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HybridZ

MS1-3.0 need help please.


kvansic162

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I'm running ms1-3.0(fuel only) using mt225. My z is N/A with a mild cam and 10:1 COMP. pistons. I'm using a stock distributor with a Crane HI-6 ignition. I've got the car running pretty good but can't figure out a few problems.

1. When I hit the gas the fuel spikes rich (9:1 or 10:1) making the car miss until it leans out then runs great. I've adjusted the accel bins but still does the same thing.I'm running 31 pounds at idle for fuel ( req. fuel 15.6)

2. When crusing I get a tach spike which makes the engine have a slight miss. The wide band will read in the 14 and 15 area and spike real quick in the 13:1 area.

3. On deceleration and down shifting the engine is back firing and the wide band reads very lean , 18:1 to 20:1. The vacume goes out side the tuning range of the VE table. The vacume drops lower 20 kpa.

ALso sometimes at idle the engine will idle up and down.

I'm getting frustrated with this and any help would be great. Thanks.

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1. When I hit the gas the fuel spikes rich (9:1 or 10:1) making the car miss until it leans out then runs great. I've adjusted the accel bins but still does the same thing.I'm running 31 pounds at idle for fuel ( req. fuel 15.6)

You should try shortening the Accel Taper Time value, and perhaps lower the End PW value as well.

2. When crusing I get a tach spike which makes the engine have a slight miss. The wide band will read in the 14 and 15 area and spike real quick in the 13:1 area.

You should try a larger 'Dave Capacitor.' Search megasquirt.info for more information on this. Capacitors of the proper size can be had at most Radio Shacks.

3. On deceleration and down shifting the engine is back firing and the wide band reads very lean , 18:1 to 20:1. The vacume goes out side the tuning range of the VE table. The vacume drops lower 20 kpa.

ALso sometimes at idle the engine will idle up and down.

I'm getting frustrated with this and any help would be great. Thanks.

 

What is your "Decel Fuel Amount" value at? If its low, try making it closer to 100%. I think MS1 might call this "Decell Fuel Cut," in which case 100% is no fuel so it would be the other way arround. The bottom line is, change the value so it doesnt cut fuel on Decel. If this fixes the probem, other values can probably be adjusted to make the Decel Fuel Cut work again.

The vacuum being out of the range of the VE table wont cause any problems, it still draws from the closest value and thats completely normal.

 

When the idle is fluctuating, open up the VE Table tuning window and see if the area where its idling is smooth or if the little green dot is moving back and forth over two very different VE values. This inconsistency can be enough to cause something like that. Hope that makes sense..

 

Do some dataloging and post em up!

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I haven't much time to drive the car, had a wisdom tooth pulled.:eek2:

I did change where the tach signal is comming from. I have a crane HI-6 ignition unit. So instead of pulling a signal from the - coil ... I am pulling the signal from there. I also have the decel cut at 100%. SO that's probably why I get back firing on down shifting. But I haven't had a chance to drive the Z yet....hopefully this weekend. Thanks Gavin.

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  • 2 weeks later...

One trick I've used to avoid resets has been to put a radio noise filter in the 12 volt power line. Definitely cut down on the number of resets on my Dodge Dart, which has a very noisy electrical system. The engineers didn't expect it to power any electronics more sophisticated than an AM radio...

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I have been fortunate in never having a reset problem in any of the cars Ive worked with. Aside from the filter I dono what to tell you. Maybe put the power source for MS closer to the battery? Maybe the ground as well?

 

Why would one 280 have this problem while another doesnt? Strange... Could it be the alternator?

 

For non-reset related problems, I'd be happy to look at those datalogs. Email em over to gavinwilliams(at)mac.com .

Send your .msq as well.

 

You do have the wideband wired into MS, right? That would be key.

 

Dont throw in the towel... I dont see a better option for you, except a hugely more expensive EMS, which wouldnt necessarily fix the resets, plus probably wouldnt be any easier to tune. And screw that anyhow.

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