General Miata Chat A place to talk about anything Miata

Crank no start, with a twist?

Thread Tools
 
Search this Thread
 
Old 04-01-2017, 11:22 PM
  #1  
Newb
Thread Starter
 
blackdbl9NB's Avatar
 
Join Date: Oct 2012
Location: Sioux Falls SD
Posts: 39
Total Cats: 3
Default Crank no start, with a twist?

And yes I have searched:

I have a 90 with a 1.6 that will crank, but will not fire. My initial thought was CAS. Tried 3, no change, next on to coil packs, tried 2, no change, AFM, have 3, tried them all no change. Also have a few 1.6 ECU's laying around and tried them also. So at the suggestion of a friend I sprayed brake cleaner in the intake manifold. Engine pops off and idles, as long as I keep spraying brake clean. Ok so on to the fuel system.

Started with a new fuel pump and also tried an older one that I know worked on another car. Crank and no fire. Checked voltage at the pump plug with the fuel pump/GRND in the diagnostic box jumpered. Good voltage there. When the car is cranked, voltage drops to 9.8 or so. I checked for fuel pressure and the gauge I used didn't move the needle. I blew out the fuel lines, back to front and then front to back. Ran a short fuel line to a bottle and cranked the engine, getting very obvious low pressure there. Removed the fuel filter from the fuel line, replaced with a union for free flow, still no change in pressure. Checked for pressure at the fuel pump and I get the same trickle of fuel straight off of the sending unit. I swapped out the circuit opening relay and nothing has changed.

So my question for you all, what the bloody hell am I missing here? Any insight would be helpful, and I am not opposed to throwing a match in the fuel tank.

I will be posting this on other forums as well.
blackdbl9NB is offline  
Old 04-06-2017, 07:36 AM
  #2  
Junior Member
iTrader: (1)
 
cnano8's Avatar
 
Join Date: Jan 2012
Location: Boston
Posts: 90
Total Cats: 8
Default

Hmm sounds like you tested a good amount of stuff. Did you check out the fuel press regulator?
cnano8 is offline  
Old 04-06-2017, 07:49 AM
  #3  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,501
Total Cats: 4,080
Default

does it start and run if you jump FP and GND in the diagnostics box?
Braineack is offline  
Old 04-06-2017, 09:22 AM
  #4  
Junior Member
iTrader: (1)
 
BarbyCar's Avatar
 
Join Date: Apr 2007
Location: Toronto, Canada
Posts: 469
Total Cats: 25
Default

If you feed the pump with 12V directly from the battery with a couple of wires, do you get fuel flow at the tank?

Did you replace the in-tank filter?

Is the tank full? If not, any chance there's a leak in the suction side of the pump?
BarbyCar is offline  
Old 04-06-2017, 09:43 AM
  #5  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,501
Total Cats: 4,080
Default

Originally Posted by Braineack
does it start and run if you jump FP and GND in the diagnostics box?
do you buy this thing not running or something, or did this just happen?

I checked for fuel pressure and the gauge I used didn't move the needle. I blew out the fuel lines, back to front and then front to back.
is your fuel filter clogged?
did you check fuel pressure on the return hose and not the inlet?
Braineack is offline  
Old 04-07-2017, 10:52 AM
  #6  
Newb
Thread Starter
 
blackdbl9NB's Avatar
 
Join Date: Oct 2012
Location: Sioux Falls SD
Posts: 39
Total Cats: 3
Default

So, I figured out the problem. I had 2 sending units that must have been running low voltage to the pump. Found another sending unit in the garage, drained the old crappy gas out of the tank and put in fresh gas and she fired up.

Thanks guys
blackdbl9NB is offline  




All times are GMT -4. The time now is 12:22 AM.