Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

DESPERATE for help with '93 impreza starting problem


  • Please log in to reply
20 replies to this topic

#1 MaroonDuneDoom

MaroonDuneDoom

    Stick It To The Man!!!

  • Members
  • 604 posts
  • Casper,Wy

Posted 22 January 2004 - 03:27 AM

'93 impreza wont start. it just won't fire. what should i go about checking? how can i test to see if it is getting fuel/spark?

#2 Nug

Nug

    Lurker/off-topic poster

  • Members
  • 1,966 posts
  • West Point

Posted 22 January 2004 - 07:37 AM

Easy way to test for spark is to pull a plug wire and put a plug in it, and lay it on the intake. Crank, and it should spark.
All it needs to spark is a signal from the crankshaft position sensor, to the ecu, a signal from the ecu to the ignitor, and signal from ignitor to coil pack. Get a multimeter. Check for a voltage pulsation from the crankshaft position sensor. Check the specifications for resistance on the coil pack. I guess if both of these are good, replace the ignitor.

Oh, before you do anything, check the ecu fuses.

#3 intrigueing

intrigueing

    USMB Regular

  • Members
  • PipPipPip
  • 115 posts
  • IL

Posted 22 January 2004 - 08:59 AM

Try pushing the gas to the floor and hold it there while cranking, if it does not start pull off the intake hose at the throttle body and smell for gas.

Ditto check the fuses for critical items such as ecu, fuel pump, etc.

Don't forget about timing. If you find spark and gas pull the timing belt covers and check to make sure the belt is in tact and the timing marks line up.

#4 gotsubarus

gotsubarus

    Eat, Live, Breath Subaru

  • Members
  • 259 posts
  • Canton, NC

Posted 22 January 2004 - 10:06 AM

I think you are having the same problem as me! You can get it started with enough cranking, but then you wont have fast idle it will putter till it warms up...

I am getting ready to change the IAC valve today..If that doesnt work i will change the Crank sensor. I will let you know what happens!

#5 Subie Gal

Subie Gal

    GC84Ever

  • Members
  • 1,443 posts
  • WA

Posted 22 January 2004 - 02:22 PM

ironically enough,
just went through this with my next door neighbor only days ago

if the spark is there

DEFINATELY pull the timing belt cover off.

see if the cam/timing marks line up.
if the marks are off - your timing has jumped

if this is the case, hopefully the teeth are all 'good'
get a timing belt
and a new tensioner

this should do the trick.

oh and... i do not recommend standing firmly on the gas
when the car will not start,
this will only "flood" the car
and make it even more difficult to start or
diagnose once you've found the actual problem.

good luck
jamie

#6 Setright

Setright

    Elite Master of the Subaru

  • Members
  • 3,176 posts
  • Denmark

Posted 22 January 2004 - 03:28 PM

Flooding a car with a catalyst is a very bad idea, you might blow up the cat. Makes a big bang, and splits down the middle.

#7 intrigueing

intrigueing

    USMB Regular

  • Members
  • PipPipPip
  • 115 posts
  • IL

Posted 22 January 2004 - 03:47 PM

It is my understanding that with any car Fuel injected or Carburated in order to clear a flooded condition you hold the pedal to the floor (not pumping the gas) in order to fully open the intake and allow additional air into the system, and stop the choke condition. Anyone else hear this or am i crazy? By no means would I sit cranking a car for a minute like this, or try this repetedly, but it can get a flooded car started. You should find the source of the problem, and this would verify fuel delivery.

#8 99obw

99obw

    this space for rent

  • Members
  • 1,595 posts
  • Ithaca area

Posted 22 January 2004 - 05:16 PM

Could be a coolant temp sensor. In cold conditions the car won't start because the ECU isn't supplying enough fuel. If you crank long enough eventually the fuel will build up and the car will start, but it won't run well until it is warmed up.

#9 Nug

Nug

    Lurker/off-topic poster

  • Members
  • 1,966 posts
  • West Point

Posted 23 January 2004 - 11:44 AM

Did you figure it out yet?

