Cold start problems


J

jackhdc2

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Joined
Dec 24, 2010
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74
my B18c ek9 wont start when the engine is cold. it will turn over and try to fire up once but after that it just turns over and over.
if i bump start it, it will start up no problem but it feels like its overfuelling as when i put the foot doen it tries to cut out sometimes.
also if i let it heat up then stop it, it will start again no problem as long as the engine is warm.
someone mentioned it could be a cold start sensor? could it be this and where is this located on the car? or what other sensors could it be?
cheers
 
Once you get it started, even cold, does it idle fine or keep trying to cut out?

Check for unplugged vacuum lines, vacuum leaks etc.

Once warm and idling does it idle ok, or do the revs hunt?

Worth a shot replacing Coolant Temp Sensor, check your IACV if it's trying to cut out on idle.

Is the ECU throwing any codes?

I'm no expert, but have had to tackle idle issues myself, just my first thoughts!
 
could just be a loose connection to the battery, or its simply not holding its charge? try the simple things first.
 
Joshm88 said:
Once you get it started, even cold, does it idle fine or keep trying to cut out? it idles dead on but every so often it splutters as if its missing. only tries to cut out if you put the foot down in a high gear as if its overfuelling.

Check for unplugged vacuum lines, vacuum leaks etc. had a quick look and seen nothing but il have a better look when i get home.

Once warm and idling does it idle ok, or do the revs hunt? same as when cold it stutters occasionally

Worth a shot replacing Coolant Temp Sensor, check your IACV if it's trying to cut out on idle. the coolant temperature sensor would make sense if it controls fuel flow depending on the temperature? or is it just used to operate the temperature guage?

Is the ECU throwing any codes? i dont think so as the CEL isnt on but il check that when i get home also.


I'm no expert, but have had to tackle idle issues myself, just my first thoughts!
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Cheers for the advice, ive answered best i can without being near the car at the minute. ill take a proper look at the weekend.

chunky- cheers, but i dont think its the battery or connections as its turning over fine just not firing up?

im thinking its some sort of sensor controlling the fuel flow because i get the feeling when i turn the key its flooding itself on the first few turns of the starter. could this be right? and if so what sensors control fuel flow?
 
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new plugs...

...have you changed the fuel pump lately?
...FPR OEM is non-adjustable and would need to be "adjustable" to increase/decrease fuel pressure.
unless you have tinkered with these items there is no other way that I know of to increase/decrease fuel pressure.
The ecu controls the injectors at all times and has cold start settings, OEM non-adjustable.

My fuel setup runs between the two silver dots on the gauge below. Left dot idle, right dot high rpm [oem settings via FPR]. The fuel system is constant pressure in other words.
Interesting tidbit of info, If you look at one end of the oem fuel rail you will see a fuel pressure surge absorber, this allows a more constant fuel pressure. But this is not your issue, if this failed, you most likely wouldn't know it.
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tama666 said:
new plugs...

...have you changed the fuel pump lately?
...FPR OEM is non-adjustable and would need to be "adjustable" to increase/decrease fuel pressure.
unless you have tinkered with these items there is no other way that I know of to increase/decrease fuel pressure.
The ecu controls the injectors at all times and has cold start settings, OEM non-adjustable.

My fuel setup runs between the two silver dots on the gauge below. Left dot idle, right dot high rpm [oem settings via FPR]. The fuel system is constant pressure in other words.
Interesting tidbit of info, If you look at one end of the oem fuel rail you will see a fuel pressure surge absorber, this allows a more constant fuel pressure. But this is not your issue, if this failed, you most likely wouldn't know it.
picture.php
Click to expand...

i put new plugs in a few weeks ago. and i havent changed the pump but i did change the fuel filter, but its not leaking or anything.
i know what your saying about non adjustable fuel pressure but there must be a sensor to control the fuel rate depending on how warm the engine is, for the cold start settings to work like you said? would this be the coolant temperature sensor?
 
