Got some bad news man, pn 17104288 is a 305 injector, I actually got a set, they came in my first 454 tbi off ebay, and that page makes reference to the tbi casting pn for the 454, not any injector. They only flow 45 pph, you might want to try like 160 bpw.

Are you sure thats not your old injector pn????

 

If you are running the stock 350 units at 34psi then they are flowing much more than 62lbs/hr. Like 115 lbs/hr, which puts you at roughly 365hp.....

What is your race weight and trap speed? That'd give an idea of RWHP just for grins.

 

Do you have EGR enabled? If so, check out your BPC vs Vacuum (EGR on) table. Not only do you need to change the global BPC but all the BPCs in this table. Look everywhere to make sure there isn't something you're missing.

 

Brent: I think I see what you mean...since the BPW constant is a global change, it may have my BLMs around 128 at upper rpms, but I'll actually have to make some changes to the VE table at lower rpms because the BLMs are so low in that range. That would make sense because I have driven the car and found it to run better once I get the rpms up a little.

Low C1500: I'm really confused now...why would a 305 injector be causing me to run so incredibly rich? I think that JPrevost orginally ran a stock 305 TBI (w/stock injectors, I assume) on his 350 H.O. and was able to drive it like 500 miles or something with no mention of a rich condition. As for the 17104288 part number, I found that number on the injector itself, not the casting, which makes me believe it is referring to the injector...right? How did you know you had a 305 injector when you got that 454 TBI on ebay?

kevm14: I have my "EGR On (Speed)" constant set to 255 mph with the understanding that would disabe the EGR and prevent it from turning on...is that sufficient? Should I also increase the "EGR On (Temp)" constant from 70.25 degrees up to the max temp?

 

Man , you gotta trust me, that part number is for a 305 injector, call a gm dealer and see if they have an injector part number listing. Black smoke can mean lean too. Some jerk off ebay kept the 90lbs injectors from my 454 tbi and put his 305 ones in, then just listed it as a 454 tbi.


I've only weighed my truck at the "big" truck scales, and it varies from 4000- 4300 lb, with me in it. And the only trap speed I have is from g-tech ( i know its probably not very acurate) and its right around 100mph.

 

Kevm14 makes a good point. I did a little testing with the 7747 a while back and it seems that you need to set the EGR Enable Temp to 01 to get it to disable the EGR. The MPH didn't seem to work for me.

In the 747, the enable temp is inverse. DOn't know what ECM you are running, so it might be different.

 

My point about the EGR was that my ECM ('6965) appears to use a different BPC when EGR is on. For instance, I recently change my BPC from 120 to 130. I looked at my BPC vs Vacuum (EGR on) table and it went from 121 (low vacuum) to something around 109 (50kpa), so I had to scale that so the highest value was 131 (to mimic the stock calibration).

I was only making the point to show that the BPC as a constant isn't the only thing you have to change if you want to make a global change to fueling (if you use EGR; you said you want to disable it).

 

I'm running a 1228746 ECM...I wonder if the same rule applies since it's similar to the 7747? That is odd that you had to set the enable temp to "01" to prevent it from turning on. I may very well be having problems because the EGR system actually is not disabled and it is using some other BPC to scale the table.

Looks like it just boils down to logging the WinALDL data and seeing what I get...I'll try to knock that out this weekend. By the way...what would be the impact of the ECM not getting a signal from the VSS? I'm in the middle of trying to get my Dakota Digital box hooked up properly and I am currently not getting any signal at all. I may be able to figure my wiring problem out before I do the data-logging, but will it be a problem if I don't? Also, how long does it take for the system to go into closed loop so that I can data log after I fire up the engine?

 

Well, I think I was wrong about the BPC change not making a difference in how my engine runs. It runs the same at idle, but not when you drive it . Not the brightest move on my part. Anyway, I drove the car after setting the BPC to 100 and it was MUCH smoother than when I drove it before with a BPC of 134. My apologies for thinking it didn't do anything.

So, now all I have to do is get my car to work with WinALDL and I'll be able to made adjustments in my VE table to pull some of the fuel out at lower rpms, e.g. at idle. I hooked everything up yesterday with no luck, but I'm going to try it again today with a different laptop because I appear to have an inadequate +12v power source coming from the old laptop I was using.

 

had the same problem as you. It Idled and ran fine at idle, as soon as you put it in gear, it would screw up and idle around 1900rpm. I tried every damn wiring combination under the sun (incl. the ones posted on this old thread). and bought a new IAC and it still would not work. When I WOT it hesitated and screwed up...I switched back to the SB TBI with 55pph injectors and it ran great...I forgot how good the car ran with the SB TBI.

 

Well Fredless, I'm about ready to do the same thing myself, as in throw on my old little injectors. Actually, all I have are the 40-45 pph 305 injectors, so I don't even know if that would work.

I don't think my problem is a whole lot like yours, though...my engine idles horribly but runs better once I get above 2500 rpm (and I've got a T56, not an auto).

I've got so many different problems going on I don't know where to start...I'm about to start a new thread to try and explain everything.