GAH...Need Help. ASAP

[techy101]

I'm running on empty with this problem. The SVX has been down for a few months now. The first thing that happened was during a snow storm, I took her out to play and get a feel for how she handled in the snow. After holding a short drift with the gas down the car started shuddering and shut down. After that it wouldn't start again. It would crank, kinda get started then stall out again. My friend towed me home, and there was rattling from the exhaust. Found out that one of the pre-cats had gone bad. Funny thing is that when we got it home it fired up just fine.... After cutting out the pre-cats I discovered that one of them was partially melted.

Fast forward to a few weeks ago. I replaced the pre-cats with used, and replaced the main cat with a new magnaflow 2-1 unit. Took the car for a test drive, and it seemed to do just fine. For about 10 minutes. After that it started stalling again. But this time it was different. The car would keep running if I started it and gave it some gas at the same time. As long as I kept on the gas it was fine. When I let off, or gave it just a tiny bit it would crap out again. I nursed it home, looking like a drunk driver. It started after I gunned it to accelerate onto a highway.

The oxygen sensors have never been changed, and the car has 130,500 on it. The melted cat seemed to point to running rich and getting unburnt fuel igniting in the exhaust. So yesterday I got them in from the dealership and installed two new O2 sensors up front. Didn't bother with the rear since AFAIK it is just for emissions. For good measure I also swapped out the MAF with another one that I nabbed from a junk yard, and had it on my car for about 200 miles to test it out, and it had worked just fine.

Car seemed to be running great. Then after gunning it again (i sense a theme here) the car stalled out on me again. I've been just driving around my neighborhood so I was close to home. It behaved just like the last time. Gave it gas and nursed it home.

I think I'll try and take a short spin again after it has a chance to cool down and see if everything is working again.

Anyone have any ideas?????? I'm getting very frustrated with it, especially since my other car is in the shop and I'm having to rent a daily driver.

Thanks!

[TomsSVX]

are there any check engine lights?? When the cats melt down it is usually due to incorrect timing... Which pre-cat melted?? I am thinking one of two things is wrong here... The timing belt jumped, or the cam angle sensor on the driver's side head is bad....

Tom

[techy101]

There's a CEL when the car dies, it's on for a split second, then the whole dash lights up like christmas.

The cat the melted was the passenger side.

If the timing belt jumped, would the car drive like normal, then crap out, then drive well again, then crap out...?

[TomsSVX]

that all depends on whats wrong. You need to check the codes to see what that is.

Tom

[longassname]

your sig says you have a 92 but you said you have 3 o2 sensors?

[TomsSVX]

Originally Posted by techy101

There's a CEL when the car dies, it's on for a split second, then the whole dash lights up like christmas.

The cat the melted was the passenger side.

If the timing belt jumped, would the car drive like normal, then crap out, then drive well again, then crap out...?

More or less it seems like you have a intermittent cam angle sensor... sometimes it works, sometimes it doesn't. This means your spark may be coming late and expunging your combustion out the already open exhaust valves and sending screaming hot air and still burning gas straight into your exhaust.. Thus the reason your old pre-cat melted and probably the same way you will melt your new main cat unless you take care of it immediately

Tom

[techy101]

Um, now I feel stupid. I just thought they all had three, I didn't even bother to check.

[techy101]

Tom you are a genius. Got a code 13 for the cam position sensor. How might one go about fixing this problem?

[TomsSVX]

get a new sensor.

Tom

[techy101]

Cool, thanks for the help. Hopefully this may fix the issues. Is there any harm in looking for used for this sensor? Our club pricing from the dealer is about $170

[TomsSVX]

no harm in using a used sensor, but remember this one failed... whats to say a used one won't do the same soon enough??

tom

[techy101]

tom, you are awesome!

just put the new cam sensor in and she,s running better than ever. i was pleasantly surprised at how easy it was to swap out.

so again, many thanks.

[Mike621]

Glad to hear it was an easy fix!

[TomsSVX]

Originally Posted by techy101

tom, you are awesome!

just put the new cam sensor in and she,s running better than ever. i was pleasantly surprised at how easy it was to swap out.

so again, many thanks.

Glad you found the problem and it is fixed... Always a happy ending when you don't have top throw parts at a problem to try and fix it

Tom