satch

iTrader: (1)

When it comes to a hot start try disconnecting the vacuum hose to the FPR and leave it be uncapped. Then try to start the car. Vacuum should not be present on this hose for a short period of time immediately after a hot start.

DairokutenMaoh

iTrader: (4)

Ok, just wondering what can I find out if I do that. Do I just get easier start when disconnect the FPR hose when hot? or it will indicate a vacumm leak or something?

Man that rain is coming down, gotta do it after it stops!!

satch

iTrader: (1)

If you have vacuum on the FPR hose during a hot start it would make it harder for the car to start and the presence of vacuum would indicate something in the system is not operating as it should.

DairokutenMaoh

iTrader: (4)

ok, you mean if there are pressure present in the vacuum lines, or do you mean if there were no pressure present in the vacuum lines. I'm gonna guess you mean if there are pressure present and caused the pressure regulator to increase fuel line pressure which causes it to not able to deliver as much fuel as it should, since fuel vapor occupied the rail mostly in high pressure? Or is my concept of hot start assist completely off?But I'm gonna test it out tomorrow. For now I have the FPR connected to the LIM nipple that's tilted toward firewall.

I have the rats nest removed while keeping the dashpot, thermowax, thermovalve, bac, asv, twin scroll, and the acceleration diaphragm.
I removed the OMP, ABV, PCV, and all solenoid except twin scroll.

Do you know if there is a way to install the pressure regulator solenoid valve without reinstalling the entire rats nest? I'm considering reinstall all of the solenoid, purge control valve that was there to help with idle and start. However looking at the diagram I'm not too sure if there is a way to install it while bypassing Air pump, ACV..etc

Another problem is that I frequently hear the engine either advance or retard (not sure which) its ignition timing and cause the spark to fire when the rotor is at exhaust phase, which leads to loud clicking sound from exhaust making it sound almost like a exhaust leak. This happens usually when the engine is hot, but it almost occurs all the time when the car is operational. I was wondering what could've caused the ECU to trigger the mode that retard or advance timing?

And thanks a lot for the help!

satch

iTrader: (1)

No vacuum to the FPR bumps up the fuel pressure to about 40psi. The Air Supply Valve and the PRC Valve are part of the hot start process. Not sure if this car always had the hot start problem or if it ran fine with regards to hot starts.

DairokutenMaoh

iTrader: (4)

What I mean is, by vacuum, the way I understand vacuum is that there is nothing in it, so do you mean there were no pressure going to FPR or there were pressure going to FPR. Sorry I'm kind of slow at understand stuff.

The car never ran fine, although it didn't have problem when starting hot, it did have the timing issue and runs lean. I got the car with removed emission and rats nest, all idle assist blocked off, throttle body modified, dashpot removed, secondary butterfly removed, and thermowax removed. I swapped a complete engine with everything original and removed the rats nest while keeping some of the modules and rerouted the vacuum. Now the car has problem starting hot, and has rough idle when hot while starts fine and idles smooth when cold.

satch

iTrader: (1)

And also check the Water Thermosensor as it helps select the fuel used on start up be it hot or cold. Should read 2 to 3 volts engine cold w/key to on and .4 volts fully warmed and key to on.

Vacuum should mean suction so no vacuum means no suction.

DairokutenMaoh

iTrader: (4)

ok will do, the water thermosensor was from the old engine. hmm, didn't think of that.

DairokutenMaoh

iTrader: (4)

Ok, so no suction to the FPR, let it be a vacuum leak when hot or something malfunctioning (water thermosensor) will cause the fuel pressure to go up, or the wrong fuel type selected (btw I didn't know there are different fuel type within the same fuel tank) and making the car harder to start when hot.

And when the fuel pressure go up, does the engine floods? or less fuel is getting to the engine and make engine run lean? Because the car also idles rough and runs lean when hot.

satch

iTrader: (1)

I left out the word "amount" as the Water Thermosensor sensor selects the "quantity" used.

DairokutenMaoh

iTrader: (4)

ok, final question before I give in to the sleep demon XD. When testing water thermosensor, do I test it with wires connected or disconnected. If connected, how do I test it? If not, do I just simply ground my mulltimeter and test the positive?

Thanks

satch

iTrader: (1)

All you have to do is take a voltage reading from pin 2I of the ECU w/key to on when the engine is cold and when it is completely warmed up. .4 volts fully warmed and 2 to 3 volts fully chilled.

13bbuggy

iTrader: (2)

Did you ever check the compression on both rotors as was mentioned earlier? I just got through pulling a motor that was running on 1 rotor and it sounds a lot like mine did (granted mine was an NA). Mine wouldn't idle below 1000 RPM and it ran a lot better if I advanced the timing a little bit. i didn't even need to check compression, i just got it running and pulled the spark plug on one rotor and it almost died, then put it back on and it ran the same, pulled the other one off and it didn't make any difference. Then I pulled the spark plug and started it while someone had their finger over the hole, and there was nothing on that rotor. It's worth checking so you don't drive yourself crazy like I was looking for something else that's causing the problem. That motor was also pulled from a running car according to the guy I bought it from (and it did run, just only on 1 rotor). Good luck!

Shadowscreed

iTrader: (1)

I was having similar hot start issues with my last engine before it finally blew. My coolant seals were blown and my injectors were stuck wide open. But it had the same trouble starting anytime and usually wouldn't start hot. My new engine is having similar issues to your issues at the beginning of the thread where it will turn over but not start, and when mine does start it dies instantly after revving to 3000rpm. all of this lasts for about 1-2 seconds and it takes forever cranking it to get it to do even that.