MSefi.com read only forum (Jan.15,2018)

Well I have a 350 TPI, Turbo, walbro fuel pump, new 80lb injectors and megasquirt.



Good compression, no vac leaks, all sensors calibrated and working on megasquirt/tuner pro, has 12.5 volts (old battery), everything kindof checks out thats whats weird.



Problem is I was cruising around doing the Autotune feature on tunerpro and it was running absolutely awesome than after 30 min of driving, it died instantly. Thought it ran out of gas because if I pump the gas petal I could kindof get it to run half behind. so after 2 5 gallon tanks of gas I filled it up and same problem. seems its flooding the engine badly but has spark. fuel pressure reads 38 psi but its on the EBAY adjustable fuel pressure regulator ($30). I thought that was the problem so I disassembled it and everything looks okay but the return fuel line hole is only 1/16 in dia so I dont think thats okay for the size of fuel pump I have. Anyway please let me know if you have any info on what it might be. Also heard it might be an ignition coil problem but I have a 1 year old msd (might have went out). Please help me. I've searched with no luck and have tried everything. thank you



Nathan

Seems like TunerPro changed a setting that shouldn't have been changed. I would try reloading the firmware and reload a map from before you started using autotune. See if that gets you back to where you started.

As a footnote, I've never seen anyone use TunerPro with MegaSquirt before, only on OEM ECUs. Do you have any info on how you pulled that off? Just wondering.

sorry its tunerstudio. I used tunerpro when i was burning my own chips. megasquirt is much better.

Well now Im stumped! I changed out the ignition module inside the distributer with 2 different modules from the auto parts store and nothing changed, still flooded out bad and managed to keep it running but only with the gas pedal half way down. Everything went wrong instantly when I was driving around using the autotune. I dont understand what would cause an instant problem. I checked almost everything and re loaded the code and still having the same problem. If someone could let me know of any other ideas. Im really frustrated. Thank you for your time.


Also when I lowered my fuel pressure to 5psi it ran better but still terrible. I think these injectors are stuck open or something isnt closing them. What could be doing this?

Nathan

A log and MSQ would help I think.

Ken

Here is the msq. Some of the mods are on the comment. I have a FIRST (tpi) intake to. Please look over the msq if you can and let me know if theres anything that would cause this insane instant flooding.

That's a lot of cranking pulse width.

Also, are the 80 lb/hr injectors low or high impedance?

Matt Cramer wrote:That's a lot of cranking pulse width.

Also, are the 80 lb/hr injectors low or high impedance?

What would you change it to please let me know and I'll try it. The are 12 ohms high Imp

Went out today and tried getting it going... well I took the wiring harness out from under the dash and checked everything, looks good. fuel pump leaks back very rapid but the regulator and injectors check out ok with the clamping hoses method of testing. Here is a data log with the ecu timing disabled ( i have a plug by the distibuter). looked it over and I cant see nothing. I'm almost think it might be the distributer itself if its not even running on base timing. let me know what u guys think.

Fuel in upper plentium, freaking to much fuel. what is keeping those injectors open so long? can fouled plugs keep it running like this? Maybe I just fould the plugs while tuning but woulding the somewhat fix themselfs. They are NGK V powers and only about a year old. I checked the 1 cylinder and the plug had black powder as expected but when I hooked up and tested the spark it was white and bright. anywhat check base timing and its 8 btdc and stays there. Its got to be fouled plugs or ebay FPR is allowing full fuel pump pressure while the gauge is reading 38 psi. (tested 2 gauges). Im about to loose my patience, anyone have any ideas. please

I was looking over Megalog view and I think there is a problem with the "trigger +-" its stuck at -3 and doesnt move. I read this website said the VR (variable Relucture) tells the megasquirt when to fired and it takes 2 readings for crank position. They suggested to get a trigger wheel but could this be my problem. A bad trigger on one bank or at all. please look at the log and tell me what you think. Im working really hard to find this problem because I just spent 4k on this turbo setup/ injectors/ FIRST setup and thats hard earned money. And it drove so damn go for those 30 minutes!!!!!

Anyone help?

Your ignition looks fine - you want the trigger+/- to NOT move, that would mean your triggering is bad. I believe you have two problems: the first is that you are getting a huge amount of accel enrichment due to a jumpy map signal. The best way to fix this is to just use tpsdot rather than mapdot or a combo to trigger accel enrich. That should smooth things out. The second thing is to reduce your pulsewidth and see what that does. Do this by reducing the ReqFuel and see if it helps. If so set it back to original and start reducing the VE table in the rpm/ map region you are idling in.

Ill give that a try tomorrow. I bought a new distributer online last night. I hope i didnt get it for nothin... oh well. Im going to remove the plugs and clean them. what would you suggest on plugs for my engine. I have a set of NGK Vpowers and I think I gapped themm at 30...let me know. Thanks for the help

A .030-.035 gap is perfect for getting started as it makes it easier to fire the plug. Once you have the engine up and running reliably you can increase it to whatever your ignition system can handle.

Well pulled all the plugs today..... I think I found the problem. About 4 of the 8 NKG plugs are firing down inside the threaded part of the plug. All I see is little puffs of smoke that come out in perfect order when cranking the engine over. What the heck happened. There was alittle black stuff but why is it firing inside the plug. I had an Accel set of header plugs do this about 3 years ago. Oreilly guy told me it was defective from factory. Did something crack down inside there? Would be interesting to find out what the heck happened to my almost new NGK Vpowers....

All I see is little puffs of smoke that come out in perfect order when cranking the engine over

Are you saying that it's leaking between the metal base and the porcelain?

Weird! I have never seen that in the last 50 years. Sounds like badly made plugs to this old guy!

So much for NGK's QC department, huh?

Ken

What torque did you use to install the plugs
NGK= No Good Kind

Well bad news... after replacing the spark plugs with new ones gapped to 28-30 the problem with the engine still ongoing. I just put in a brand new distibuter and aeromotive Fuel pressure regulator today too. the phrase "alll for nothing" comes to mind... here is a updated data log of what its running now. seems the ignition advance is jumping on and off. I noticed while checking base timing that the timing light would pulse normaly about 3 times than mis a light up. Like it was mis firing every 3-4 cyles on a few cylinders. With brand new distibuter, moroso ulta 40 wires, coil I looked into a bad power connection on the coil, wired it directly to battery and still have the same issue. I am thinking it might be a bad connection in the wiring from the 4 pin plug on the distibuter that goes to the megasquirt and other places. Please let me know by looking at the data log if you think its a bad connection with the jumpy ignition adv. thanks guys for all the help to far. hopefully I can get this thing going soon to enjoy this nice weather that finally came this way!

Nathan

Now that I've got a data log, I can see the jumping is a result of your unusual spark map. For some reason, you have set the spark advance below 1500 RPM to transition from 27 degrees advance at 70 kPa, to 15 degrees of advance at 80 kPa. Your MAP reading at idle is fluctuating from 65 to 78 kPa, resulting in the advance table doing what you have commanded it to and making your spark advance change through a very wide range. A spark table that's flatened out to a single advance number at idle will make for a much more stable idle.