Over the summer i picked up a very low mileage ZZ3 crate motor for a $ 500 steal.
zz3 marked on the block by the water pump

i replaced my lb9 that was haveing knock issues ecm keep pulling timing.

i installed the zz3 useing the 305 injectors and 305 prom . did have to raise the idle to 800 and bump base timing to 8

so far it runs great more power all around rolling burns and all but i still expected a little more i havent took it to the track yet but it it dosnt seem like i gained alot for what it being a basicly a cammed out l98 with forged internals

it sounds great the exhaust tone changed completely

but id like more power on the freeway its only a little faster then the 305 was.

but then other times it flat out hauls ie will rolling burn from 60 on the freeway that got me confused.

but im thinking its running very lean on the freeway atlest most of the time ie flooring it from higher speeds has an odd smell .
freind said its from running lean , now i dont know if you can smell a lean running engine or not

but the car runs a little rich at idle and normal driving not excessive but you can tell.


i picked up some 22lb injectors but cant seem to hunt down a 350 prom
i also picked the knock sensor for a l98 mind you i have not installed them knowing they wont work with the 305 prom

i was also thinking of doing a lt1 converted intake for it i prefer the way the lt1s pull on the freeway

also i was going to add my 1.6 roller rockers but im worried the exhaust would be 2 high of lift

 

Any time you modify an engine (ZZ3) it changes the knock characteristics. So adding the 350 knock sensor may still make the ECM pull timing. I had to get a tune to solve that problem. You may a well get some 24# injectors to feed that new motor and give the timing a few degrees. I would be concerned about leaning out and having issues with long highway trips..

 

oh the current engine isnt pulling time the old engine was.
but im still using the 305 prom 305 sd injectors 19lb and knock sensor 305sd .
i know its not the best but i needed the car on the road .
i picked a set of 22lb 350 injectors in expectation that id be able to easly find a 350sd prom
i also got a 350sd knock sensor
i also have a set of lt1 24lb injectors
i cant seem to find a cheap 350 prom ie under 300
and getting a prom burner and all that jazz is about the same .

i mean i figure the zz3 is basicly a l98 with a cam so the knock should be the same as l98

another thought i had was just getting a vortec timing cover with crank sensor. lt1 throttle body since the tps and iac match the tbi vortec parts and converting to obd2 . i already have a 4l60e sitting in the garage as well as a vortec tbi obd2 ecm would have grabbed the harness, had it not been cut up atlest the cost would be about the same for a harness and obd2 tuner as buying a single chip.
im currently showing no codes with the 305 prom just i cant just toss the larger injectors in id need a prom thats set for them right?

 

You can burn your own prom easily. with 19lbs injectors and a 305 fuel curve, you are definitely running lean.

you can always just pick up something like this as well...
http://www.ebay.com/itm/90-92-CAMARO...ht_1375wt_1266

 

You can run the 22# injectors but it will be slightly rich at idle. I have a spare SD custom prom from when my car was auto. So you can go that route if you're interested pm me.

**my prom was made by the seller in that eBay ad.

 

i did find that but was worried it wouldnt work
he said he could set it for the 24lb injectors delete the egr engine came with a emissions sticker stating it no longer needs egr aparently something about cam overlap

well if those proms worked for 2 others ill pick one up ive had alot of bad luck when it comes to custom stuff on ebay

 

i got the out for spring still useing 305 prom and injectors

ive really been paying attention to it it runs rich most of the time atlest from the smell of the exhaust but when looking at the plugs it looks like a engine running im prime shape odd

i got it to the track and ran a 13.7 with wheels spinning not from the start but once it shifted to 2nd

im not sure but i noticed the front 4 injectors are pulseing much harder then the rear 4 as you can feel a differance if you put your finger on them

i wanted to have a prom made for the the engine but cant seem to tell what size the injectors i have are i pulled them from a 94 caprice lt1 but they come up as 22 lb and on other sites 23 lb and also 24 lb so im not sure what they are

oddly the 305 prom seems to run the engine very well once i completed the ecm learn lol driving about 10 miles
from all the postd i used to read of how touchy the speed density system is
i never would have thought the car would have run let alone run well
this engine should have been out of the learning curve
but this prom/ecm has amazed me ive thrown 5 differant engine combos at it
and it always works
i when from a stock tbi lo3 with tpi on it wrong heads wrong cam but it ran well then added 1.6 rockers changeing its cam a bit and it ran better

i then ran its proper engine lb9 with l98 cam ran like a top the added 1.6 rockers to it aswell and then from once shut down to next start up a zz3 350
and it never skipped a beat short of a few stalls comeing to lights till i set the timing and idle
i would have expected that from a maf engine but never a speed density

i figure i could get better power and proper timing with a prom ment for a 350
i swear it advances timing to fast in low rpm ranges

 

so i picked up a 730 ecm with aujp memcal in it as well as the 22lb injectors
ill install it tommarro and see how much of a differance it makes im really hopeing for an improvement

 

your on a better track but a zz3 or zz4 you should be running 24#hr injectors.

