but if you are going to blame the injectors, then the ONLY and I mean ONLY change you should of made was going from 41lbers to the 50's. NOTHING ELSE

At this point with me only knowing 1/1000 of the total picture, I'd say you are the victim of the age ole to many mods at once.

Now you should (have to) back track until you find out what is NOT making sense.

You can try masking the issue with adjustments and that's your call, but you'll only be compounding issues in the future.

parish8

iTrader: (6)

dude, chill out, it took me 6 hours to change those injectors and would take just as long to change back. the truck injectors are diferent than the car injectors so i had to modify my fuel rails, fuel cross over, injector conectors and pull the blower to do the work. since i had the blower off i got rid of the egr while i was there. the egr has been unpluged for months so that is nothing new.

i got the 41's from rc engenering and they came with a flow sheet, they are not a part number you or anyone else will know becasue they fit the trucks and no one in the car section would be using them, the numbers on the injector are delphi 0030C C3A 25176061

i have checked, listened, looked, used propane and carb cleaner to try and locate any vacume leaks, the truck idles smooth and runs fine. with the blower growl and taping injectors and exhaust sound it is hard to tell for sure that there are no vacume leaks. is there any other way for me to check. i would think it would be idleing high or ruff if there was a leak, it also seems like the ltrims would start lean under vacume and go rich under low vacume or boost and the ltrims seems prety steady to me.

edit... i do apreciate the help

<small>[ December 07, 2002, 09:07 PM: Message edited by: parish8 ]</small>

parish8

iTrader: (6)

hmm, after looking at it for the 50th time and looking at all help i have recieved i decided to double check where the injector plugs into the manifold, Big Tex told me the orings are kinda small but i had them instaled and running before i read his mail. it looks like i may have a huge vacume leak at many of the injectors, i just wasn't using enuff carb cleaner to hear a diference. once i held the can of cleaner wide open i could hear the truck start to stumble a little. i think thats the problem and i am going to try and fix it right now.

JAS

Jim - Drop me an email with what's on the flow sheet for those injectors. btw, I don't know if a BAP will be enough in the long run.

<img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

<small>[ December 08, 2002, 01:37 PM: Message edited by: JAS ]</small>

parish8

iTrader: (6)

i am prety sure i had a small vacume leak around some of those orings but fixing it didn't seem to help much. my ltrims moved alittle so now i am -6 to +4 or so across the range. i don't understand what is going on but before i do anything else it looks like i better get the fuel pump issue worked out. it runs good, my ltrims are good, it seems to drop presure alot sooner now wich would indicate the injectors are asking for more than the pump can give sooner. just have to get a pump and see what happens then.

Pro Stock John

iTrader: (34)

I have friends who have made 630rwhp with 42's and 699rwhp with 50's so I think you have a different problem assuming you have the right injectors.

IMO you are losing too much fuel pressure and you need to fix that first, my car has had bad pumps and we could not properly dyno the car.