Help I think I'm going mad

[2themoon]

Help help help Please

Ok so I scored this 94 sti the other day.

It had a few issues, rev counter not working, blow off valve on backwards arrow pointing towards the y-pipe ? y-pipe installed on an angle leaving air gap, sorted all that out.

Then I noticed it idles at 1500rpm.

Took it for a 40 minute drive, in that time the idle went from 1500 to 800 a couple of times when it felt like it ?

Came home turned it off to open garage jumped back to start it then it would not start. I tried starting it for 5 minutes then it slowly chugged up to 1500rpm and I put it away stunk of fuel. it only doesnt start when its hot.

I thought this might have been IAC valve or maf sensor, but it is not, I swapped out parts from another working wrx and still the same symptoms.

has anyone had a similar problem ?

The car goes really good anything above 3000rpm doesn't miss or backfire.

Is there a way to set the IAC valve properly ?

what resistances is it suppose to read ?

Also could this be the engine temperature sensor, Crank angle or cam shaft postion sensors breaking down when they are hot ?

Does anyone know the correct resistance values for these sensors.

Another thing is for the life of me I cannot get the engine check light to work so I cant diagnose it myself. I changed the bulb still no luck, Someone told me that if your ecu was chipped with a possum bourne chip then that might be the case? my car has a possum sticker on it.

Hoping someone can shed some light on my situation

cheers

Rob

[2themoon]

Engine is stock standard. I do not have a Picture at the moment

[wrx_lou]

I didnt think Possum did chipping. Only the link ECU's.

Have you checked it for fault codes?

Does it hunt on idle? MAF maybe?

[ADIKT]

make sure the butterfly in the throttle body is set correctly, and nothing is jamming it...

[2themoon]

 wrx_lou said:

I didnt think Possum did chipping. Only the link ECU's.

Have you checked it for fault codes?

Does it hunt on idle? MAF maybe?

yeah not sure if it has a link computer ?

It doesnt hunt on idle it just goes up to 1500rpm also wont start properly when its hot.

I will have to check the ecu maybe it has a link replacement plug n play ?

[wrx_lou]

If it turns out to be a factory computer then check it for fault codes.

Theres a guide somewhere on here, just find it using the search.

If its a link you may need to take it in or depending on the verions someone on here may be able to plug it into a laptop and have a look for you.

Thats my 2c's but someone else might be able to suggest something else based on symptons.

Either way its not a bad idea to spend 10 minutes and pull the ECU out to see what its running.

[2themoon]

[

Just checked it has a link computer inside, (1996 SUBARU V3.3) it says on the back of the motherboard.

Kaka!!!!! that means I will have to pay $$$$ to get it tuned. Fingers crossed hopefully not ;D

[ADIKT]

Having a link is a good thing!!! Better than standard ecu!!

[wrx_lou]

Does it say what version link it is? Does it have a slot for the cable?

Will have to open it up to see from memory.

Shouldnt cost a fortune for them to see whats happening. And you shouldnt need a tune either unless they only stuck it in on a base tune or it was tuned for another car.

[wrx_lou]

Actualy, just thinking about it it was probably tuned for mods that have been taken off.

The fact that the y pipe and bov were on the wrong way may suggest they had a front mount at some stage.

Maybe other things were removed also.

[2themoon]

http://img856.imageshack.us/img856/4584/sam2745k.jpg

http://img27.imageshack.us/img27/7703/sam2746.jpg

http://img812.imageshack.us/img812/2104/sam2739t.jpg

Not sure what model this is at all, might be an earlier model.

[Koom]

Pretty sure the WRXROAD chip is PC Link tunable so you are lucky there. Alot of tuners won't touch the rally chips on the Possumlinks anymore as they require the hand tuning module and are a pain in the ass. If it has been tuned in the past, it could probably do with a roadtune to freshen it up. Mine always had either a hunting idle or to fix that, it was easier to make the idle quite high as they don't have the best resolution for making it run nice and smooth like a factory ECU.

[wrx_lou]

Out of curiosity, is it still running a MAF?

[2themoon]

 wrx_lou said:

Out of curiosity, is it still running a MAF?

Yeah lou it was still running a maf, I talked to a tuner today who told me that it should not be plugged in haha, the guy I got it from also told me he replaced the maf because it wasnt running right, I unplugged it so now it starts first pop every time and runs so much better but it still has a high idle and I could hear a relay under the dash switching sometimes when I rev the engine and sometimes it doesnt, turns out it is really really hot to touch, I unplugged it and wacked it a couple of times put it back in and the car runs sweet, this is not normal hopefully if I replace this Silver relay it will solve the problem.

Heres hoping

[2themoon]

Ok so heres an update, turns out the MAF being plugged in was not the reason for high idling, bad idling, over fueling and hard starting, it was the water temperature sensor this is the one underneath the intake manifold near the throttle body checked the resistance readings and they were jumping up down and all over the show, so i replaced this sensor and it now runs perfectly and wow does it go fast it comes on boost really well, im really impressed with its performance. Thanks for everyone's input

[wrx_lou]

Awesome to hear mate! Good luck playing.

[slystiguy]

Am I the only one who thinks this is alil suspect? one moment the car isnt running right an causing issues the next you "fix it" and now its on trademe.... and both posts within 5mins of each other. I really hope you're and honest person

I get the feeling the new owner is going to get a very interesting car...

[2themoon]

 slystiguy said:

Am I the only one who thinks this is alil suspect? one moment the car isnt running right an causing issues the next you "fix it" and now its on trademe.... and both posts within 5mins of each other. I really hope you're and honest person

I get the feeling the new owner is going to get a very interesting car...

I actually got the car to make some money off it ;D yes it had a few problems obviously why the guy who had it got rid of it because he didnt have the knowledge to fix it, but now its all fixed and goes really good ;D

Its only smart that I advertise it on here with all the Subaru enthusiasts ;D