ECMlink stutter/misfire/backfire WOT

[bryanzomg]

hello all. I've been chasing an issue for a while. The issue is intermittent, happens more often in lower gears. I will have a slight stutter or no stutter at all WOT up until around 7k rpm it'll backfire like it hit limiter and then proceed to misfire for a few seconds and eventually it'll settle and the car can be driven normally again. I have changed the following, fuel filter, head with new valve springs (thought old ones were bad), new turbo, new bov, new coil pack, new wires (ngk), new plugs gapped around .018 (pump e85), Power transistor unit, new alternator, manual boost controller. I haven't swapped ecus but i have taken a look at it and no visible damage. I have provided logs, this happens regardless of boost level. Mod list is accurate, running speed density. Mechanical timing is good.

 

[GST with PSI]

What plugs are you running?

 

[Widgmaster]

Can some one please tell me what I need to read the .elg files...

 

[bryanzomg]

What plugs are you running?

NGK BR7ES

Can some one please tell me what I need to read the .elg files...

Are these not the standard format for ECMLINK? I can re upload if they’re not.

 

[1990TSIAWDTALON]

I don't think @Widgmaster has Ecmlink. I'm on my phone or I'd verify the files are ok but I'm sure they are. When time allows me, I'll look at them as I have an issue a little similar to yours.
Marty

 

[bryanzomg]

I don't think @Widgmaster has Ecmlink. I'm on my phone or I'd verify the files are ok but I'm sure they are. When time allows me, I'll look at them as I have an issue a little similar to yours.
Marty

Yeah my tuner was confused about it too. Just noting WB on link is off from my gauge it reads a bit leaner in LINK. Once it hits that wall up top around 7300 it begins to run like if it’s on 2 cylinders and eventually it’ll settle

 

[1990TSIAWDTALON]

Make sure that the ground for your gauge/WB are at the same point as the ECU ground. Tip from a well respected member and my tuner. It will help the gauge and Link match. Many thanks to @95GSXracer.

 

[DSMPT]

Can some one please tell me what I need to read the .elg files...

Download a ECMLink software for your computer or tablet and install. You wouldn't need to connect to ECU to launch the software and read .elg files.

http://www.ecmtuning.com/downloads.php

Just sharing an experience. This may not be the OP's case but I had a similar issue long time ago. When I exceeded 6500-7000RPM, I got like a rev limiter. And this never happened at lower engine speed. The issue was injectors plugs. Terminal's contacts were getting loose at higher engine speed even with holder clips. So I replaced all injector plugs and the issue was gone, never happens again.

 

[bryanzomg]

Just sharing an experience. This may not be the OP's case but I had a similar issue long time ago. When I exceeded 6500-7000RPM, I got like a rev limiter. And this never happened at lower engine speed. The issue was injectors plugs. Terminal's contacts were getting loose at higher engine speed even with holder clips. So I replaced all injector plugs and the issue was gone, never happens again.

I wonder if that’s the issue I had a injector plug come out at low rpm and it was a similar symptom when it happens at high rpm. (No clips) so I zip tied them, new plugs no clips tho will invest in some clips maybe it’s that

 

[GST with PSI]

I'd definitely guess this to be an ignition issue.

I had something similar happen to be shortly after I swapped to E85 while I was still on stock ignition. I swapped to iridium plugs and gapped them tight AF and that fixed the issue.

You could try a set of NGK iridiums and see if it helps. Easy cheap check to do.

 

[Vegas Smith]

I can't notice anything extraordinary on the log. I've heard of people having similar issues with stuck lifters that cause misfires for random amounts of time.

 

[NOSLO2PT0]

I'd definitely guess this to be an ignition issue.

I had something similar happen to be shortly after I swapped to E85 while I was still on stock ignition. I swapped to iridium plugs and gapped them tight AF and that fixed the issue.

You could try a set of NGK iridiums and see if it helps. Easy cheap check to do.

IRIDIUMS aren’t cheap and they certainly don’t belong in a DSM

 

[bryanzomg]

I'd definitely guess this to be an ignition issue.

