ECMlink Car Stumbles When about to hit boost

[Breadvans]

So usual suspect was boost leak. Runs fine under vacuum but starts stumbling and falling flat on its face when about to hit boost. So I assumed boost leak, double checked and it was fine. I didn’t have a gauge attached, but i had the regulator set at 10 psi and it held and I turned it up a bit and it blew a couple vacuum caps off.

Recently got new spark plugs and wires, NGK coppers. Double checked the gap and they were gapped too much to like .035, I don’t know if that much overage would cause that much of a stumble. But I lowered it to .028 and then was revving it before I wanted to drive it, and it was hesitating a lot just sitting there. From idle there would be a 1-2 second delay from hitting the gas to my rpm’s actually moving.

I just got done installing my intercooler, I checked it after the install and it would idle but felt not great because I’m no longer recirculating my BOV, then finally got my new GM MAF, so hooked up the MAF and the MAFT. It’s a 2g MAFT but I believe it was the 2.02 but I know it’s one people said are universal, so I set the dials to the stock 450cc injectors on a 1g, and was going to tune the actual injectors through ECMLink. From what I gathered that’s what I should do. I got a 1g to 2g mag adapter, and then wired the white wire into a tach signal.

Not sure what’s going on here, and would appreciate some ideas, it had a slight stumble at about 4500-5000 rpm’s before. My AFR is around 11 under boost because I’m on pump gas

Forgot a couple things. MAF is blow through not draw through anymore, it is between throttle body and BOV. Fuel filter had been changed on the car but it was a couple years ago and hasn’t been driven more than 100 miles, a lot of sitting.

 

[curt-s]

You list that you have link.. post a log

 

[Breadvans]

You list that you have link.. post a log

Unfortunately I broke a tbolt clamp while doing boost leak. I hope to get one tomorrow because the car is at my parents an hour south. For what it’s worth I’m no expert but I didn’t see anything that would make sense in there to cause it, but I’ll still try and get one.

 

[Breadvans]

I know being speculative probably pisses some people off but it’s all I can do with living this far right now. I went to work on it yesterday and broke the v band clamp so it’s oos until the new clamps gets here tomorrow.

But something I’ve been thinking is it’s gotta be fuel related if it passed the boost leak, and I was thinking maybe it could be the o ring on the fuel pump? I’ve been researching it and it seems to cause similar issues as I’m experiencing but not the exact same. I just don’t know why it’d be worse after the intercooler install, but maybe it’s reacting weird to the MAFT.

Either way I ordered the Toyota little gasket for the fuel pump to see if that fixes it. I’m obviously going to try other stuff in the meantime because it’s not supposed to be here til April 10th. But just rambling

You list that you have link.. post a log

Here's a log. I also have a video from the log, it died at the end but started up right after. I’m leaning towards fuel pressure still

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I’m running ridiculously rich and not sure why that happened either. I’ll try and adjust and get back to it but not sure if it should’ve made it kick like that.

 

[steve]

You got a ton of injector deadtime dialed in between the 472 to 550 from InjBatteryAdj and the additional 300 usec from your Global. You sure you need that much?

What's your AFPR set to?

I'm not sure I trust the wideband data in the log, it seems pretty off.

Perhaps somebody can comment on your MAFT settings.

 

[Breadvans]

You got a ton of injector deadtime dialed in between the 472 to 550 from InjBatteryAdj and the additional 300 usec from your Global. You sure you need that much?

What's your AFPR set to?

I'm not sure I trust the wideband data in the log, it seems pretty off.

Perhaps somebody can comment on your MAFT settings.

I can confirm the wideband in the log is pretty dialed in, that’s how rich I’m running. I tuned it some more and it smoothed out quite a bit, not enough for me to say good because it was doing it before the fmic but I will update when it dries out and I can do some serious tuning. Afpr is at 38 with the vac line off, should I change it to 43 since I have link and can edit it? Or just leave it at stock and never touch it.

I’m not sure about the injector dead time and such, I just dialed in what I should according to ecmlinks website for the 750ccs from fic. For the injbatteryadj I just plugged in what was on the chart that fic had with injectors, but I just read that that’s total dead time? So I might have plugged that in wrong, if so that would explain the very extended cranking

 

[steve]

Use one or the other, not both. Zero out the global and see if the car idles better and if the fuel trims settle within 1-2% plus or minus. Deadtime has a much greater effect at idle than at WOT. Then lock the car in closed loop and see how close the WB reads to 14.7:1 at various RPM. Don't go making pulls just get a better handle as to what's going on.

Double check all your MAFT settings and which version you have. You can't really tune when you have multiple questionable variables.

 

[Breadvans]

Use one or the other, not both. Zero out the global and see if the car idles better and if the fuel trims settle within 1-2% plus or minus. Deadtime has a much greater effect at idle than at WOT. Then lock the car in closed loop and see how close the WB reads to 14.7:1 at various RPM. Don't go making pulls just get a better handle as to what's going on.

