Another won't start thread... Starts but doesn't idle.
 

I can't understand.

The only way to have the car rise in RPMs is to pump the gas pedal. If I keep the gas pedal to something like 5%, it will die. I really need to pump gas pedal.

Short story:

Premix a little bit too much yesterday. I thought I was empty so I've put 800 ml 2-cycle oil for 46 litres. So there was about 1.4L of 2-cycle oil in the full tank.

But the car was running well, I made a 250 kms trip with it. Today, cold weather -10 Celsius, the car won't start. Since my 250 kms trip burnt some fuel, I've just put 25 new litres of pure gas to dilute the 2-cycle oil and it still won't start. I really have no idea.

I've tried:

-Unplug battery
-Unflood engine, easy way: pull EGI fuse and let it crank for 20 seconds, 2 times.

i would start by checking the obvious....vacuum lines(especially the one going to the pressure sensor on the drivers side firewall), verify spark is fine on all four plugs and that plugs arent fouled, fuel pressure etc... if still no luck id verify the tps sensor is in spec and no codes are in the system.

also compression test would be a good idea

Compression checked, OK!
Spark on all four plugs checked, OK!

I explained my problem to a local mechanic friend and he told me it could be the fuel filter! What do you guys think?

I ordered it, I'll have it tomorrow.

Sounds fuel related. I'd pull the plugs crank it and see if any fuel is being pushed out. Or try starting it with some starter fluid.

Yes, there's fuel being pushed out!

If it's not the fuel filter, I'm pretty sure it's something related to the throttle body. Or something stuck in the fuel tank?

sounds like your injectors are dumping a load of fuel. I'll check on those injectors of yours or injector O-rings.

-AzEKnightz

"A load of fuel", you mean they are injecting way too much fuel???

Un-calculated fuel. Leakage that was not meant to be there. Hence you have a flooding issue causing you to "not start".

-Eric

Thanks, is there an easy way to check for leakage?

Jumper the fuel pump terminal to GND @ the diagnostic pin-out box while you have a fuel pressure gauge hooked up. Pressure should stay constant, if it is slowly bleeding off. You have a leak.

-Eric

Fuel filter changed, it wasn't the problem.

Do you know where to hook a fuel pressure gauge? Car is constantly flooding.

I thought of an easy way to know if an injector is stuck open. I'll take a battery and splice two wires (+ and -). I'll connect them to each injector connector and I should hear a "click". Am i right?

clicking means you're activating the injectors. That does not prove if it is stuck open/close.

I personally recommend tapping a fuel pressure gauge into the fuel supply line at driver side (tap a Tee) and jumper F/P and GND together, watch the fuel pressure move up and let it sit.

Keep an eye on the pressure, it should be steady ~35-38psi stock.

If it slowly dropping, you have a leak in the engine since you're flooding like crazy.

-Eric

Oh thanks, good idea! Gonna check this tonight or tomorrow.

Hard to tell... So I removed the primaries. I don't know if they are aftermarket, they are SUPPOSED to be but I really don't know...

BTW I found an old set of primaries in the back of my garage, why my old primaries doesn't have the "rubber ring"?

Primaries I just removed: RIGHT.
Primaries I found: LEFT.

https://fbcdn-sphotos-b-a.akamaihd.n...05640108_n.jpg

Different injectors maybe? They should have an upper and lower O-ring on each injector.

-Eric

I think those to the right are supposed to come from secondaries!

If you put secondary injectors into your primary rail, you will have a sh*t ton of uncalculated fuel being dumped into the engine.

-Eric

Well I think I need to ask my tuner... But I'm pretty sure he did put 4x850cc.

Could it be bad fuel?

bad fuel can cause hesitation, stumble, lack of power, misfire etc etc.

But it will not cause a "flooding" situation.

-Eric

I started changing 4 injectors yesterday, I'll be done this afternoon. If it still doesn't start, 2 possibilities are remaining:

-Bad fuel
-TPS sensor out of range

Update: changed injectors, without success. I put some oil directly in spark plugs holes and it started but can't keep idle, just like in the video.

Water thermo sensor changed, without success.

TPS readjusted, was a little bit offset but now it's #1 - still no success.

Is there a way to "measure" sparks? I've tested spark on all 4 wires/spark plugs and it was ok...

Here's another video, still the same issue. Elbow was removed, that's why it has a strong weird sound from the engine. 0:55 is a backfire. If I remove my foot from the gas pedal, it will die. If I let my foot on the gas pedal, it will also die. I need to pump the pedal.

