Sometimes Impreza won't start

[SVX_commuter]

I got a problem with my Impreza. Sometimes it won’t start.

 

I was looking at the trouble chart for the SVX that I think is very helpful.

 

I think it’s the fuel injectors. I think that the injector stays open sometimes and after the car sits for about an hour and a half, too much gas has leaked into the cylinder. When it does start it runs very rich and bucks until the gas clears out.

 

 

Do the fuel injectors make sense?

 

 

The car runs great all the rest of the time. No CEL codes or anything.

 

 

I think it is not the ECU power supply or the fuel pump or pressure regulator, or ignitor or coil or plugs because I think when these items break they stay broken and don’t start working again. Does anybody know if it could be one of these items?

[SVX_commuter]

Well I cleaned out the air control valve that sits on top the throttle body and I checked the fuel pressure regulator. That seems to be working okay.

 

Does anybody know how to check injectors for leaking?

[SVX_commuter]

Yesterday the Impreza would noy start after sitting fro 40 minutes. Got it running by holding my foot to the floor while turning it on. IT coughed and rand rough and then smooth out. I really think an injector is leaking.

 

Today I turning off the engine by disconnecting the fuel pump and letting it run out of gas. Then I turn off the key and reconnect the fuel pump connector. I think this will help get it started. I found out the 93 1.8L fuel injectors are the same as 97 2.2L injectors. I got four of those in a used engine so I think I'll give them a try.

[Setright]

Or coolant leaking into the combustion chamber?

[82bratavenger]

Setright has a valid thought as is the injector leak theory. If you have the injectors that will save you some $$$. The easyest way to start checking is to pull plugs when it won't start and see if it is water or fuel on the plug. Or just pull them to see how they are burning. Good luck and keep us posted.

 

When it does start after sitting is there any smoke and what color is it?

[SVX_commuter]

Well I started to disconnect the fuel pump to kill the engine and thought I was on to something, fuel injectors. Then I hooked a pressure gauge and even after the pressure dropped to 13 psi a half hour later on hot engine, it still started.

 

So then the check engine light started to come on. It was thowing a code 21, temperature sensor. It took the ECU an awful long time to start showing the code and the engine light would only stay on for about 30 seconds.

 

Replaced the sensor for about $21 dollars and all is well. Unfortuniately, I replace the starter and alternator before that. I was relieing on other peoples discription of the problem and got in a rush to fix it. Oh well it runs great now. The idle speed is lower also.

[botscooby]

I am having exactly this same problem on My 94 Impreza Wagon! I will replace the sensor and see if that improves the situation.

[botscooby]

My 94 wagon is throwing the following codes 14,15,16,17,21 . I have made an order for the coolant control switch. Does it mean I have to repalce all the injectors also? Also I cant find the loation of that control switch for the coolant temp.

 

Pls help.

[Cougar]

The sensor is not a switch. It is a thermistor, which changes resistance as its' temperature changes. It may have two wires going to it and don't confuse it with the sensor for the temperature gauge. That sensor should have one wire going to it.

 

Hopefully changing the sensor will straighten things out. I can't see all the injectors leaking at once.

[Cougar]

Hopefully this will help you. It is a picture by one of the members here.

 

http://main.experiencetherave.com:8...rs/DCP_2477.JPG

[botscooby]

Thanks Glen. I changed the sensor and the car is fine. The error codes are gone and the start is Okay.

 

Botscooby

[Cougar]

Glad you got it fixed. Thanks for the feedback.

[idosubaru]

be observant on the coolant sensors as normally as vehicles age the problem isn't the sensor, but the contacts of the sensor. the plug/wiring harness connector and the sensor develop corrossion and that causes intermittent and poor contact causing the come-and-go aspect of the associated problem. changing the sensor will often alleviate the problem....but it'll come back because the real problem wasn't addressed. be sure the wiring harness and contacts are all clean on the sensor AND the wiring harness side that plugs into the sensor. they can be really annoying to clean. i eventually just cut the harness and soldered it to the sensor so i don't have that problem anymore. i've drive a few soobs over 200,000 miles and never had to replace the sensors, just clean the contacts.

 

when cars don't start people typically think fuel or exhaust is clogged....those are very rare in my experience. i don't think i can count how many people come to me and say "gary, my car won't start and i think it's the fuel pump or the converter is clogged". maybe those used to be common problems on older cars or something and that's some relic diagnosis but i've yet to find any of those problems on my 12 subarus (a few of which over 200,000 miles) and the dozens of friends cars i've worked on. my point in all of this is that when someone mentions the fuel or exhaust they probably don't know what they're talking about. no offense to those who have had these problems but i've worked on alot more cars than just my own and hate to see you guys get inaccurate information and think something is worse with your car.