I had something similar happen to be shortly after I swapped to E85 while I was still on stock ignition. I swapped to iridium plugs and gapped them tight AF and that fixed the issue.

You could try a set of NGK iridiums and see if it helps. Easy cheap check to do.

Part #?

 

[NOSLO2PT0]

You got the right plugs in there. Stick with the BR7ES

 

[GST with PSI]

Part #?

If you stick with the 7 heat range then BPR7EIX if you want the projected tip or BR7EIX for non-projected. I'd go with the projected for your build, personally.

You got the right plugs in there. Stick with the BR7ES

I used to be a diehard copper core guy, until I started running Iridium plugs. In my personal cars, they last about 5 times longer, and run better at high boost on E85. Personally, I'd never go back to copper cores on even a decently modified 4G63. The copper cores are definitely cheaper, but if you're replacing them often, the cost offset is negligible.

It's personal preference based on what works in your build. Iridium plugs worked better in mine, hence the suggestion.

 

[bryanzomg]

Can’t figure it out, leaning towards valve float???

 

[NOSLO2PT0]

What cams and valvetrain are you running? Highly doubt you are floating valves at only 7k rpm unless you are trying to running some very aggressive cams (Kelford 272 or bigger) on stock or mild single spring upgrade.

If your mod list is correct, you aren’t floating the valves on that cam\valve spring combo. I would start leaning towards an ignition issue. Is this happening at 28 psi? Turn the boost down and see if the problem persists. What do the ground wires from your battery to firewall look like? I would look into replacing all of your ground wires. They could be extremely corroded and not providing enough voltage for the coil pack to fire strongly at higher boost levels

 

[1990TSIAWDTALON]

Neck the plugs down to
018"

 

[bryanzomg]

What cams and valvetrain are you running? Highly doubt you are floating valves at only 7k rpm unless you are trying to running some very aggressive cams (Kelford 272 or bigger) on stock or mild single spring upgrade.

If your mod list is correct, you aren’t floating the valves on that cam\valve spring combo. I would start leaning towards an ignition issue. Is this happening at 28 psi? Turn the boost down and see if the problem persists. What do the ground wires from your battery to firewall look like? I would look into replacing all of your ground wires. They could be extremely corroded and not providing enough voltage for the coil pack to fire strongly at higher boost levels

I’m running *FP3 Cams with kiggly steel streets (had stock cams and stock springs had same issue) i have new battery grounds since we relocated battery recently (issue was there before relocation) I’ve ran it on 18psi on 14b before and still had that same issue. Suggested valve float as the symptoms are similar,high rpm misfire then misfire for a few seconds at idle until the lifters are able to bleed down all while the valves are hanging and eventually settle down

 

[NOSLO2PT0]

Your profile says FP2’s. The FP3 is a stroker cam and has a much more aggressive ramp rate. I actually ran a set of those for a while. GREAT midrange. Tough to keep between the lines on the road. I can’t remember if I had single or dual springs at the time. I’m guessing single cuz when I would no-lift-to-shift, I would get valve float, but that was at 8800rpm.

You said you got this same issue with such cams and stock springs. Valve flat is almost impossible to do on stock parts. Id start looking at ignition

 

[bryanzomg]

I've noticed my PacketInt in my logs shoot up like crazy WOT anything abnormal as to this issue?

what should my voltage at fuel pump be reading at idle/WOT? I remembered I had an issue where the fuel pump rewire was under my clutch pedal and everytime I would clutch in it would shut off the car. Ended up moving it out of place? Think there was enough damage from that, that the fuel pump isn’t getting enough voltage

 

[NOSLO2PT0]

Anything over 14v is good. Measure voltage at the battery while car is running, then measure as close to the pump as possible. You want the voltage to be the same at both spots. You almost always incur a little voltage loss through wire resistance. You just want as little loss as possible.

 

[bryanzomg]

Sent my injectors to get cleaned and flow tested, all have good spray pattern, flow within each other except for one. Flows about 10% less could this cause my misfire issue??

 

[Vegas Smith]

Yes.

 

[bryanzomg]

Yes.

Not to defy you but how? I like to know how that plays out.