Hi, I took some injectors out of a 454 and im not quite sure what the history of the engine was, so i wanted to make sure they are the big block ones. I can see the numbers on one but not the other, and the paint codes are wore off so that wont help.

52341057 and 5454 or the bottom. I searched on here and yahoo and came up with nothing. Let me know if any of you guys have came upon some with the same number.

Another question. with a tbi 355 with stock heads and a mild cam (204 int and 214 exh, .421 and .444) , even at 12 psi that the regulator is set at, it should be running really rich and have black smoke right? Before i had the 52352057? (cant really read them, but i know they were the pickup 5.7 injectors)

My truck has always ran lean at ALL rpm's (with stock 1227747 prom and mail order chip (sorry guys i had to )

Everything is new, including a fuel pump a couple weeks ago, so im going to use the 454 injecors (if thats even what they are) and jack the fuel pressure up to around 15 or so and do a dattalog and put up here so you guys can look at it if you dont mind.

Before the p/w was maxed out and like i said it was lean at all rpms and it would load up when i start it when its freezing cold out in the mornings. So i replaced the injector O-rings cleaned the injectors, took out and cleaned and adjusted IAC, so i should be ready to go do a datalogg.

Thanks

 

Ok, with those injectors, i got the psi to about 15 3/4 , took it for a spin and just like before, in 3rd gear (or any gear really) when it hits around 3900 to 5K rpms, the engine tone changes drastically, it sounds dull and get a little quieter and when it shifts into the next gear and is at 3K it sounds normal again.

The timing wouldnt be thrown way off at that rpm would it? Im sure its because its lean though. NO smoke what so ever, im also getting 13mpg.

Any ideas would be appriciated.

 

ok, got a datalog of cruising, idle, and wot passes up to 5100 rpm.

After i zip them into a folder, how can i post them on here?

 

Well, here's part of one of the charts

Narrow Latest
RPM \ MAP 20 30 40 50 60 70 80 90 100
400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
800 0.0 145.0 145.0 156.0 0.0 0.0 0.0 0.0 0.0
1200 0.0 150.0 145.0 139.0 145.0 136.0 0.0 137.0 0.0
1600 135.0 145.0 145.0 145.0 145.0 0.0 0.0 0.0 0.0
2000 135.0 139.0 140.0 149.0 143.0 0.0 0.0 0.0 0.0
2400 135.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.

I ran it past 5K but it only shows up to 2400???? (i cut off the rest because it was all zeros)

I cant figure this thing out. 15 psi with 454 injectors and its that lean!

I wonder if i dont have an intake leak? Ive sprayed the intake with carb cleaner and found nothing but i didnt put much on because it was ruining my buitiful engine but i mad enough i dont care anymore so im going to soak it on tomarrow. Im not sure how to tell it but brain said my injectors were about maxed out i think when i sent him a datalog along time ago.

Like i said, lean and bad milage, intake leak is all that comes to my mind......

 

Some later 454s used 45 lb/hr 4.3 injectors at 26-28 PSI!

TOO MUCH CARB CLEANER=ENGINE FIRE!!!

Post the Wide AVG chart.

Brian is REAL bad about sending you STATIC at 4,000 rpm or about.

 

IM not running lean enough to do any damage am I? Ive dont so many wot runs im sure it would have blown up by now.....

Wide Avg
RPM \ MAP 20 30 40 50 60 70 80 90 100
400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
800 0.0 144.5 144.4 150.3 145.0 143.0 137.0 141.5 0.0
1200 140.5 144.0 145.0 144.2 144.5 141.8 138.0 140.6 0.0
1600 139.4 145.1 141.3 144.3 143.8 139.3 138.0 146.5 0.0
2000 135.0 141.4 142.4 142.5 143.5 143.9 139.5 138.5 0.0
2400 134.2 142.0 142.0 0.0 0.0 135.0 0.0 0.0 0.0
2800 130.0 128.0 0.0 0.0 135.0 0.0 0.0 139.0 0.0
3200 135.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
3600 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
4000 0.0 0.0 0.0 134.0 0.0 0.0 0.0 0.0 0.0
4400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 

You are lean, but if the BLMs are higher than 128 (adding fuel), it keeps adding fuel when you go into PE. That can make you very rich on the top end limiting power. The GM code was written like that in-case you had a fueling problem you would not burn up your engine going to WOT and PE. Now lets say that you were lean and your BLMs were lower than 128. When you hit PE it will reset the integrator and BLMs to 128 to keep you from going lean.

Let me do a math example for you to show you how lean you are. Lets take the 800 RPMx50 MAP cell that is showing 150.3. Take 150.3 and divide by the ideal 128. That is 1.174 now multiply that by 14.7 (ECM target is 14.7:1 @ 128 BLM). Without ANY compensation from the BLM you air/fuel mixture would be close 17.3:1!!!!!

