MonsterMaxx

I'm off on an 1200mi trip and doing tweaking.

I'd wanted to jump the distributor one tooth to add some more advance (since I'm maxed out on the travel now.) First I checked the timing. 28deg!

Jumping a tooth took it to 38deg. I ran it for a little while, but it's clearly losing power...too much advance.

Put it back. But at the same 28deg.

Where I came up with that was to lower EGT and get more power. The more I advanced it the better the temps got and the more power the truck had.

Right now I run just tickling 1400deg (which is a lot better than it was doing before) and or a 3.turd it's flying. If you know the rolling hills of SC/GA you'll know it's running real good when I say it stays in 5th on cruise AC on and never floors it running 75mph. It'll flat out pull away from any PU/SUV on any hill. It got 15mpg on the trip down.

If I run stock or like 15-20deg of advance EGT heads north of 1500 and have to back off, I won't even let it do that long.

I think I could run a little more advance too by modding the distrib a little. But first I'd like to figure out why it's behaving the way it is and why it likes so much advance.

It's a xcab 4x4 w/ a bunch of steel wrapping and a cap (so it's pretty heavy), has some pretty big meats and I'm sure they cost me some mpg. they are street meats but still put a full 12" of rubber on the pavement, they are 33"s, but it's been regeard to 4.88.
Runs a 3VZE, ported & polished & gasket matched & balanced & blueprinted, Crower cams, oversize valves, headers, 2.5" exhaust, ceramic coating on everything that sees fire, stock or Jacobs ignition, FPIC, (5-10 kmi on fresh build) etc = 3.slow as far as it'll go

O2's new. The AFM is new (unmodified), however no detectable change from the old one so I think they are both good. I have the tools to open it and tweak it...

The return trip is tomorrow and I'd sure like to get some more mpg out of the lil pig.



ps I think this computer is killing the performance and have been looking at the megasquirt closely...but I hate to waste yet another $1k on the 3vze....

norcalsvx

yea i'm leaning on getting a stand alone ECU to get a little more HP

91Toyota

No offense to your intelligence or anything, but aren't you supposed to jump two terminals E1 and something else and look at your timing? Just not sure if your doing that or if that even exists with a 3.0. Good luck!

taikowaza

monster maxx- I am wondering if the jacobs ignition has anything to do with your timing. I have the pro street kit and it likes advanced timing in my opinion...have you compared timing with it on and off? (are you using the secondary trigger fed off your stock ignition, going to an ultra coil?)
just a thought...I have been having some timing issues lately and may have traced them to jacobs wires, which are good but which pull apart easily after a (too short) while. (terminals stay stuck to plugs).

MonsterMaxx

Yes 91T, I know to Jumper TE1 & E1 to set timing.


taikowaza
Actually I'm not running the Jacobs right now, it quit and I've sent it back to them for service. Yes, it had the trigger thing. I think this is what failed because the plug prong was loose.
I agree the wires do fail easily, I have to handle them carefully, make sure you twist before you pull. I wish I could find something better but not much is out there. There's some crazy high dollar ones with some gizmo in it.


It's running like a raped 3.slow, I kinda hate to mess with it.
15mpg pushing a pushing something with the aerodynamics of a brick at 80mph isn't all that terrible, especially considering it's a 30 year old design.
I think the megasquirt would clean it up a little below 3krpm too. But it's another $1k+ a lot of work and I think I'd just so much rather 'swap' than hopup the 3.slow any more.

dcg9381

Max,
Where are you measuring your EGTs?
I measure EGTs outside the #4 cylinder - about 1" outside of the exhaust port. My peak EGTs are probably in the 1450 range with a turbo.
You're running cast pistons, right?


I don't know why you're measuring 28 degrees of base timing - clearly that's completely wacky, I'd think that something else is amiss on that motor. You can't argue with better performance, but maybe there is a cam timing issue if it's taking that much advance... Have you ever checked the cam timing on that motor?

I could see 28 degrees of advance at WOT, that's possible.. but I can't see 28 degrees of base timing and then adding another 15-20 degrees at WOT.
No detonation at all?

More advance will give you lower EGTs as you've indicated - I consider 20 degrees of timing (not base timing) at throttle the "line" in terms of safe/unsafe - timing tends to vary a quite a bit between engine designs and I haven't ever tweeked a 3.0L.

Interesting deal though.... I'm really suspicious of cam timing on that thing.

