2G Misfires and Idle surge. Tried everything.

[Andrew_99_GST]

Let's start with the first problem
Misfires-
I've had misfires ever since I got the car. I rarely get a code, but the 2 times I have, I got 0300 and 0302. I can feel it at idle and then when accelerating.
Idle Surge-
I had idle surge for quite a while. I don't remember what I did, but I tried a bunch of different stuff and got it fixed. I then was getting a surge under light throttle. Fixed that by simulating idle switch in dsmlink. Today, after rebuilding my throttle body and boost leak testing, I start it up, and it idled really high. The Idle kept climbing and climbing. I tapped the accelerator and the idle dropped down, and surged like crazy. The only other idle thing I did, was one of the valves on top of the throttle body was boost leaking. So I put a new cap on it and fixed the leak there.



What I've tried-
3 different spark plugs
New wires
New coil packs
Boost leak test (leak free)
Rebuilt Throttle Body since I had a leak there
New IAC
New BISS O RING

And here's a log from today after warming up-

 

[Andrew_99_GST]

UPDATE: Idle surge was because I forgot to plug in my IAC

Still have misfires however. Not sure what else to do. I got all my ignition stuff replaced and boost leak tested.

 

[Mitsu725]

Misfires like under load or just sitting idle. If just sitting at idle and you have replaced all ignition components, I would suspect a bad cam. Also have you done a compression test?

 

[Andrew_99_GST]

Under load (accelerating). I have a fairly rough idle, but I believe that is a dead time issue (tuning). I do not think it is misfires I feel, because if I raise my idle, it feels ok.

 

[Ep1c]

Is it random multiple misfires? Have you done a compression test? How is your fuel pressure? Last thing I would check is the Injectors. Most misfires I've had were either spark plugs fouled or gapped incorrect and or dirty fuel injectors.

 

[snowborder714]

What cam angle sensor do you have?
Why the direct access adjustments in your tune, especially the large increase in tip in?

The car is acting really weird at idle - it's actually shutting the injectors on and off. You can see it at the end of the log you posted. I'd suggest going through all the tests in this thread, resetting all of your link settings back to stock (no adjustments at all in ECU Config or Direct Access sections), and see how the car runs.

 

[Andrew_99_GST]

Is it random multiple misfires? Have you done a compression test? How is your fuel pressure? Last thing I would check is the Injectors. Most misfires I've had were either spark plugs fouled or gapped incorrect and or dirty fuel injectors.

I got 0300 once and then 0302. I rarely get a CEL. I have not done a pressure test. Check fuel pressure and it was right on (42.5 I believe?). Spark plugs are gapped and are clean. Checked all the injectors (they are all brand new). All are clean.

What cam angle sensor do you have?
Why the direct access adjustments in your tune, especially the large increase in tip in?

The car is acting really weird at idle - it's actually shutting the injectors on and off. You can see it at the end of the log you posted. I'd suggest going through all the tests in this thread, resetting all of your link settings back to stock (no adjustments at all in ECU Config or Direct Access sections), and see how the car runs.

I am running the stock CAS. I was actually have a lot of problems with the CAS. I got 3 bad ones in a row. All the packages were already open. But this last CAS is working fine.

You will need to elaborate on the direct access adjustments and the increase in tip in. I am new to DSMLink. The previous owner of the car may have fiddled with the direct access section. The only thing I have done is changed fuel settings to compensate for the new injectors and did a little maf comp tuning.

Lastly, that log was with the IAC unplugged and that's why the idle was so messed up. I will take a new log now that the idle is better and post on here. I will reset back to default, first.

you still running stock maf try cleaning that if you are. try the compression test like others have said.

Stock maf and just cleaned it.

 

[Nick97dsm]

what setup are you running for boost controler, internal or external wastegate?

 

[snowborder714]

You will need to elaborate on the direct access adjustments and the increase in tip in. I am new to DSMLink. The previous owner of the car may have fiddled with the direct access section.

I will reset back to default, first.

This makes sense. As long as you reset the adjusted direct access tables back to stock, no need to worry about it. You can click the double ended black arrow icon at the top of each of the AirflowSmoothing and LTFTSelect tables to toggle the stock values back and then copy all to the ECU. For the BaseTipInTPSAdj, right click anywhere in the graph and choose "Reset to stock" and then click copy to ECU.

 

[Andrew_99_GST]

This makes sense. As long as you reset the adjusted direct access tables back to stock, no need to worry about it. You can click the double ended black arrow icon at the top of each of the AirflowSmoothing and LTFTSelect tables to toggle the stock values back and then copy all to the ECU. For the BaseTipInTPSAdj, right click anywhere in the graph and choose "Reset to stock" and then click copy to ECU.

Got everything back to stock. That was from the previous owner during which it had 1000cc injectors and 20g turbo. Will go for a drive later and post up a log.

