Can I run 42# pound inj. with out a custom tune?

[Danny's 94Cobra]

I am completing my rebuild 306/w S-trim. Currently I have 30# with a Cartech adjustable FMU and Aeromotive regulator. I have also installed a 255 intank and a T-rex inline. I have already purchased 42# with the meter to tune my car without the Fmu. However I wanted to break in the motor prior to tunning it with a custom chip. Should I break in the motor with the 30# and switch them at the time of tunning or can I still install the 42# right now with out a custom tune?

 

[a50sn95]

The meter should allow for it to run ok to break it in. 42's are notorious for idle issues though.
I use a Tweecer R/T...

 

[Venom351R]

just install them now, you dont need to break in the motor w/ a specific injector Its not part of the internal moving parts that require a period of break in. I was running #30's for awhile but they were still not enough so I bought a set of #42's and there were in the day before I went down for the dyno tune.

 

[SQUEEZE&STROKE]

The 42's are gonna make your car surge, stall, die, and waste alot of gas without a tune. I had just the 42's and calibrated mass air and it ran like crap until I got the chip

 

[1slow95]

Im running 42#'s with no tune and the car runs pretty good. I even have it idling at 850rpm's with only a small amount of surging. Just make sure you have a MAF callibrated for the 42's and you should be ok.

 

[final5-0]

Im running 42#'s with no tune and the car runs pretty good. I even have it idling at 850rpm's with only a small amount of surging. Just make sure you have a MAF callibrated for the 42's and you should be ok.

Mike

I'm not doubting what you say but .....................

I think you are the exception to the rule in your particular case.

I'd really like to see your complete combo and anything else you have done to make that feat happen.

btw ...... do you have any cold/hot start issues?

Later
Grady

 

[SQUEEZE&STROKE]

Mike

I think you are the exception to the rule in your particular case. ( I CONCUR)

I'd really like to see your complete combo and anything else you have done to make that feat happen.

btw ...... do you have any cold/hot start issues? (AHH YES, THESE ISSUES...ALL TO FAMIALAR

Later
Grady

J

 

[1slow95]

Mike

I'm not doubting what you say but .....................

I think you are the exception to the rule in your particular case.

I'd really like to see your complete combo and anything else you have done to make that feat happen.

btw ...... do you have any cold/hot start issues?

Later
Grady

No cold start issues, but I def. have hot start issues because of my stock starter. I just ordered a new one, so I'll let you know about the hot start situation next week. I think it does take longer to start if I try to start it after I just shut it off....

 

[final5-0]

Say Mike

You do know about the .......

hold the pedal to the floor trick, right?

Later
Grady

 

[1slow95]

What does that do?

 

[final5-0]

Shuts off the flow of fuel to the inj's while starting the motor

Later
Grady

 

[1slow95]

Cool, I'll keep that in mind!

 

[Danny's 94Cobra]

Thanks for the advise

Thanks for the advise guys I think I will leave my 30#s to break it in and install the 42# right before the tune. By the way I do have the meter calibrated for 42# already but it is not the funnest thing to remove from inside my fender. So at this time I think I will leave my 30# in and remove my meter only once to tune.

 

[Venom351R]

No cold start issues, but I def. have hot start issues because of my stock starter. I just ordered a new one, so I'll let you know about the hot start situation next week. I think it does take longer to start if I try to start it after I just shut it off....

mine suffers from the same thing. If I go to start it soon after shutting it off it just cranks but wont turn over. I have to hold the gas all the way to the floor then it starts up fine. Its only done this since the #42 install.

 

[final5-0]

mine suffers from the same thing. If I go to start it soon after shutting it off it just cranks but wont turn over. I have to hold the gas all the way to the floor then it starts up fine. Its only done this since the #42 install.

Hey Travis

Maybe you could ask the guys who tuned your car if they could dial back a bit of fuel in the start up table

Later
Grady

 

[Wi Stang]

I must have got really lucky then. I have 42# injectors and matching maf with my setup, and I haven't had to change anything yet. The first time I fired it up, it ran pretty good. It idles around 850 rpm, and I don't have any stalling, or hot, cold start issues. It fires right up every time (so far). I am going to the dyno in a week to get it all dialed in.