• Should I install 24 lb. injectors with my current setup? I currently have 19 lb. injectors and factory fuel pressure regulator will that large of an injector require a custom prom? Im planning on installing an adjustable reg. and setting to 50 psi with the new injectors??? heres my current setup, thanx alot in advance...
• L98 355, 5-speed T-5,borg warner 9 bolt 3.70 gears 3,500 miles 9.5:1 compression,Lunati-voodoo 256*adv. duration .454 lift hyd. flat tappet cam, stock cast heads,comp magnum roller rockers,accel... 8mm wires,coil,ignition module,cap,rotor. Ac delco platinum plugs, modified airbox-open K&N filters with forced induction through foglamp delete openings,edelbrock headers and Y-pipe, hollow cat.,3 inch SLP cat back... Currently has 19 lb. 305 injectors and a hypertech 305 chip runs great but is def. held back!

 

I think 24# would be overkill, the 350 only requires 22#'s but either way you would need to get a chip that matched your injectors.

 

Get a chip and a memcal for a 350 and you would be decent as long as you don't end up running too rich @ WOT with that FPR.

Ideally with that cam though a custom tune would be the best option regardless of injector size.

 

Thanx guys, any rec. for proms? they want 400$ at local speed shop to tune one. my engine is pretty mild and I cant use vette 5 speed chip due to oil temp sensor which I dont have. thanx,patrick

 

f-bodies with 350 didn't come with 5 speeds at all you will need to have a custom chip made.

another option would be to buy the equipment and burn your own, it won't cost as much as a custom chip, but there is a learning curve involved.

 

Yep thats why I said vette 5 speed chip lol
What all do I need in order to burn my own prom. Im sure I could do it with some research and the right equipment, I am a forklift mechanic and worked previosly worked in gm dealers. thanks john

 

There was 350 6-speed cars, but I'm not sure how easy it would be to find a tune file for one, and I think they were SD.

 

New to this forum, any help would be great. This is what I have. 1985 Trans Am with Modded 355 TPI engine. Cam is a Comp Cams 218 duration 456 lift. Roller rockers, Headman shorty headers, heads are cast iron ported polished, decked, bowl cut with 3 angle valve job. Stock distributor with Accel 8mm wires. Comp Cams double roller timing set. No tuning or chip. The car has a hesitation on acceleration at any speed almost acts like a misfire, sometimes you can hear it backfiring through the intake. My question is, are the stock 305 19lb injectors enough for this engine? I have installed a adjustable fuel pressure reg. and set it to about 56lbs. It still acts like there is not enough pressure there. Would the 24ib injectors be better and if I installed them would I have to get a custom tune for it? Thanks in advance for any help.

 

install 22lb injectors, set the fuel pressure to stock 43.5 psi. First of all you need a 350 chip in there now, and a 350 knock sensor along with the 22lb injectors.

 

24lb would be fine with a custom tune,but you would have to have the inj. constant changed in the tune so the car would perform like you had 22lb inj, so it is pointless.

 

What cam is in it now? What is the LSA on that cam?

 

It seems as though your setup is much like mine used to be. I had a mild engine -much like yours and ran both 19 lbs and 24 lbs injectors and it ran fine both ways . Obviously has more ***** with the 24lbs although I did have a hypertech stage two chip. I wouldnt set the fuel pressure any higher then the rec. by the producer of the injectors or it will cause them to wear out prematurely . But anyway it sounds like you have a vacuum leak,intake gasket leak or head gasket leak. Trust me it is not the injectors causing your misfire. Although you should get larger injectors and a tune. Spray the whole intake manifold and rubber boot(after maf sensor) with starting fluid to verify you dont have any leaks. Get back to us with your progress

 

24lb injectors will run overly rich and waste tons of fuel and hurt performance. I got faster after i got my prom adjusted to think there were 22lb injectors back in there. Car would probably have more ***** with the 19lb injectors. In fact, when i ran my 24lb injectors without any computer work , i had to turn down the fuel pressure to get it run good/good power. Stick with the 22lb stock. A hypertech chip has nothing to do with anything. Not sure why that was mentioned. Hypertech chips are set to work with what ever the stock injector size is.

 

You need to get the correct chip/prom in there first for a 350 tpi. Then 22lb inj, then the correct knock sensor. Then go from there. Also,what is the LSA of your cam? It needs to be above 112 or you may need custom prom burned. That is probably why it is running the way it is. You also need to turn that fuel pressure way down to 43.5 psi after you get the correct chip, etc.