meyer30

iTrader: (2)

Well I've got the 355 up and running. Took it out for a spin and while ideling I got a code 44 after that the exhuast started smelling really rich. I guess the computer was dumping fuel into the cylinders. So I'm only running 21.5lb injectors from bosch and DD puts my engine in the upper 400 hp. I called a company and they got my info and said I should be running 30lb injectors. Does that sound like too much or will it work for me? Next year I plan on adding a supercharger. I figure I'll have to get a chip burned for the injectors but I need to anyway due to the larger cam. So just need to know if the injectors will be too much or just about right. Appreciate the help just need to get this done. Been down too long now. By the way all my engine specs are in my sig.

mnorton

You probably could use more fuel than the 21.5 lbs are delivering. I'd think that 24 lbs. would be the better choice, though to get to 400 HP you probably would need to go with 30 lbs. and a chip burn. You probably could use a little more timing advance with those aluminum heads too.

How's your fuel pressure? I'd think that you could run it at 48 psi (to get a little more fuel) with the current setup and do pretty well.

meyer30

iTrader: (2)

Right now I have the timing set to 13degrees. The idle is real low tho. It seems to idle better when it's around a grand, but when I bump up the idle I can't set the tps to .54 it will only go to .65 or somewhere around there. my fuel pressure is around 48psi. The idle is real lopey sounds good but the exhaust smell is just awful. I unplugged the map sensor and the engine started running like crap so I plugged it back in and it got better so my map is working. Just trying to figure out what I need to get to get this thing running right. Fuel wise. Is 13 not enough advanced? Should I go further? I thought I could run this with my current injectors. I know I would not get all my hp potential but should run ok. Doesn't seem to be doing that.

mnorton

I think that you need to set the base timing with the dizzy back to stock, which is 6 degs. Maybe you could go with 8 degs. Setting it at 13 degs. is probably too much.

You'll need to adjust the timing table parameters in the PROM in order to tune for Aluminum heads.

meyer30

iTrader: (2)

Ok, I could try that. Would a chip burning company be able to set the parameters? I would have to mail order a chip, no one around here that can do that. Is that a possibility?

grumpyvette

ITS NOT a GUESSING GAME
chips may control the flow but ONLY UP too, the MAX EFFICIENCT FLOW RATES, the INJECTOR and fuel pressure can supply
you can figgure EXACTLY whats required
you just need to know the hp levels needed, the fuel pressure and that the a/f ratio tends to produce the best power close to a ratio of 12.7:1 and the best mileage closer to 14.7:1 on the A/F ratio.

http://www.rceng.com/technical.htm

in your case a 32-36 lb injector is needed, Id go 36 lb if further mods are in the future plans

(theres a calculator near the botom of the page....USE IT)

set the BSFC at .45
the duty cycle at .85 MAX
and inseart your REAL fuel pressure measured at the fuel rail.

BTW Im running an 11:1 cpr 383 full roller sbc with a ported stealth ram, ported trickflow heads heads and pulling 475-480 rwhp, the 36lbs are maxed out and Im running 45 psi fuel pressure

mnorton

There are companies that do custom mail order PROMS. If you were to ask anyone who burns their own, they'd tell you to buy the equipment and learn to do it yourself. Then again maybe you don't want to have another project....

I would suggest doing a search, then going with someone who's willing to give you a fair deal with a good return policy.

You have a MAP car, with Aluminum heads, (higher compression pistons too?), increased air flow, bigger fuel injectors, and a bigger cam so you'll need to change at least the fuel injector size constants, and timing table. Probably the VE (fueling) table, and Max Air Flow values as well. I have a MAF car so I'm not so clear on what all you'd have to touch.

If you are going to add a super charger you'll probably want to re-tune at that point again as well.

With all that you are planning to do, I'd suggest getting a Wide Band O2 Sensor, ALDL cable, an Ostrich, and TunerPro RT. I suspect that with a Super Charger you'll need to make some custom tweeks. You're looking at building a pretty powerful engine, it would be a shame to ruin it by running too lean.....

meyer30

iTrader: (2)

Alright I'm gonna look into the Ostrich and see if it's possible for me. I changed the timing back to six and did a vacuum test. At idle it was 13psi and when the throttle was hit it went to 20 and then back down. I tested my friends trans am and it pulled 19psi at idle. After that I got a code 34,42, and 44. But the exhaust smelled really rich so I don't know how it's running lean. Unless the computer detects it and then dumps more fuel in.

meyer30

iTrader: (2)

