Recently the WRX (MY95 with STI4 block) has had trouble starting. First thing in the morning it always starts first time & if you leave it for a few hours it always starts first time.

The problem is if you go on a quick trip to the shop a mile away or something. It starts, you drive for 5-10 minutes & stop. You get back in (anything between 5-30 minutes later) & it doesn't fire. It turns over but just doesn't fire up. Sometimes if you then leave it for 5 minutes it will start okay but sometimes you can be stuck for up to 20 mins waiting to set off

We had some idle problems a little while back but after replacing the water temp sensor that fixed that. My first thought was the crank position sensor but the symptoms are different from that when the other scoobs went so i'm not sure.

My second theory is that it's the battery. The car was in the garage for 6 weeks a couple of moths back for an engine replacement which in itself can lessen the battery power. We went away to Dublin for a week a few days ago & the problem is a lot worse now than it was after being sat idle for a week. I tried a little experiment & did the usual little journeys without using the fans, radio, lights or even the alarm and it started every time after the 5 places I stopped which is (IMHO) because there is less power being drained from the battery but my mind is telling me that it could still be something else?

Does anyone have any ideas or agree with me? Just wanted an outsider perspective before I blew £47 on a battery or over £100 on a crank position sensor....again!

Cheers

MAFFA

 

Are you sure that these little runs are short enough for the car not to be warm and still running on excess fuel for cold start, then when you stop and start it again, the ecu is still saying the car is cold and therefore pumps even more fuel in hence flooding the engine. This is quite a commom problem with alot of cars where drivers start the car, back out the garage. Stop the car and get whatever and come back to find the car wont start.

I've had to help many a person out whos done that, including the girlfreind!

It sounds like a combination of that and somethinbg else thats noit quite right, have you done an ECU fault check?

Comper100

 

Can't! It's running a Motec

 

Oh bugger. Thats a pain. Maybe because you have a motec on it, it puts more fuel in than a normal ecu hence exagerating the problem?

Comper100

 

Yeah the journeys are definately not long enough to get to proper running temperature so that's a possibility. I'm gonna buy a new battery today & see if it sorts it.

I tried my old CPS in the car last night as that was replaced & the car definately didn't like it so the on the on the car is fine. That eliminates that problem I spose

MAFFA

 

Having the same problem at the mo. Subaru told me my battery needs replacing

 

Just replaced it....made no friggin difference It does turn over better but still won't start!

Next port of call...spark plug spacings.

After that...no friggin idea?

MAFFA

 

i would go with the flooding theory. i had this exact problem on a primera gt, but only if the car was running for less than about 20 seconds before being turned off.

parents my00 does this also - even after a couple of minutes run, but it starts 2nd or 3rd try.

 

Any way to fix it? It happened again when I went to the motorfactors to get the battery and I was there for 15 minutes

Could there be something wrong in the ECU map?

 

Maffa I get this prob too, although the lenght of drive can be between a few min and 20 mins. If you find a solution I'd love ot know what it is, I thought it might be alarm related as resetting the alarm or setting the alram off seems to cure it.

 

had exactly the same prob with my 95 wrx, if it does it again disconnect the crank sensor then reconnect if it starts then its defo the sensor for some reason it fools the ecu i,ve heard

 

Done that but with no difference made . It's deffo not the CPS or the battery & I now know that for sure. I tried another experiment yesterday when I did a few short trips & locked the car with the key everytime I stopped. Risky I know but every time I went to start it it started first time afterwards which leads me down the alarm route now

I also took out the plugs to check the spacings. Some were slightly to wide so I corrected that. Unfotunately that didn't make a difference eitherbut it did drive better . The one thing that did concern me though was the fact every spark plug was white on the end? I don't recall them being like that on the other scoob ever so I instantly think the worst. Is this normal?

MAFFA

 

crank or cam sensors first

£35 each grade a

the other one..

battery connections.. daft though it may seem, i had furr build up on mine..

allowd enought to keep the immob and associated bit powered, but when the starter wanted the full monty it gave up the ghost,,

a quick clean 7 lube , and hey presto

mart

 

Cam sensor is something I haven't tried. Everything else I have. Maybe when I get my car back i'll swap a few bits & experiment a little to see if it fixes the problem

MAFFA

 

has this car got an imobiliser on as i had similar problems with another car, my aftermarket imobilser was playing up and it wouldnt start if you left it for 1/2-1 hour it would start but it was a right pain havung to sit about waiting to start the car

 

I thought it could be that as well. A trip to the car alarm gaff wouldn't hurt either I spose

MAFFA

 

Maffa

Have you managed to find out what's wrong?

My UK MY95 has been doing exactly the same for a couple of months - starts fine from cold, starts fine if you leave it a couple of minutes (filling with petrol), sometimes won't start when left for 15-20 minutes.

One possibility I thought of was the fuel pump - I can usually get mine to start by repeatedly turning the ignition on and off, and each time I do I can hear the pump make a slight noise.

Matthew

 

Looks like it was the crankshaft position sensor after all. It was the Motec being over sensitive with it . Took the one out of the other scoob & it was fine. Just got to shell out the £110 for a new one LOL

Also the Motec MAP sensor had a dodgy connection which was causing misfire/stalling. Thank god Pat found the warning on his laptop & soldered it

All fixed now though

MAFFA

 

its the crank sensor mate me and my mate had the same trouble next time it dont start push the wire and the crank sensor and it will start it drove me and my mate turbo ray mad for months

 

Read my post LOL

That's what I said it was

MAFFA

 

and wheres my thank you for pointing out cam sensor??





well done mate



Mart

 

It wasn't the cam sensor it was the crankshaft position sensor

Thanks though

MAFFA

 

funny enough thats what mine was!!!

still got spares for both now

Mart