LT-7

I have some, they are supposed to be 30#, but they are not acting like it. They are acting like they may be closer to 40# or so. Does anyone know if there is a different redtop injector that has a lb/hr higher than 30?

On the datalogger it makes the car run pig rich, really really rich. Like peg out to 108 rich and the short terms in the 80's and 90's. I compensated for fuel pressure differences, the 39 to 43.5 difference and then compensated for my car at 48-50 psi. still rich. Fuel pressure takes about 2 hours to drop 10psi, so I don't think they are leakers.

I put the stock ones back in and the car acts correctly again, so it has nothing to do with anything other than the injectors.

thanks for any insight.

whitehooptie

I thought blue was the 30 pounds and the red were 36's. I don't remember for sure though.

stroked383z28

Nope reds are 30's and dark blues are 36's.

Loadre

Are you positive that you'rs using the right injector constant?

LT-7

Loadre,

Im pretty sure. This is how I came about the constant.

My fuel pressure is at about 50 for reference.

43.5 = LT1 pressure

39= Ford pressure

(43.5/39)sqroot = 1.056

1.056*30= 31.68

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(50/43.5)sqrt=1.072

1.072*31.68= 33.96

You can get the same numbers by doing (50/39)sqrt also, but I wanted to go the long way to show that I had gone that route.

33.96 is what I initially put in there. It ran really rich, so I went up to 36 and it still pegs out at 108.

I thought they might be staying open and not closing off properly, but they don't lose pressure when the car/fuel pump are turned off.

Loadre

How are you running 50 psi of pressure? Have you verified that with a gauge?

LT-7

Yes verified with a gauge. I put a Walbro 255hp in (this setup is in a RX-7) and ever since the pressure has been higher. At idle, its at about 44 and with the vac line off its at 50.

Loadre

Do you run it with or without the vacuum line?

LT-7

I run the car with the vac line. Tested both on and off.

TobyZ28

@ 31.68 my car runs a tiny bit rich with the redtop FORD SVO #30 injectors.

LT-7

I wish I had that problem

Loadre

You need to be running that 31.68 constant. If you're running the vacuum line how can your fuel pressure be 50 psi, which is what your tune was calibrated for?

LT-7

Ive tried both ways, the 31.68 and the 34. 31.68 was very rich and when I changed it to 34 (effectively leaning it) it didn't help any. The higher I go on the injector constant the more the ecu should be decreasing duty cycle to compensate at idle and it still runs so rich that it bogs down when I try to go WOT.

BlkLT1Z28

I thought the red's were 30lb the brown were 36lb and the blue were 24lb.

LJ93Z28GM

Can you read us the exact number on the injector so that we can verify it.

I am assuming you bought these used?