BTW, MS is about $400 (assembled) + integration work... Dunno where you heard $1k.

runethechamp

I assume you have checked that your TPS is adjusted correctly? I think you can get your reading if it is set at 15 degrees BTDC but with the TPS out of adjustment so that it thinks it's not idling.

Green93

Well whatever your engine is doing, mine is doing the same thing. Just got it running and tried to time it but doesn't want to run at 10*. When we adjust the dizzy by ear and check it, it's way high. Basically he same as you are describing. Not sure why but she purrs nice and smooth with lots of advance. Anyone here see the same thing running Weasy2k's cams? What grade of fuel do you use with timing that far advanced? I'm running regular right now and don't want to wreck something.

I can't wait to get my catback from LCE. My headers are just dumping into a stock cat and exhaust right now. Still sounds nice though.

Jason

MonsterMaxx

Yes, TPS is perfect. Checked. Set, all that. You can clearly feel it shut the fuel off just prior to the plate closing, just as it should.

From diyautotune
MS2357-C $430 Assembled Megasquirt-II with V3.57 PCB
MOD_2357-IGBT1: Single Ignition Output through IGBT (VB921) $20
MOD_x357-VR_IN: Jumper unit for VR Ignition Input $0 JimStim-C $95 Assembled JimStim diagnostic board StimPower $7.50 Power supply for JimStim MSHarness $65 12' wiring harness IATwPiggy $22.25 IAT Sensor 38NPT-Bung_S $8 Bung for mounting IAT sensor (steel weld on, or JB-Weld on) TuneCable $5.50 6' DB9 tuning cable USB-2920 $20 (Only needed if your laptop doesn’t have a true DB9 port) Subtotal without wideband-- $673.25

Wideband begins at $200

I doubt I can get it finished under $1k


I think it just likes a lot of advance. Green, take the distrib and crank it as far as it'll go, see how it runs.


The way we used to time them in the old days was to keep advancing it until the idle rpm peaks, then back it off just a smidge lock it down and reset the idle. You don't need anything but a good ear.

Froggy93

When I checked the timing on my stock 3.0 it was reading farther advanced than what it was supposed to be. I don't remember what it was but I know that when I turned it back, it ran like crap. so I set it back to the mark where it was. Granted I'm only running a K&N and custom duals, nothing to the extent that you guys are but I am begining to think the 3.0 likes lots of timing. just my opinion.

dcg9381

Max,
MS-I (MSnSE) -which is what most people with Toyotas have been running, assembled with the input/output mods - you're looking at under $400. I actually avoid the MS-II units as they don't seem to be as well documented or supported with these toyota trucks.

Why would you buy a Stim or Stim harness if you're have a reliable vendor produce a tested unit for you? The Stim is a test device, typically used for bench testing after home-assembly... Buy it if you're assembling your own MS unit - but that takes your cost down below $200 for MS.

You can use the Toyota IAT sensor that's in your AFM. Free. You already have it.

Ditching the AFM?
A GM sensor is around $20 some come with the connector. Pull one out of a junk yard for less.
The GM IAT sensors are threaded 1/2 NPT in most cases. You don't need a harness, it's a two wire connection - the pig tail comes with some of the GM sensors. You're talking about tapping a 1/2 NPT fitting into a tube on your intake - or on your manifold..

You don't have a wideband now. You could use the stock 02. You're not doing force induction, so it's not as critical. If you did want a wideband - which would really make it easy to tune, the LC-1 retails for $199.. You can pick it up for a little less, not much.


Ever thing that there might be something else going on if you're cranking 28 degrees of base timing and it runs "well" at that point? :-)

MonsterMaxx

I was wondering about that stim thing. I just didn't get that far when I sent them the email last week. Thanks.
They say I have to cut teeth of the distrib. That right? So no easy 'go back to stock?'

I'd go wideband for sure. I use them on my Vrod and it's kickin for tuning. Just set what you want and the comp will adjust fuel to match. I was wondering if one of those $50 ebay widebands would work.

That LCD they offer is really cool, but 400 beans is rich.

I think I'd get rid of the whole AFM and everything and create a new tube and all, maybe even cold air duct it.

First blush at megasquirt seemed to be $1k+
But even if it can be done for $500 I'm not sure I want to spend it on the 3vze,,,on the other hand, if I could get better mileage...

