DOHC injectors

it has been said that 91-93 3.4 DOHC injectors may be a cause for what seems to be a phantom stalling issue. The '96+ injectors from a 3.4 DOHC fixed the issue, and they run quieter than their earlier counterparts. The problem is they only come in a few cars (most of them are not in the j/y's in my area (96-97 monte carlo(Z34), 96-99 lumina LTZ, Grand Prix GTP (not sure what years))

The flow rates for those injectors are approx. 24lbs/hr (i've been told about 23.96)

Does anyone know if the injectors for the '00 Grand Am GT (3400 eng.) will work with the older 3.4 DOHC (I read that the injector flow rate is 22.5lbs/hr)??? :1zhelp:

I assume you are keeping an eye on cost, as you are looking for injectors from salvage, but if not, have you checked prices at Summit Racing for improved injectors for GM V6's?

Yeah, I had looked into some Accel injectors on jegs website (seems that jegs is a little more expensive than summit) and jegs didn't list the exact injector for which engine - you kinda had to know what flow rate you were looking for.

I was a little skeptical about Accel parts though because of their bad reputation with coil packs, and my own personal experience with their plug wires.

I was seriously considering ordering a set though, I have a pretty good looking lower intake from the j/y (the ear on mine is cracked), and since i have to perform 3.4 surgery, I figured I may as well swap the injectors while I have them out.

Someone has a set of injectors from a 3400 for sale, but of course they're no good to me if the flow rate isn't compatible with my engine.

I did some searching, and that flow rate is also used in GM's LT1 (5.0) and LT4 (5.7) which includes corvette, camaro, and firebird (none of which i have found in the j/y) The only LT1 I found in the j/y was in a 96 caprice, which someone had gotten to, straight down to the lifter valley.

FYI- LT1 is a 5.7 as well. LT4 was an upgraded LT1 with better heads and induction, puts out 330 hp vs 260.

Yes, a lot of the 90's Caprice had the LT1, they should be fairly available, but the LT1 is in high demand, usually gets pulled outta a wreck is it runs, and non-running aren't common, it's a very good motor. I'll see what's available around here and let you know.

ohhhh - didn't know the LT1 was a 5.7 - that's cool though - thanks jeff... :thumbsup:

edit... That's a sobering thought... is that why the local j/y has 9 or 10 rows of lumina's and only 2 rows of caprice's? :icon16:

Yeah, most times when I find a Caprice at the boneyard it's got the TBI 5.0 if it still has a motor in it. Piece of crap. Had one in a '91 Olds Custom Cruiser (wagon). Good fuel mileage, but couldn't get out of its own way.

They also came with a 4.3. Bet you could outrun one of those with Yugo.

Off topic, but you got me thinking about Caprice/Impala, one of my favorite subjects.

Ever see/hear about the original prototype Impala SS put together by the Impala project manager (his name escapes me at the moment) to present to the GM execs for approval to go to production?

It had a port fuel injected 454, six-speed manual Getrag cogbox, 4.10 posi diff. :eek7: :evillol:

Obviously, they made some compromises in the production version. :disappoin

Still, my '94 with the LT1, chip and Flowmasters was a pretty formidable car for a land yacht. Stomped those damn Civic SI's, that all I cared about :lol:

It was probably makin' about 280 hp or so.

That's not even that tough for a mid-size FWD sport sedan now. It was the shit when it first came out, but no more. I got a run from a guy with a supercharged Gran Prix once, I almost hit him cuz I didn't expect him to be right alongside at 130 mph!

My, my... I drool at the thought of my very own '96 Impala SS. I hadn't heard about the prototype though...

That car is definately on my wish list if I ever hit the lottery.

and yeah, you're right about the Grand Prix - the L67 is a beast. I had a race with one not too long ago. Just so happens that we were at the toll booth. Our gates raised both at the same time, and I guess we were both thinking the same thing, cause we both punched it out of the gate. We were kinda (notice I said kinda) even for the first 40 feet or so. I heard the supercharger whine, and I saw him leave me like I was on the side of the road thumbing a ride.
:eek2:

oh yeah, you could only outrun a 4.3 with a Yugo if the Yugo's tranny didn't fall out on the highway :lol:

actually happened to a friend of mine.

My, my... I drool at the thought of my very own '96 Impala SS. I hadn't heard about the prototype though...

That car is definately on my wish list if I ever hit the lottery.

and yeah, you're right about the Grand Prix - the L67 is a beast. .

Me too! I really wish I hadn't sold mine. I've been jonesing for another one ever since. Luckily, there's still a lot of them around, and will be for some time. I'll get another one....

The Chevy Dealer here had a '96 last summer in their showroom that they took on trade, had 6200 miles on it. Still had the invoice in the window, etc. $24,500. You better believe if I'd had the money, it'd be mine.

But I paid $9400 for the '94, just turned 100,000 miles, and needed a little TLC, nothing major, just elbow grease. Thta's the other good thing. that engine is so durable, that buying one with even high miles for cheap is still a good buy. I drove one Dark Cherry Metallic '95 with 266,000 miles ($4500) and even it still ran strong and smooth, but the tranny was going and the seats were shot.

An accquaintance owns a performance shop that specializes in GM muscle, they did some work on it for me. He has one of those GP's that is very modded, he's a terror at the local track, lotsa trophies. You'd never know it to look at the car either, that I like :evillol:

Can you really get a performance edge from so called high performance injectors, or is that just marketing strategy?

If the intake, throttle body bore, valves, cam, and exhaust have the ability to actually flow air so much in excess of stock that it needs more fuel than the stock injectors can deliver, yes.

That's kind of a grey area for me. I suppose that a stock motor could probably make more power with higher flow injectors, provided enough air was available to the motor to make use of it.

That's the kind of question those import tunerz are good for. I don't know enough about FI outside of factory apps to really say.

I found the injector flow rate formula if anyone is interested:

HP x .5 / no. of cylinders = injector flow @ 100% duty cycle.

It appears that most injectors are listed @ 80% duty cycle. to get the result take the product of the above equation and divide by .80

example: my DOHC is rated @ 215 HP:

215 x .5 = 107.50

107.5 / 6 = 17.9

17.9 / .80 = 22.375

the DOHC came stock with 22.5lb/hr injectors.

That's a good formula to know. Thanks! I'm saving it.

Jeff - I bought the 22.5lb/hr injectors from the '00 grand am gt (3400) - thanks for the assistance...