 

Im definatly not rich at wot either, BUT i did notice in winaldl I only had like 80% or so throttle becuse there was a big piece of carpet under my pedal but i wasnt quite sure is 80% enough to enable PE?

What you said made alot of sence, i dont understand though, its trying to correct the a/f ratio and its still within the limits, but it never does richen it up, correct?

I checked my intake for leaks (ruined all the paint ) and came up empty handed. There has to be some physical reason why its staying around a 145blm right?

Wide Avg
RPM \ MAP 20 30 40 50 60 70 80 90 100
400 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.462
800 0.000 0.459 0.332 0.261 0.893 0.347 0.057 0.057 0.000
1200 0.050 0.391 0.327 0.386 0.575 0.451 0.252 0.131 0.000
1600 0.086 0.215 0.399 0.355 0.600 0.144 0.126 0.466 0.000
2000 0.124 0.397 0.346 0.554 0.367 0.396 0.206 0.835 0.000
2400 0.300 0.676 0.186 0.000 0.000 0.877 0.000 0.000 0.000
2800 0.414 0.831 0.000 0.000 0.950 0.000 0.641 0.888 0.000
3200 0.875 0.000 0.000 0.000 0.000 0.000 0.000 0.941 0.000
3600 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.932 0.000
4000 0.000 0.000 0.000 0.899 0.000 0.000 0.000 0.898 0.000
4400 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.877 0.000
4800 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.804 0.000
5200 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.287 0.000

 

The reason it is staying around 145 BLM is that it is begging for more fuel. Chances are the BLM function is giving it plenty of fuel. Maybe not. Only real way to tell would be to put a wideband on it. Why not get an adjustable fuel pressure regulator and bring the pressure up to about 15-20 PSI and try again. Make sure you have a TPI pump or equivalent in the tank. You could have 12 psi at idle and 8 under load!

 

Na, just bought a brand new pump, granted its only the 4.3 pump, it is set at 15 3/4 PSI, and doesnt dip any when i snap the throttle wo.

I've read other guys getting over way over that so i think the pump is capable for my 5.7. Havent done a volume check but like i said, i can never get the pressure to dip down.

 

And one more thing i dont understand, if im so lean, wouldnt be getting a heck of a lot better than 13mpg? Maybe i am getting the fuel i need and somthing else is wrong. IDK

 

Did you set your timing with the timing wire disconnected? It is under the passenger side floor mat, right at the firewall on my 1987 GMC S15 Jimmy. Try setting it between 0-6* with the timing wire disconnected.

You can lose fuel mileage from being lean!

What kind of manifold vacuum are you getting?

 

Yeah, i had the wire disconnected. Brian said to have it at 0, so thats where i set it at when i got the chip.

When i very first put the 350 in and i still had the v6 computer in it i had to have the timing around 4 or so for it to run decent.

I dont have access to a vac gauge so im going to check it when i get to work tomarrow.

 

Yeah you do! What was the MAP reading at idle?

 

oh

Umm, does 14.2 sound right? i can hook the laptop back up if it doesnt.

 

I would think somewhere between 20-50 for most engines.

 

ok, hooked a gauge up and it was around 55 or so on tb ports.

Double checked vac routing and everythings going to the right place, i did find that me map sensor wasnt mounted horizontally it was all slidways and stuff, but i got it straitened out and it doesnt realy seem to make that much differance if any. I umplugged the map sensor and it went all crazy like if should of course, but could maybe the map sensor be bad or would it most likely be all rich if it was bad?

 

With all that being said, injectors are the only thing left it can be right?

Im going to check the injector pusle width this weekend and see if its maxed out.

 

WOHOO` got er fixed, it was a combination of wrong injectors/fp i guess. anyways, its not a little too rich and i think i should back the pressure off a lbs or so, what do you guys think?

Wide Avg
RPM \ MAP 20 30 40 50 60 70 80 90 100
400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
800 0.0 118.4 121.2 121.0 0.0 0.0 0.0 0.0 0.0
1200 124.1 118.5 117.9 119.0 118.3 121.0 0.0 0.0 0.0
1600 126.9 122.5 116.9 118.9 121.1 132.6 0.0 0.0 0.0
2000 127.6 120.1 119.3 118.7 119.3 129.0 129.0 0.0 0.0
2400 0.0 117.0 0.0 120.0 0.0 0.0 117.0 135.0 0.0
2800 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
3200 0.0 125.0 120.0 0.0 0.0 0.0 0.0 128.0 0.0
3600 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
4000 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
4400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
4800 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
5200 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
5600 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
6000 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
6400 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

 

im also still not sure why its not showing over 2400 rpm???

 

Well, im now getting 24 mpg out of the engine.

Still alot of work to do in the engine bay but heres what i got so far