383 w/Hot Cam tuning problems (tune/log inside)

[Sherk]

Hey guys,

I can't figure out this tuning thing for the life of me. Can someone please have a look at my tune/log?

She's a 383/Hot Cam running off the 411 ('01 Express van base) with stock Vortec injection.

She starts up just fine and sits there idling (RPM does jump some though), but according to the wideband O2 sensor that I installed today, she's on the rich side of things. Also, I bumped up my idle speed, but I still get random backfiring (misfires?). The truck isn't driveable in the condition it's it, I can't rev it over about 1500 or so RPM. At that point, however much throttle I have in it, it bogs... I don't know if that's the correct term for what it does, it acts like it wants to stall and RPM falls.

[Goldfinger911]

Have you done an RAFIG and AutoEV tuning? Your VE map looks very close to stock. Also, what kind of injectors are you running? Your IFR table is flatlined at 2.9141 grams ? Is starting a problem? Your VE While Cranking is all zeros. You might want to start with a stock VEwC map then when AutoVE is done, calculate a proper one.

[Sherk]

Starting isn't an issue at all. Truck cranks and immediately fires...

The injectors are the upgraded MPFI spider, but still stock style injectors (so I didn't change much of the tune, cyl volume and some other minor stuff).

I haven't done a RAFIG... I'm looking into that now. I'm 100% new on this stuff, and lost. Will RAFIG help me reach past 1500 rpm or so?

[mikeyayell]

Is your MAF still plugged in?

[Sherk]

It's unplugged currently, I should have everything set up for an SD tune.

[Goldfinger911]

RAFIG is a tuning process for desired airflow at idle only. AutoVE is tuning the entire operating range. Have you done AUtoVE according to the FAQ that EFILive provided?

http://download2.efilive.com/Tutorials/PDF/AutoVE%20Tuning%20Tutorial.pdf

Looking at your VE map, it doesnt look like it.

[Sherk]

Well, I can't do much AutoVE-wise, as the truck isn't driveable (I did make some adjustments to the VE table myself to try and give it less fuel down low, which it seemed to like). I still can't get it to rev over about 1600 rpm now...

It will sit there and idle, when it's revved up it will bog/stumble down and go under my set idle, and backfire. Anywhere between 800-1400 or so rpm and it runs decent. Outside of that, it just won't go there.

I don't know how to proceed with the AutoVE process in the current state, is what I'm trying to get at...

[hquick]

Sherk...have you got a wideband connected?

[Goldfinger911]

Well, if you plan on sticking with this tune, you are probably going to have to first set your Injector Flow Rate properly first. Then, run the tuning tool while logging and watch what regions of the VE map are being touched when it bogs and runs poorly. If it is rich, remove fuel. If it is lean, add fuel. Get it driveable... then start the AutoVE process. You are going to need a wideband installed and the 5v linear output wires to your FlashScan device so you can properly calculate the BEN factor.

[Sherk]

Yep, she's got an LC-1 connected, and working properly. I've been logging all that I can for the short periods that I run it.

Here's a log (I know it's not the greatest) of some of the later stuff I was messing with. It gets lean with higher manifold pressure and doesn't really give any clues as to why it won't rev past 1600 rpm.

Any ideas?

Also, I left the IFR table the way it was because they're stock injectors. School me as to what needs to be changed, please. Most of the stuff I understand, however some of it is completely new to me, like this.

I appreciate the help guys.

[5.7ute]

Sherk, what have you programmed the voltage outputs on the LC-1 to read?

[Goldfinger911]

I notice a few things right off the bat...

....when you say it revs to 1600rpm and thats it... are you giving it more than 23% throttle? According to the log, you're not.

Also, your coolant temp starts at 131 deg C and never moves? Dont know if this is a cause, but it is weird behavior. Is it unplugged?

Also, your Intake Air Temps never move from 57 deg F.

With regards to your fuel injectors... you are running the stock 28lb injectors? What fuel pressure? I realize the stock tune has a flat IFR of 2.9114, but if it is the typical LSx 58psi, you could try an IFR table that looks like this;

3.617188
3.640625
3.664063
3.687500
3.710938
3.726563
3.750000
3.773438
3.796875
3.812500
3.835938
3.859375
3.882813
3.898438
3.921875
3.945313
3.960938

Speaking of the stock tune... does it run better or at least rev better with the stock tune? If so, you may want to start over with a stock tune, make adjustments for the increased displacement, bump up VE by a few percent and then start tuning from there. THats what I did when I first started with my TransAm. The tune that came on the car was garbage... and I wasted weeks dickin' with it before I decided to start over.

[5.7ute]

If the fuel pressure regulator is manifold referenced it will be a flat numerical value.
There is also a bucketload of DTC codes in the log.

[MICK]

Shrek,

You need to Fix some of the DTC's like 5.7 said.

First get the Crank Relearn Done.

In your tune you need to make adjustments to B3605 open loop commanded fuel table. You can't run 14.68 AFR under load with PE turned off.

Something like this will get you out of trouble for now, you can change it to whatever later.
This is from 50 deg c and up.

LABELS MAP kPa {link: SAE.MAP}
ECT °C {link: SAE.ECT} 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
50 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
60 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
70 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
80 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
90 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
100 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
110 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
120 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
130 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000
140 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.000000 1.020000 1.020000 1.080000 1.080000 1.120000 1.120000 1.180000 1.180000

[hquick]

Sherk...I expect you're running the stock 19lb/hr injectors (poppet or mini....makes no difference...same rating) at the stock 58psi of fuel pressure at the rails?
Mick....if he can't rev past 1600....he can't do the relearn. Needs to rev to 4500 or so (from memory).
All the P0000 codes are phantoms I believe.
I would think the oil pressure is an issue.

[5.7ute]

First thing I would check with all those codes is the wiring. All it takes is one bad earth to stuff up the whole show.

[Sherk]

Well, I had some posts on another board about the issue, and well... :bash:

Some sense came into me, I swapped on the IAC and TPS from my old throttle body, and she'll rev now. I had it over 5k. I still get the oil pressure output circuit code, which I don't know what is. The wiring looks good, however it started happening after we pulled the dizzy and re-dropped it. It's possible that we bumped something back there so I'll get that pulled later and double-check all that stuff.

I think now I'll be able to tune the thing properly. I'm going to go flash another bunch of settings into it and take it for a test drive... :rockon:

[Sherk]

Well, now it's back to not revving up. I'm lost.

[hquick]

I noticed in those logs the TPS seemed a bit whacky. Didn't seem to have any pattern/correspondence to the RPM.
I'd check your TPS connections. Make sure that plug is in properly.
Give it a wiggle whilst it's running and try operating the TB via the linkages at the same time as moving the TPS cable around.
I drove all the way to the other side of town one night to pick up some headers. I got to the guys house and the Burb died.
It would start...I'd put it in gear and it'd die as soon as I tried to accelerate.
As soon as I touched the pedal.
I hadn't long done the 0411 swap and I had needed to extend my TPS/IAC cables.
I popped the hood, unplugged and replugged the two units and it's been fine ever since.

[Sherk]

It's broke. I don't know when I'll be able to get it fixed, so...

Thanks for the help guys, and the ideas. Too bad it wasn't a simple fix.