Justin96z28

I have 2 bad injectors on my car right now so I am going to be replacing the entire set obviously. Currently the car has a dynotune from pcmforless for the stock 24lber's with a cc503 cam lt's etc. Anyway I wanted to know if I can get away with running 30lb injectors on said dynotune for a little bit till I have SOLOMON do the email tune. Or should I just get 24lbers again. I plan on getting ported and polished heads in the near future. Oh along with the injectors swap I will be putting on my 58mm tb that I have laying around too when I put the new injectors on. Also will be putting on my ported MAF too. Like I said I will be retuning within the next month via solomon, as I really do not like the dynotune PCM4> did on it. All help appreciated, thanks guys

hrcslam

No, you'll need to tune with the new MAF (I wouldn't recommend using it ever), you'll need a new tune for the 58mm TB (especially if auto), and you'll need a new tune for the injectors (that's a 25% increase in fuel flow, the PCM can only remove 18% and that doesn't mean it will, also need to account for injector voltage offset).

I'd do everything (not the MAF, ever) at once with the head swap. It'd be cheaper to have your current injectors sent off and cleaned/refurbished.

Justin96z28

CANT AFFORD THE DOWNTIME..... I can get new 24lbs for 164$ And I am a M6. The new maf I know to stick on at time of tuning. As for the 58mm tb i've had it so I'm throwing it on when I do the injectors. So I couldnt run a month on 30lb's?

Justin96z28

but I also could get 30's for 110$ so thats where I am.. But if the 24s arent going to max out with new heads than I would just stick with 24s

hrcslam

M6 helps with the TB, you don't have to worry about cooking the trans. It should still be tuned (along with the MAF) when installed but should survive just fine for a little while. The MAF will change your calibration and should be tuned when installed, although it's (the MAF) not needed, at all.

The injectors will not do well without also changing at least the flow rate constant in the tune from 24 to 30. It will run very poorly and rich and it is well outside of the range for the stock PCM to trim out. You'll also want to adjust your injector voltage offsets, but that's not going to effect the engine nearly as much as the flow rate will. The injector voltage offsets will effect the engine, noticeably depending on how much different they are from what is installed right now, but not as much.

Can you buy just the 2 you need? That's better in a pinch than putting 30lb injectors on a tune for 24lb injectors.

What are the two injectors doing? Is it an electrical fault? Are they clicking? Or are they not flowing anything? You could try cleaning them out your self instead while you wait for the new injectors and tune. That would be the cheapest way if the solenoid is still clicking away. If they are not clicking, did you swap them with working ones to make sure it's the injector and not a bad connector? If the injectors are not clicking, I'd say buy only two and swap those until you get the tune and 30lb injectors in.

Justin96z28

not clicking at all. bad fuel was ran through them that was sitting for 5yrs the previous owner told me and just killed em i am assuming i hook up a random set of ev1 injectors and they click away. cy 6 doesnt click cly 2 doesnt either... i sure i have others nothing pumping either lol.... Just installed a new 340lph fuel pump and fuel filter also, its getting fuel, and spark also as I swapped the opti 4times before i got one that actually worked, put a new ICM in and coil to, as I originally thought the problem was opti relate and just swaped everything on my ignition system, come to find out its just bad injectors and I could of saved myself a pretty penny and frustration. Guess I will just pick up a set of 24lb injectors and throw them in. there ev1 w/ the 4hole spray pattern. new from tre or some ish. after this if the car doesnt run im burning it to the ground. btw what lb injector u running with the 414rhwp?

sorry the 24lb injectors claim to be 250cc which I would think is 25lb injectors... I dunno but I went ahead and just got the 24's for now and hopefully i can get away with using these without maxing the duty cycles out

AdsoYo

iTrader: (1)

FWIW I'm putting about 360hp to the wheel and at 6,000 rpm the stock 24#ers were at 98%. Now with 30's they're at about 85%.

hrcslam

36lb SVO. Not sure on the duty cycle. They were cheaper than the 30lbs.

Justin96z28

Dammittttt yea see I know I'm on the verge of maxing 24s out but my car is my daily and I can't afford a tune till next paycycle..... So it sucks I'm going to throw 24s in and know they are running close to 100% duty from when it was dyno tuned last.... Running 30's really tat bad untuned??

hrcslam

Yes, your fueling will be all jacked up. Too bad you don't have access to a tuner, it's a quick change to up the constant.

Jaxem

iTrader: (3)

If you have a way to upload the tune, i can modify yours and send it back to you...

Justin96z28

I ordered new 24s already :-( I'll iust get some 36s when I do my heads... With the 340lph fuel pump I'm not to worried about the 24s with a cam only setup... I wish I could find a cable or someone in the Phila had a cable I could use

hrcslam

Just curious, what program do you use for tuning and loading tunes on OBD2 LT1s?

ACE1252

Do not use a ported MAF. Keep the stock unit, un-ported, with the screen installed.

If you want to buy a new stock unit, that is fine, but porting a MAF will completely screw up the MAF transfer function in the PCM.

It can be corrected, but you'll need tune it on a load bearing dyno.

Jaxem

iTrader: (3)

I don't have anything for OBD 2, only OBD 1, i assumed since he is running 24# sticks he was an earlier LT1, since the later ones have 26# sticks i believe

hrcslam

I assumed he had a 96 because his user name. Lol

Justin96z28

Naw I got a 95 I had a 96 but even on that did an ODB1 conv. lol.

hrcslam

Do you have the ALDL cable and programs? Man, you need a signature with your vehicle details. I would've told you to get the 30# injectors and post up your Tune. Anyone here could've changed the injector constant. If you supply the part number with the injectors we can find the Voltage offsets too. Easy change.

Justin96z28

FML....... LOL I already got the injector's and installed them.. I went and got BOSCH 24#s which end up being like 25#'s on our fuelsystem solomon told me... FML see I knew I shoulda got the 30's!!! Dammit installed ran and cant return em.... Guess ill do a signature

Typical Flow Rate in CC per minute: 250 CC/min @ 43.5 PSI Actual flow rate of your injectors may vary, but will be matched together Resistance: 12 ohms (High Impedance, High Resistance) Voltage: 8-15 Volts, nominal 13.5 Volts Amperage: 1.0 Amps Pressure: Min 24 PSIG / Max 100 PSIG O-Rings Included: Yes, on the injectors Injector Body Design: Metal and composite plastic Fuel Delivery: Upgraded Four-hole disc fuel delivery nozzle for superior fuel atomization Electrical connector type: EV1 (Minitimer, Jetronic) Overall Length: 2 7/8 inches, 74 mm O-ring to O-ring Length: 2 1/2 inches, 63 mm Diameter: 16 mm Orings: Top and bottom, 14.5 mm -

AdsoYo

iTrader: (1)

Where/how do you get the voltage offsets? I couldn't find them for my Ford red tops and had to do a bunch of trial and error.

If you're running a cc503 on stockish heads you should be okay. Like I said, I hit 98% at 6,000rpm and I have a cc503 with lightly ported heads on a 383.