04 With Newly Rebuilt Engine Won't Start
 

So I just picked up an 04 with 121k on the chasis. I previously owned the car, it was totaled and a friend bought it off of me, fixed the body and drove it for a while.

The car started burning oil like crazy so he decided to rebuild the motor. The motor has brand new rotor housings and the plates were machined. The rotors were reused. All new seals and gaskets were used when building the motor.

He put the motor back in the car and couldn’t get it to start. Frustrated and distracted with other projects, he sold the car back to me, and I am going to build it into an STX car for Autox.

I am currently going through the no-start diagnostics from the FSM, but wanted to start a thread here to see if anyone has experience with something similar or any guidance on where to focus my efforts. I am fairly confident in the build of the engine, so pulling it will likely be my last resort unless there is some resounding reason I am missing.

Items of note:

I pulled the fuel pump to check the sock. The sock looked clean, with the exception of some small metal flakes on the top (from the pump?) but a large amount of black sludge came out of the fuel pump when I tipped it on end and sprayed it with carb cleaner.

The lines from the OMP to the rotor housings have been removed, with the ports on the OMP and the rotor housings being plugged. The OMP is in place and the sensors are connected, but no oil is being pumped. When the rebuild was done, I believe the PO thought the OMP wasn’t working properly and decided to go premix. The fuel in the tank appears to have plenty of 2-stroke oil in it.

There are no DTCs, which isn’t surprising since the car hasn’t run.

Any help and suggestions is appreciated.

Thanks,
Glen

Well, you didn't mention the basics:

Have you confirmed spark?

Have you confirmed fuel?

Have you confirmed that the engine is turning over?

If you have a "yes" on all 3 of these, then there aren't too many options left. If you have a "no" on any one of them, then we might have a good place to start diagnosis.

Ah, forgot the basic stuff.

Confirmed fuel, spark and cranking. (Although I haven't confirmed fuel pressure.)

When cranking, small amounts of smoke and/or steam would come from the tail pipe and there was a faint smell of gas.

Hmm, what method have you used to confirm each?

The only really for-sure method are a timing light, using a spark tester, or removing the plug and grounding it

You should confirm fuel in the housing, not in the tail pipe. Pull the plugs and dry them, re-install, crank it over, pull them, see if they are now wet with fuel.

Spark confirmed by grounding the plug wire.

Fuel confirmed by running the pump and pumping to a bottle. But like I mentioned, I haven't confirmed the pressure at the engine.

I'll pull the plugs tonight and do as you recommended, then report back with my findings.

Thanks,

Glen

At this point, I see a few possibilities:

If you CAN'T confirm fuel at the engine...
A) a problem with your fuel injectors, likely the fuel injector harness connections are wrong. It appears like they can't be messed up, but they actually can, and will cause lots of problems. I expect that there is a harness configuration that can prevent any of the injectors from firing properly while cranking.

B) the ESS profile is off, and the ECU is firing the injectors and the spark at the wrong point in the rotation. Clean the ESS and reset it with the 20-brake-pedal-stomp

If you CAN confirm fuel at the engine...
B) the ESS profile is off, and the ECU is firing the injectors close enough, but the spark is at the wrong point in the rotation. Clean the ESS and reset it with the 20-brake-pedal-stomp
(slightly different from the above, and could easily cause C)

C) The engine is simply flooded. Could be because of B, because of an initial start attempt that failed due to any now-fixed problem (weak battery, ignition, starter, grounding points, etc...) or something that is still un-resolved.

D) Your cranking speed is too low to achieve compression (battery, starter, or compression itself)

Very insightful. And a good bit of info that is fairly easy to check.

The battery was fairly weak when I got the car back.

I'll check these things and report back.

Thanks for the input.

Glen

Often it's as simple as needing a pull start to clear it out and get it running......a minor flood with the assembly lube crap makes for fouled plugs rather easily

Yeah it usually floods pretty badly after it has been pulled apart.

You need to jump it from another car while doing a full deflood procedure (crank with plugs out and eshaft disconnected)

Crud will fly out of the plug holes and you will hear a suction sound, thats a good sign.

Put plugs back in reconnect and try again.

Forcing oil in thru the two lower intake nipples while someone cranks it over is the best de-flood method short of a pull start IMO. It has to be forced in with a squeeze bottle or pump though. It will not drawn in properly by vacuum alone. This assumes the motor was assembled properly and actually has sufficient compression.

Just as an update:

I pulled the plugs, and they were fairly wet with gas/oil.

I cranked the motor for 10-15 minutes with the plugs out. Some sludge definitely came out.

I disconnected and cleaned the ESS, though you could tell it had been recently cleaned.

I did the 20 stomp reset on the brake pedal, and the oil pressure gauge indicated that it worked.

I think I'll try a pull start tonight/tomorrow just to see if it works.

Thanks for all of the suggestions everyone.

Glen

Pull Start seemed to do the trick. I think the fuel pump may be weak, but it starts and runs.

The idle is fairly rough, any one have thoughts on that?

It will get better. ..plugs might be fouled up a bit

Give it a good run to clean it up and see if it improves

Fuel trims still have to be relearnt too.

grounding the plug wires doesn't confirm spark, because it still leaves the plugs out of the equation.

additionally when you mention he had the plates machined, how were they resurfaced? you can't treat these internal parts like you would with a traditional piston engine head for example. a rough surface from grinding the end irons will result in oil being pushed into the engine until they lap and smooth out the surface.

grinding plates is not for a novice rebuilder because the plates have to be smoothed out otherwise the engine may always consume oil and have plug fouiling issues. add on to that if they remove more than .040" then the nitride layer is completely gone and the irons will wear rapidly. ground plates must be re-nitrided.