T3 T4 Hybrid Turbo OHV

[Caejxr]

Haven't noticed a problem yet with braking and I've gotten on the brake a handful of times.. i think its working kind of the same as when Im braking with the engine off. Theres enough pressure/vac in the cylinder to brake once or twice with close to normal operation. So in that split second before the vacuum returns the truck still brakes like normal. I could see a problem occurring if I ran like that for a while and had a major vac line that blew or a bad vac leak... luckily the once or twice i had a brake line go out I learned Im pretty good at using the e brake....
But in all seriousness I haven't noticed an issue yet. But it's something I will be cognizant of.

There is a vac ball on the passenger side and the valve jn it works under normal pressures/vac...and heater vents work well until boost is at about 2lb and it switches to defrost. Then back to vents when vac returns. It's not every time though...so maybe the valve in the ball is work or is overpowered by the boost.

Edit: I added a one way check valve in the vac line that splits by the fuel rail to block off the flow under boost. Been having trouble with the cold start tuning but once I have that sorted I'll report how the check valve worked out for the vents.

 

[Caejxr]

I was reading #4pointslow post from August last year on the SCT forum as I was looking for some answers regarding the actual lambda changing from the commanded lambda in the base fuel table cold. I was wondering if you ever found the root cause of this 4pointslow? Right now I am using the cold start enrichment decay table to work the issue I am seeing with mine being too lean cause of this factor. It could just be that the cold engine requires more fuel to run until warm... Anyone else please chime in if you know the answer.

 

[jd4242]

If you put a ""@"" in front of his name it tags him.. [MENTION=81804]4pointslow[/MENTION]

Good job on tuning so far

 

[4pointslow]

Tuning

I was reading #4pointslow post from August last year on the SCT forum as I was looking for some answers regarding the actual lambda changing from the commanded lambda in the base fuel table cold. I was wondering if you ever found the root cause of this 4pointslow? Right now I am using the cold start enrichment decay table to work the issue I am seeing with mine being too lean cause of this factor. It could just be that the cold engine requires more fuel to run until warm... Anyone else please chime in if you know the answer.

I never found the cause or fix for that. My commanded lambda(as shown in STFT at WOT) always seems to go to .832
I figured it may have something to do with some IMRC tables (intake manifold runner controls) that are not visible even in my Calibrator status access to my tune.
I pondered it for a while and just forgot about it because my target lambda was where I wanted it. With a factory scan tool STFT doesn't even show commanded lambda anyway, STFT's usually go to 0% at WOT indicating open loop drive.

Good for you for getting into tuning your own vehicle, it can be a real pain in the butt sometimes but I think being able to make your own changes all the time is very rewarding.

If you have not already, you should become elite and post pictures of your build.

 

[4pointslow]

Nice looking truck!

There's the victim.

Old girl still looks good in the evening light .

I just found this picture, Nice looking truck! congrats on the turbo install too!

 

[4pointslow]

cold engine

It could just be that the cold engine requires more fuel to run until warm... Anyone else please chime in if you know the answer.

A cold engine needs more fuel and a higher rpm.
Fuel has a tendency to condensate or puddle in a cold engines intake manifold leaving less fuel in the cylinders to run with.
Having more fuel going in when cold means more fuel that actually makes it to the cylinder.

Normally you tune the air fuel mixture when fully warmed up first(and idle rpms to prevent stalling, then spark etc), and if you have cold start problems later when you are at the end of tuning you can work them out. (you may be doing it that way).

 

[Caejxr]

If you put a ""@"" in front of his name it tags him.. [MENTION=81804]4pointslow[/MENTION]

Good job on tuning so far

My bad, I don't do social media much.

Thanks for coming back with the input [MENTION=81804]4pointslow[/MENTION]. If I find out what causes it I'll post back. I've have been logging the tune when warm other wise things get really off within the tune from skewed readings. I enriched the cold start decay and it fixed my cold start being lean but now I have a gap between where it hits the time limit on cold start and where it picks up the base fuel table and starts running the commanded afr. Changing the cold start afr table hasn't helped the only thing I can adjust that would make a difference is the cold enrichment decay time but that would then run too long at warmer outside temps and not long enough at cooler temps.

 

[Caejxr]

Well an interesting thing happened today I was getting a data log and it died at idle...that's a different issue though. In the process while the oil pressure gauge fluctuated it quickly went side to side and then flipped around 180. No pressure points straight down and normal is topped out on the stop peg for low press....not sure if I can fix it but I'll be tearing the dash apart to get to it tomorrow....not an ideal use of time.

 

[Caejxr]

There's the fixed gauge... took one of the rubber ashtray bumps that I wasn't using, since I've mounted my wide band in its place, and glued it on at the "point of no return" where the needle keeps going and drops strait down. Now it should bounce back into the normal operating range if it happens again. Ordered the other oil sensor too so that I can have a working oil pressure gauge rather than an on/off switch. Plan is to tie in an oil cooler over there too, pre-turbo since between cooling the turbo and the exhaust running under the pan the oil is probably getting much more heat exposure.

