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-   -   No fuel on start (https://www.miataturbo.net/megasquirt-18/no-fuel-start-102344/)

Jgilby 03-12-2020 02:22 PM

No fuel on start
 
2 Attachment(s)
Hello everybody before I start describing my issues I'll first list the mods that I've done.

1992 motor
Built bottom end with Manley rods and Supertech pistons 8.5:1 compression with Weisco rings
Brand new head (stock just new hla lifters)
DW 340 L/HR pump
DW 1000cc injectors with stock rail (could be the issue)
Garrett gt2252 Turbskie with stock wastegate (7lbs)
UPP custom manifold and exhaust
Megasquirt ms3pro
Brand new stock ignition
ATI superdamper
I am running AC and Power steering, the manifold allows me to
Fidanza lightweight flywheel
ACT fullface sprung clutch
GM AIT sensor
Koyorad Radiator
Flyin miata variable tps upgrade

So, I started the car for the first time in mid december of last year. The car did not want to stay running for more than 5-10 seconds and when it did run, it was lean, REALLY REALLY LEAN. 22ish afr. I didn't start the car for another 2 months due to work reasons. So then I try starting the car now and nothing happens at all. So I check the base timing, good, check ignition timing, good as it is locked at 10 degrees adv, take the spark plugs out to see if they fire, obviously while grounding them, and they check good. Then I go to check if there is fuel and there is a little in the cylinder but I don't think it's enough. Also I don't know what this could be, but it looks like there is little black specs on top of the piston. Could just be carbon buildup from when it did run briefly. So I check the fuel lines and it shoots out fuel so I'm not worried about that. then I check the rail and there is fuel there as well. Therefore my hypothesis is that the injectors are not spraying enough fuel and Im pretty sure I proved this because I put a little bit of fuel into cylinder #1 by removing the spark plug. Then when I tuned it over the motor caught for a brief second then died, which makes sense. I then received a dead time sheet for my injectors since they are 1000cc and punched that in. No change, still not catching. I then sprayed starting fluid in the turbo and it ran for about 2 seconds. I am now convinced that my injectors are not working. Problem is, I don't know why, and it's really getting frustrating. I have the Req fuel correct in megasquirt, which is 2.7 for 1595 cc engine with 14.7 afr and 1000cc injectors. In megasquirt it reads that there is a pw and I tested the injectors with the can test mode in megasquirt and they were firing. I'm running out of options folks.

So I guess I have a few questions
#1: Even though the injectors are brand new, could starting the car that lean make them dirty or clogged up? I wouldn't think so since they're brand new injectors but I guess it's just an option.
#2: Is something not calibrated that should be, maybe I missed something while installing them?
#3: Could the new compression ratio come to effect since stock it is 9.5:1 and mine is now 8.5:1
#4 Could it be that I'm running the stock fuel rail with huge injectors?
#5 Could it be that the stock fuel pressure regulator is faulty, I've read that they are good for a decent amount of HP, which I am only shooting for around 200-225 whp
#6 I the Req fuel wrong in megasquirt? I will list my current tune and a datalog from the starter fluid start below. Again my req fuel is 2.7 which is really low but it's what it calculates to.
Any Help would be Very appreciative since I am out of ideas and my field of "expertise". Thank you all if you read this and again any ideas or advise would be a true blessing.
https://cimg1.ibsrv.net/gimg/www.mia...4a8342a987.jpg








Jgilby 03-13-2020 04:36 PM

*UPDATE*
I took the injectors and rail off and cleaned them both. I had good fuel flow spraying out of the injectors so that would lead me to believe that I have poor fuel pressure. Although on megasquirt is states that the engine is receiving 101 kpa of fuel pressure but I will check the fuel pressure with an actual test set.

acedeuce802 03-13-2020 04:47 PM

101 kpa is the "fuel load" which basically means map pressure, Miatas don't have fuel pressure sensors. Run the test with a fuel pressure sensor/test kit.

Jgilby 03-13-2020 10:03 PM


Originally Posted by acedeuce802 (Post 1564246)
101 kpa is the "fuel load" which basically means map pressure, Miatas don't have fuel pressure sensors. Run the test with a fuel pressure sensor/test kit.

ok thank you, I'll get right on that

Jgilby 03-13-2020 11:24 PM

*UPDATE #2*
Megasquirt reads "RPM NOT SYNCED". I didn't think anything of it because the car is able to start with it but apparently its an issue. I'm still in the process on trying to figure out possible causes but if anybody has any ideas, that would be great.

acedeuce802 03-14-2020 08:43 AM

Run a composite log to see what the crank and cam sensors are doing. Screenshot the page in TunerStudio when the 3 lines show up (crank/cam/error).

