04 Silverado

[Jamescorbett]

I have an 04 Silverado. I recently posted a thread were I needed help with injectors. But this thing is hard for me to understand. I have bought the Greg banish gen 3/4/5 dvds. But I haven?t really had time to study them a lot. But I?m learning some.

I put a stage 3 special cut cam a friend had,cold air ,headers a new body style intake with the 30 lb injectors I had to buy the adapters for injectors to work. But I can?t for the life of me get this thing to idle and not flood.

I?ve had to change the oil and already fouled out 3 sets of plugs. Getting expensive. I just need help to get it to ideal and maybe we?re I can drive it around some

I still have to put a posi unit in it as it is a one wheel peeler.

[blindsquirrel]

What is the fuel pressure as measured with a mechanical gauge on the rail? What's the fuel system? What pump and what is it using for a regulator?

[Jamescorbett]

The fuel pressure is 55 to 58 psi .If i remember correctly if i need to check again i will its just the stock fuel system . with no return .

It will idle but you can smell its rich and when you rev it up a little it smokes and smells to be running richer and then throws a miss fire code .

[kevin87turbot]

I have an 04 Silverado. I recently posted a thread were I needed help with injectors. But this thing is hard for me to understand. I have bought the Greg banish gen 3/4/5 dvds. But I haven?t really had time to study them a lot. But I?m learning some.

I put a stage 3 special cut cam a friend had,cold air ,headers a new body style intake with the 30 lb injectors I had to buy the adapters for injectors to work. But I can?t for the life of me get this thing to idle and not flood.

I?ve had to change the oil and already fouled out 3 sets of plugs. Getting expensive. I just need help to get it to ideal and maybe we?re I can drive it around some

I still have to put a posi unit in it as it is a one wheel peeler.

You have a problem on the passenger bank of the engine. Do you see how it's maxing the fuel trims on that side? That typically indicates that you have a misfire issue on that side. The PCM sees the oxygen in the exhaust as a lean condition and begins to dump a lot of fuel to compensate. If you're using the MAF sensor and have it running in Dyn mode, you can simply look at individual cylinder misfires on the HP Tuners Scanner. If you're running it in SD mode, the PCM will not show individual cylinder misfires. Here's a quick way to diagnose the problem. Start the engine, let it idle for a couple of minutes. Use HP tuners scanner to force Open Loop during this process. Use a temp gun to check the temp of each header tube. You'll likely find that there is at least one header tube that's colder than the rest. That's the dead cylinder. At that point, you can check plugs and plug wires, coil and injector on that cylinder to determine the root cause if the misfire. It's also possible that it could be a mechanical issue. A quick compression check will determine if that's the case.

[kevin87turbot]

The fuel pressure is 55 to 58 psi .If i remember correctly if i need to check again i will its just the stock fuel system . with no return .

It will idle but you can smell its rich and when you rev it up a little it smokes and smells to be running richer and then throws a miss fire code .

Post your current tune when you can.

[Jamescorbett]

Tune thatis in my truck now

[kevin87turbot]

Tune that is in my truck now

Load this one when you get a chance and look at individual cylinder misfires on your scanner. That will allow you to determine cylinder or cylinders that are misfiring. topside base tune injector change 12580681 kw mod.hpt

[Jamescorbett]

Load this one when you get a chance and look at individual cylinder misfires on your scanner. That will allow you to determine cylinder or cylinders that are misfiring. topside base tune injector change 12580681 kw mod.hpt

Ok I will try in it a few mins

[Jamescorbett]

Do I have to set up individual cylinders on the scanner to do this. If so I?m lost lol

[kevin87turbot]

Do I have to set up individual cylinders on the scanner to do this. If so I?m lost lol

Just load this configuration file in your scanner.

P01ChannelList4.Channels.Channels.xml

[Jamescorbett]

look at this its miss firing like crazy

[kevin87turbot]

look at this its miss firing like crazy

The aftermarket cam will cause the PCM to show misfires on every cylinder. In your case, cylinder 6 appears to be the worst offender by far. I would start on that cylinder and determine what's causing it to show more misfires.

[Jamescorbett]

this is after compression check at 150 and new coil

[Jamescorbett]

Maybe the cam is to much

[kevin87turbot]

Does it have an exhaust leak on the passenger side?

Load this revision and post a datalog. This will force it to SD mode.


topside base tune injector change 12580681 kw mod sd ol tune.hpt

[kingtal0n]

Your diagnosis begins with mechanical aspects and setup related

1. make sure you are using high quality injectors such as Injector Dynamics, FUel injector clinic, or OEM cleaned and tested injectors which are authentic.
Poor quality injectors can create all the havoc no matter what you do tuning wise. This is #1 offender for new customers I encounter.
Next, check injector wiring. Make sure the right injector is firing on the correct cylinder. The plugs orientation in the harness could be backwards.
Ideally you will trace each injector and coil back to the corresponding cylinder at the ECU.