 

[snowborder714]

Make sure you go through that checklist of tests and such I posted above before posting a log in the proper sub-forum. We're gonna ask if you went through it

 

[Andrew_99_GST]

Make sure you go through that checklist of tests and such I posted above before posting a log in the proper sub-forum. We're gonna ask if you went through it

Went through the checklist and the only thing I haven't done is the compression test. I also don't have a wideband. I didn't feel it was necessary until I actually start tuning. Here's the log from today. I didn't start misfiring until 800 seconds. And I started misfiring pretty hard, especially toward the end. However, I only misfire while accelerating. I never misfire right away. It's always after driving for a while.

 

[snowborder714]

Your log looks normal - nothing stands out.

Make sure to include all the reference log values from this thread to maximize the amount of data you collect.
http://www.dsmtuners.com/threads/list-of-values-to-log.444831/

Have you replaced your power transistor with a known working unit?
Do you have any way to get a different, known working set of injectors to try to rule them out?

Keep in mind the 0302 CEL is specific to cylinder 2, so I'd start all my investigating in relation to that.

If all else fails and you've tried everything and nothing has fixed it, uncheck the "cylinder misfire" box on the DTCs tab in link and it won't throw it again.

 

[Andrew_99_GST]

Your log looks normal - nothing stands out.

Make sure to include all the reference log values from this thread to maximize the amount of data you collect.
http://www.dsmtuners.com/threads/list-of-values-to-log.444831/

Have you replaced your power transistor with a known working unit?
Do you have any way to get a different, known working set of injectors to try to rule them out?

Keep in mind the 0302 CEL is specific to cylinder 2, so I'd start all my investigating in relation to that.

If all else fails and you've tried everything and nothing has fixed it, uncheck the "cylinder misfire" box on the DTCs tab in link and it won't throw it again.

I tested my power transistor and it tested out OK. Also, my head is freshly machined and rebuilt, so my compression should be ok, right? I got the work done at a trusted shop that does work mainly for drag cars.

I do have the old 1000cc injectors laying around. I know they worked, so I will throw them on.

The CEL isn't what bothers me. The misfires makes it hard to drive long distances. I also rarely get the CEL (twice in the past 2-3 months).

I will swap out the injectors and get back to you. Thank you for all the help, it means a lot.

 

[Andrew_99_GST]

No bueno on the new injectors

I thought for sure this was going to fix it. I tested the injectors by unplugging each injector and seeing how it effected my already crappy idle. If I unplugged 4,3, or 1, the car almost dies. I unplugged #2 and almost nothing happened.

After swapping out the injectors, the idle was a bit better. Not sure. I went for a drive. Everything going smoothly for 10 mins. I decide to do a very light pull up to 10-12 psi (3500 rpm) and I got a few misfires. I drive normally again and the misfires are gone. I do another pull and it pulls beautifully. Keep driving for a few mins, everything is smooth, when I start misfiring again. It misfired all the way home.

I don't understand how it can go from being smooth to misfiring and back in a few minutes. Especially because almost the entire engine except the block and intake manifold is either new or rebuilt.

 

[inthemidst]

Definately do a compression test before all else.

 

[Calan]

This sounds like an intermittent electrical issue somewhere in the ignition path. Have you checked all wiring and connectors for broken wires, loose pins, etc?

 

[Andrew_99_GST]

Definately do a compression test before all else.

With a rebuilt and machined head, do I still need to do one? I will pick up a tester.

This sounds like an intermittent electrical issue somewhere in the ignition path. Have you checked all wiring and connectors for broken wires, loose pins, etc?

I have checked, but I will recheck tonight.

Thanks.

 

[inthemidst]

We are human sometimes we make mistakes so ya you have to make sure to do basic engine tests before assuming other problems.

 

[fmars62]

look at your fuel trims at idle.

what percentage are they at?

rev it up, and what do they go to?

 

[dgdsm]

No bueno on the new injectors

I thought for sure this was going to fix it. I tested the injectors by unplugging each injector and seeing how it effected my already crappy idle. If I unplugged 4,3, or 1, the car almost dies. I unplugged #2 and almost nothing happened.

Have you tried doing the same with the wires to the spark plugs?

I think you're groping in the dark a bit if you don't do a systematic diagnosis. But I would guess based on everything you posted, that you have some intermittent electrical issue going to injector #2.

 

[Andrew_99_GST]

look at your fuel trims at idle.

what percentage are they at?

rev it up, and what do they go to?

I will check tonight, but my LTFT Los have been terrible. Like -15+ before I did mafcomp. I believe my 50hz slider is -12. But my LTFT Mids have stuck around 0 (0.2 is highest it goes)

Have you tried doing the same with the wires to the spark plugs?

I think you're groping in the dark a bit if you don't do a systematic diagnosis. But I would guess based on everything you posted, that you have some intermittent electrical issue going to injector #2.

Yup I've done the same with the plugs. I took out my coil packs yesterday and made sure the connections are tight.

I also changed out my fuel filter. It hasn't been changed while I've had the car. Haven't been able to test drive yet.

 

[Andrew_99_GST]

Picked up compression tester along with a fuel injector node light tester.

 

[Andrew_99_GST]

Compression is 170 across the board. Getting power to all the fuel injectors. The spark plug wires were sort of loose, so I got them tighter on the coil packs. Still getting misfires. Ordering a new power transistor now.

 

[Nick97dsm]

maybe new wire are needed if there loose they are probably done.