OK, to start off, I am running a 1986-1989 13B in a sand rail, and I am running the msII . I have my fuel pump set up to turn on and off with a dash mounted switch. the rail is a little hard to start when it hasn't run in a few hours, and cooled down. I have to give it about half throttle to get it to start. once it starts, it runs rough, and there is a good amount of black smoke coming from the exhaust. If I give it some throttle, once it hits about 2500RPMs, it smooths out. so it appears I am giving it too much fuel. at an idle, if I turn off the fuel pump, it smooths out, and runs great for about 10-15 seconds until it runs out of fuel and days. I believe the fuel pump is between 65-75 PSI. is this too much pressure? andust alittle side note, i just got this pump, brand new, and I have only run the pump, all together, maybe an hour. it died on me today. I turn it on, and you can feel it try to move, but it wont turn. it may just be a faulty fuel pump, and have nothing to do with it, but I thought I would throw it out there.

 

I may be wrong, but normally most regulators will bring it down to 42 psi or so. Do you have a wideband o2 controller on there? It sounds like you are nearly flooding the engine when it is cold. You should be able to tune around the pressure unless your injectors are too big.

Ken

 

the injectors are stock, low imp injectors, I have the resistors wired in with them. my required fuel is set at 9.5. if I tune it around 5-7, it idles very smooth, but I try Wide open throttle, and it goes great to about 3000 RPMs and then it dies, I let off the throttle, and it starts running again. I am checking to try to get the actual fuel pressure of the pump I was running, but from what I have found, it could be as high as 90 PSI. is that too much for the stock regulator? maybe my regulator is bad. I am trying to find a pump that will work, I am hoping to find something around 45-50 PSI, and hopefully that will fix my problem. does anyone know what fuel pressure the stock pump puts out?

 

A few things I left off. I dont have a wideband 02 sensor yet. it is not just doing it when it is cold. It was around 85 degrees outside when I was doing this, and it had run for over half an hour. I guess what I need to do is adjust my table lower, like almost half down around the 900 RPM mark were it idles, and then slowly taper up to the 3000 rpm mark were it starts to run good. I will check tomorrow to see if there is any black smoke past 3000RPMs. does this sound about right? I am new to tuning, so if I say something that is completely stupid, do be afraid to call me out on it.

 

The death at 3000 rpm could be any number of things... not having some form of O2 feedback is going to make it more difficult to debug, but if you post a datalog, it might be easier.

It could also be CAS noise, misconfiguration of the trigger wheel settings, fuel too lean, spark timing wrong, etc...

Ken

 

you may or may not remember, but you looked over my MSQ and set up my vex files. I did some studying on the tuning process with MSII, and I have a better understanding of what can be done. I will try to tune my fuel table to and see what that does, but my fuel pump wont be in for a few days, so I am on stand by until I get that. I will keep everyone posted. I think the wide band 02 sensor will be on my Christmas list this year.

 

You will not regret getting the wideband!

 

OK, I tryed a few things, and it runs better, it stumbles a little if I try to accelerate hard but it doesn't completely cut out like it used to. the first thing was fixing my ignition settings, somewhere, somehow, my settings got changed from falling edge to rising edge.I set it to falling edge, and it smoothed out a bit on the acceleration. the second thing I did was change the settings in my accel enrichment. it was set to 90% TPS, I changed it to 50% , so now it reads more from the map sensor. Im still working on getting a wideband O2 sensor, and I found a few guys locally that tune with megasquirt that can help me out. I will post more when I get more info.

 

well, I finally got a payoff. I took the rotary powered sand rail out to the dunes this weekend, it runs pretty good, but that around 5000 is killing me. if I slowly work into the throttle, it still hesitates a little. I found that when I am climbing the big dunes, if it starts cutting out, I can let off of the throttle, and then slam it to the floor, it pops a little, and then sends it right to the rev limiter. I am thinking fuel is the problem, but until I get a wideband O2 sensor, I am at a stand still.

 

I don't know that I would have even driven it without a wideband or some kind of tuning!

Ken

 

well, I have done a little tuning, but with no wideband, I am limited. the main reason for going was to see what it was doing, and what needed to be done to it. it has been parked for a year and a half, and the last 10 months have been trying to get the rotary running, being in a sand rail, I cant just go out whenever I want. I have to go when there are people going with me(in case I need to be towed back) and the weather in Utah is about to change drastically. I will have a wide band in the next few weeks, but the next trip to the dunes will be Easter 2010. this way I know what needs to be worked on this winter when I wont be going to the dunes, and I can have it running better by Easter.

 

Fair enough. Any chance of getting it on a dyno before Easter?

Ken

 

I am hoping I can get to a dyno in the next couple of months. I want to get the wide band o2 sensor in it and try to get it running the best that I can, then I will get it on the dyno and see what it is doing. this is a paycheck to paycheck project, so I am jut trying to do what I can when I can.

 

ya i think once you get your wideband in and adjust your accelerator enrichment u will be ok. tuning blind is a hard thing to do. shot tuning with a wideband is hard as well if your the driver and tuner :P
good luck with the project

 

Wideband is on its way. I ordered the LC1 setup and it should be here in the next couple of days. tuning will start next weekend!!!

 

well, wideband is not here yet, so I'm messing with some other stuff this weekend. I am needing to put a water temp gauge in, but I was wondering. is it ok to tap into the coolant wire that runs into the computer? I just want to make sure that it wont screw up how the compter reads it, or worse, with the gauge having a hot wire running into it I want to be sure that it cant send a charge back down the wire and into the computer. has anyone done this before?

 

OK, I have a log file. you can see what it is doing pretty clearly. I hold it at 4000 rpms, bump the throttle a little more and hold it, the motor basically dies until it falls to 3000 rpms, and then accelarates like it should. I will have the wideband o2 on tuesday, and have it installed by wednesday. I will post another log when I get that in, to give a little more information as to what is going on.

 

OK, I got the LC1 kit, I got it all installed, and I configured megatune for default settings for the LC1, but it doesn't appear to be doing anything. I can increase my cells by 30, or decrease them by 30, and the needle never moves off of 10.30. any ideas?

 

Connect with LogWorks and see what that reports the LC1 reading as. This will let you know if the problem is on the LC1 end or the MS end.