2. Inspect all plugs, use cheap plugs, brand new plugs, keep extra brand new cheap plugs for diagnosis. Don't try to diagnose a misfire with awful fouled plugs, the plug may foul causing misfires, you can't un-do that with tuning. Its chicken and then the egg with plugs.
Plug tips:
NEver touch plugs with human hands, use brand new disposable gloves when handling.
Dont use anti-seize when diagnosing misfire issues if you are novice with anti-seize how to apply it properly.
Plugs need to go in clean, and stay clean.

3. Inspect the wiring for coils, i find some people put the wrong harness or wrong wiring without realizing it, its firing the wrong coils at the wrong time. Inspect firing order related wiring. I almost did this by accident once because I lengthened the wires for the coils in a swap and somehow they got crossed left to right.
Inspect the coils plug ins, and the spark plug wire plug ins, look for bad insulation. Replace the plug wires if they are old. Its too cheap to make this mistake. Use known good coils. If you are not sure a coil is good, ground a plug and crank the engine without fuel to test the coil one by one to ensure they actually fire the plugs.

4. Compression test, you did this so good. But it remains a gold standard for diagnosis worth mention and good job.

5. Air leak testing. You should pressure test the intake system to find all leaks. Small leaks around the intake ports of aftermarket manifolds is common. I recommend OEM intake manifold until you sort out a combo.


Here is what I would do
A. test the fuel system with engine off, check if the injectors are leaking. Check the system bleed down rate and find out where the fuel is going if it bleeds off rapidly.
B. Disable closed loop and unplug narrowband sensors. You do not want narrowbands active or closed loop active when there is some issue to diagnose related to mechanical and electrical aspects.
C. Make sure the correct tune file settings for injector size, flow rate per fuel pressure, engine dispacement, etc... use a proper tune file, don't just assume or random the tune file.

SO now we have good compression (air), good spark (correct wiring and coils work and plugs are new) and fuel (injectors are good, don't leak, correctly wired).
Thats all engines need.
Your next step will be to:
D. Run the engine using the scanner in real time, use the scanner to CONTROL the a/f ratio directly, the timing directly, to get the engine idle acceptable. Dial up and down the A/F ratio in the scanner in real time to achieve a idle a/f ratio on the wideband of 15:1 and play with the timing to make sure it 'feels right' by that I mean does really low timing values seem to reduce RPM and try to kill the engine? Does very high timing values cause the engine to seem jittery, pop and a bit of misfire? You will want to idle roughly 15-20* btdc of timing range for stable idle quality 15:1 air fuel ratio. You must have a wideband. Do not try to diagnose or ruin more plugs without a wideband as it COULD waste your time.

Now the engine idle acceptable, you will perform the misfiring test finally:
E. Use the scanner software in real time to disable each injector one at a time to listen for the appropriate cylinder misfire. Each RPM drop per injector should be roughly the same (cylinder balance). Each misfire should be noticable and detectable. If you cannot detect a misfire when you disabled an injector there is a chance that cylinder wasn't firing in the first place. You will then check the corresponding spark plug for this evidence and go back to step 1 for diagnosis of wiring insulation pressure etc...

Once you disabled every injector manually you will know for 100% accuracy whether the engine is misfiring or not.

[Jamescorbett]

I would like to ask a question and tell what happened to this truck before i started adding cam and other stuff.

This was my uncles truck and he died in it . He was driving around his pond looking at tree limbs were he was having the trees cut and slid off in the pond and died in it . Now he was 80 years old so it was cold when this happened .

Since this happened in 2012 i flushed everything thing out . But truck has been ok till about a year ago and it started to flood and missfire .

So when the truck was given to me i decided to cam it and go to a new body style intake and fuel injectors , then i added cai and headers .

so while i was replacing the cam i had some down time so i ported the trottle body and was opening the butterfly by hand and ive heard that can mess the sensor up.

Bud the trottle body is only thing i have not replaced do you guys think the trottle body is the culprit for the miss fires .

I,m just asking

[kevin87turbot]

The throttle body isn't causing the issue. However, Corrosion on some of the connectors could cause an issue.

When you get a chance, load that last tune I posted. It's going to run much better with it.

[2xLS1]

Highly unlikely a TB would cause misfires. As stated any aftermarket cam is going to show misfires on all cylinders because of cam lope at idle. Misfire diagnostic looks for smooth rotation of the cam reluctor. You lose that with a cam that lopes. I can't look at the logs but someone pointed out one cylinder has way more than others and the fuel trims are out of balance bank to bank. You have a mechanical issue that needs to be resolved.

[Jamescorbett]

The throttle body isn't causing the issue. However, Corrosion on some of the connectors could cause an issue.

When you get a chance, load that last tune I posted. It's going to run much better with it.

Does it have an exhaust leak on the passenger side?

Load this revision and post a datalog. This will force it to SD mode.


topside base tune injector change 12580681 kw mod sd ol tune.hpt

I didn?t see this revised tune I will load it tom and see what it does