Injectors Vs Fuel Pressure

[Roadknee]

That does run really strong! My stock 1995 K1500 LO5 will pull 37 to 57 mph in second gear in just over 6 seconds. You're under 4. Wow!

I understand you're running base timing at 0 BTDC in this datalog. So your WOT timing is about 26 degrees. I think your combo could run 32-34 with your heads. Cruising at 2000 rpm and less than 50 MAP you're only running about 28 degrees total. I think your combo could use 40 or more. BLMs are rich in this area already and they'll become richer if you increase the timing so you'll need to reduce the VE tables too. These changes should reduce EGTs.

I think you could add 8-10 base timing for a quick test and go for a cruise to see how it impacts EGTs. Watch knock counts very closely if you're going to lean into the throttle.

[EagleMark]

I turned the idle screw in 1/4 turn, I get 1 to zero counts, is this too low? should I back it out an eighth?


Thanks again.

BLG

You could go out an 1/8th, but really your OK for now. Come middle of summer check it again after a good run, hovvering at 0-1 is perfect in park, you'll always get a few more in Drive.

With the cleaned injectors and added fuel pressure you are very rich at cruise low load situations, probably the cause of bog and high EGTs glowing the manifolds? I'm no expert, just my take on your log Your truck sure does pull hard, makes me wish I'd modded mine more.

As brain noticed it is very rich, right on the MAX allowed BLM low side at cruise low load situations, but it is more likely the extra amount of AE I added for the Vortec heads and was not looking for that much pressure... could also be a spark issue? Something is just not right with spark and even 2 timing lights are telling you something is not right? So it's set to 0* with bypass disconnected... or 4* what about bypass connected? Should be around 20* but it is going to be jumping around a little, just part of idle control of the PCM.

What 2 cylinders are glowing? Could there be a crossfire in those 2 spark plug wires? How do the plugs look on those 2 cylinders? Really sounds like a mechanical issue and not something that can be tuned out.

[BLG355]

could also be a spark issue? Something is just not right with spark and even 2 timing lights are telling you something is not right? So it's set to 0* with bypass disconnected... or 4* what about bypass connected? Should be around 20* but it is going to be jumping around a little, just part of idle control of the PCM.

What 2 cylinders are glowing? Could there be a crossfire in those 2 spark plug wires? How do the plugs look on those 2 cylinders? Really sounds like a mechanical issue and not something that can be tuned out.

It is actually all of them. it's easier to see on the back half of the manifold because there is no heat shield, but the whole log glows. I am 99% sure the base timing is actually advanced 4 degrees now. The timing at an idle is off the pointer for sure, my current light that does advance is telling me it has 46-48 degrees of timing, roughly, at an idle. so I'm not sure I trust the light, it's a cheap one. If I back the advance down on the light, it does correspond with the numbers on the pointer though. I am working on getting another on today. Also, the distributor was replaced before I got the truck with a NAPA cheapie, like $90. I replaced the pickup coil and module with GM parts, but the actual distributor is different, it more closely resembles the 70's HEI style inside. I have a brand new GM one in the box, should I swap them out and see if it makes a difference?

I just went from R44TLS plugs down to R42LTS plugs the other day and they are looking brand new yet. I attached pictures of the R44LTS plugs I pulled.

I noticed the idle seems smoother with the bypass disconnected, are they supposed to idle glass smooth or rough when bypassed? The engine has no shake at idle, and its super smooth. with timing bypass connected, the engine shakes at an idle. But I am going to get another light and verify this. Here is a youtube video of it idling with bypass disconnected.

https://www.youtube.com/watch?v=cLI_IXMTC-U

[EagleMark]

The timing at an idle is off the pointer for sure, my current light that does advance is telling me it has 46-48 degrees of timing, roughly, at an idle. so I'm not sure I trust the light, it's a cheap one. If I back the advance down on the light, it does correspond with the numbers on the pointer though. I am working on getting another on today.

Also, the distributor was replaced before I got the truck with a NAPA cheapie, like $90. I replaced the pickup coil and module with GM parts, but the actual distributor is different, it more closely resembles the 70's HEI style inside. I have a brand new GM one in the box, should I swap them out and see if it makes a difference?

