I'm still learning lots of stuff. Each time I find a problem I end up retuning. Case in point... something I should have figured out much sooner. I was using the external port by the pcm to power my fuel pump. So power had to come from the trunk to the front then back down that tiny wire.

I though it drove the relay, it doesn't. I wired a relay from the battery straight to the pump. Went from 38psi idle to @ 50psi. Time to redo the VE tables.

I am just eyeballing the lineup of my reluctor ring at this point. I did get a keyed hub on it, so I at least have a mechanical mark to go by. I have not put a timing light on it. I think I am at least closer than I was before - see my other thread - I was having some nasty heat problems but those are all gone.

I went out today before fixing the fuel pump and had some issues with it breaking up at higher rpms. AFR showed about right but afr doesn't mean anything when cutting out. I am failry confident that it was a fuel problem.

As far as beating on the car, its a toy at this point. I would have never done turbo on a daily driver. Its got a $300 set of used srp slugs in it, and leftover parts from a previous build. She will hold together a little.



I should throw a thank you to Will. He helped me with some initial planning and answered some questions when I first started looking at megasquirt.

 

too little timing will cause that break up at high rpm if you have a weak-ish spark system. along with little power. 8psi should be a pretty hot ride on street tires.

What coil (s??) are you using?

One of the reasons i left the stock pcm in place...it runs the fuel pump

I gotta say, eyeballing the crank wheel might not be the best idea because of the consequences of a mis-timed (did i just make up a word?) motor.

 

also should realize the MS either detects rising or falling edge of the crank/cam trigger.

Take that into consideration if you are going to guesstimate the timing.

 

Running stock motorcraft coils.

Now that you mentioned it I did just switch from falling to rising edge. The old documentation said use falling for EDIS, now it says use rising. I know I need to get a light on it.

My stock pcm runs the speedo still but thats it.

 

I forgot you don't have an opti. The low res signal (i think) from the opti is what keeps my fuel pump working.

It should not matter is you use rising for falling, as long as your trigger offset is correct for the one you are using.

 

Well fuel is worked out... my previous tune was getting me 12ish AFR and last night she was running 7.0 (pegged) anywhere under boost. So I started working on the tune but now I have a new issue. Its like the EDIS module and the MS get out of synch. It will jump timing at random and run like crap. May very well be wiring. Sometimes the MS will reset - sometimes MS keeps running like normal but the module will fault back to its limp home mode which is 10* btdc. When this happens my tach dies (output from the EDIS) and MS keeps reading its tach signal (different output from EDIS)

So its either the sensor/wheel - wiring - tuning. There are settings in MS for tolerances and such on skipping/dropping teeth so I will have to play with those. I got a timing mark on it and I was only a few degrees off. (retarded)

But hey she was spinning them at 40+ so if I can lean it out and get the bugs out... should be mean.

 

There is lots of info on resets on msefi.com and megasquirt.info . Resets MUST be addressed before any real tuning can be done. Mainly, if the MS resets while the engine is running, the initial MAP reading the MS reads is remembered as the outside pressure. I'm sure you know the problems with that.

Most of the time, resets are caused not by poor wiring, but incorrect wiring. The MS has to have its own ground and 12v source. Now, I've got my MS and WB o2 grounded and powered the same without issues, but its really not the right way to do it. If need be, run a relay with power directly from your battery, and put the switching side of the relay to wherever you have the MS powered now. might take care of ya.

There is also "Sensitivity" for lack of a better word, that can be adjusted on your crank trigger pickup.

If you tack is dieing, its because of a reset, i've seen it on my buddies car. I put a MS on it, and he proceded to power two fans, and a fuel pump off my MS wiring. It reset all the time, car was almos undriveable.

 

I'm reading everything I can get my hands on.

Looking at my log from last night, MS does not reset. Voltage stays good - Well I say that 13.5-13.9 under all conditions, except the point right after it cuts out shows 13.1 for one entry on the log. In fact the log looks normal except for some strange afr readings afterwards.

Was in the throttle and @ 4300 it stalls like a really bad misfire - Let out of the gas and limped it home from there. I'm going to make a post up on their forums soon. Ran like crap after that - hard starts - really wierd.

I have a fan and my fuel pump relays on seperate outputs from the MS, but I'm sure it can handle a relay or two.

I wish I had a scope so I could look at the pip and saw between the module and MS.

 

I lied again.... Looking at the logs it doesn't show a "reset" but the IAC command resets and goes through its startup, it take a new baro sample.... I'm going to double check my wiring.

 

lie alot

 

I confuse myself easily... especially trying to keep track of a million things. What I wired to this, what I wired to that.

Further looking at my logs, right as it resets my WB goes lean for 1 frame... which means a voltage change somewhere too.... hmmm. I wonder if I wired my power to the same point for them since they are close.

Found some shielded stuff here at work. Going to redo my power and signal wires and go from there.

 

If you kept the opti would the MS be easier to figure out? I'm thinking of getting one to run my injectors, but i'm trying to figure out what the advantages would be over just getting a set of 79lb high imp injectors from racetronix and using the stock pcm.

 

I have read that it will work with the opti. I have not found any documentation showing how to do it. There is a person or two here with knowledge of it, and I hope they eventually share this with me. The amount of local tuning I do may be expanding before too long.

I know people are using the obdII crank trigger off of the 96/97 cars to run fuel with MS and using the stock pcm and opti for sprak.

 

I have not heard of a successful MS install using the opti as a trigger. Im using an obdII crank trigger and the MS is controlling fuel and spark. Opti is just there to throw spark, and the low res signal allows me to utilize the stock fuel pump wiring. But the stock pcm is not controlling anything but my trans functions, speedo and fuel pump.

--Jsetzer. The lean condition might be right on after a reset, the MS will deliver no fuel while reseting, causing that dead lean reading.

 

Ok, well how would you setup the system if you had my car? I still have my crank position sensor as the car was obdII, then I converted to obdI pcm, but still have obdII knock sensor. Madz28 just fixed the computer so it would read my stock knock sensor. I was going to run some 79lb high imp injectors. I know I need to get a 3bar map, and tune in SD since my maf will max out correct?