New 5.3 swap - tuning issues and gauges - help needed!

[gibygreen]

Hey everyone, This is my first thread on this forum. Hooray! Though I was hoping I wouldn't have to make one.

To make a long story short-er, I bought a 2002 RCSB silverado with a 4.3 in it. Super nice truck, got it cheap, Thought It'd be a good platform to do my first LS swap in it since the v6 had about 245k miles.

Fast forward 3 months. Brand new rebuilt 5.3 in the truck. New stock everything except, Flat top pistons, blue valvesprings, 42 lb 8.1 injectors, Dorman 3 piece intake, and a BTR Stage 4 Truck cam. Finally got the truck running on a tune I found in the repository for a similar truck, though with stock injectors.

I've got the truck running great now. Aside from the fact that I was a dumb-ass and reused the old oil pickup tube ring and now the lifters are collapsing when it's hot. But for the life of me, I cannot get it to run when adjusting the IFR table. The truck runs great (when cold) smooth even, too smooth actually. I wish it had more chop. But it seems that any deviation from the 25.2 lb/hr setting in the IFR table makes it run terrible. Barely idles, and touching the throttle kills it.

This is my first time tuning with HPtuners, and only the second car I've tuned thus far. So, What am I missing?

I've attached my most recent tune that It's running on. I believe the upper section of the VE table is probably wrong, but I haven't been able to drive it a whole lot yet.

Also, the Tach seems to be reading wrong. The VCM scanner seems to be pretty accurate though. Is there some way to fix this in HP?

Attachment 78206

[Ben E]

The injection timing normal and makeup may need to be changed back to stock values(0.05 ref periods less). Messing with that changes when the injector fires, and I don't know enough about when it should be changed. You want the fuel to hit the back of the valve and vaporize instead of shoot directly into the cylinder but that's about what I know for that.

Is the part number on the injectors 17113739? From what I can see there is no injector data available for those. You have to do 'old fashioned' tuning according to people. There is a thread on ls1tech that had information, but it looks like they were values derived from tuning with a supercharger on it the engine.

There was a few people that said start with the data from the truck 8.1l injectors (which I see you've done), then you have to play around with the IFR or something like that. I believe they are supposed to flow 42-43.8 lbs/hr. Then even after that you may have to play with the transient fuel tables to get part throttle good.

From what I can see people that don't want the hassle of messing around with injector data just find a different injector with all the data available from purchase.

Have you tried pulling more fuel from the 400-1200 rpm columns in the 'VE' table or even adding more fuel? Making mine leaner made my truck snappier but idle rougher, richer made my truck smooth and sluggish. I think I'd start from a stock 5.3l 02 'VE' table; perhaps even pulling 30% fuel from 400 rpm column, 20% from 800, and 10% from 1200. Then try tackle the injector control data. That is definitely the key here. Perhaps for the moment being you want an even higher idle RPM, like 1000-1100? Then tune it lower as you can make it stable and run correctly.

That smoothness you're talking about, like I mentioned with idle, it's too rich, and idle is too high, or spark is even too high. Lower spark, leaner fuel mixture, and lower RPM will make the engine lope harder.

I was just looking at your spark tables they seem kind of strange to me. In the low+high octane tables why is 0.08 and 0.12 g/cyl rows so jumpy? I don't believe the truck will idle there. I'd again start with a stock high/low octane table. Maybe you need a bit more spark at idle, like 22-26 could help idle as well. You want your spark to be as smooth transition as possible or you'll get surging. Same thing with fueling.

[gibygreen]

I'll need to take a look at the tune again, It's bits and pieces from various tunes. Like the one tune I found that actually made it start. and some stuff from 02 camaros/corvettes. I think I'm going to try restarting with a speed density tune.

I'm unsure of the injector part number, and I wont have access to the truck until this weekend so I'll have to see then. But the information i got from the ebay seller was this:

"Injector Design: Metal & composite plastic
Coil Resistance: 12 Ohms / High Impedance
Static Flow Rate 42lb/hr at 43.5PSI ( 300kPa )
Static Flow Rate 440cc/min at 43.5PSI ( 300kPa )
Fuel delivery type: Multi-hole, fog-type spray, excellent fuel atomization
Overall Length: 2-5/16 inches, 58 mm
O-ring to O-ring: 1-7/8 inches, 48 mm
Diameter: 17 mm
O-rings: Top and bottom, 14.5 mm"

Maybe this helps some? I'll recheck what I've done soon.

[gibygreen]

Well after lots and lots of look and fighting with hptuners. I finally managed to figure out the issue. I was unaware HPtuners had an option for "Basic" tuning mode. Which is what It's been running in. ughh. and to think I wasted all my credits trying to license my truck.

[Ben E]

Hahaha, Sorry. I should've started with that. That'll help a lot as it opens all of the tables. Like I said earlier though, the injector timing you'll probably want to go back to stock. Change all of the injector controls (Offset, Limits, Pulse corrections) to the 8.1 data and see what that does for you. It'll still not be correct since they are two different injectors. Such as, the truck injector has 2 holes, the marine one has 3, and the modified ones have 4.

I'd take a look at spark, and the VE table and get fueling better once you have the injector controls in order.

