Just another 91 Miata VVT swap no-start
#1
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Just another 91 Miata VVT swap no-start
Hey guys,
So here's the background:
-91 Miata w/ 2003 1.8L VVT with 39,000 miles.
-MS3X
-Currently has oldish E85 in the tank
-FF640cc injectors converted to sequential injection.
-Using 99-05 Miata OEM trigger wheel (FM 36-2 in the mail)
-RB Headers
-Using 91 Coils and wires
-Followed the VVT swap guide
As for the problems, the car will crank but won't start. I have attached both regular and composite logs as well as my tune. Basically the car will crank, kind of fire, and not catch. After a while it smells like fuel. I feel absolutely defeated. This thing is kicking my ***. Any ideas?
So here's the background:
-91 Miata w/ 2003 1.8L VVT with 39,000 miles.
-MS3X
-Currently has oldish E85 in the tank
-FF640cc injectors converted to sequential injection.
-Using 99-05 Miata OEM trigger wheel (FM 36-2 in the mail)
-RB Headers
-Using 91 Coils and wires
-Followed the VVT swap guide
As for the problems, the car will crank but won't start. I have attached both regular and composite logs as well as my tune. Basically the car will crank, kind of fire, and not catch. After a while it smells like fuel. I feel absolutely defeated. This thing is kicking my ***. Any ideas?
#3
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Yeah i saw that. I don't know why though. I redid the wiring and doubled checked it today. It has power, ground and signal coming out. Unless there is another setting that I have to change in Megasquirt for it to work. Or the sensor could be bad I suppose.
#7
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Thanks guys. Hope everyone had a great Thanksgiving.
So here's what I did:
-Set tune to falling edge.
-Tune still set to going high instead of going low.
I'll post a picture of the fuel lines but I'm 90% sure it's right. When I swap them, the fuel pump makes a different (weirdish) noise. Below is a picture. Red is connected to red, blue is connected to blue.
To do today:
-Test all grounds
-Now that I have another helper, I'll go through the ECU and test all my wiring.
-Install 36-2 wheel
-Potentially empty E85 and put in new 93 octane and adjust tune.
Will keep you guys updated. If that doesn't do it, could it be a cranking pulsewidth issue? Keep in mind the car is cold. Colder than it's ever been ~35 degrees F.
So here's what I did:
-Set tune to falling edge.
-Tune still set to going high instead of going low.
I'll post a picture of the fuel lines but I'm 90% sure it's right. When I swap them, the fuel pump makes a different (weirdish) noise. Below is a picture. Red is connected to red, blue is connected to blue.
To do today:
-Test all grounds
-Now that I have another helper, I'll go through the ECU and test all my wiring.
-Install 36-2 wheel
-Potentially empty E85 and put in new 93 octane and adjust tune.
Will keep you guys updated. If that doesn't do it, could it be a cranking pulsewidth issue? Keep in mind the car is cold. Colder than it's ever been ~35 degrees F.
Last edited by Goingnowherefast; 11-24-2017 at 12:45 PM.
#8
and post another composite log.
Not to be rude here, but when I step into a job to take over and all the wires are the same color....First thing I do is re-wire with colors. I just assume the wiring is fucked up if they couldn't use different wires per circuit.
You can ebay high quality wire in a color assortment for really cheap.
Not to be rude here, but when I step into a job to take over and all the wires are the same color....First thing I do is re-wire with colors. I just assume the wiring is fucked up if they couldn't use different wires per circuit.
You can ebay high quality wire in a color assortment for really cheap.
#9
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Will do. omw outside to try it now
You're good dude. No hard feelings here. I have it labeled with a label maker before, this is it the second wiring redo so that's why it looks like a ****-show. If everything works, then I'll clean things up a bit.
Not to be rude here, but when I step into a job to take over and all the wires are the same color....First thing I do is re-wire with colors. I just assume the wiring is fucked up if they couldn't use different wires per circuit.
You can ebay high quality wire in a color assortment for really cheap.
You can ebay high quality wire in a color assortment for really cheap.
Last edited by Goingnowherefast; 11-24-2017 at 01:16 PM.
#11
I had a similar problem on my engine where it would crank but not start. I reloaded the basemap from DIYautotune and scaled the VE table by 1.5 and was able to get the car to start. Long story short, it ran like crap and the cause was the car's timing belt being way off. The belt wasn't aligned at TDC on the crank and the intake cam was 1 tooth off.
#12
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Okay, testing spark plugs. All 4 plugs are getting spark.
-Pulled a plug after crank and it's pretty dry. I suspect it's a fueling issue. Can anyone smarter than me confirm the fuel line orientation as seen above? Is the fuel regulator upside-down?
I suspect the timing could very well be off in addition to fueling issues.
-Pulled a plug after crank and it's pretty dry. I suspect it's a fueling issue. Can anyone smarter than me confirm the fuel line orientation as seen above? Is the fuel regulator upside-down?
I had a similar problem on my engine where it would crank but not start. I reloaded the basemap from DIYautotune and scaled the VE table by 1.5 and was able to get the car to start. Long story short, it ran like crap and the cause was the car's timing belt being way off. The belt wasn't aligned at TDC on the crank and the intake cam was 1 tooth off.
#13
Thread Starter
Junior Member
iTrader: (1)
Joined: Oct 2015
Posts: 397
Total Cats: 36
From: Metro Detroit, MI
Anddddddddd we're good!
A combination of checking grounds and flipping the polarity fixed it. Car fires right up and idles great. (A bit rich).
I owe you guys a beer if I ever see you in person.
A combination of checking grounds and flipping the polarity fixed it. Car fires right up and idles great. (A bit rich).
I owe you guys a beer if I ever see you in person.