Poping sound at idle, help..

[LuminousX]

got a 96 Camaro 5 speed, FJ250 injectors from the 3800 SC that is rated at 36lb/43psi, also running a 97 Camaro pcm.
did rods and bearing, and installed new gaped piston rings for boost because I'm running a single turbo, higher rated valve spring and then some..

I've been having this issue where the car would run and idle perfect when it's first started in the morning and running rich 12ish.. the closer I get to 14.0-14.7 the car starts making a popping sound out the exhaust, I've tried messing with the injector data, i tried messing with the spark, and noticed the car would pop way less at like 14 degree of timing, but no matter how much I try changing the main spark advanced it doesn't stick and just goes back to 25 degree.

it does it in open loop, and closed loop.. so far I've changed pretty much all the sensors, spark wire, coil pack, spark plugs.. I don't think it's a internal problem because i can make it stupid rich and it idles fine with no popping.

if their is a 3800 god out there I would love to get this problem solve

Closed.Loop.6.21.2024.hpl

Open.Loop.6.21.2024.hpl

Tuning.106.Stock.10.hpt

[LuminousX]

yet another subject that none of the so-called "tuner pros" know about... if the answer ain't easy you people don't even try, and yet this is suppose to be a support forum... this forum is pretty much useless

[blindsquirrel]

Poping sound

?

screenshot.20-06-2024 17.20.14.png

[LuminousX]

?

screenshot.20-06-2024 17.20.14.png

do you have another way to describe a "popping sound" ?

[blindsquirrel]

Popping and Poping are two different words. Communication through the written word only works if everybody is using the same system.

You did not post your tune file. You did not post a log file showing your problem happening. Your spelling is worse than my cat, and she's only 3 months old. I do not have high confidence that any mechanical work you did to the car was done with any more skill and attention to detail than you have shown so far on this page.

[LuminousX]

Popping and Poping are two different words. Communication through the written word only works if everybody is using the same system.

You did not post your tune file. You did not post a log file showing your problem happening. Your spelling is worse than my cat, and she's only 3 months old. I do not have high confidence that any mechanical work you did to the car was done with any more skill and attention to detail than you have shown so far on this page.

k........

Closed.Loop.6.21.2024.hpl

Open.Loop.6.21.2024.hpl

Tuning.106.Stock.10.hpt

[SiriusC1024]

Aftermarket vacuum-referenced reg? Set with vacuum line disconnected to 43psi? Reattach after setting.

What cam is in it to where you set idle so high?

[LuminousX]

Aftermarket vacuum-referenced reg? Set with vacuum line disconnected to 43psi? Reattach after setting.

What cam is in it to where you set idle so high?

stock fuel rail with regulator attached. 43 on a cold start, drops to about 41-42 when hot. 340LPH fuel pump in the tank.
Turbo car with AC delete, alternator can't keep up if I try to idle below 850 or so.. It could be due to the routing of the belt, but I do have 14.0 volts at idle. stock cam.

[SiriusC1024]

Have you tried adjusting open your throttle stop then doing a relearn? Looks like spark is being ramped up because it's running out of airflow.

Here's with correct injector data btw.

L36 or L67?

[LuminousX]

Have you tried adjusting open your throttle stop then doing a relearn? Looks like spark is being ramped up because it's running out of airflow.

Here's with correct injector data btw.

L36 or L67?

I'm going to test the new data out in a few, but I've never been able to find the proper way to do the relearn, I have messed with the throttle stop before. if you have the info can I get it.

[SiriusC1024]

Should be the same as the V8's.
https://ls1tech.com/forums/pcm-diagn...procedure.html

[LuminousX]

Should be the same as the V8's.
https://ls1tech.com/forums/pcm-diagn...procedure.html

ColdStart.InJ.Data.6.22.2024.hpl

I made the changes, adjusted the throttle set screw, and fired her up (L67).. my iac count dropped which is no surprise, the wideband have never read this stable at idle, but the car never went into closed loop, but it acted like it did and then I stated hearing the popping sound once the timing jumped from 15 to 25, I'm running a 5SPD by the way..

[SiriusC1024]

I kinda have an idea of where to make changes. When did this start? On it's own or after a mod or work?

I'm surprised you said L67. So you swapped the SC engine into your Camaro. That's pretty cool. Entire engine or just the short block?

[LuminousX]

Sorry it's the l36 N/A engine, I get them confused sometimes.. I've had this issue since I did spark plugs and wires on this car maybe 4 years ago and till this day I can't get it figured out, one time I found out I had a bent rod and ended up replacing all the rods and doing new bearings with rings gapped for 15lb of boost so compression is somewhat lower than what is used to be, but I had the problem before that..

I've done everything and did every test I could, no vacuum leak.. no nothing.. I did notice that I had sparking between the spark plug wires boot and the engine block, I'm starting to thing that those metal boot thing I took off years ago might have helped the sparking somehow..

I'm just out of ideas because this thing runs fine when it idles 13.8 and below.. and if I play with the spark in the low 12-15 range I can get it to idle fine at 14.7 no problem. but that's in open loop, and by the next day all the fueling is off for some reason and I'm back trying to get it right, and after a drive the timing goes to 25 and the afr is off again.. it's just a mess..

P.S I should add that I have ac delco wires and tr6 gap at 45.

[SiriusC1024]

If it is a tune-related issue I'd start by restoring everything to factory settings except for the injector data. This includes DTC's. If the problem resolves adjust one thing at a time. I've seen incorrect settings cause odd issues like this. It's an easy thing to do.

[LuminousX]

is it possible to have a bad file? or an incompatible file.

[SiriusC1024]

As requested at
https://forum.hptuners.com/showthrea...l=1#post787721

Bosch 0280155831 data in the attached tune.

Only potential issue with these injectors is that they are V-style spray pattern for DOHC instead of narrow cone. Might have excessive port wetting. Make sure they're all indexed the same in relation to their intake port.
https://forum.hptuners.com/showthrea...l=1#post745110

[LuminousX]

yeah, Thanks for the data.. works pretty well, turns out my fuel pressure only goes up to 54 psi, so I lowered the IFR to match..
I keep getting hits on cylinder 2/5 and I'm thinking I have a bad ICM but I've got 3 of em... maybe they're all bad.. gonna have AutoZone check all 3.

P.S pulse width is kinda high sitting at 2.4 at idle... any suggestion to lower it??

[SiriusC1024]

I don't see anything wrong with that PW at face value. Got a log? You could have to retune MAF. Need to see O2 voltage anyway.

Still popping?

[LuminousX]

Idle.Log.7.1.2024.hpl

It only pops when the idle goes from the commanded timing of 15 degrees to 25 degrees.. in the log idle was smooth for the most part, no popping or anything, but once it warmed up and reached open looped AFR at 14.5 the spark jumped up and the popping starts.