Engine swap - no start.
 

Hi Guys,
Long story but the car has been sitting for a number of years but it has been resurrected with a new engine, fresh fuel etc.

Details - Car ran fine before engine swap. Year 94, stock ecu.

New engine TDC confirmed
Has Spark
Has Fuel Pressure - fresh fuel
Has voltage at the injector harness
No codes - except purge solenoid valve (shouldn't matter)
Everything is hooked up

Car turns over but doesn't start. No fuel present on plugs, but is getting spark.

Tried MAF, Coil Pack just in case.

Something is keeping the injectors from firing, if the CAS was bad would it also not get spark and throw a code?

Thanks in advance

Do you have old fashioned starting fluid? Give it a shot of that and see if the engine runs for a hot second. If so, it’s a fuel problem.

How did you confirm fuel pressure? Do you hear the fuel pump run? Have you jumped the relay through the diagnostic connector in the engine bay so that it runs all the time?

are you getting any ignition events? If you’re getting a pop or two but not running, you might be 180 out (check you’ve connected the coils correctly and that you have the plug wires right).

that’s it from my brain right now.

I have an aftermarket FPR with a gauge, shows 45psi when starting. I've also jumpered the pins and get the same result.

Confirmed the plug/coil connection and order, no pops or anything.

I'll try the starter fluid and may get a noid light for the injectors.

Welp starter fluid was not a great idea, I guess I sprayed a bit too much. The #2 plug on this 50k motor didn't feel great going in originally and managed to make a rapid exit after a bit of starter fluid. It would have likely failed without the starter fluid, but it will definitely now.

Helicoil is next on the list unfortunately.

Good news maybe is that I got a noid light and when turning over the light comes on.

Decided to go with a Time-sert instead of a Helicoil after doing some research.

Besides that issue, what is keeping the car from starting? I'm running out of bad ideas https://forum.miata.net/vb/images/smilies/wink.gif

Well, if it didn't survive starter fluid, it wasn't going to survive combustion...but it sucks to hear you've gotta fix that up.

But that makes it sound like you're getting ignition, right? Some kind of ignition event happened to blow the spark plug out, unless it was just in there so loose it shook out on that particular start.

Your injectors should be getting 12v constant. The ECU is grounding them to make them fire so your noid light should be flickering while cranking, not on steady. Is that the case?

Yeah, check all the (remaining) plugs are tight. No compression, no start.

They are all good, fuel is getting to the rail it just isn't making it through the injectors. Noid light says they are getting a voltage pulse. Maybe all 4 are bad? That seems aggressive but I guess it is possible.

You’re sure you didn’t swap the feed/return lines? You’d still see pressure if you checked the feed line, but it wouldn’t be in the rail.

Curly!

Hi

https://cimg2.ibsrv.net/gimg/www.mia...5c246637a4.png



https://docs.google.com/drawings/d/1...it?usp=sharing

I have seen multiple stuck injectors, so it's possible. You may try letting fuel pressure to zero, then hit the injectors with 12V. You should hear them clicking. No clicky, no fuel.

if they don't open, try higher voltage to unstick them. I've seen one that took almost 30v to unstick. And I've seen one that 30V did nothing it was still stuck.

It sorta runs! It was the injectors, just seeing your post but I tried a myriad of other things and swapped in some crusty ones and it fired right up... and started leaking immediately, but it ran so I called it for now.

I'll update once I get it actually running properly.

BTW the Time-sert install went great, 10 out 10. Great product

Glad you found out it was the injectors. I would not trust any of them. You should get new ones. Also, do some research on which ones to buy. I have heard a lot of stories of people getting non-functioning injectors from amazon.