 

so i swaped the injectors and the computer
had no change in power other then from a 20 roll it Really tears off
and also noticed the torque converter locks up later
i took it on the freeway the car just didnt feel as fast as it did
also noticed it gained a back fire or exhaust pop that it didnt have before

so i drove around some more other then the 20 roll it really didnt seem to be any better

so for s#!ts and giggles i tossed the 305 computer back in with the new injectors major differance car is faster on the freeway then it everwas and it was decent before
and just overall driveing it just feels smoother and more powerful
and the exhaust pop went away again

im wondering if there is a timing differance with the 305 to 350 comp
with the 305 comp and 22lb injectors it runs only a tick rich wot

it makes me wonder if i should toss the 24lb injectors in with the 350 comp to see if it reacts the same as the 305 comp with 22s

right now im just a little confused

 

I would install the 24#hr injectors and buy a dynamic efi ebl p4, other wise you need to data log with a wb s-aujp and reprogram from there. Your lb9 memcal will work it's just that the knock boards are different between a 305 and 350 run a different frequencies so it will not be effective. It may work if you use a 350 knock sensor and a 4k resister in series .

 

Caprice got the baby LT1 that was smaller than a 305
http://autotrend.activeboard.com/t16...-its-too-late/

 

i did some research at work "i work at a dealership"
the injectors i have are 24 lb i pulled them from a caprice but i also know the differance from an l99 and a lt1 i have both 91 camaro and 2 94 b-body lt-1 cars caprice and roadmaster you just look at the side of the block near the oil filter l99 says 4.3

i was getting miss information looking up the injector codes online some sites saying 22 others saying 24 but according to gm 17095004 these are 24 lb
and i verified the other set i bought are 22lb 350 tpi injectors

 

i was reading up on some very old posts on here

it helped me understand why the 305 prom feels a little better

i have also read that the 305s have a more agressive timing table

when i compare the ecms in the car by how it drives the 305 prom the car feels faster and is but i think its more so on the freeway at lower speeds the 350 prom the engine makes more power ie torque and it wheelspins to much but once it hooks it dosnt pull like it should
its hard to explaine honestly

but the 305 prom it spins but not as much and once it hooks it just pulls
both off these would be from a 20 roll speed

yes i understand it needs a proper tune
i had assumed a 350 prom would work best since the zz3 is basicly a corvette l98 with a cam atlest to the computer forged internals mean nothing to the ecm
i also read the corvette l98s got more timing so maybe thats why my car likes the extra timing

all in all it feels fine now once my budget open back up im going to look into tuning ie getting components and software to do it

edit
i looked into the ebl p4 flash and 450 bucks seems a bit steep for that i could get junk yard parts and do an obd2 conversion and pick up a used obd2 programer just alot of extra work

and on top of the 450 i would still need a cable and software sounds like a lot

 

well i took it to the track again with the 350 prom and 350 22lb injectors
13.8 @99 but i will say my posi is broken one wheel peeling

i think ill have to look into tuneing it or haveing it tuned

 

Have you done any suspension work to your car? A worn out suspension will take away power getting to the ground as efficiently as compared to one that is in shape. Thats the next round of mods that I am going to go through for my car.

 

less then 10 k miles on kyb rear shocks , kyb front struts, front strut mounts, poly A-arm bushings , poly lower control arm bushings, poly panhard bushings, poly engine mounts , poly transmission mount , poly torque arm mount all poly stuff is energy suspension

less then 5 k on moog idler arm , moog centerlink , moog inner and outer tierods i reused the factory tierod connectors just replaced the bolts , durlast ball joints

also replaced the gear box with a new one it got loose just returned it then picked 2
used ones one broke the other i installed lastweek and did an alignment at work


im pretty sure thats all of the suspension and steering
ive also bolted the lower control arms to stiffen them up didnt feel like boxing them

i honestly try my best to keep the car in tip top shape other then the paint since thats something i cant do well myself

 

Thats good. That answers the suspension question. Well hopefully getting your rear end rebuilt with new posi will help things out too.

Have you thought about going to a company like pcm for less for a tune?

 

for right now i think ill get a posi 1st im good with power for now and im getting decent fuel mileage so the tune will have to wait

 

Yeah get that posi working right. Once you get that done, you will be surprised how well your car will hook coming out of the hole or out of corners.

 

I do no think pcm for less will fine tune the ve off a sent in datalog. It would be a guess on there part for tuning and is a waste of money if its not tuned off a datalog.

 

www.dynamicefi.com ebl p4 will do a learn on the ve. pretty awesome stuff. save you hours of remaping and smoothing the ve.

http://www.dynamicefi.com/EBL_P4_Flash.php

 

here are 2 runs useing the 350 prom and 22lb injectors
1st run
r/t .409 ya i was rusty
60' 2.008
330 5.785
660 8.909
mph 78.57
1000 11.612
car was running about 210*
1/4 13.882
mph 99.58

2nd run
r/t .178
60' 2.066
330 5.807
660 8.918
mph 78.77
1000 11.614

1/4 13.875
mph 99.84
car was running about 230*

here is a run with 305 prom and the 22lb injectors
r/t .089
1.956 60 ft
5.641 330 ft
8.723 660 ft @ 80.04 mph
11.373 1000ft
1/4 13.598 @ 101.52 mph
car was running cold needle bearly moved

i changed the rear axle fluid im getting a little less wheel spin but its still slipping toward the pass rear
ive been swapping ecms back and forth the 305 ecm runs what smells like rich but the plugs dont show it
the 305 ecm runs much better above 3500 rpm then the 350 ecm

the 350 ecm runs best for daily driving but honestly at full throttle it feels like the 305 prom did with its stock 19lb injectors
for the heck of it i may toss the 24lb injectors in and see if thats the problem
but my guess is it needs the timing at this point
or just needs to be correctly tuned

im currently running times close to what gm had these running in the 350hp package
those had better exhaust ie slp headers into dual cat into totl catback
but they had the modded l69 carb and tune to match
so i dont think im doing to bad
im decently happy with how its running