You can type here any text you want

New Combo running lean, MSD 50s or something else? (injector ID)

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!

GinoRin

Member
Joined
May 23, 2001
Messages
367
I just got around to straightening out the new combination in my 87 Limited, and I must say I'm quite confused. For some reason the car feels like it has a misfiring cylinder and is running lean, all the way throughout the powerband. The injectors are suposedly MSD 50s, but there is 45.2 - 45.3 etched in each injector. I'm assuming this means they're flowing about 45lbs, but I also know that PTE flows these injectors at 85% duty cycle. Can anyone else chime in as to what's etched on their MSD 50s? Ive used many sets of MSD 50s before and have never had a lean problem like im having, even at idle. I can crank the hell out of the fuel pressure just to see if it idles better, and it still feels like it has a miss. Fuel pressure is consistent with boost. I have also tried numerous Jay Carter, Turbo Tweak, and Caspers 50# chips with no avail. The car is also slow to spool up, sputters a little under full throttle (even part throttle sometimes) and others it will clean up and pull like a maniac. I thought this may have been an ignition problem intitally, so I put in a new delco 02, and known good GM MAF, CR42TS plugs, MSD wires, GM coil/module, and reset the cam sensor. All GM stuff, not reman or aftermarket crap. The car has a walbro 340 pump (hotwired) PT51, champ irons and intake, 210/210 billet roller, the 50s, a front mount, 3" THDP, single shot, bla bla bla. Also, interestingly enough, i had a old jay carter 009 chip laying around and i threw that in the ECM and took it for a drive. It idled WAY better, still not perfect, but it was super rich and still breaking up under boost. My next idea is to send the injectors out to have them re-flowed, but theres only about 500 miles on them, and I pulled them out of the car today and they all look great. Also, I pulled the plugs out to see if I had a fouled cylinder, and all the plugs are clean as can be. I'm totally confused on this one! Any help would be super appreciated!

Thanks in advance :cool:
 
by the way, the numbers on the injector is: 3143 17113738 can someone verify this for me?
 
nope, I didn't touch the cam sensor, but this is a new engine so that's why I wanted to check it.
 
I bought some used 50s and they idled terrible and ran very lean.
I popped some 30s in this weekend and all problems are gone.
These injectors looked to be low milage.
I am sending them out this week to be checked.
 
Back
Top