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Lh2.2 3" amm....

Mylesofsmyles

A Member
Joined
Jan 18, 2010
Thinking I want to try a 3" amm on my LH2.2 setup...I hit fuel cut by 12psi...

I'm curious, is there any correlation to AMM diameter and Throttle Body Diameter?

I still have the 2.75" AMM
 
The throttle body shouldn't cause any problems, the turbo is stuffing the air in. You need bigger injectors for a bigger amm. My k-jet to 2.2 swap doesn't have an overboost switch, maybe it's something you can bypass or disable.
 
throw a resistor inline to the maf, so you dont max it out, but 12psi fuel cut does not sound like a maf issues. are you sure you have good fuel pressure? not hitting knock enrichment?
 
It runs strong...

Overboost switch on 2.2/ezk117??? Where

It's a 75 with a custom 2.2/ezk117 harness. Stock 8v turbo computers...b230ft+16v and a 15g

I have a larger pair of injectors to accompany the 3" AMM...had fuel cut issues with my 242...that one has lh2.4 and PZ cams...3" AMM and larger injectors solved the problem....

Didn't know if there'd be a colossal issue with unmatched TB and AMM...they seem irrelevant.

Regardless, I go way rich with just 8 psi like 10:1 AFR. I think I'm running out of metering capability.
 
2.2T normally has an overboost switch under the dash.

The AMM/TB thing, so many of us have run 012's on stock without issue, can't see that would really change on 2.2. I dunno if 2.2 does the same as 2.4 in terms of knock enrichment, but those are the AFR's I was seeing, sometimes into the mid-upper 9's.

For the record, what size injectors in there now?
 
2.2T normally has an overboost switch under the dash.

Yep, left side somewhere underneath the driver's side dash. Heat up the wax/plastic/whatever in the middle, scrape it out to get access to a screw. Run it out a few threads to get a few more boost units. Nice little failsafe though, especially on 2.2.
 
Given I wired the car...I never installed a over boost switch. It's your typical b230 lh2.2 install in a 240

Cruise AFR is stoich...14.7:1

Running 33ish LBS injectors...plan for 46 LBS with 3" AMM
 
Given I wired the car...I never installed a over boost switch. It's your typical b230 lh2.2 install in a 240

Cruise AFR is stoich...14.7:1

Running 33ish LBS injectors...plan for 46 LBS with 3" AMM

Why not slap the 3in amm in with the injectors you got or better put your guts into a smaller then three larger than stock size. I think your over fueling and not hitting boost cut...because im pretty sure you dont have one haha
 
The current injectors with the big maf, yeah, have fun with getting THAT to run right.

I know on the 3" on 2.4, 46 is still a touch on the small side, I'd go 50's or bigger to keep things somewhat in check. I'm on 65's, 72's if I'm running straight e85 and it's pretty solid. Right now it's sitting 10.9-11.2 at WOT on a 60/40 91*/E85 blend. Straight 91* it'll hit knock enrichment and go low 10's, high 9's consistently if it's over about 50* out.
 
Then it is not a fuel cut you are hitting at LH 2.2 only has that from the over post switch. You issue is either somethung along the lines of an intake hose sucking shut or some kind of spark issue possibly. Could evenbe a. Overfueling causing a big rich bog because you cannot light and burn that fuel.
 
Yeah...I'm going to try the 3"/46lbs for now...it's what I've got.

Ordering the pieces today.


I think it's "overfueling" because the AMM is too small
 
Probably going into safe mode of some nature. #33 with a 15g and 16v is a bit small. Any chance you have a 4-bar FPR you could toss on just for testing?
 
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