Can't get past 2500 rpm

[AlanJ]

My research found this, my problem exactly. But different setup.

http://www.msextra.com/forums/viewtopic ... 31&t=50619

Could this be the problem?

[billr]

The spike at 895.124 is simply because AE has been invoked. I would turn off all AE until you are past the present issues. The only way I know to do that is to set the AE thresholds way high; no simply "AE off" selection.

The PW shown at 899.358 looks about correct, using just the VE (99.0), MAT correction (90., and req_fuel (21.9) for a simple calculation of PW. There are other factors, I'm sure, in the PW calc, but just those three main ones gets it pretty close to the PW shown (18.69). If you want more PW, just increase the VE cells. I gotta ask, though have you flowed those injectors for rate and dead-time? You/we need to have confidence in the "req_fuel", or the VE table is never going to make much sense.

Can you provide a link to where somebody said to fuss with the pots, even though you don't have sync loss? I would like to study that discussion.

While looking through this thread for the above, I did notice that your mainboard injector drivers are more iffy the the MS3X, so understand trying those right now isn't an easy option. However, I would fix those anyway. Also, I would disconnect any of that tachout stuff that has been discussed, get that out of the picture for now.

[AlanJ]

i had the same problem (it was cutting at 4000 rpm ) and i was able to fix it by adjusting the 2 pod r56 and r52 to lower the voltage at r54

Did you show sync loss before the mods? I don't have any sync loss even when forcing high rpm by downshifting...

no sync loss it was cutting like a rev limiter the engine was pulling hard and cutting at 4000 rpm

This thread back a few posts.

Here is a list of things I have tried and their results for this issue. Side note of a past issue. 2 injectors dropped out because of faulty factory splice, repaired. Now this issue.

Tried;
Increase dwell - no change
Decrease dwell - way worse, problem starts at lower rpm and longer to recover.
Replace all injectors - no change
Replace damaged components not prior known about but have definite reason for failure ( all transistors on the heatsink) - no change
Readjust distributor - allowed me to pass the limit at low throttle
Reinstalled factory computer - limit problem gone, geek cred dropped, power dropped, was called a quitter, overall manilyness feeling lost
Wire ignition coil correct to battery to insure proper voltage - no change temp wire removed
Run separate ground to Ms heavy wire - no change
Change to not use map sensor - no change
Removed all frills from Ms settings ( tach, AC, alternator, fan etc) - no change
Regap plugs - no change set back to factory
Increase fuel pressure 20 lbs - no change changed back to stock
Move cam pickup re adjust settings and timing - no change
Moved coil to msx output using main board flyback transistor - no change
Re soldered and washed main board - no change
Used profane language and threw stuff - no change, mental state questionable.

Changed to batch fire - this gets its own because I did it today and it tells the most. The missfire were there but the AFR did not drop to zero. Only shows lean jumps for each miss. Over all rich mix but not flooding. If I force past (downshift) 100% lean until it starts hitting again then shows rich spikes. Ve table set to 90 for all cells above and just below the area. - spark drop? Bad coil?

Direction to go from here?

[billr]

What thread was that "bobdion" quote from? I couldn't find it. Oops, this thread... I'll go look again.

I can't help more until you get a good timing light to thoroughly check out the spark, and flow the injectors so the req_fuel is known to be correct. Those are basics that need to be done right at the beginning, you need to start over. Are the mainboard injector drivers operational now?

A big guess is that it is running lean, have you tried increasing the VE in that area? What do the plugs look like?

Edit: OK, I found the "bobdion" discussion. Without knowing the MSQ, MSL, or what type CKP sensor it is impossible for me to make sense of that. I gotta stick with what I said before, "if there is no sync loss, don't fuss with the pots".

[AlanJ]

I can't help more until you get a good timing light to thoroughly check out the spark, and flow the injectors so the req_fuel is known to be correct. Those are basics that need to be done right at the beginning, you need to start over. Are the mainboard injector drivers operational now?

The problem does not happen unless under load.in neutral it will pass the problem area. Do you have a suggestion for how to get to this area? (High map)
I am researching and ordering the items needed to flow the injectors.

A big guess is that it is running lean, have you tried increasing the VE in that area? What do the plugs look like?

Yes, the cell that works good in the next rpm bin lower is 85 I have tried all the way up to 255 for the problem area. Still lean as read by my aftermarket o2 display ( uses the same sensor as ms) like off the display lean. Plugs are always dark brown.

[billr]

So, you have "snuck it up" from 85 to where it is now (and past) with no joy? Have you tried lowering the VE to lean it out?

One of your problems is how to watch things (like the spark timing) when the engine is loaded? Indeed, that is a common problem that those of us without access to a dyno are plaqued with. I'm guessing you don't have an auto trans, or you would be simply loading it against the converter. Another possibility is to cut injector pulses/power to all but one or two cylinders. You can load the running cylinders pretty well just working against the compression in the non-firing ones. Least practical, or safe, is to remove the engine hood/cover and ride around sitting up on top of the engine with your strobe.

[AlanJ]

I think I found the problem. Finally... I was researching the engine logger of tunerstudio and I made a log. The reason is hard to explain but basically my cam signal is not set correctly and during the missfire the ms3 is firing injectors in the order of 1,6,5,1,6,4,3,6,5,1.... That's just a short sequence. The raw cam signal drops out and re appears randomly during this time. I am at a loss as to explain why or how the ms doesn't call this sync loss... The broken cam signal is causing ms to change between the 0-360 and 360-720 phases. Why is this not coded for?

Log will be posted as soon as I get off work and get the laptop going.

