gergrx7

Hey guys,
I have had my rebuilding running for a little over 900 miles. it is running great with 720cc primaries. i was to tired to try to mess with it to get 550cc injectors to work so i haev been running 720primary/550 secondary for a while now. but today i put 550cc back in primary to see how it would run but it wouldnt run right at all. it fells like its stariving for fuel. it pops like crazy adn wont rev up. when the 720cc injectors are in primary it runs dececnt. i can actually drive it this way although it runs rich. i have never herd of anyone running to lean down low with 550cc injectors on the stock turbo with jsut a streetport. oh yea the injectors were professionally cleand adn both are working. right now they are being used as secondary adn it drives runns fine over 3800 when they turn on. any ideas?

HeffBoost

But you didn't mention what you're doing with the safc. If it was set to run the 720s as primaries, then you switched to 550s w/o making a safc change, it would run bad.

It's only logical to run the bigger injectors as secondaries.

gergrx7

well that happend at first because with 720ccs i haev it -5%--8% from 1200-3400 adn first time i started it i forgot to switch that. so i set it all back to zero adn still ran like ****. i dotn kown what to do

ilike2eatricers

Did you use resistors for your 720s? Maybe you need to take them out if your 550s are high impedence.

gergrx7

i have a 3/87 low imdependence. and 720ccs are low imdependence btu i dotn know if my 550s are high or low. but they either came from thsi car or other t2 adn both are less than 6/87 so would be low imdependnce.

gergrx7

bump

rotaryrex7

Tan top 550s are low impedence.

gergrx7

they are tan top with the 1370 part #

SonicRaT

iTrader: (6)

sure they're functional? Take an ohm meter to them.

gergrx7

my car is running over 4k right now, adn i also tested them with jumper box adn they are coming out with steady pulses. my car SEEMS to be runnign fine over 3800 when secondaries are comign on, which is where i haev 550s right now.

HAILERS

Spend some dough on a wideband and solve your problems.

Donn Hecht

From what my understanding is, and from what ive seen and heard on this forum is that you cant run 720's in the primaries running the stock ECU. I would like to know how in the hell did you get the car to run with 720's in the primaries ? Im not saying it cant be done, however the car would run so pig rich its not even funny, and you would be wasting a lot of fuel. Looking at your setup I would run the stock 550's in the primaries, and the 720's in the secondaries, thats exactly the same setup im running on my Turbo-II with out a S-AFC. I know for a fact you can run 720's in the primaries using a aftermarket EMS of your choice, but running 720's with the stock ECU impossible in my opinion, yet it can be done at the expense that your car runs like crap. I think that your injector combination for the setup that your running is overkill in my opinion, after all your not running a bigger Turbo so why would you go with that injector setup in the first place ? You should be fine running 550's primaries, and 720's in the secondaries assuming your running the stock turbo. Any ways to fix the problem start with the 550's in the primaries, and the 720's in the secondaries, and as "Hailers" said spend some money on a wideband, and hit the dyno to fine tune your S-AFC. Or even better sell the S-AFC, and get a real aftermarket EMS. If after this you still cant fix your problem talk to NZConvertible, or RETed they could lead you in the right direction. Good Luck

Bukwild

not to sound like a ******* but are you sure you have your primaries and secondaries straight. Sounds like you might have them swapped in the fuel rails

gergrx7

Donn Hecht i am running 720s in primary adn 550s in secondary right now, not by choice. the car will not drive with 550s in primary this is the whoel point of this thread. i dont understand why it wont run on those. i would like to run on 550 primary btu my car wont run like that for some reason. my car idles fine adn drive fine with 720s although its running RICH as hell. its so bad i have safc leaned out to -7% from 800-3200 but its still rich. i wanted to try to figure out injector problem before i went to dyno so i dotn waste money. i guess im just going to have to save up soem more or find someone witha widebadn and see what a/fs are with 550s in primary. because when i put them in the car feels like its leaning out REALLY bad. and i dont konw what you mean its impossible to run 720s in primary because i am doing it, its the only way teh car will drive.

Bukwild i have 720s in primary adn 550s in secondary i WANT to run 550s primary but for some reason the car doesnt want to run like that.

ilike2eatricers

720s will work in the primaries but are a little harder to tune. What impedence is your car stock? I'm not sure of the switch over from high to low impedence on 88s. It could be that your stock impedence is low and your secondary 550s are high impedence so that isnt working out. Do you have an oem resistor pack?

gergrx7

DUDE read the damn thread i already said that i haev a low independce car with low imdependence injectors and even then why would they be working in the secondaries btu not primary.

HeffBoost

The following is meant in earnest. Something's funny here and just to clarify since it just doesn't make sense.

The Primary injectors are the ones in the intermediate plate and the Secondaries are in the manifold, right?

Unless somebody wired it backwards or something, I just don't get it.

gergrx7

yes the primaries are the 2 that are next to each other on the intermideate plate adn teh secondaries are on teh LIM. i haev rebuilt my engine i know all this stuff, i jsut want to konw why my car wont run with 550s. i didnt do that big of a port to make it need more fuel than that i wouldnt think.

ilike2eatricers

Is there any chance you might have the injector harnesses on the wrong injectors? This is pretty confusing. Right now you have 720s in the primary and 550s in the secondary. Hypothetically, what if you had the harnesses for the injectors switched around? Your primaries harnesses would be telling your 550s (in the secondary to fire). Maybe this is why when you switch the 720s to the secondaries you are having trouble running correctly. If my theory is right then, when you swap the 720s to the secondary they are firing as the primaries causing you to run like crap.

This might seem kinda far out there but something isn’t right here.

gergrx7

no i haev the wiring right, but the car will literly pop adn will not rev up. before the motor blew i had 720s firing in secondary stpo as primaries adn it didnt run like its runnign now. with 550s in primary section with primary harness pluggd into it it just runs like crap. with 720s in primary with primary harness it runs decent, enough to idle adn ride around town with. i am going to take 550s out and have them flow tested to make sure they are working properly adn haev them install new screens. i hope that will fix it.

gergrx7

ok well after 8 hours today of messing with it i can it to where i could drive it. 550s are in primary right now. i had to adjust the timing so much its not even funny. there is still a problem though it runs like crap from 1k-2k. hesitats REALLY bad, btu once im over that its fine. i dotn konw what i should do. btu im just glad i got it running with 550s in primary. just would like to haev little hesitations gone. need to reasearch streetport timing.