svx dies after running for a few mins what to try?

[jrturbosvx]

hi im having a problem with my 94 svx as its shutting off after a few mins running when i have changed alternators,changed in 5 diff maf sensors,along with a few other parts over the last 2 days.it will die but start back up with no problems until it starts running real choppy and then quits.i have discussed this problem with svxess aka john who has taken alot of time to try to help me with this problem.any suggestions of what i should replace tommorow. ihave a complete parts car to take parts off. thanks josh

[SoCal LS-L]

Try the crank and cam sensors next.... heat makes the magnetic tips lose functionality... so if they are weak already.....

[svxcess]

Originally Posted by jrturbosvx

Hi,

I'm having a problem with my 94 svx as its shutting off after a few minutes running. I have changed alternators, changed in 5 different MAF sensors, along with a few other parts over the last 2 days.

It will die, but start back up with no problems, until it starts running real choppy and then quits. I have discussed this problem with svxcess (aka John) who has taken a lot of time to try to help me with this problem.

Any suggestions of what I should replace tommorow? I have a complete parts car to take parts from.

thanks, Josh

Originally Posted by SoCal LS-L

Try the crank and cam sensors next. Heat makes the magnetic tips lose functionality... so if they are weak already...

I was leaning towards checking the cam sensor also. At first I thought it could be a bad ignition switch, as I thought the car just died. Its almost like he was turning off the key. But Josh says it it seems to run erratically and choppy just before dying. I was also leaning towards a MAF as the culprit, but he said he changed out 5 of them, and surely they all can't be bad.

The FSM troubleshooting charts suggests the cam sensor if the car starts and then stalls (but doesn't say if the stall is immediate)

I thought a bad crank sensor would keep the car from starting at all.


.

[oab_au]

I would agree that it sounds like the position sensors. Swap the three of them see how it is then.

Harvey.

[jrturbosvx]

ok so ill replace the cam sensor and crank sensor tommorow morning so i can rule out those or possibly fix my problem i hope.this svx has never given me a problem so it figures it happens right before reading meet.anything else i should try to change tommorow? i need to get my svx fixed asap so any suggestions would be nice.thanks

[Trevor]

Originally Posted by oab_au

I would agree that it sounds like the position sensors. Swap the three of them see how it is then.

Harvey.

The correct procedure is to swap one at a time. Then you will know which one of three is faulty. Otherwise you will wind up with three sensors all, suspect and useless.

[jrturbosvx]

what are the 3 sensors?cam,crank and what other sensor?forgot to write no check engine light so i dont know exactly where to go if these sensors dont help.thanks guys

[oab_au]

Originally Posted by jrturbosvx

what are the 3 sensors?cam,crank and what other sensor?forgot to write no check engine light so i dont know exactly where to go if these sensors dont help.thanks guys

There are two crank sensors above the crank pulley and one cam sensor on the left side cam cover .

Harvey.

[jrturbosvx]

ok thanks that what i thought so i guess out comes the alternator for like the 6th time in morning.grrrr. i hope its these sensors if not i have no idea what to throw at it next.its been such a bad couple of days for me and i have other svx projects to start and not working on my daily driver for 2 days which i have been doing.thanks

[lhopp77]

I also vote for cam sensors and recommend replacing the one on the left side of the engine first. Of course you do not have to take the timing belt covers off to replace it.

Lee

[green_eyed_lady]

Originally Posted by jrturbosvx

hi im having a problem with my 94 svx as its shutting off after a few mins running when i have changed alternators,changed in 5 diff maf sensors,along with a few other parts over the last 2 days.it will die but start back up with no problems until it starts running real choppy and then quits.i have discussed this problem with svxess aka john who has taken alot of time to try to help me with this problem.any suggestions of what i should replace tommorow. ihave a complete parts car to take parts off. thanks josh

Originally Posted by jrturbosvx

ok so ill replace the cam sensor and crank sensor tommorow morning so i can rule out those or possibly fix my problem i hope.this svx has never given me a problem so it figures it happens right before reading meet.anything else i should try to change tommorow? i need to get my svx fixed asap so any suggestions would be nice.thanks

Originally Posted by jrturbosvx

what are the 3 sensors?cam,crank and what other sensor?forgot to write no check engine light so i dont know exactly where to go if these sensors dont help.thanks guys

Originally Posted by jrturbosvx

ok thanks that what i thought so i guess out comes the alternator for like the 6th time in morning.grrrr. i hope its these sensors if not i have no idea what to throw at it next.its been such a bad couple of days for me and i have other svx projects to start and not working on my daily driver for 2 days which i have been doing.thanks

Wecome to the world of SVX ownership. We have YEARS of experience and we still get hit with "surprises".

[SVX10]

I had this exact problem and it was related to my fuel pressure modulator. It's located under the rear parcel shelf in the trunk. I checked everything that was mentioned already to no avail.

The key thing I did to trace it down was to start it up, and just before it was about to die (it was very predictable for me...the car would get to operating temp, the idle would slowly get lower and lower, it'd stumble a few times, then die) I would spray starter fluid into the air intake via one of the vacuum tube holes (disconnect the tube, obviously). The engine would keep running, though not very well, but it kept running indicating that the issue was fuel related.

I then immediately realized that I had possibly left the fuel pressure modulator unplugged when I was testing it because of some earlier issues I'd been having. I went back into the trunk and checked...the fuel pressure regulator was unplugged. I plugged it back in, no more issues.

Here's a link to the ordeal...
http://www.subaru-svx.net/forum/showthread.php?t=52196

And another link to the entire process leading to this point...
http://www.subaru-svx.net/forum/showthread.php?t=49743

I hope this helps you out. It was a GIANT headache for me, and it'd be great if I could help you fly right through this.

[jrturbosvx]

Can someone post a Pic of fuel resistor and fuel modulator so I Can check them out please.thanks

[jrturbosvx]

update. my svx is now fixed! thanks to the fuel pump module being unplugged in the rear trunk parcel.when i was working in the trunk the other day on the stereo system i must have unpugged it.i will be going for a long drive up to the berlin turnpike in a few mins to pick up some more parts to install on this svx before the reading meet in a few weeks.everyone will see the suprise parts im going to be installing when my car gets to reading. i want to specially thank john svxcess for all the time he spent trying to help me with this problem i had.im running the same alt upgrade setup on this svx and its been working great.thanks guys for all your suggestions.see everyone at Reading!

[svxcess]

Josh,

That's great news!

In the past whenever my car was working perfectly and then started acting abnormally, I would always think back to the last thing I did before the trouble started. I did not know you were in the trunk working with the stereo.

I would like to know in detail just how this fuel pump module/ fuel pressure modulator works. Could save many of us time in diagnosing problems.

This should be in the How-To documents somewhere.


See you at Reading!!

.