stalling like symptoms

Hi All,
Jason Stock - proud aurora owner
97 Aurora 227K

1st of I'd like to thanks the people involved in posting the solutions to "my lights are possessed" and providing the solution for the "dirty" multifunctional switch - I took apart my dash and successfully fixed the problem for about 20 bucks! You guys rock.

Here's my new problem and I didn't see it specifically addressed in any posting:

My car's idle would go up & down and would begin lagging (rough acceleration between 1500 and 3500 rpms) this happens only in city driving & only after car is warmed up. I was about 30 minutes away from my mechanic and on the island of Montreal - I raced home and when I got home it stalled and I couldn't start her for about 2 hours.

I took her to a garage the next day (not one known to me but close) - read the posts re: fuel pump, etc... The garage performed the diagnostic and got EVAP SOLENOID... they said I had a leak on my tank that was bringing in air - replaced a ring with a GM part that goes on top of the tank....they had my car for 3 days - I was real upset with them (couldn't get a straight answer)...now, car does the exact same thing... now, they said fuel pressure was low (due to air) - and are saying I will need a new tank...I don't believe them.

Normally if I burn 91 octane I can smell the "extra" octane out of my exhaust - so I've been running 87 and sometimes 89....the smell I got recently was very different after a fill-up at a service (I fill up myself 99% of the time) now, this place has ethanol....could the guy have accidently put in ethanol? I filled about 25 litres....now, I've through that gas - I gassed up at 91 and ripped it on the highway to help "burn" the remaining possibly contaminated fuel...my "extra" octane smell is back and the car is somewhat less sluggish...but not sure if this is the cure.. Any advice out there?

Thanks.

Hi Jason,
I don't know if this will help you but thought I'd offer a similiar story with my '95 Aurora. I recently had issues that started with hesitation, which progressed to a periodic rough idle & then stalling -- the stalling finally became so severe my car was not even drivable. This happened over about a month. I read many posts on this sight & got some great tips -- I replaced spark plugs, wires, fuel filter, PVC valve, fuel pressure regulator, cleaned throttle bore & EGR valve . . . & perhaps a few other things. Everything I did helped but it still didn't seem to be running right. After a couple days of driving in some heavy rains the stalling got so bad it was not even drivable so I took the car to a dealer to get it checked out. (BTW, at the time I had no idea the rain had anything to do with my problem). It ended up that my fuel tank was badly rusted with multiple holes (topside), I suppose that would mean I did not have adequate fuel pressure -- although the car ran "OK" but I still felt something was wrong. Driving in the heavy rains allowed to get water in the fuel which caused the severe stalling.
So, in my case there was no way around it, I needed a fuel tank -- dealer quoted $1,500 for a new one but found a used one for ~ $650 . . . still expensive in my opinion. BTW, I recall a strong gas smell after every fill up that lasted until the tank was ~ 3/4 of a tank or so. Thinking back on it, I feel pretty stupid not thinking something was wrong when I noticed the fuel oder . . . at the time I thought it was lawnmower in the garage or whatever.
Anyway, after reading many posts on this great forum I learned alot about my Aurora & basically gave it a much needed tune up. Thanks to all who are regular contributors. I'm a novice with not much to offer here (yet) but greatly appreciate your collective wisdom.

Hope this helps,
Rob

i thought the gas tanks were made of plastic ??? how did yours rust ???

Thanks for the replies guys...my mechanic also said that I had a gas leak and that I should replace the tank...but I didn't believe him (I know the tank is plastic-and it makes no sense to me to replace the whole thing) - the ring around the gas pump is metal and that was rusted out...they did change a seal or ring which based on what I've seen in part catalogues would be the neck filler(maybe?)... but if I look anywhere online - no one lists FUEL TANK for prices - all the components are there...which leads me to believe that it can be repaired... any ideas?
-jason

Air in the tank will not have an effect on fuel pressure, the EVAP system is just an emissions thing to keep gas fumes from leaking out of the system. A hole in the tank however which would allow water to leak in would cause serious problems, for obvious reasons. If your not sure about their being a hole in the tank drop the tank and take a look...

Hmmm . . . so it's a fact that the fuel tank is plastic!?!. I never saw my "rusted tank" -- I was out of town on business & trusted the GM dealer who advised me of the problem. (Actually I'm out out town now & can't wait to get home & inspect the material of my "new" tank.) I did see rust on the filler neck so I just assumed everything was metal.
So - Now I'm wondering if I was taken advantage of . . . what do you all think? The service manager told me it was "rusted thru" & since the car spent a few years in Michigan before I owned it so I didn't question him about it. But if the tank is non metalic - is it common (or possible) to develop holes in the plastic do to rust on adjacent parts?

Thanks,
Rob

Also, remember these cars have a plastic intake and a backfire blow-out flap on the passenger side of the intake. These seals can get worn and cause an air leak. This can cause the bad idle, acceleration, fouled plugs, etc. Almost seems like a fuel problem, but it's really a fuel-air problem. Anyways...I had the problem. I replaced lots of things, but it was finally fixed when I replaced the $18 blow-out flap!!!

just an idea

Good luck - Drew