Question on removing FMU
Thread Starter
Racer
Joined: Sep 2002
Posts: 337
Likes: 2
From: New Orleans La
Question on removing FMU
A few years ago when I was trying to sort out a problem (too lean)
A/F ratio on a stock LT1 93 Vette a lot of you suggested I throw away the procharger FMU and get bigger injectors.
I eventually purchased #30 SVO injectors but also kept the FMU and everything was OK.
Now I installed LT4 heads, LT4 intake, Lt4 hot cam and EM long tube headers and again I am running lean.
So, I called Ed wright and told him I wanted a chip but I didn't want to keep the FMU.
Ed said "can't be done on a 93 Vette" It just doesn't work!
I forgot to ask how a lot of you on the forum are doing it and I'm waiting for his return call.
So I'm asking: What's the story?
Thanks
Herb
A/F ratio on a stock LT1 93 Vette a lot of you suggested I throw away the procharger FMU and get bigger injectors.
I eventually purchased #30 SVO injectors but also kept the FMU and everything was OK.
Now I installed LT4 heads, LT4 intake, Lt4 hot cam and EM long tube headers and again I am running lean.
So, I called Ed wright and told him I wanted a chip but I didn't want to keep the FMU.
Ed said "can't be done on a 93 Vette" It just doesn't work!
I forgot to ask how a lot of you on the forum are doing it and I'm waiting for his return call.
So I'm asking: What's the story?
Thanks
Herb
Thread Starter
Racer
Joined: Sep 2002
Posts: 337
Likes: 2
From: New Orleans La
I see no one has answered my post!
In the mean time I just got off the phone with Ed Wright an he explained that on the 93 LT1 he cannot keep the injectors open at WOT
without the FMU.
He stated with the 94 and up it's no problem but your smarter than him if you can figure it out.
He also said a GM engineer friend that is now retired could not program
the 93 LT1 without the FMU for the same reason.
In the mean time I just got off the phone with Ed Wright an he explained that on the 93 LT1 he cannot keep the injectors open at WOT
without the FMU.
He stated with the 94 and up it's no problem but your smarter than him if you can figure it out.
He also said a GM engineer friend that is now retired could not program
the 93 LT1 without the FMU for the same reason.
Le Mans Master
Joined: Jul 2001
Posts: 6,252
Likes: 2
From: Silicon Valley Kalifornia
Best compromise is to run injectors that are large enough and idle fine and then at WOT allow for lower line pressures induced by the FMU.
I'm running 30lb injectors and a FMU on my L98.
I'm running 30lb injectors and a FMU on my L98.