[AlanJ]

Log File as promised

[AlanJ]

Okay, no matter what I do I can not get the ms to fire in the correct order. A,b,c,d,e,f seams to be impossible. Engine logger shows an eratic firing order and no sync loss. It seams to rarely go into the second firing sequence and jumps out of it when and if it does. The transition to the eratic order starts at 3000 rpm and is fully eratic and random at 3500 and above. Below that it is mostly okay with once in a great while jumping out of the proper sequence. I have tried removing the cam sensor and still get this error. Something is wrong. In batch fire it will switch around as well, dropping injections for a whole 360°. Dropping random injectors, but When they do fire they are always the correct timing. But not always the correct order.

Timing issue resolved, put the truck on roller jacks and gave it some gas. Timing is excellent up to and past redline. Moves 1 to 2 degrees during quick acceleration at high rpm (4000 and above) but that I think is due to valve float. Redline is supposed to be 4500)

[AlanJ]

There has got to be someone who can solve this problem.....

[jsmcortina]

I'm not seeing any problems in that engine log.

You are using "Dual wheel with missing tooth". In that decoder, once full sync is established, the cam signal is ignored.

James

[AlanJ]

Okay, Let me try and explain things....

Record 40 Injector A starts
Record 89 Injector B starts
Record 137 Injector C starts
Record 186 Injector D starts
Record 235 Injector E Starts
Record 296 Injector D Starts (Skipping F,A,B,C)
Record 344 Injector E Starts
Record 393 Injector F Starts (For the first time)
Record 441 Injector A Starts
Record 490 injector B Starts
Record 543 Injector E Starts (Skipping C And D)
Record 591 Injector F Starts
Record 639 Injector A Starts
Record 689 Injector B Starts
Record 737 Injector C Starts
Record 791 Injector A Starts (Skipping D,E and F)
Record 840 Injector B Starts
Etc. Then follows a short run of proper running. Then back to the jump and skip.
Injector "F" Fires only twice during this. "A" fires twice as many times......
Is this jumping around and skipping really "Normal" I thought Sequential was A,B,C,D,E,F no skips... I have to be missing something...

graph.png

[jsmcortina]

As with all of the high speed loggers, there are discrete datasets. This is not a continuous log. Notice the red vertical lines.

James

[AlanJ]

Ahhh so it's more snapshots not a gap-less log. That does explain things. I thought they were time scales. I have been removing them because they were annoying..... Oops...

[AlanJ]

Okay, Last attempt.....

Mega squirt will not work for me and I can not find a reason why. Here are all the log files I can get for the problem. the local tuning shop says MS is not firing the injectors properly. I don't have the money to put it on the dyno for a session. Especially if it turns out to be a physical MS problem.

So I ask you all again. WTF? How is this not working properly? All settings are correct, I have red and re read the manuals. I have gone down every troubleshooting avenue i can think of and no difference. my only options at this point are to assume its a ms hardware/software problem but it obviously works for all of you guys.....

I have no direction left to follow. Please point somewhere.

[AlanJ]

Supplement, Only 3 attached files limit

[jsmcortina]

Datalog looks ok? What's the problem you are seeing? It gets past 2500RPM and a few days ago you were saying you can reach redline.

James

[AlanJ]

I can get past it. But not under load. I'm inclined to say that the MSX card can not hold the injector open for the high fuel demand. I have never gotten past it under heavy loads. My research leads me to believe the MSX is trying to use PWM to keep the injectors open, Witch is ineffective. But then again every other thing I have thought of or tried has turned out wrong.....

[jsmcortina]

I can get past it. But not under load. I'm inclined to say that the MSX card can not hold the injector open for the high fuel demand. I have never gotten past it under heavy loads. My research leads me to believe the MSX is trying to use PWM to keep the injectors open, Witch is ineffective. But then again every other thing I have thought of or tried has turned out wrong.....

The MS3X injector outputs do not do PWM.

Looking at one of your logs and MSQ, you have about 10 deg timing at 100kPa - why so low? Recent engines will need maybe 24 deg and older less efficient engines perhaps 34 deg at 100kPa. Running such retarded timing can easily hold the engine back.

The PW is staying "flat" in your log because that's what you've asked it to do. MAP is about 92 and not changing and VE is about 99% and not changing. So the pulsewidth doesn't change.

Looking at your log for free-revving and comparing it to the "full load" log, you seem to have double the fuel in the full-load log where it won't rev up.

Read your plugs. What do they show. I'm guessing they will be very black indicating rich.

James

[AlanJ]

Sorry, I forgot the most recent tune file.
I changed the timing and corrected my tooth angles. They were giving timing drift. I have that corrected now. Timing is great. The logs posted today are from this tune file...

How I made the logs today.
Use VE table generator and make the table for my engine.
Start engine and let it warm up.
Drive for a bit with VE auto tune on to get a better baseline.
Park, Start logging, Mash gas. Save log, Start next log and repeat.
The Auto tune by this time has moved the VE table to max out in that cell.

The table is dead on for 14.7:1 until that limit then it goes 100% lean, No transition - Just like a switch - until RPMs Drop. Then instantly jumps back up in rpm and fuel mix, then goes 100% lean again. Nothing that I do to the VE table will get it past that spot.

The plugs range from Black rich and clogged to Melted tips. I'm on a 2 step colder plug until I get this issue resolved because detonation is becoming an issue.

I wish i could show a Whole log, I start every day with a new table from the table generator because it is spot on. By the time i get to work all the cells bordering the problem area are maxed out and o2 is still lean.

All O2 readings I'm quoting are from a separate narowband o2 sensor and dash gauge, although the ms records its own sensor in the logs.