I've just completed my wiring and got my new MS 2 3.0 built. It's on stock 87 Iroc 5.7 TPI with 65# precision turbo injectors.
First question.. the fuel pump primes but stays running even if I don't start. Looking at the data on Megatune, when the key is on, the status is "Running". If I crank, the "Cranking (or maybe it says Starting)" also lights up as it should. This is my first MS so I'm not sure, but I would think "Running" should only be indicated when the engine is actually running. I'm thinking this is the reason the pump is running. If it's normal for Running to be on when the MS has power then obviously I've miswired the fuel pump relay somehow.
Next issue.. I've got the external coil 8 pin HEI and I'm having problems with misfiring, really rough idle and lower RPM and popping through the exhaust in higher rpm. I'm familiar with the problems some people are having with the 8 pin, but in every case I've read about on these forums, the problem includes unstable RPM data. On mine, the RPM is always correct and I haven't seen a single jump on the display gauge. Am I thinking correctly here that is the megatune RPM gauge is working properly then I'm *not* experiencing the dreaded 8 pin issues mentioned in other posts? I have already replaced the entire ignition system (well, new plugs, coil, module, rotor and cap) today with no changes. I'm coming from a stock ECM that was running Code 59 and experienced some similar issues with that when running these particular injectors.
Other than these two, the whole process of building and installing the MS went smoothly. I hope I can get this worked out soon so I can move forward with my turbo install.
Thanks for any help...
new install.. question about "running" status and misfiring
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0). For tuning/troubleshooting questions, please attached a datalog and your MSQ file to your post.
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: new install.. question about "running" status and misfiring
I found the cause of the ignition problem... or at least a big part of it. The Trigger Offet had to be set to 29.5 to get the timing mark to match the desired timing in megatune. I was under the impression this number should match the base timing degree (when the bypass 5v is disconnected) which I had set to 8 degrees. It's running ok now, but I'm experiencing a couple of issues I've never had. Around 1500-2000 I get an occasional misfire and at the same time, the tach needle jumps around. Other than that, it's running great and we drove it around tuning it last night. I've got my wife pretty comfortable with working the numbers now 
Still haven't looked into the fuel pump staying on problem.
Still haven't looked into the fuel pump staying on problem.
Re: new install.. question about "running" status and misfiring
Interesting... On a hunch, I flipped the setting on the rising edge/falling edge to opposite of the MS instructions and the trigger offset now matches the number of degrees of base timing exactly to get the timing light happy. All of the misfiring I had in the midrange is gone and the dash tach is smooth.
Now I'm down to some wacky IAC behaviour, crazy differences in idle AFR between starts and a few misfires at idle that might just be AFR related. I'm going to clean the IAC and bypass the two resistors in that circuit and hopefully it will start working consistenly. I've already set the minimum step to 5 and tried various settings to no avail. It works sometimes but not always.
Now I'm down to some wacky IAC behaviour, crazy differences in idle AFR between starts and a few misfires at idle that might just be AFR related. I'm going to clean the IAC and bypass the two resistors in that circuit and hopefully it will start working consistenly. I've already set the minimum step to 5 and tried various settings to no avail. It works sometimes but not always.
Re: new install.. question about "running" status and misfiring
I can't comment on your other problems, but I was having the same exact problems with an occasional misfire at 1500-2000 RPM.
I have a 1984 Camaro with a Holley Stealth Ram setup, running MSII v3.0 PCB on 2.89 code with an 8-pin HEI module and the Hall effect input circuit.
Switching from Rising Edge to Falling Edge and recalibrating the trigger offset cured my tach drops at low range RPM just above idle. My datalogs showed the tach signal dropping to 0 for exactly one cycle every time it happened. My dash tach also bounced every time. Now it hasn't dropped at all. On to tuning!
I have a 1984 Camaro with a Holley Stealth Ram setup, running MSII v3.0 PCB on 2.89 code with an 8-pin HEI module and the Hall effect input circuit.
Switching from Rising Edge to Falling Edge and recalibrating the trigger offset cured my tach drops at low range RPM just above idle. My datalogs showed the tach signal dropping to 0 for exactly one cycle every time it happened. My dash tach also bounced every time. Now it hasn't dropped at all. On to tuning!
Re: new install.. question about "running" status and misfiring
Yep sounds like the same situation as you. Well it works fine now but I do still have these idle misfires.. more like the spark just quits for a cylinder or two then comes back.
I did figure out the IAC problem - I had to set the beginning position (not sure how it's worded in megatune) of the IAC stepper to 255 instead of the default 0. This runs the stepper all the way to closed and gives the MS a reference point to work from. Maybe I didn't read the manual well enough but I don't recall seeing much about this. It sure made for some crazy random idle speeds and IAC positions that changed on every restart. All is well now and I think this was causing the AFR problem at idle.
I did figure out the IAC problem - I had to set the beginning position (not sure how it's worded in megatune) of the IAC stepper to 255 instead of the default 0. This runs the stepper all the way to closed and gives the MS a reference point to work from. Maybe I didn't read the manual well enough but I don't recall seeing much about this. It sure made for some crazy random idle speeds and IAC positions that changed on every restart. All is well now and I think this was causing the AFR problem at idle.