ok so far i have what aaron has posted on the site about ms1 programing burned into my ms1. i have to finish up some wiring stuff before i fire up. but other than that is there anything i should change cause the car idles at 1600. i seen i have to change my kpa to tps cause i dont pull high vac like a stock or streetported engine. up the fuel cause hbp takes alot fuel to fire n run. is there anything else i would need to do or does anyone have a table i can use to atlease get me in the right direction for my start up an base tune. so far everyone on the ms forum has been a big help with my problems so thank you all.
matt

 

So do you have any specific questions? The tables on my site should start and run the car, but will need to be fine tuned. You should be OK using speed density. That's how I tune bridgeports anyway.

 

ok cool. mostly my thing is what should i do about my car idling higher than 1000 with all the stuff on the ms that it rpm based. will it matter or should i bump some of the things up to around my idle. also what should i do about the fuel under my idle for like when my fan turns on an kinda drops the idle a little should i just turn my idle down an tune on those rpms to? i hope that makes sence

 

half bridge need a high idle to stay running. You will have a hard time keeping it running below 1200 with light and fans on. I used speed density for my car worked great under load but difficult to get low rpm driving tuned. But thats really got to do with the hbport more than tunning. I had to keep it pig rich in low end to get good drivabilty then when I would cruise on the highway I would just load a leaner msq for economy.

 

Expect the car to idle between 1200RPM and 1600 RPM, depending on the size of the bridge. You can get it lower but the idle will tend to be intolerable. It should pull between 10" and 14" of vacuum at a ~1400 RPM idle.

I've never had an issue using speed density to tune bridgeports on the Megasquirt. But I do use TPS to run the acell pump and open loop threshold.

Brigeports want a lot of timing. At idle, try running about 20 degrees on 15 degrees of split. It should idle around 13:0-13.5:1 (I actually idle mine around 14:0).


The fan is always going to drop the idle unless you are using an idle valve. Unfortunately, the BAC control in the MS1 isn't capable of dealing with a bridgeport. I have spent about an hour trying to make it work but it just can't handle it. But by bumping the timing up you should be able to minimize the idle drop.

 

ok sweet i wasnt really planning on using the bac on mine cause like u said ms1 not very nice with bac. but i have a question thats been bugging me all night.

the way mine is ran is im using the stock harness emission an body so on. the person i bought the ms from made a plug n play kinda of thing to the ms1 plug its kinda hard to explain. but on the cas plug on the emissions theres the blue and green wires its the g an the white an red is for the NE but on the ms theres a sheilded wire for both an two wires inside. a red an a black i have them ran to the two colors for the right sides the NE an G. but do the red an black matter what one is goes to like pos an neg . like black to white an red to red for NE an black to blue red to green for G part of cas. i hope that makes sence

 

 

You can certainly use the BAC as a cold start idle valve based on the standard duty cycle table. But it won't work in closed loop idle due to the idle pulsations natural with a bridgeport. Maybe, after a LOT of tweaking, you could get it. But I suspect it would still oscillate.

Um, what?

If you are asking whether the polarity of the VR sensors matter, then YES. Otherwise I don't understand what you are trying to say...

 

ok so what i was asking was just forget i even have the plug n play thing. so if i had the two wires off the mega squirt for the NE an the G of the cas. theres two wires inside the sheilded wire there black an red on both. this is off the mega squirt harness. at the cas on the wires were the plug is theres a red white green blue the for wires for the cas. Red and the white are the two wries for the NE part of the cas an blue an green are the G part. What im asking is will it matter if what wire i use on the NE or G i know they have to be the right wires out of the mega.

What im asking is so lets just say im just doing the NE right now Red and white on factory an on my ms harness the sheild wire red an black wire. will it matter if i take the red to red an black to white or red to white black to red. i know they have to go to the correct part of the cas ne to ne an G to G. im juyst asking about the wires inside the ms to the stock cas

 

nevermind i think i got it i was reading threw the wiring diagram in ur write up an u said it was the factory colors to the cas so i know now what colors are neg an pos. i should looked harder at that before confusing u an wasting time

 

You think? I used to run full mechanical advance (distributor) on stock and street ports, but for the bridge, to make the idle and drivability tolerable, I put one of the springs on. More advance means more vacuum and more vacuum means more exhaust gases pulled up and more exhaust gases pulled up means it runs rough.

It idles at roughly 10-12 degrees, but it will idle at 1000rpm and 60KPa as indicated by MegaTune. It doesn't brap at all, just a kind of rolling cammed-V8 rumble.

Probably 90% of the idle air is coming through the secondaries. (Primary blade is fully shut) Idea is, by idling on the secondaries, there's less vacuum there to pull exhaust gases up. It works.

AFR is... unknown, from all of the free oxygen in the exhaust.

 

ok so i gave up on that damn plug n play thing. it was more of a pain in the *** to try to figure that out then i was to just pull wires. so thats what i did today was run all new wires. but i have one question i have a wire on my ms labeled pwm idle what is this is this the wire i run to my bac?

 

If you are using the V3 board then you have to mod it to support the BAC.

http://www.aaroncake.net/rx-7/megasq...andmodding.asp

 

no mine is a 2.2 board old school cause im a cheap *** lol

 

Then you'll have to look up how to mod the 2.2 board in the MSnSE hardware manual.

If you are using the Zeal, I think it comes with a BAC driver circuit.

 

hey aaron do u have a split table for the bridge. cause u told me to go 15 split an 20 normal. On the split u provided do i just add 5 to the whole table. Keeping it like u did. cause the orignal is like this

 

also on the other table the main spark should i just table shift it 5 degrees

 

I would leave those timing tables alone until you have AFRs at least close to where they should be. Don't just add timing across the board.

 

aaron why must u be so mean do u not like me i like u lol only kidding u have been a great help to me so far so thank u. but i was just asking if that would work out. i haven't done it yet, im still reading the manual on what everything is. i've got it running idling an low load n stuff.

 

I think you'll see a smoother idle by bumping the 30 and 60 KpA tables up a few degrees, but you won't see any real gains by running more then 15 degrees of split under boost. You can certainly put more timing into the main ignition advance table between 60 and 90 KpA above 3000 RPM.

 

ok well i ran into a problem an its really starting to drive me up a wall. this is what going on i try to start the car an nothing like its low voltage. I check my volt an it says 11.1-11.5 when the key is on on. I try to start it an my tach off my leading coil bounces. But no its like there no fuel going into the engine. is this a voltage problem or maybe the part in the ms that runs the injectors. What is it what number or U chip?

 

That voltage is very low, assuming the battery is fully charged. You should be seeing at least 12. That's not an issue though, as the Megasquirt will run down to 8V or so.

 

yeah i know. My volt gauge is off by .3 .4 so its around 11.8 11.4 still kind low i know i need to figure it out. But as of right now i ran into a problem for somereason. its not firing now