#10 MaroonDuneDoom

MaroonDuneDoom

    Stick It To The Man!!!

  • Members
  • 604 posts
  • Casper,Wy

Posted 23 January 2004 - 02:05 PM

nope, i'm gonna go over today and tinker with it a bit. going to check timing and spark and fuel delivery. FUSES. thats the biggest one i'm gonna check firs. he said that he checked them, but i'll double check before i dive in over my head. i'll keep everyone informed.

#11 intrigueing

intrigueing

    USMB Regular

  • Members
  • PipPipPip
  • 115 posts
  • IL

Posted 23 January 2004 - 02:14 PM

http://www.alldata.c.../20001204a.html

How to Start a Flooded Car Engine
Q: Would you explain what could be reasons for flooding of an engine and how to start the car if flooding has occurred?...Lal Singh

A: So we’re all on the same page; a flooded engine is an engine that has received too much gas for the amount of oxygen available for combustion. When this condition occurs the inside of the cylinders, as well as the spark plugs, will become wet with gasoline. A cylinder wet with gas will result in a reduction of cylinder compression, loss of lubrication to the piston and rings and cause spark to the spark plug to be misdirected. Because the large majority of engines on the road today are fuel injected we’ll cover how to start them if flooded. The computer has a program in it that is called the Clear Flood Mode. For the computer to activate the Clear Flood Mode it needs to see information that is out of the norm. This abnormal information is the sensor on the throttle reporting to the computer that the throttle is being held wide open, along with a crank signal to the starter. This combo of information causes the computer to respond by reducing, and in some cases completely shutting off, the fuel injectors. This process allows air only to enter the cylinder and dry out the abundance of gas. As the correct balance of air and fuel return you will feel the engine start to fire at which point the throttle can be released and the computer will return to normal fuel delivery.

http://www.securityd...article-26.html

If the engine should flood press the accelerator down all the way to the floor and hold it. On a fuel- injected car this sends a message to the computer that the car is flooded, and the computer in turn shuts off all fuel. On a carbureted car, pressing the accelerator all the way to the floor allows more air to pass through the manifold, evaporating the excess gas. Don't pump the accelerator while you crank the engine.

#12 Soup

Soup

    USMB Regular

  • Members
  • PipPipPip
  • 35 posts
  • Ottawa, Canada

Posted 23 January 2004 - 02:22 PM

Have you checked to see if the fuel pump is operational?

#13 Cougar

Cougar

    Elite Master of the Subaru

  • Members
  • 6,342 posts
  • Anchorage

Posted 24 January 2004 - 12:08 PM

My first check would be to look for spark. If you have a spare spark plug you could put that in one of the wires and check it so you would not have to remove a plug.

If you don't see spark then you will need to check a number of things. I would use a testlight to check the fuse power. A bad CAS will cause this problem to happen along with other things.

If the spark is there then try a small shot of starter fluid into the intake (a 1 second shot) and try to start it. If you have spark and compression it will try to run on the fluid. You will have to check for a fuel delivery problem if it likes the starter fluid. One thing that works well is to listen for the fuel pump while you turn the key to the ON position. It should turn on briefly when you do this. You may have to cycle the engine by cranking it first, then to OFF, and then to ON.

#14 MaroonDuneDoom

MaroonDuneDoom

    Stick It To The Man!!!

  • Members
  • 604 posts
  • Casper,Wy

Posted 24 January 2004 - 01:49 PM

i've got it narrowed down tothe fuel pump. got a new one in the mail coming from junkyardgabe. damn thing is just shot i guess. no fuse problems or anything like that.

#15 Supaglu

Supaglu

    USMB Regular

  • Members
  • PipPipPip
  • 61 posts
  • South East. UK

Posted 24 January 2004 - 02:35 PM

Hi,
If you look under the dash you will find two green single pin connectors and two black single pin connectors, if you connect the green connectors together and switch the ignition on you wll hear the fuel pump pulse on and off every couple of seconds (if the pump is ok).