 

[Caejxr]

So, the real question is how big to go on the cooler. Without running a thermostat controlled valve, which would add a large amount to cost, too big and the oil won't get to temp properly, too small and the oil will be too hot. Between the turbo introducing extra heat to the oil and the y pipe/inlet running under the pan and up the side of the block there is much more heat being added to the equation. The most accurate way would be introducing a oil temp gauge to take readings and pick a cooler based on the ratings. My thought is a good SWAG should be enough to accomplish the goal. Being in the desert currently I'll err on the side of bigger. Input is welcome.

Edit: Anyone know the size of the threads/fittings to the 2ndgen OEM radiator trans cooler? May re-purposed that...

 

[Caejxr]

That's the original sender on the new ones box. Part number for the new one is on the box there. Pretty good representation of the size difference without having both side by side...new one is 3 or 4x larger with a much much smaller inlet but same threads.

Fittings line and oil cooler are on order. I'll see how pre turbo goes . If it doesn't work out the way I want I'll do one of those filter sandwiches or a temp triggered bypass/cooler controller depending on results.

 

[Caejxr]

Back from the holidays and back to business as usual. Open loop is pretty much perfect. Closed loop is all kinds of craziness right now. It's close but not close enough and cold start fueling is still too lean after enrichment decay stops, the ecm switches to closed loop and before the truck hits 170deg. Eventually I'll get it figured out. I want the benefit of o2 sensor feed back.

 

[Caejxr]

Quick update...work sure has been putting me and my staff through the wringer lately. I did get a pinch of my own time and got an oil cooler installed the other night. I changed my mind and went with a filter sandwich adapter, allowing me to use larger lines for the oil cooler maximizing the effect of having a cooler at all. It's a really tight fit for the lines exiting the sandwich. The only good place for them to come out was pointing at about 5 o'clock (12 being at the front) putting the lines just above the frame rail and between the header and down pipe. That's a lot of heat right in there so I put extra aluminum/fiberglass wrap around the braided lines through there. I'll try and get some pictures up if it at some point. Tuning is still a work in progress with closed loop, forced open loop is perfect. And honestly since the last post I maybe had time to log and tune once. Biggest issue still just being the kinks with cold and start my maf curve is only slightly off at 400 to 600 counts should be perfect next time I am able to get time to tune.

 

[Caejxr]

I figured out what's goin on with the cold start. The base file I got from Lasota had changed the temperatures the ecm switches to base fuel from cold fuel. The second part was the cold start enrichment was way too high for the injectors. And third the open loop closed throttle multiplier needed to be reduced to nearly .6 or so to bring up the fuel making it to the cylinders and also keep the truck from choking when it switched to open loop idle after running closed loop.

I have the Maf curve as close as I can get it without adaptive learning it does good for about 15 or 20 min of driving at temp it goes rich. The only settings I can think are the safety for the cat, exhaust flange, etc since those dump fuel in to cool temps down. Reason I think this is the case is because in cruise my turbo stays spooled just under boost anywhere between 40 and 100% (+) load. Under those conditions the stock settings presumably trigger an overtemp parameter in the ecm. I'll turn up the temps on those and see how it works. It's so so close.

 

[Dono]

Isn't the overtemp parameter based on coolant temp?
When your truck goes rich when it should be in closed loop, what are the stft's?
Do they think that the a/f mixture is exactly where is should be? I'm assuming you still have adaptive learning turned off.

 

[Caejxr]

I think the exhaust/cat over temp is based on coolant temp yes, but also load, I would think rpm, maybe some other parameters but, it takes multiple readings into account.

Afr's are the closest they will get to what I am commanding in the fuel tables. If I add the minimum to the maf counts it jumps past the correctable range, same if I subtract the minimum from the maf counts.
Adaptive is still off.

 

[Dono]

I'm learning also, thats kinda why I asked. It does seem to be an odd issue on the outside.

 

[Caejxr]

No worries, sorry I couldn't be more exact on the answer for the exhaust over temp stuff. I'll keep posting as I go far ward with the positive results

 

[Caejxr]

Did a lot of adjusting , turned out my entire MAF curve was about 20% too high. Bring it down fixed the majority of the problems I was seeing. I've also noticed that increasing only the very top number on my MAF curve also increases afrs on the low end of my curve which also helped get my Afr's in check. Adaptive learning on and no codes so seems good now.

 

[Caejxr]

Update, I've been playing with the tune here and there just to work out some imperfections I've noticed at a few points.

I'm starting to think its time to plumb the wastegate back into the down pipe before the Cat. All the noise the dumped gate is making is getting a bit of unwanted attention from the local chp and sheriff. That's not to say I'm driving like a jerk, just the way this turbo spools at such a low boost, my gate, dependent on load and throttle pos. can open up pretty quickly.

It's also such an effective gate when dumped like it is that it barely allows the turbo to spool up to 7lb when it's fully opened up which could be fixed by a dump pipe to reduce flow but no matter what dumping it is LOUD. I'm not convinced either way that the effect of putting it back into the catback will have a major neg effect or not.. I would think it to be negligible if noticeable...Worst case, a 3" pipe catback wouldn't hurt to help the exhaust breathe and reduce any lag caused by plumbing it in.

Not sure what the best option is really at this point.