Fuel pressure is constant at all engine temps, there is no up and down of pressure while in operation unless done by hand. No sensors control fuel pressure, only the fuel pump generates the pressure. Either its on or its off. If your fuel pump starts to die, it will produce less and less pressure as it ages with the problem. [255 lph pumps are nice and low cost]

Fuel rate is controlled by the ECU, sending open and close signals to each fuel injector. The longer the fuel injector stay open the more fuel flows. A dirty fuel injector will not atomize fuel as well and could cause issues with bad fuel economy and performance. [clean your injectors]

Note: Increasing fuel pressure via FPR will force more fuel through the injector but is not the preferred path to increasing fuel rate, too hard to control and manage or monitor. Fuel rate should be managed by both; ECU and injectors, easy to monitor and control.
 
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i would also check your distributor as B18's are notorious for burning them out due to the high rpm nature of the engine. could be putting out a poor spark which is causing your car to die out?
 
I think i may have had a similar problem a few months back, when you say you put your foot down and it tries to cut out, does it sound like its running on three cylinders? because thats what mine did. Wouldnt start very well in the morning and when it got running it would idle fine but one of the cylinders cut out whenever I put my foot down, untill the engine warmed up and everything worked again for the rest of the day. then the same thing would happen the next day...

all I did was change the rotor arm and distrubution cap and its worked fine ever since.
 
is there any way of checking the distributor without trying a new one?

bipbip216 said:
I think i may have had a similar problem a few months back, when you say you put your foot down and it tries to cut out, does it sound like its running on three cylinders? because thats what mine did. Wouldnt start very well in the morning and when it got running it would idle fine but one of the cylinders cut out whenever I put my foot down, untill the engine warmed up and everything worked again for the rest of the day. then the same thing would happen the next day...

all I did was change the rotor arm and distrubution cap and its worked fine ever since.
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cheers man.
 
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anyone any more ideas?
the car is running 100% when the engines warm, starts first turn of the key.
but when the engine is cold it wont start. when i turn the key it turns the engine over quickly but will not fire up.
it will start with a push and ticks over ok but if i put the accelerator down quickly it tries to cut out.
ive checked and there are no CEL codes stored. im going to try and get the lend of a distributor to rule that out at the weekend. and after that i dont know what to do.
 
Q. What ECU are you running?

Just thinking here... you may have a broken/bad wire someplace.
If your issues tends to go away when warm, it may be due to the metal in the wire expanding as well as the casing of the wire, this will allow a bad connection seem to fix itself. Once the wire cools, overnight, several hours, metal wire and casing will again shrink causing a broken circuit, until its again warm.

I am running the s300 Hondata with the obd2 to obd1 conversion done inside the ECU, very nice. Well it would be nice if the workmanship was better from Hondata. And getting back to my Q above, it may be the ECU itself if your running a setup like Hondata for an ECU. In my ECU the Hondata workmanship was poor in soldering. Some of the solders failed causing an issue exactly as you are describing.
 
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im running a standard ECU so hopefully it isnt the problem you described as that sounds like a nightmare to find and fix. but thanks for the input.
does anyone know if there is a cold start sensor on the B18?
 
Your problem sounds similar to mine on my B16B. Same difficulty w/ cold starts, but runs fine otherwise. I did a simple compression test and found my problem...I have one cylinder below spec. Hope this helps.
 
iwantgrillcheese said:
Your problem sounds similar to mine on my B16B. Same difficulty w/ cold starts, but runs fine otherwise. I did a simple compression test and found my problem...I have one cylinder below spec. Hope this helps.
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:lol:

...thank you.
 
jackhdc2 said:
im running a standard ECU so hopefully it isnt the problem you described as that sounds like a nightmare to find and fix. but thanks for the input.
does anyone know if there is a cold start sensor on the B18?
Click to expand...

There are two coolant temp sensors on the head, one goes to the dash and the other goes to the ECU. The one going to the ECU is what the ECU reads to coordinate cold idle map settings, but again, this is all locked up within the ECU if you looking to adjust. But the sensors may be faulty, low cost fix and easy to replace. I just did mine while tracking down my issue, which turned out to be bad workmanship from Hondata.
 
^My bad tama! Is it not a possibility though? I am an amateur at best ;-) His situation just sounds exactly like mine, that's all.
 
iwantgrillcheese said:
^My bad tama! Is it not a possibility though? I am an amateur at best ;-) His situation just sounds exactly like mine, that's all.
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Sorry iwantgrillcheese, I think you have a touched on something previously not thought of, and is the reason for the "thank you". It is possible...
 
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