[SOLVED] New Head, No Start, Runs on Starter Fluid

S

SpeedyThrees

Greenie N00B Member
Greenie Member
Just replaced the head and now I have a no start situation. But car starts and runs on starter fluid.

2012 Speed3 - all stock except for junky Corksport Cold air intake
Purchased car with a burned valve in cylinder 4, but engine ran. I drove it down the block and into my trailer.

I just replaced the head, timing and injector seals. All parts OEM Mazda. Pushed the go button and dreaded no start. Starts on starter fluid and then dies.
Compression approx 175 in all 4 cylinders
Fuel pressure at inlet to HPFP 60 PSI
Fuel rail pressure between 9k kpa and 10.5k kpa (1000-1400psi) at 2k rpm while running for a few seconds.

I've checked every harness connection that I can find. The grounds on passenger engine mount, HPFP plate, transmission and driver fender are all good.

I had this issue once on a 3S and after searching high and low, I found a harness connection that needed a final click. But haven't found one here yet. Are there particular ones that I should look at that might be related to the injectors? Or a ground that maybe I overlooked?

I don't have a high level scan tool that I can command injectors with. I do not have a factory service manual>

I've read a number of threads in this forum on the topic of injectors not firing, but I haven't found a specific direction to head in that fits my situation.

I guess, my next course of action is to tear everything apart so that I can get to the fuel rail/injectors.

Grateful for any suggestions or resources that you may have.
 
Unplug the MAF and see if it starts then.
If you have some kind of tuning tool, getting a log of the failure to start would be a good idea.
 
Copy. Thank you.
I will try unplugging the MAF and report back.
Also, will try to get my hands on a Snap-On scan tool and see if it will let me manually trigger the injectors, or graph them during the brief 5-10 seconds that it runs.
 
MAF unplugged. No dice.
Just for giggles, in the am, I am going to swap in another ECU just to eliminate that variable.
 
I was able to get to the connector for injector #1 without taking the intake manifold off. Noid light confirmed no signal to injectors. Looked harder at back tracing signal circuit. Blue injector relay was vacant from under hood fuse block and found in the cup holder. I knew that it was going to be something stupid. wish it wasn't me. Wasted a couple hours chasing my tail.

Vroom Vroom Zoom Zoom
short version. I'm an idiot. Head install was a success. Sorry to have wasted any of your time or brain power. Thank you for your time and suggestion.
 
Shit happens, at least it was an easy fix. Also if you want to turn the engine over without the injectors firing, all you have to do is hold the gas pedal to the floor. It won't inject if it's WOT.
 
Update.
Went for test drive. 1st 5 miles was great, then began to stumble and stall. Now in a no start issue. I will start a new thread with relevant topic.
 
Update - SOLVED
New Thread here about performance decaying rapidly from running perfectly to not running at all, over and over again.
https://mazdaspeeds.org/index.php?threads/stumbling-rough-running-stalling-now-no-start.17548/

Culprit was a bad fuel pressure sensor. Sensor worked correctly when cold, but once heated up, it degraded signal all the way down to zero rail pressure. Which of course was not true. Part number for OEM fuel pressure sensor is Bosch 0261545058. Not available from Mazda or parts stores. But, 0261545038 is available in parts stores and will work in a pinch. But not certain of the range limits and would suggest ordering the correct one online.

Enjoy
 
Congratulations! It's almost always something small and stupid.
 
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