Hi, my name is Anthony, I just bought my first car today, an 82 Camaro Z28 with a 305 in it. It's got new exhausts from Dynomax and a new injection system from Holley, installed a few years ago.

The injection system needs tunign as now it gives way too much fuel to the engine, making it choke and stop, and it burns almost 4 L of fuel to do 4 miles.

I don't know if the engine is a TBI or TPI, nor if it's 2bbl or 4bbl, maybe you can answer that question for me.

I'm waiting for an answer from Holley to tune the ECU properly as I have a metal interface in my glovebox with 5 ***** on it to tune respectively : choke, idle, low range, mid range, high power.

It has been tuned like crap and I ran out of juice in the battery after trying to start the car as it actually was running out of fuel.

At low range, if i release the throttle the car chokes after a few seconds, it doesn't idleing. At mid rpm (around 2000-2500 rpm) it runs quite well but if you try to accelerate more, then again too much fuel and the car loses all its power and starts backfiring at the exhausts because of the amount of fuel not burnt in the engine.

If you need any other informations, just ask and I'll try to give you everything I can know. I'll do photos of the system tonight to post them so that might help.

I have the injection system serial number, if that can help someone?
My problem is that on the ECu box, there's no part name like 950 Commander or anything, and I don't have the bill for the purchase of this part, so I can't know exactly which it is, and therefore find the tuning details on Holley's website.

Thanks by advance to all, and I hope I'll find help on this forum.

 

If it has an aftermarket injection system it doesn't matter what induction setup the engine was previously.

**DISCLAIMER** I have never seen one of these systems in person or read any documentation on adjustment, the following are merely suggestions based on my education and general knowledge of engines, your description, and a bit of common sense.***

As far as tuning, if it's that bad I'd try and find a decent baseline - I'd assume a reasonable place to start would be to position the choke and idle ***** between a quarter and half travel. Look for a way to physically block the choke open, make sure your idle speed is right (if it's too high the low range adjustment could affect it) then start adjusting the idle ****. I'm assuming you don't have an air/fuel ratio indicator, so your best bet is to dial the idle **** for the highest idle, then go ~25-50 RPM slower on the rich side. Once the idle is set up properly you could probably unblock the choke and adjust it - I have no idea how the system works but it should start opening shortly after startup and be fully open when the engine is warmed up at the very latest. For low power setting, go for a drive and once you're up to speed maintain a constant throttle position on a stretch of flat highway and slowly adjust for maximum speed. This one will be tricky without an A/F gauge, and will affect your highway mileage the most. Mid and hi-range should be set for maximum acceleration under part and full-throttle respectively, then dialed back a touch toward the rich side, especially the hi-range adjustment.

Of course, Holley's instructions are gonna be much better but if you can't wait to hear back from them the above is what I'd try. Just make sure you figure out early which direction is lean or rich and if you start hearing knocking go richer.

 

Sounds like a good start to me. Also, check your ignition wires and overall system condition. The popping in the exhaust is most likely caused by loss of spark under load.

 

Hi

Thanks a lot for the tips. I went back to my car tonight and tuned it a bit, it doesn't stall anymore as I made it a bit richer, but I still have a problem when i put full throttle, the engine revs up a bit and then falls back to idle.
Anyway I also got news and instructions manual from Holley so I should be able to fix all that during the WE. I'll keep you updated.

Meanwhile, here are a few photos I took of the system, if then you have more advices.

 

Looks like Holley's original Pro-Jection 2 system. It is 2-barrel, TBI. If Holley has a closed-loop kit for it, it's worth it. If not, it would be worthwhile to upgrade to the Pro-Jection 2Di computer, for which Holley does offer a closed loop kit. That alone should boost your gas mileage from 4 MPG to over 20 MPG.

 

I've tuned the engine a bit, and now it starts very well.
My problem now is that, even at idle, it burns a lot of fuel because I think the throttle control system on the injection part is n't attached at the right place.
By that I mean that it's always too open and the engine gets too much fuel.
I've found a screw at the front of the throttle system to adjust the limit of the closing of the butterflies so I'm going to try to adjust it at noon.

 

I've tried a few things at mid-day and improved a bit the response at the throttle, but it still sends too much fuel.
I've found a BTR (6 sides) screw on the top of the injection system, right between the injectors, and it's screwed as down as possible.
I've read the instruction manual and it appears that it manages the height of the injectors and therefore how big the hole are to throw fuel, so tonight I'll try to play with that screw and see if it does anything good...

 

that looks similar to what ESC is running. hit him up on the boards and maybe he can help you out some.

 

I've gone through the system and got it running almost properly. But after i've done this, I've discovered that the car has another problem, a major one.
My return fuel line is blocked, nothing can go in it, so all my fuel just drops in the engine and floods it quite quickly.
I've unhooked everything and checked all the pipes and it appears that whatever is blocking the return line is very close to the fuel tank as I've blown in the pipes and up until the rear axle, everything is fine.
My problem is that I have very few tools (recently moved to UK from France and left everything at home) and I don't really fancy dropping the fuel tank and exhaust system to access the last pipe.
I've been told some owners do a fuel trap in their trunk to access their fuel pump and other pipes. My car hasn't got that so I was wondering where to do it, and if it's safe and/or good for the car (chassis structural integrity, cutting metal next to the fuel tank, etc)?

 

Sorry for the double post, apparently my slow connection created it twice...