Double check all your MAFT settings and which version you have. You can't really tune when you have multiple questionable variables.

Just to double check, when you say one or the other you’re talking about dead time and then the batteryadj? And if that is what you’re talking about I should prioritize dead time first? Since that has an effect while driving. And okay I’ll try that tonight

 

[curt-s]

They both do, they're additive. The deadtime is a good way to make small adjustments at the time and if they prove beneficial, you transfer that to the DA table by adding it to the current values and zeroing out global.

Not strictly necessary but it does paint a whole picture at once because the global dead time is added to all voltage ranges whereas the DA table you can tweak 12 and 14 because the values are interpolated depending on voltage at the ECU.

 

[Breadvans]

They both do, they're additive. The deadtime is a good way to make small adjustments at the time and if they prove beneficial, you transfer that to the DA table by adding it to the current values and zeroing out global.

Not strictly necessary but it does paint a whole picture at once because the global dead time is added to all voltage ranges whereas the DA table you can tweak 12 and 14 because the values are interpolated depending on voltage at the ECU.

Okay awesome thank you! I’ll play with it a lot more tonight, make sense cuz I really had to add a lot of fuel for my idle through the maf comp table

 

[steve]

’ll play with it a lot more tonight, make sense cuz I really had to add a lot of fuel for my idle through the maf comp table

Why are you adding fuel? You said you were "ridiculously rich". MAF Comp is to adjust the computed airflow with the goal to accurately measure the airflow across its range. You need the injectors dialed in so you know you're not fixing fueling issue by tweeking the airflow.

 

[Breadvans]

Why are you adding fuel? You said you were "ridiculously rich". MAF Comp is to adjust the computed airflow with the goal to accurately measure the airflow across its range. You need the injectors dialed in so you know you're not fixing fueling issue by tweeking the airflow.

Well they’re dialed in on the fuel page, and I was running like 17:1 or 18:1 at less than 50 hz for my idle so I added fuel to bring it to that 14.7:1 at idle, but I only left it for the idle, I brought down the fuel for everything.

Also the global scalar came default on my Mafcomp table at 1.6? Is that correct and should I mess with that at all?

I played with the batteryadj today and lowering that made it crank the same, then resetting it made it crank way longer than before. Talking like 15 turns and no start and then fired up almost immediately the second try

 

[jed344]

First i would adjust your tps. You want .63v at idle.

I never used a translator, back in the day i always used the ecm link cable with gm MAF so i cannot comment on the settings for that.

You have a lot of maf comp added. This will cause it to be rich.

The air flow per rev looks to be high depends on if you have cams and what cams. That would be from the maf comp being to high in the idle HZ.

I suspect its a combination of injector settings being wrong and the maf comp causing the bulk of the issues.

The number in dead time is added on top of what ever the values in injbatadj table says.

 

[steve]

Well they’re dialed in on the fuel page, and I was running like 17:1 or 18:1 at less than 50 hz for my idle so I added fuel to bring it to that 14.7:1 at idle, but I only left it for the idle, I brought down the fuel for everything.

As we have been pointing out, they are NOT dialed in.

Also the global scalar came default on my Mafcomp table at 1.6? Is that correct and should I mess with that at all?

Perhaps reading these will help, because I don't seem to be expressing the idea well. I don't have any logs from cars with MAFTs but I suspect it should be 0 until proven that it needs to be different.

v3mafadjcombft [ECMTuning - wiki]

www.ecmtuning.com

quickieafsetup [ECMTuning - wiki]

www.ecmtuning.com

I played with the batteryadj today and lowering that made it crank the same, then resetting it made it crank way longer than before. Talking like 15 turns and no start and then fired up almost immediately the second try

If the data FIC provided with the injectors is correct then all you would need to do is plug that into InjBatteryAdj and leave the Global deadtime parameter set to 0. What's on ECMTuning's table is assuming you don't have access to InjBatteryAdj like with V2 and earlier and ALL you had was the Global.

The problem is you have made multiple adjustments to try and make the car run but they were wrong and now changing one isn't going to give you accurate information while the others are still out of wack. Save a log so you can revisit, reset to stock, and start over with only the basic setting needed for how your car varies from stock. When you change things only do one thing at a time so you know what the effect is. If it doesn't do what you wanted/expected change it back.

Everything depends on the fueling and airflow measurements being correct.

 

[Breadvans]

As we have been pointing out, they are NOT dialed in.

Okay I had zero clue that’s how it worked with the dead time and it needs to be zeroed out. I’ll zero it out, sorry i wasn’t understanding but I get it now. And okay I’ll zero out the global scalar as well, car is oos rn. Waiting on a couple gaskets. Should be arriving on monday

 

[Breadvans]

Okay finally got it taken care of, when I put the scalar to zero and the global dead time to zero the car went lean like 16.5:1 currently as it sits I have to have my mag comp table at 68% to put around 14.7:1 when I’m between 0-50 hz. This doesn’t feel right at all?