"The computer has a program in it that is called the Clear Flood Mode. For the computer to activate the Clear Flood Mode it needs to see information that is out of the norm. This abnormal information is the sensor on the throttle reporting to the computer that the throttle is being held wide open, along with a crank signal to the starter. This combo of information causes the computer to respond by reducing, and in some cases completely shutting off, the fuel injectors. This process allows air only to enter the cylinder and dry out the abundance of gas."

I must say I've never heard of this ! - been a tech for 26 years and on subies for 14 of them,
The way I've always understood a fuel injection system - an engine can get flooded when it fails to start within the first minute, and to overcome this you fully depress the throttle to allow maximum quantity of air into the cylinders.
If you touch the throttle at any other time whilst starting a subaru then the E.C.U will assume that wherever the throttle is positioned then that is the idle postion and will remain so until you switch off and restart without touching the throttle.
On quad cam subies the two black wires under the dash when connected will cause the E.C.U to reduce the amount of fuel injected on cold starting
Regards
DaveH

No disrespect to intrigueing intended.

#16 intrigueing

intrigueing

    USMB Regular

  • Members
  • PipPipPip
  • 115 posts
  • IL

Posted 24 January 2004 - 05:15 PM

No offence taken, I'm just trying to get to the correct answer.

Supaglu, are you saying that

"The way I've always understood a fuel injection system - an engine can get flooded when it fails to start within the first minute, and to overcome this you fully depress the throttle to allow maximum quantity of air into the cylinders."

That is what I understood and only came upon FI cars computer shutting down the gas to the injectors after doing a web search looking for the answer.

I respect your knowledge and am sure that you have more insight on the subject than I.

#17 Supaglu

Supaglu

    USMB Regular

  • Members
  • PipPipPip
  • 61 posts
  • South East. UK

Posted 24 January 2004 - 05:53 PM

I wouldn't be surprised if F1 cars have this ability but i would say that very rarely do road going vehicles get anywhere near the technology available from F1 racing.

Regards
DaveH
It would be interesting though if there is some one out there who could confirm whether Subaru has this technology !

#18 MaroonDuneDoom

MaroonDuneDoom

    Stick It To The Man!!!

  • Members
  • 604 posts
  • Casper,Wy

Posted 24 January 2004 - 06:53 PM

Originally posted by Supaglu
I wouldn't be surprised if F1 cars have this ability but i would say that very rarely do road going vehicles get anywhere near the technology available from F1 racing.

Regards
DaveH
It would be interesting though if there is some one out there who could confirm whether Subaru has this technology !



WHAT??? I guess you've never driven a 1988 GL wagon 5spd. D/R
with 1781cc of fuel injeced FURY!!

#19 rallyruss

rallyruss

    Subaru Master

  • Members
  • 1,653 posts
  • San Jose CA

Posted 24 January 2004 - 08:07 PM

clear flood mode is verry common on just about all makes of cars.

so yes intrigueing is correct in the statement about clear flood. I have been a tech. for almost 10 years but only learned of this a few years back. It is understandable if poeple have never heard of it. it is just a little bit of logic built in to protect the engine and cats. think what could hapen if cars did not have this safety feature?

#20 Supaglu

Supaglu

    USMB Regular

  • Members
  • PipPipPip
  • 61 posts
  • South East. UK

Posted 25 January 2004 - 04:44 AM

Well, I've been doing a bit of searching on Google (didn't take long either !) and yes looks like you are right Intrigueing and Rallyruss - so I take my hat off to you, you learn something new everyday.
Im sure the other techies in my workshop dont know about this either so will be discussing it with them on Monday.

Regards
DaveH

#21 intrigueing

intrigueing

    USMB Regular

  • Members
  • PipPipPip
  • 115 posts
  • IL

Posted 25 January 2004 - 09:43 PM

I fully expected to be wrong on this. I have no formal training, unless you count the training from my ole man owning 6 ford pintos when I was a kid. He is a true backyard mechanic - one of the pintos had a screwdriver as a stickshift, and he had me change a clutch almost completely by myself at the age of eight. One of the pintos he purchased new and had over 250 K miles, not bad for a bomb on wheels:D




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users