Car Starting Then Striaght Away Cutting Out

[Michael_1882]

Hey guys, i didn’t' exactly know what section to put this in, so i posted here:

I know these topics are hard to answer over the net, and without seeing the car as it could be lots of things, but I’m just after ideas or experiences so i can attack this with a process of elimination.

Basically my car has been driving fine, no problems nothing. Two days ago i started it and moved it out of my garage, then drove it around and parked in front of my house. This was fine and nothing out of the ordinary, started straight away like normal and ran fine. Anyway yesterday i started my car and it kicked over started, then just as it started it cut out, (stalled) I did this again and again each time it would start perfectly and then the same seconds it started and you normally think ok cool it's running now it cut straight out. Today i tried again and this time it started ( i throttled this time thinking it would do the same as the day before) and it idled really rough with the aid of my right foot for about 10 seconds then did the same thing, i tried to start it again and the same as the day before. I've gone over the whole car and made sure everything’s plugged in etc. I’m really stuck.

Thanks for your time guys, any opinions are welcomed, I’m really stuck, and i cant' exactly drive it to a mechanic atm =/

Edited November 24, 2006 by Michael_1882

[Cubes]

Check your AFM.

With a stuffed afm or break in the afm wire the car will start as the use dials in fuel based on its injector ms cranking time table. So there's enough fuel to get it started then the afm takes over so the ecu is able to push in the right amount of fuel based on the afm output.

I had a similiar issue did exactly the same as you describe except mine 'sometimes' would drive ok then all of a sudden cut. My problem was a stuffed afm wire due to previous tampering when fitting up an safc.

[Michael_1882]

Thanks cubes, i appricate the reply, that was one of the first things i checked (when i was checkign for plugs) made sure he was plugged in. Can an AFM just root itself over like that in a day =/

I forgot to mention engine wise my cars pretty stock.

[Cubes]

If you have a multimeter check the volts leaving/entering the afm.

Depending if you have a series 1 or two there should be at the very least a 12v feed and a value that reads ~0.4-0.5v with the car not running but ignition ON (not aac but on showing all dash lights). The others will be grounds/earths.

So check its first getting battery voltage and then check the off state but with ignition on is around 500mv or so.

Once started this value should spike up to around 1.2-1.4v

You can check via the afm plug or the ecu pinout.

If the afm appears fine the next step may be to check a break in the wire some where, so that means checking it at the ecu to ensure its receiving the value.

Also.. Do check for any green goop (corrosion) on the afm plug connections.

If its not the afm... It may very well be a fuel pump or some thing. Let the tracing begin.

Multimeters are excellent tools. Grab a cheapy and do some googling on how to use the sucker.

[Michael_1882]

I'll go grab my old mans Multimetre and give it a go now, thanks bud i'll get back to you.

BTW it's a S1

Edited November 21, 2006 by Michael_1882

[msnismo]

I'll go grab my old mans Multimetre and give it a go now, thanks bud i'll get back to you.

BTW it's a S1

Hey Michael!

If you have no luck I've got an ECU consult - if you can manage to get it running for a brief time we could check all the voltages on the AFM, AAC, O2 etc

Just give me a buzz if you need to do it this way

[Cubes]

Definitely a much easier way.

[Thunderbolt]

I actually had a similar problem with my previous car (rb20 Silvia). However I was able to keep it running after about 6-8 trys. Never discovered what the problem was though, so cannot help you there.

I'd definately be checking the O2 sensor though, as this helps control cold start.

[Michael_1882]

Funny you say that, i have a new O2 sensor sitting here waiting to go in, just can 't crack the old one =/

AFM seems to be functioning fine.

[RANDY]

Happened to a mate of mine. AFM died while he was out for a few hours. Consult see's that it's there, but you can't start the engine for long enough to check the flow/voltage readings.

I can't remember if I unplugged it or left it plugged in, but I started it with 1/4 to 1/2 throttle, and it ran VERY lumpily! Couldn't rev past 3K, but it was enough to clutch 1st and 2nd to get it back to his house.

Another AFM in, and it works a charm again.

[msnismo]

Funny you say that, i have a new O2 sensor sitting here waiting to go in, just can 't crack the old one =/

AFM seems to be functioning fine.

Easier to crack the O2 sensor while its hot - trust me did this a few weeks ago

[RANDY]

Hot = expand? I did mine cold, with a little bit of that pener-8 stuff to lubricate the rusted area.

If you are quite confident, you can get a socket and ratchet, cut off the old o2 sensor wire, and provided your socket is long enough, you can get onto it with an extension. From there, torque is your friend!

[msnismo]

Mine wouldn't budge when it was cold - took it for a drive and warmed her up and was easy as to undo.

BTW I was using the proper O2 sensor socket

[RANDY]

Oh fair enough!

Worth a try!

[Michael_1882]

Hmmm i cut a spanner and put that much torque on it, that the ring end opened.

Anna does your socket have a slit in it to go over the cord?

Thanks guys for the reply, i'll try my mates AFM

[blind_elk]

I'd definately be checking the O2 sensor though, as this helps control cold start.

Nothing at all to do with cold start . The only time the ECU pays any attention to the O2 sensor is under cruise (constant throttle) conditions.

What to look for when you have trouble with cold start was posted a few weeks ago - just <search> for my post.

[msnismo]

Hmmm i cut a spanner and put that much torque on it, that the ring end opened.

Anna does your socket have a slit in it to go over the cord?

Thanks guys for the reply, i'll try my mates AFM

Yeah the socket has the split in it. Il get dad to bring it home from TAFE if you want?

[Michael_1882]

That would be awesome, woudl you be abel to bring it tonight??? I can get out there in my old mans car.

[msnismo]

That would be awesome, woudl you be abel to bring it tonight??? I can get out there in my old mans car.

Il let u know - Il send dad a message cause he is on class today. Hopefully none of the other teachers are using it at the moment!

Il know by 2pm

[Thunderbolt]

Nothing at all to do with cold start . The only time the ECU pays any attention to the O2 sensor is under cruise (constant throttle) conditions.

What to look for when you have trouble with cold start was posted a few weeks ago - just <search> for my post.

Okay my bad. Got open-loop / closed-loop operation confused for a moment there.

Lucky you are on the ball to set the record straight.

Edited November 23, 2006 by Thunderbolt