 

[steve]

I hate to sound like a broken record but please post a log with those settings.

As I mentioned before there are likely multiple things that were changed and now that a few are corrected it's time to look for more. MAF Comp changes the calculated air mass value so if everything else is correct it would suggest that there might be something going on with your MAFT and GM MAF.

Without a fresh log we can't see the full picture.

 

[We're on Boost]

Just quickly, it looks like you ran a MAFComp Adjust on your log and believed the suggested values. Because that's where your sliders are. But the suggested values are no good in any of the Open Loop areas of operation. So you got a whole lot of no good MAF Comp numbers.

Your open loop is starting at around 300 to 400 MAF Hz. Basically all your mafcomp sliders from 300 Hz and higher need to be lowered drastically. Just for a quick test you could lower all of those to an Adj% of 0. Or 10. (Most of them are like ~32 right now.) And try it out to see how the AFR's look on your wideband. Leave the lower Hz (below 300 Hz) sliders where they are for now. Because even as they are your idle is too lean and the MAF Hz numbers at idle are unrealistically low.

Don't know what would be causing this at the moment, but if you do this much and it helps, then it's a start.

The log I am talking about is the one you posted in post #4.

 

[Breadvans]

I hate to sound like a broken record but please post a log with those settings.

As I mentioned before there are likely multiple things that were changed and now that a few are corrected it's time to look for more. MAF Comp changes the calculated air mass value so if everything else is correct it would suggest that there might be something going on with your MAFT and GM MAF.

Without a fresh log we can't see the full picture.

Here's the log with the new numbers. Wayyyy better numbers. I realized when it was idling before the first run that it's been unplugged and plugged it back in, then it was dying when shifting. Then I unplugged it again and it was no longer dying while shifting, and fuel trims were fine. Is it a bad sensor?

Also just want to add, the MAF is a blow through set up. It's in between the TB and BOV

 

[Stapl3]

WOT suggests you're 2 points lean. Idle (600rpm, really?) suggests you're 4 point's lean.

Your MAFComp is ridiculous. How did you arrive to those adjustments? I'm not trying to put you down or embarrass you, I'm genuinely curious. The only time that your air/fuel ratio is near correct is about 350-400hz during cruise which is about the only place on your MAFComp table that has little to no adjustments.

You're also on pump gas and using that timing table? My dude, between that and your air/fuel ratio being into the 14's during WOT it's a miracle the engine is still together. I don't think you realize how bad this is. I've looked at hundreds of datalogs and yours is nightmare fuel to me.

If I were you and was bent on keeping that MAFT, I would zero out the MAFComp sliders, be sure the MAFT box was set up for 450cc injectors (the 750cc adjustment is done in 'link instead), then play with deadtime *at idle* until LinWideband = AFRatioEST. And without question load in a stock 2g timing table for now. If you can't get the car to work properly with the MAFT you have no choice but to bail on it.

 

[Breadvans]

WOT suggests you're 2 points lean. Idle (600rpm, really?) suggests you're 4 point's lean.

Your MAFComp is ridiculous. How did you arrive to those adjustments? I'm not trying to put you down or embarrass you, I'm genuinely curious. The only time that your air/fuel ratio is near correct is about 350-400hz during cruise which is about the only place on your MAFComp table that has little to no adjustments.

You're also on pump gas and using that timing table? My dude, between that and your air/fuel ratio being into the 14's during WOT it's a miracle the engine is still together. I don't think you realize how bad this is. I've looked at hundreds of datalogs and yours is nightmare fuel to me.

If I were you and was bent on keeping that MAFT, I would zero out the MAFComp sliders, be sure the MAFT box was set up for 450cc injectors (the 750cc adjustment is done in 'link instead), then play with deadtime *at idle* until LinWideband = AFRatioEST. And without question load in a stock 2g timing table for now. If you can't get the car to work properly with the MAFT you have no choice but to bail on it.

Under boost I read that you shouldn’t be shooting for 14.7:1? Richer is safer and weird about the timing tables cuz I have truly never touched those cuz I have zero clue. I was the one that got this ECU chipped so idk. And this was before tuning after I set the dead time to zero on the fuel page.

And the idle rpm is inconsistent, idk why but sometimes it’ll idle that low and then others it sits perfectly between 740-760

 

[Stapl3]

Under boost on pump gas most aim for about 11:1. Leanest I would go is about 11.3:1. Personally, I have always found the car to be happier on pump gas nice and fat in the 10's.

 

[Breadvans]

Under boost on pump gas most aim for about 11:1. Leanest I would go is about 11.3:1. Personally, I have always found the car to be happier on pump gas nice and fat in the 10's.

Understood, I’ll richen her up then, and I did not see while driving at all it hit 13:1. I’ll play around with it some more and get another log uploaded, any clue about the IPS switch?

 

[Stapl3]

IPS switch?

 

[steve]

any clue about the IPS switch?

What year is your EPROM ECU?
Do you have the TB ground strap connected?
Is the IPS wire on the correct ECU pin?