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Trouble starting - too many cranks P.2. Subaru experts please give me your .02!


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My original thread is right below, but I will also give a summary of the problem/fixed items.
http://www.westernsubaruclub.com/smf/index.php?topic=35882.0

This is a 1998 JDM STi type R with approx 96k and EJ20K engine

Problem:

First time I try to start the car it will take approximately 20 cranks to start, but it will always start and never flood.

**********************************************************************************************************
-If
I leave the key on the "on" position for approx 15-20 seconds the car
will start perfect. If I start the car, shut it off, then instantly try
to restart it again it will start normal. If I start the car, shut it
off, wait 5-10 seconds then it will take me 10-20 cranks to start the
car. So the longer I wait between starts the more cranks it will take to
start the car.
-During this cranking process, after about 10 cranks
the car goes into the following cycle: almost start, crank, and repeats
until the car starts. If you ever got the timing belt slightly off this
is what my car sounds like.
-After I start the car it will surge for
about 1 minute which I suspect to be a failing o2 sensor or possibly
AICV (when I first got the car from Japan there was an o2 code stored
which never popped up after en ECU reset)
-Not sure if this is
important, but there is an abnormal gurgling sound coming from the
FPR/Fuel rail turbo side when I prime the fuel pump.
-During regular driving and at WOT the car runs and boost perfect without any hesitation or hiccups.
********************************************************************************************************
Items I've changed:
2 cam sensors from a normally working car
1 crank sensor from a normally working car
New 255 fuel pump with an assembly, I can hear the pump priming when the car is on the "on" position
New fuel pressure regulator
New fuel filter
rebuilt starter
working main relay
Yes battery is fine(car cranks fast), there is fuel in the car, and no fuses/relays are blown.
Swapped ECU from a working car
New distributor
New ignitor
New fuel injectors (all 4 with all new seals)
I
did a fuel pressure test you can see in my first thread(link at the
top) and there is a spike followed by a drop which is normal
This car doesn't have a  fuel check valve, instead there is a fuel return line.

The
only thing I haven't changed is the wires and the spark plugs which I
don't suspect are the issues because the car runs perfect at WOT. I
haven't checked the timing, but I'm assuming the car would show symptoms
while driving which it doesn't.

I will change plugs and try a different set of working wires, but other then that I'm out of ideas. I really need help smiley.gif

Edited by gc8guy
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Is it possible that the fuel lines could be mixed up at the regulator and bypass connections?

 

I took a look at a similar EJ20 setup and all seems the same. I would also imagine my car would run like spoob while driving and WOT, however it runs perfect.

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I don't understand how would that affect starts and also my fans don't come on when cold.

 

The cold start fuel mixture is also based on water temperature. This is a second sensor which is not the one for the dial. You can measure it via OBD2  probably.

 

I have a similar problem with an 1.6 from 1999. It starts fine after 3 to 5 cranks but if freezing it nearly always stalls. If I restart immediately it runs fine and stays on, if I wait it floods. This is only with a cold engine, when warm there is no problem at all. I live with it since I know what to do with it, and it starts from just a few cranks, in contrast with yours. Also if I open the throttle it prevents from stalling. I was thinking at the IAC valve but not sure.

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I don't understand how would that affect starts and also my fans don't come on when cold.

Coolant temp sensor is the highest priority sensor for determining fuel mixture when starting. This is the only sensor the ECU can really use for any feedback at all when the engine is cold. The ECU uses ECT readings to set warm-up idle speed, and enrich the fuel mixture to compensate for the colder (denser) air.

 

The engine isn't running, so MAF readings are useless.

O2 sensors have to be hot before they start to read.

If you have a MAP sensor the ECU may use barometric pressure reading to adjust for altitude, but this is a small adjustment compared to what it does with ECT readings.

 

Most of the time a bad ECT sensor will read -40° on a scanner and will not set a code. If the ECU thinks the engine is 40 below, the fans aren't gonna come on.

The way to check it is to let the car sit overnight and use a scanner to compare ECT temp to outside air temp before starting. Should be within about 10 degrees of each other. Once the engine is started the ECT should start to climb slowly. If temp stays the same for a long period, then suddenly jumps up 20-30 degrees or more, you could have a bad sensor, or poor wire connection at the sensor.

 

If you don't have access to a scanner, you can check the sensor resistance with an ohmmeter when cold, and watch for the resistance reading to drop as the engine warms up.

 

Search google and you can find temperature vs resistance charts for a standard ETC sensor.

You can also watch sensor voltage with a voltmeter, but its harder to find correct voltage specs.

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Hey guys, here is another update:

 

Here is a comparison to my other subaru with a EJ20K

Please note
this car has an aftermarket FPR (this car runs and starts perfect) and
the car that is having start issues has a factory FPR

Also note both cards have the gauge hooked in AFTER the fuel filter

The
difference: Car with aftermarket FPR spikes higher (3.5PSI)  than the
car with the starting problem (2.8-2.9 PSI), but they both hold pressure
at around 2 psi after the spike:

Also, the biggest difference is
when I shut off the car with the aftermarket FPR, the pressure drops
all the way, however the car with the starting problem holds it at 2 psi
even after shutoff huh.gifhuh.gif

Car with the aftermarket FPR:

th_leg20k_zpsebdc2d06.jpg

leg20k1_zps5706b8f2.jpg

 

Car with starting problem:

th_gc820k1_zps6bd0824e.jpg

gc20k_zps4ee545ae.jpg

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The system doesn't have to hold pressure to start properly the next time.

The pump should prime the system immediately when the key is turned. If pressure builds too slowly when cranking the fuel pump is bad.

 

Put a scanner on it and see what the coolant temp sensor says.

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Have you tried spraying some starter fluid into the intake when this problem happens to see if the engine starts up quickly then?

 

I am wondering if the voltage getting to the ignition system is low and if so the spark may be weak making the engine harder to start when it is cold.

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The system doesn't have to hold pressure to start properly the next time.

The pump should prime the system immediately when the key is turned. If pressure builds too slowly when cranking the fuel pump is bad.

 

Put a scanner on it and see what the coolant temp sensor says.

I'm not sure if I can hook up a scanner it's a JDM 1998 STi-  I will look into this.

 

The pump is brand new and I tried 2 other working pumps before that.

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The system doesn't have to hold pressure to start properly the next time.

The pump should prime the system immediately when the key is turned. If pressure builds too slowly when cranking the fuel pump is bad.

 

Put a scanner on it and see what the coolant temp sensor says.

 

Have you tried spraying some starter fluid into the intake when this problem happens to see if the engine starts up quickly then?

 

I am wondering if the voltage getting to the ignition system is low and if so the spark may be weak making the engine harder to start when it is cold.

 

Someone mentioned this to me I will do this when it warms up a little more in Canadaland.

 

Problem is If I wait 10 seconds or more between starts, the problem will come back again so the engine will be cranking 10 + times

 

If I re-start it INSTANTLY (less than 5 seconds) then it will re-start perfectly so warm or cold it doesn't matter the problem is there in both conditions.

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I suggest you verify that you are getting full voltage input to the ignition system while the trouble is happening. You also stated you hear a gurgling sound in the fuel line which suggests air is getting into the fuel system somehow.

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Hope you put NGK copper core plugs in.  I've seen may Subaru's with other plugs and they just had issues.  Cheap and easy.

yes BKR7E/BKR6E copper and IX at the end(iridiums) is what all the JDM owners here in Canada use

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