Do you suppose I could get a 3mpg improvement from the megasquirt? If so, by my calculations it'd pay for itself in about 12,000 mi (at current gas prices, at $5/gal it'd only take 9kmi.)

dcg9381

Depends on your distributor. I haven't done a 3.0L and don't recall the distributor setup. I'd need a photo of the "guts" with the rotor removed...
On the 22RE - you don't remove a tooth and can go back to stock (assuming you use factory wiring) in as fast as you can plug back in an ECU.


Don't know about ebay widebands.

It's not quite as easy as setting target AFR, but it does make it easier.

You don't need the LCD if you're using MS. It'll log and display AFR on your laptop. The log is FAR more useful than a display... There are things you simply can't see because it changes too fast (like tip-in throttle acceleration tuning).

$500 is money, but you've gone through motors and you're dealing with odd things like cranking mad timing, you've cracked pistions, and I think your EGTs are likely high (depends on where you're reading them). Worst case, you can recover most of that money with MS on resale - or use if for a motor swap project.

Better mileage? Maybe... No guarantees... Tune it safe, then lean it out under cruise, you'll gain some mileage. I wouldn't count on the mileage payback though.

MonsterMaxx

Yea, and I never really determined a 'for sure' answer to the cracked piston day. I was pushing it pretty hard that day and had been for 800mi when it puked. My theory was that I had it running on the bleeding edge and the cracked insulator on the knock sensor was a failure (it tested fine on bench) and the last gas stop might not have been good gas.

I use a aircraft 6 channel EGT which measures it right at the exhaust port of cylinder. I doubt you'll get any better than this thing. It was stupid expensive and something I never should have bought,,,but did. It works.

The DIY guy says:
I bet I could pick up another distrib on the bay for less than messing with it.

dcg9381

I thought the for sure answer was the fault of the original engine builder? :-)



I'm not "as" worried about your EGT's then... If you were measuring further down the exhaust system, those temps were too high. Pressed hard, I think 1400-1500 is par...


:

That's true too.. Again, depends on how the distributor is setup, you might not have to cut a tooth at all. DIY guys are great - but they deal with literally 100 different cars - I'd be suprised if they knew the details of MS implementation on the 3.0L off the cuff.. Then again, they do a lot of business...

MonsterMaxx

Let's not even get started going down that rathole
I've read 1400 should be peak on unleaded pump gas. Av gas (leaded) can go to 1800, but not stay there indefinitely. The alarm's set to 1425 and I back off, no chance I'd miss it. When I did a run to OH I was constantly having to back off from high EGTs. Lately it runs along in the 1350s and if it's really pulling hard it rocks back and forth on 1399/1400 on the hottest cyl.
Good point, Toyota did make changes in the 94 (and 95 runner) to the electronics. I'll have to dig into that further.
It does appear the MS could be modified to accept VAST which is what he's saying I have.

Do the DIY guys actually build the MS? I wonder if they'd mod one with VAST and USB.

It'd be really nice if I could get it so a changeback to stock was simply replace the comp and in the $500 range I'd be all over it.

dcg9381

Jerry (owner) and crew assembly the MS units, yes. They do Toyota VAST (they build the unit I have). MS doesn't do USB directly, so you buy a $20 serial to USB adatper.

The 22RE and 22RTE are VAST. IF the 3.0L distributor is the same, then you don't have to modify anything on the distributor. The VAST system is what I'm most familiar with.

I build an "adapter" harness out of a core ECU (I steal the connector).. This adapter goes between the DB37 (megasquirt) and the factory wiring harness. The only other connection is a vacuum line for the MAP sensor. It's ridiculously easy to swap in and out.

MonsterMaxx

Well that would sure make it appealing...I'll send them another email.

I'm emailing with Matt.

Are we doing MS1 or 2? Rev 3.67?

What about the knock sensor? is that functional?

dcg9381

I'm doing MSnSE. I've used done maybe eight v3 and one V3.57 boards. Anything above V3 is fine - they're a little more robust than the early boards.

The knock sensor can be made to be functional with megasquirt, but it requires a little internal circuit (which DIYEFI will charge you for) - alternately, you can use something like Knocksense (search google).. That's what I use - it triggers an LED in my cab, I can set it up to trigger timing retard on MS, but haven't done that.

Knock sensors aren't 100% they take some tweeking to get them to filter out noise but still trigger on knock... Never done a V6, but I'm assuming that your motor will be more quiet internally than a forged 22R series.

GT88Yota

I'm having a similiar issue but with a 22RE. It has a EngnBldr Crawler cam in it and when setting the timing by ear and checking with a light it is about 14deg BTDC.