[Ode]

Your fuel cuts off at around 5350rpm. Just a guess, but it might be something like launch control?

Mikelly

I pulled the file up and viewed it with the car running and checked launch control.

Guys I also pulled the pan under the passenger side and found that the unit is a Megasquirt PNP, NOT a Megasquirt2PNP.

Any other places to look?
Mike

[Ode]

It's just that queer stuff happens in megasquirts. I'd switch them on, burn, switch off and burn again just to be sure.

Mikelly

Just attempted that and it didn't make any difference. Here's the odd thing, and might show up in the below log, before the car got fully up to temps, it made a strong pull up above 6K RPM like it was "fixed". Then next time around, started the same old thing.

2012-10-15_16.52.29.msl

[Ode]

Uhm.. Took a closer look at the log and now i'm baffled. You do have wideband O2 sensor connected to ecu, don't you? For some reason i see no AFR readings in the logs. Moreover, the logs show injector pulse widths of 22ms at 6500 rpm, which is way over 100% duty cycle if i'm not mistaken. There's something going on i do not quite understand :|

Mikelly

Yup, I've got the AEM Uego set as the Wideband.

Mike

Mikelly

I'm starting to think I'm going to need to start from scratch with a new tune and first set the timing, then set the fuel map. Then go from there. I'm guessing a few things aren't programmed properly, like the GM IAT and the paramters for the larger 1.8 injectors.

This is so frustrating when you don't know what it is you need to do.
Mike

EO2K

iTrader: (37)

It sounds like you may be on the right track. IF you can wade through the documentation on the Megasquirt, it might be worth opening the case and taking a look to see exactly what's in it and how its configured. There are now 3 different generations of Megasquirts out there, along with different versions of the "motherboard" plus 2 generations of MSPNPs. There are also the MicroSquirt based DIYPNPs as well. Not all configuration options are available through all the generations... Its all very confusing.

Does your son know where the megasquirt came from originally? If you can track down the previous owner, or the person who built it, they might have documentation as to how it was built (unless its ) or how it was intended to be configured.

For example: Rather than using the factory O2 sensor wiring, my DIYPNP has the WBO2 sensor wiring coming in through the DB15 connector.

Some really good high resolution pictures of the top and bottom of the device outside of the case can help identify it, and we have users here on MT that can probably figure out how its configured simply by what components are present.

I wish I had more solid advice, but I'm a too

Braineack

iTrader: (62)

what's the cliffs of the thread?

EO2K

iTrader: (37)

I was hoping you'd show up

FM Voodoo 2 on a 1.6 in a 90 with "1.8 injectors" and a possibly unidentified flavor of Megasquirt? OP got the car from his son and it sounds like it may not be well documented. Some debate as to if the wideband is hooked up or configured correctly, but at least he has a wideband. Car is falling on its face above, what, 5350 or 6000? I'm at work so can't view the log.

I recommended pics of said Megasquirt and wiring the wastegate open before he melts a piston while we try to help identify things and get isht under control.

I dun good?

Braineack

iTrader: (62)

Well. sounds like it's a white MSPNP.

i cant view the logs here, but with boost + 1.8L injectors - FMU I'd expect you to go hella lean after a good 170rwhp or so.


Let me look through msq. I can at least do that.

Edit: I see overboost protection at 152kPa...do you hit that boost around 5500RPM? that's only like 7psi, if the MS thinks you might even hit 152kPa, much less hit it, it'll cut fuel.

When you cut fuel, the car feel like you hit a wall. If you keep the throttle down, it will cut in and out as you hit the boost limiter.

hustler

iTrader: (6)

Light detonation doesn't cause bucking usually, just a flat spot and some destruction. It's most likely a fuel problem. I can't look at the MSQ because I'm at work.

Mikelly

Guys thanks for the info... It is the WHITE case MS PNP unit. I ordered it for him this past Xmas and got it straight from DIYAutotune.com. It was new in the box ordered direct from them. Here's the thing. When I moderatetly give it gas, it will climb to about 5600 and then bucks hard. If I go WOT it bucks hard from 5400 on... Mind you, I've done this the handful of times you see in the logs. Trying NOT to kill this little 1.6L motor. It's the stock regulator, 1.8 injectors, and FM fuel rail setup.

It's also eating fuel like nobody's business... So I know it needs to go much leaner at part throttle cruising.

Mike

Mikelly

bumped kpa up 170 and it has zero hesitation now.

2012-10-16_17.29.11.msl

Eating fuel like nobodies business though!

Mike

hustler

iTrader: (6)

Hit all your target AFRs then work on enrichments. Save yourself some time and frustration and convert to VTPS. You can do an excellent job without it, but it really makes life easy with VTPS.

Mikelly

Hustler, VTPS? Remember, I'm dumb on this stuff...

Edit... Just found it on the MS website. Variable Throttle Position Sensor... God I'm slow...

petrolmed

iTrader: (8)

I've got a '91 (N/A) and just installed a bosch VTPS. It has refined my tune and drivability. My MAPdot accel was giving me garbage gas mileage and skewing my AFRs too, especially at cruise where I had more MAP noise. Now I'm seeing AFRs very close to my targets without random rich spikes.

Pick up a sensor and mod that MS and some if not most of your fuel dumping should be resolved.

4sfed5

you need bigger injectors. end of story. You cant make any decent HP with the 1800 injectors. you need at least some 365cc blacktop injectors from a GTX like i am running or even better-some of the high impedance 440cc injectors in the new (EV14?) style which idle better.

Mikelly

Drove the car to work today, since I was not going as far as normal, only about 40 miles each way. Car ran well and did nothing bad. I didnt crank it up but it ran pretty well. No temp issues. I will be hooking up with Scott tomorrow afternoon for a serious tune session. Hopefully it will be a new car when we are done.

Mike

Braineack

iTrader: (62)

I have a spare FMU if you want more booosts.