I'm out of ideas.

Who is giving you all the ideas to check all those things? I thought I had you fuel pressure check your system?

I am helping to diagnose a problem, not shot-gun a problem.

Check your fuel pressure and report back.

-Eric

I'm sorry I became a little bit crazy about fixing this problem. You are right and I will buy a fuel pressure gauge this morning. I'll report back with numbers.

I checked fuel pressure by removing outlet hose from gas pump and it seemed OK... But it'll be much more accurate with a gauge.

Thanks for your help!

I borrowed a fuel pressure gauge to a friend this afternoon because no car parts stores had a fuel pressure gauge in stock this sunday. Sadly, the fuel pressure gauge's maximum is 10 psi.

https://fbcdn-sphotos-a-a.akamaihd.n...18161697_n.jpg

I thought of another way to test the pump.

Jumper F/P to GND, it took 5 minutes 10 seconds to fill 17 litres.

My pump is a 255 LPH, so it should have taken 4 minutes to fill 17 litres. I think that's OK because when I was filling 17 litres, I was working a little bit against gravity.

https://fbcdn-sphotos-f-a.akamaihd.n...89666175_n.jpg

I'll look for a greater fuel pressure gauge tomorrow but I don't think I'm in the good path.

So fuel pressure at 10 psi. You have a problem. 3 possibilities:

1) Fuel pump is weak
2) You have a massive leak
3) You did not set up your pressure gauge properly or faulty gauge.

How did you hook up your fuel pressure gauge? Was the maximum pressure of 10 psi when you jumpered GND and fuel pump?

-Eric

Sorry, I was misunderstood! :)

The fuel pressure gauge's max is 10psi, so I couldn't have a reading. I can tell that the pressure is more than 10 psi but I can't say more (look at the gauge).

Today I'll try to get another fuel pressure gauge.

Did you check compression with an actual compression tester or did you pull the plugs and listen? I say this because I had a friend's FC that would start but not idle and it was a blown rear rotor.

I only listened because both rotor had the same "air sound". I'll check exact compression this afternoon.

Yep, you need a better fuel pressure gauge to properly diagnose the problem. A merely 10 psi pressure gauge wont do you any good ;-).

Good, next step is to check compression. Matt's got you covered on that.

-Eric

Compression is good 38-38-38 on rear rotor and 35-35-35 on front rotor, however I tested rear rotor before so maybe battery became a little weak. Anyway...

Compression CHECKED.

Also checked IAC resistance which is good too.

Hard to find a fuel pressure gauge where I live... But I'll find and I'll be back with numbers.

Ummm. How did you check compression? With it in the trailing plug hole and with the valve removed and the throttle wide open right? You should be seeing more like 110-120PSI for compression. I hope those are not PSI numbers you listed.

35/38PSI per side. 38x3=114 35x3=105

Leading hole. Throttle wasn't open.

And I only tightened the tester by hand.

From Rotary Resurrection:

"observe the needle bounces. You should see 3 in succession without skips, even bounces, in roughly the 30-35psi range."

I had to search, you scared me! :)

Fuel pressure: 38 psi with a weaker battery and against gravity.

38 psi falls in the normal stock range, iirc. Is your IAC still installed? If it is, it may not hurt to give it a good cleaning. Remove it and hit it with some carb cleaner. That should loosen up any buildup that may be causing the IAC to not function properly. Quick process that wouldn't hurt to try.

I checked resistance in IAC and everything is OK!

Update: I drained gas fluid and I put brand new gas in the tank. Without success.

Negative ghost rider. You should be seeing more like 85psi @250rpms cranking speed PER FACE at a bare minimum. You shouldn't have a difference of more than 20 psi per face.

Banzai Racing Compression Test
Rotary Tech Tips: How to compression check a rotary engine

Cranking speed and having the throttle open or closed are major factors for determining compression. Looking at your post you say the throttle was closed. Do another test with the throttle open, but even compression is more important than high compression.
Matt

Yes 38 is good, but that just mean your fuel pump is good.

Did you observe the fuel pressure after 5 minutes?

Fuel pressure should be no less than 21psi after 5 minutes of sitting.

If it is, then you have a slow leak somewhere.

As for compression test, Matt's got you covered with that video. Yes you need to have a minimum of 85 psi. A good engine compression will typically range from 110-120psi. per rotor.

-Eric

I got 105 and 114 psi per rotor. Engine is healthy.

After 5 minutes pressure gauge was at something like 32 psi.