Strange first start up problem

[mendelmax]

Hi guys.

Lately, I was improving my stroker, and swapped it in the rig today.

The problem is, that it doesn't want to start, it smokes from the intake and once it even thrown a flame through the throttle.

The engine is now a 4.6 stroker with:
- 0.040 overbore,
- pistons dished to 16.5ccm,
- 4cw crank, renix camshaft,
- block decked to 0.
- 7120 Head
- fuel pressure regulator set at 55 PSI
- 22.5 lbs WJ injectors
- WJ intake
- 60mm TB

SCR is about 10.1:1, DCR at 7.8:1

To increase low end torque we advanced the camshaft by 5*, and this is what I suspect might be a source of a problem, but still I doubt it...



So, has anybody any idea what can cause it? We already ruled out the bad distributor position (we have set it 3 times, and swapped the wires to rule out the 180* mistake), and the faulty coil (checked with two coils, each gives the same result). The fuel is only about 2-3 weeks old.
After taking plug out it was covered with carbon deposits and wet, when moving the crank it released a smoke through the plug hole.


Help me please, cause I must make it running ASAP.

[lafrad]

Sounds like your distributor is 180* off from your camshaft, to me.... (you are set to the wrong "top dead center" with the rotor)

[mendelmax]

I also thought about it as a first guess, but as I said, reinstalled distributor 3 times, and even swapping the wires (1-6 ; 5-2 ; 3-4 ) didn't help.


The other guess would be the faulty crankshaft position sensor, since we hit it when we were taking engine out, but externally it shows no damage. Is it possible that it could be broken internally without any external signs? Of course the rig drove into the workshop on it's own, it was working perfectly well, so "normal" CPS failure doesn't apply here.

[mendelmax]

I have no idea what was wrong, but today it finally started. Weird, really.

It had to be something with the timing, since this was the only thing we were setting over and over again, but honestly, I don't even know what could have changed the last time we set it.

But the most important thing is that it started, so thanks for the timing tip, and to everyone who spent their time on reading about my problem

Ps. Do we have any stroker running on propane here? Cause ours will get sequential propane injection in next few weeks, I hope it will help us to dial AFR perfectly, and we'll have 100 octane to use

[mendelmax]

Hmmm, despite it started finally, we have another problem- it stalls under load. Works fine on neutral, revs properly, but then you put it on drive, it stalls.


It has just thrown the MAP sensor code, can this problem be caused by MAP sensor, or is this code a result of some other problem?

[SilverXJ]

A bad Map sensor could cause problems like that.

[mendelmax]

Sensor swapped, engine runs better, but still low power and stalls sometimes. I have no idea what's going on On tuestady we'll install propane injection, so if it's some sort of pre-ignition problem it should then disappear, but if it won't, then I'm out of ideas.

Is it possible, that the cam advance would cause so many problems? I find it hard to believe...

[George Dickel]

I believe you are 180* out. You wouldn't think that it would run but it will. I had similar issues and went 180* from what I had, reset the computer and everything has been super great since. No more crank sensor codes either. It only takes a few minutes to do and you'll know immediately if it worked.

[SilverXJ]

I wouldn't add the propane until you get this figured out. Its not pre ignition from compression it wouldn't cause that problem.

[mendelmax]

Problem was solved, but I have no idea how. It just worked after some time of putting the distributor in and out, strange.

Now the propane is installed, we got quite good dyno torque numbers for a budget-build, but now we have oil pressure loss This engine simply doesn't want to cooperate.