Jgilby 03-14-2020 11:23 AM


Originally Posted by acedeuce802 (Post 1564265)
Run a composite log to see what the crank and cam sensors are doing. Screenshot the page in TunerStudio when the 3 lines show up (crank/cam/error).

will do thank you

Jgilby 03-14-2020 11:01 PM

4 Attachment(s)
*UPDATE*So turns out that the fuel pump wasn't installed properly, thanks to me, so after fixing that, fuel pressure was good and the car started. My issue now is that the car idles super lean. Around 18-22ish afr is where it wants to idle. The req fuel is correct, I played with the fuel ve table and that helped a little, I let autotuned do its thing and instead it brought the fuel up too much and the car started to vary in rpm WAYYYYY too much. It pulsed from 1900 rpm to 3100 rpm with the afr ranging from 15 to 22. NOTE*, that the car is now 8.5:1 but that doesn't explain why its still super lean because the base tune is for 9.5:1 which means "more fuel". Also, my rpm not synced issue went away when the car started.

sixshooter 03-16-2020 07:14 AM

The difference in compression ratios is inconsequential.

What dead times are you using? Some listed dead times are a bit off.

Jgilby 03-16-2020 12:19 PM


Originally Posted by sixshooter (Post 1564368)
The difference in compression ratios is inconsequential.

What dead times are you using? Some listed dead times are a bit off.

229 at 8v, 169.8 at 10 v, 121.7 at 12v, 85.6 at 14v, 61.7 at 16v

Jgilby 03-16-2020 12:20 PM

2 Attachment(s)
I have a feeling the my ignition map might have a lot of issues to work out as well. It is primarily untouched from diyautotune. Tune is listed below

sixshooter 03-16-2020 02:57 PM


Originally Posted by Jgilby (Post 1564387)
229 at 8v, 169.8 at 10 v, 121.7 at 12v, 85.6 at 14v, 61.7 at 16v

Hmmm.

My deadtimes are set at 1.1 ms.

Numbers in the hundreds or even in the tens are probably very wrong.

Jgilby 03-17-2020 11:25 AM


Originally Posted by sixshooter (Post 1564404)
Hmmm.

My deadtimes are set at 1.1 ms.

Numbers in the hundreds or even in the tens are probably very wrong.

https://cimg7.ibsrv.net/gimg/www.mia...7b485a378f.jpg
Here is the dead time sheet from DW Themselves

sixshooter 03-17-2020 12:41 PM

Exactly.

You have 121.7 at 12v listed in the post I quoted but the sheet you provided says 1.217 at 12v. Either you mistyped in your post above or you are putting the wrong numbers in the MS by a large margin.

There's a big difference between 1 and 121 milliseconds.

irodd 03-18-2020 04:07 PM

Jgilby
You took the deadtimes for 2bar pressure, moved a decimal point on 2 digits to the right, and than entered it as %% (1.217ms -->121.7%)
You use a serious stuff :)


https://cimg9.ibsrv.net/gimg/www.mia...32c8219415.jpg

https://cimg4.ibsrv.net/gimg/www.mia...0055148b65.jpg

Jgilby 03-20-2020 12:23 AM


Originally Posted by sixshooter (Post 1564467)
Exactly.

You have 121.7 at 12v listed in the post I quoted but the sheet you provided says 1.217 at 12v. Either you mistyped in your post above or you are putting the wrong numbers in the MS by a large margin.

There's a big difference between 1 and 121 milliseconds.

Ok, I guess I misunderstood how to enter it in megasquirt. I'll change that and post an update when I can. Thanks btw

irodd 03-20-2020 08:02 AM

Assuming your have stock NA manifold referenced 3bar FPR
and that FPR is still properly working with the oversized 340lph pump
you have to enter Deadtime@13.2V=1.187 and Deadtime Voltage % Curve = grey color highlighted numbers

https://cimg8.ibsrv.net/gimg/www.mia...c9ac39458e.jpg
https://cimg0.ibsrv.net/gimg/www.mia...acc4e84b40.jpg



Jgilby 03-20-2020 04:36 PM

*UPDATE*
After correcting the deadtime, my afr target is almost spot on! My only issue now is a high/creeping idle, but as far as the fuel issue, it seems to be fixed!


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