Ok I used the injector calc and got an injector size of 27.09. So 30lb should work. I don't know the exact hp. I ran the setup on DDyno and got 436hp. Just a guestimate I know. Not sure if it's rated at the crank or the rearwheels. And I was looking at the Ostrich the price is descent but I also found APU1 AutoProm Package at moates.com would that be any harder to use then the Ostrich or about the same seems to come with everything one would need to reprogram a chip. And my compression is around 8.5:1 since I plan on a supercharger later on. I really appreciate all the advice from you all. I've built engines but nothing high performance. I've always kept it stock. So right now I'm lost on how to figure out how to get this damn car running right. Like I said thanks for the help.

mnorton

I have Ostrich and a PROM burner, and am happy with that, AutoPROM sounds like it would be a great product as well, maybe a better solution. I run the car off the Ostrich and re-tune on occasion. Someday I'll get a new PROM socket/chipset and burn one I suppose.

You'll need a laptop computer and an ALDL cable to connect from the car to the PC, I use TunerPro RT software. The Ostrich also requires a special adapter socket to plug into the car's CPU PROM socket. Moates.net has the Ostrich and adapter.

I'm surprised that the exhaust is so rich... that makes me think that something is wrong. Does the fuel rail hold fuel pressure well after you turn the key off? If you have a Holley AFPR that could be the problem, the diaphragms often (maybe always!) leak raw fuel into the vacuum side, and then into the Plenum port.

meyer30

iTrader: (2)

No I'm using the stock fuel pump. The fuel pressure goes down a little after the key is off. The book says 5psi in 5 min is ok. Could that be my problem, a fuel leak?

mnorton

It sounds like your fuel pressure is fine.

The fueling loop is monitored by the O2 sensor in the exhaust manifold. You have headers right? So is there a problem with the sensor? Did the wire burn? Is it old?

If you can get a PC loaded with TunerPro RT and an ALDL cable you could see if the car ever goes into closed loop, and see the O2 sensor voltages etc. It sounds like it's time to get that much together and take a look. You can always buy a PROM Emulator later.

Is the car running really rough? If it is, the ECM might be in "limp home mode". That will make the exhaust smell awful. The car will idle rough and sound really cammy, also the fan will be running even when the engine is cold.

I just looked at your web page. It says that you have 24lb. fuel injectors. No?

If the PROM that's in the ECM is set up for stock injectors, whick I think are ~22 lb., and you really have 24lb. injectors, (and 48 psi) the engine will run rich.

meyer30

iTrader: (2)

Yes I do have headers and I don't think the wire is burnt for the o2 but I will check it. So your telling me alls I have to do is plug an aldl cable up to my laptop and run the software and I can read the computer? That's too easy. I thought I had 24 injectors, but I called the company to double check and they said they were 21.5 injectors. Bosch yellow tops. I installed this cam straight up, like compcam said it would be fine. Now if it's not fine could that be causing these problems or is it just fuel and computer related? I have a B&M AFPR bought earlier this year. Now when I was installing this engine the nipple for the vaccuum on the AFPR got knocked off. I was able to tap it back in. Could that have damaged the afpr and causing all the extra fuel?

meyer30

iTrader: (2)

Well I went to look at the o2 wire looks fine. But checked my oil and noticed it was low and smelled of gas. It was clean still but smelled of gas. So I think somehow way too much gas is getting into the cylinders. I really don't want to start it anymore until I figure this out. I guess I'll change the oil so nothing gets hurt internally. AFPR or injectors maybe? There only a few months old.

mnorton

Yes, just plug the ALDL cable into the port under the dash, connect the other end to the PC, and run TunerPro RT. The software is even free, if you like it you can send a donation later.

I don't think it's a cam issue. The lifters are adjusted properly right?

Vacuum on the AFPR diaphragm actually lowers the fuel pressure in the rail.

It sounds like you need to start by lowering the fuel pressure to the stock 44 psi. Do this with the engine running, vacuum line disconnected from the AFPR. If a fuel injector is stuck open you'd see the fuel pressure fall quickly after an ignition key off condition.

meyer30

iTrader: (2)

Well I just ordered the Ostrich from moates and the adlui+cable1 combo so hopefully that will solve some of my issues. This weekend I'll drop the fuel pressure and readjust the valves, maybe even a new o2 sensor just in case. I appreciate the help and I will let everyone know how it turns out.

meyer30

iTrader: (2)

Well I backed the fuel pressure down and it's not running rich anymore, adjusted the lifters and it idles alot better so that problem is solved. Now I've got an even bigger problem, I'm hearing a kind of knock sound really high pitched and intermittent. I used my scope and I can only hear it coming from the front of the intake manifold. What in the hell could it be? Am I gonna have to pull this stupid motor and disassemble it? I can't believe this crap!!!