I also cannot find a solid answer. All sellers list those injectors as 42 lb/hr at 43.5 PSI, but then some people just reference them as 42 lb/hr or 42 lb/hr at 58 PSI. Guess you'll have to try 42 lb/hr and/or 48.5 lb/r calculated for our 58 PSI fuel rails.

[gibygreen]

Alright, After lots of testing and tuning. I got the truck to run on different than stock injector data. So far, I've tried info i found online, stuff from other tune files, and stock 8.1 data. So far, the best has been the injector data from a 2002 Camaro, with the exception of 42 lb/hr linear flowrate. The truck will Idle and rev, but stumbles hard while driving on this tune. But, If I set the Stoich AFR to 9.7-10:1 the truck runs really well!

So, What am I missing here? How do I get this thing to run without having to command a ridiculous Stoich afr?
Amongst these problems, It's rev hanging pretty badly, and It backfires through the exhaust when going slow, say like slowing from 60 mph - 10 mph, It backfires, idles fine then dies when you stop.

The VE table, power adder, and main spark tables are from a stock 6.0 with a Radix supercharger. (similar injector)

I should mention, the Narrow band B1S1 o2 is reporting around 600-680 (mv) throughout the rev range, but it does go a little lean around cruise (300-350 mv) I got the tach fixed aswell.

Attachment 78389
Attachment 78390 <- 6.0 file used.

[Ben E]

Idle hang can be cured different ways that I've seen. Is it idle hang at well, idle? Or is it coasting and it's in a cruise like mode? If it's at idle you need to remove base running airflow or, perhaps with a manual you can remove timing to slow down the engine that way. Basically it hangs the idle because the computer cannot compensate enough for what you have entered for data. Too much air, the best the computer can do is burn enough fuel with it to keep the engine running smooth. Too much spark, too much torque and that speeds up the engine.

Now, the backfiring can be a few different things as well. One thing you can look at is the 'Deceleration Fuel Cutoff'. It cuts fuel the best it can when coasting and if there is too much fuel it'll burn it as it exits through the hot exhaust. Backfires can also be with too much fuel, as it again, just gets shoved out the exhaust and burns in the pipes.

As far as I know, 0.450 (MV) should be stoich. It may depend on vehicle/engine but that's what it is on my truck. As well with the o2 sensors you want them to fluctuate back and forth. Going from rich, to lean, to rich, to lean. I don't believe it should be a flat line, but I could be wrong. The only time the voltage should be the same is during open loop when o2's are disabled OR during power enrichment mode. Now, if you're in power enrichment mode it'll command a certain AFR and if it's default it is very rich to begin with. Last note with narrowband o2's the voltage doesn't matter all that much. They're not very accurate above or below stoich (about 0.5-1 AFR)

[Edit: Change your 'Enrichment Ramp In' to at least 2.0. You can go further, but I've heard it'll overshoot the commanded AFR.]
[Edit2: Stoichiometry should really be the value of the fuel you're using. AFR 14.68 for pump gasoline. AFR 9.765 for E85 (I think).]
[Edit3: Also, AFR spark correction I believe should be left as default. Some remove all corrections since they want what they request; others leave it stock as spark changes depending on AFR if I remember correctly.]
[Edit4: If you've changed your stoichiometry I'm not sure what that plays with. There is also an 'Open Loop EQ Ratio' table that changes your commanded AFR based on coolant temperature and manifold pressure.]

[gibygreen]

Hey Ben, Sorry I've been so busy lately. Yes, it hangs at idle. Say you want to rev it 800->2000 It usually revs up pretty fast, then hangs at 1500-1300 and comes down really slow.

Now that you mention the DFCO, That makes sense because I have it turned off right now.
And yes, as far as i can tell .450 is stoich. It is using Speed Density though so that's why the o2 volts is pretty linear. Speed Density so far has been the easiest to make it run. Though I have noticed that when re-enabling the MAF it pretty much never goes to closed loop.

But, I'll try adjusting that stuff you said.

[Ben E]

If you're in P/N I'd still look at the base running airflow and see if maybe it's too high. My truck had a defaults of 17@-4, 15.20@32, 10@104, 6@176 (Grams p/sec), mine are now 23.50@-4, 22.82@32, 14.43@104, 10@176(P/N in gear is a point or two lower depending on the temp). Now of yours are going to be higher. I have the BTR stage 2 truck cam in. So I'd lower yours just a bit, try multiplying everything by 0.80 it'll bring it down 20%?(Whatevenismath) -- Another thing to look at if you want is the 'Rolling Idle' if it applies, and/or 'Throttle Cracker' + 'Throttle Follower'. I don't think those tables will be your issue though.

If you don't have a turbo then using the MAF is a good idea as it can more accurately see the air that comes into the engine rather than hard data(I've read some people use MAF with turbo'd engines). Even with it enabled it does a cross with data in the VE table and MAF table I believe. I think the MAF becomes a problem if it's not reading right, or if there are vacuum leaks, or if you're sucking in too much air for the sensor (turbo). If it's a vacuum leak you can search hoses/intake gasket/etc with some kind of cleaner, like brake cleaner; if the engine revs then it's got a leak.

I have limited knowledge of cars and what not, but at least on my truck I get no popping if DFCO is off/not activated. When it activates at 50+ mph you can hear a pop or two and louder engine braking; Not sure why it exactly does but sounds cool