The one in there is like a large cap HEI? They have differant settings for spark latency which throws the spark advance off... A brand new GM has got to be a better choice but it should be a small cap external coil type distributor. Couldn't see anything in the video... but something is wrong. Any light should be able to read a regular distributor... any signs of cross firing in distributor cap? Black traces, arcs etc...

[BLG355]

The one in there is like a large cap HEI?

I meant as far as the internals like the pole piece and the shaft. The new one from GM has a huge brass cover over the pickup and you can really feel the magnets in it as where the current one I haven't isn't near that strong, but it seems to work. The GM one seems much better build than the current one I have. I'm going to pull the cap and check it all out. Is it possible to get cross firing and all with a miss? I ruled that all out right away based on how smooth it pulls under a load. When the timing bypass is unplugged, are they always smooth or should it idle bad due to low timing?

BLG

[Fast355]

When the timing bypass is unplugged, are they always smooth or should it idle bad due to low timing?

BLG

Really depends on the camshaft specs, idle speed, and initial timing setting.

[BLG355]

The one in there is like a large cap HEI? They have differant settings for spark latency which throws the spark advance off... A brand new GM has got to be a better choice but it should be a small cap external coil type distributor. Couldn't see anything in the video... but something is wrong. Any light should be able to read a regular distributor... any signs of cross firing in distributor cap? Black traces, arcs etc...

The one with the brass collar is the GM one.

Ok, I got a good timing light, with base timing at zero, It has anywhere from roughly 19 or so to 22 at an idle.

I double checked everything, looked for vacuum leaks, everything seems good, and it runs great. Could it just be too rich when I coast or not enough timing when I am coasting to a stop? What is the max timing you can run on these motors, generally?

I see moates.net has two emulators that would work on my truck, the 'APU1" and Ostrich 2.0. Should I be going after one more so than the other? What do you guys use?


BLG

[Fast355]

What is the max timing you can run on these motors, generally?
BLG

I am tuning one right now. Has a 369 ignition module in it. That style of module has been tested to provide 2* more spark advance than the ECM is commanding from 3,200-5,000 rpm. Has not been tested over 5K to my knowledge.



22.85 + 3.16 + 1.98 + 2 = 29.99* @ 4,600 rpm. This is a stock L31 with a 268 roller cam, an edelbrock 2116, and a Holley throttle body and running on 87 octane.

[BLG355]

I finally got stuff from Moates, but I am having an issue. I try reading chips and I get nothing. When I load it in to tuner pro there is nothing to edit on the parameter tree, do I have to manually add everything or something? This makes zero sense. I quadruple checked everything, the BIN reads fine in the flash and burn software, or so it says, and that's it. nothing past that point. I tried with both chips that the truck runs on, but I get no data to edit. If there an easier way to get the data to come across?

[Roadknee]

Did you load the appropriate xdf file into tuner pro?

[BLG355]

Did you load the appropriate xdf file into tuner pro?

Yes, I got one here, $0D. I think that's the right one. When I load the BJYK from this site, I got data on the parameter tree, but when I switch it do the bin from either chip, I get nothing...maybe I am not doing it right. I am going to read again to see what I am doing wrong. I did just notice the one BIN is only 1kb, and the other is 16kb. the BIN I downloaded from here is 64kb.


BLG

[Roadknee]

Sounds like you're not selecting the right chip style to read from. I only did it once and it was back in January. I can say for certain the file you read from your chip should be 64 k

[EagleMark]

You need to set up your offsets correctly for the stock chip or the Moates 27SF512 chip. In the end the chip should be 64k. Read this and it will all fall together.

http://www.gearhead-efi.com/Fuel-Inj...Flash-and-Burn

[BLG355]

You need to set up your offsets correctly for the stock chip or the Moates 27SF512 chip. In the end the chip should be 64k. Read this and it will all fall together.

http://www.gearhead-efi.com/Fuel-Inj...Flash-and-Burn

Thanks Mark! This is what I needed.

[BLG355]

I am pretty sure I have to change something here. Do I need to make this match my flow rate?

flow.PNG

It appears there are other specs for MPFI and CPI, do I just leave them alone since I am TBI?