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sier 04-30-2004 07:35 PM

Stalling During Acceleration ...
First time poster, just signed up today. Glad to see there is a place where I can ask some questions that actually generate *real* answers.

I bought my saturn in 1997 with 7 miles on it. I got oil changes at around 2000 miles with my (now miniscule sounding) 48k mile warranty w/ free fluid level changing. At around 45k miles or so, the engine starting having acceleration problems. During acceleration, I could clearly hear the power level in the engine suddenly drop and my car would start dogging. It wasnt ever severe enough for me to hold up traffic or anything (I would just have to press much harder on the gas pedal and the car would downshift and sort of take off). This didn't happen every time and, in the beginning, it didn't really happen that often...

So of course I took my car in before my warranty expired. I was a complete car idiot back then (not that I'm not now), and honestly had no clue what they said they were doing. I only know that my car was in the shop for a 4-5 days about 4 times. They replaced fuel injectors, lines, filter, and god knows what else (sorry my information is so choppy. This was a pretty long time ago). It would still occasionally do it even afterall the work and - of course - by this time my warranty had run out. I decided to just deal with it since it really wasnt too frequent.


I let my mother drive my car for about a year or so, and at some point my radiator scoop on the bottom of the front bumper got ripped off,so little air was getting to the radiator. The car started smoking like it was going to explode one day (apparently mothers do not know how to read temperature gauges), so she took it in and the engine was completely rebuilt.

And then I got my car back with a somewhat brand new engine and it was fantastic. For about 3 months and the problem started all over again. I mean, the car had been used and abused,given a second life, and that same problem exists to this day.

This leads me to believe that problem has to exist somewhere else. At one point, my first gas tank imploded (due to some kind of "reverse pressure" according to Saturn of Kansas City). The bottom of the tank was literally touching the top. They had about 12 guys come and look at it when I brought it in. Does this lend an idea to what could be wrong?


Is this a transmission issue (which I really really really dread)?

Sorry for the huge post, but I figure the cars history would play a big role in a problem like this and thanks for any help.

lifting iron 04-30-2004 08:27 PM

The first thing that comes to mind about your gas tank is a gas cap that is sealing your fuel system and not letting in make up air as you use gas. A vacuum strong enough to implode your gas tank might have been enough that your fuel pump had a hard time supplying the proper fuel to your engine. This could then cause a lean operating condition that could damage your engine. I've never heard of an imploding gas tank before.

Some other people might have more ideas.


wolfman 04-30-2004 08:53 PM

The tank is vented through the carbon canister via some rubber and metal lines that run from the tank to the carbon canister which is located in the passenger side front fender. This system allows air to be drawn INTO the tank but NOT be vented from it except when the PCM commands the CCPS (carbon canistor purge solenoid) to open and vent the tank into the canistor, and then into the combustion chambers via vacuum lines to burn up and vapor. You should NOT be able to draw any air out of the tank when the engine is NOT running, you SHOULD be able to draw air into the tank when the engine IS running. The tank vent and EEC (Evaporative Emmissions Control) system needs to be evaluated by someone who knows what they are doing, it's sounds to me like the tank is not being vented properly causing and intermittant vacuum lock in the fuel supply system. This could very likely be nothing more than a defective check valve at the carbon canistor.

lifting iron 04-30-2004 09:27 PM

Directly from the Saturn Service manual.

Fuel Cap

The fuel cap seals the inlet end of the fuel filler pipe and prevents the escape of fuel liquid and vapor. It is tethered to the fuel door on the vehicle body to prevent loss. The cap requires a 1/4 turn (plus an additional 1/4 turn to activate at least 3 "clicks" of the ratcheting top feature) to engage the filler pipe neck during installation.

The cap also incorporates a spring-loaded, free-spin feature (about 150 degrees) noted during removal.

The cap is vented to the atmosphere in both the positive and negative (vacuum) pressure modes to prevent build-up of excessive pressure in the system. The cap is designed to vent at a positive pressure of about 2 psi (60 in H2O) and negative pressure (vacuum) of about 1 psi (26 in H2O).


It sounds like your EVAP system AND cap both failed.

wolfman 04-30-2004 09:44 PM

Of additional note. You may be able to salvage the cap if it's orifice is clogged. It sounds quite hinky, but remove the cap and run it through a cycle in the top rack of the dishwasher (including the dry cycle) this can unplug and salvage a marginal cap. Keep in mind that the cap is designed to "vent" only when the EEC system is not active (engine running) or beyond it's set points (2 or 1 PSI or vacuum respectively) as fuel vapors should not be venting to the atmosphere at all with the cap in place unless the cap is actually removed, or the system is malfunctioning.

ssicarman 04-30-2004 10:19 PM

Let us not forget that 97 had the potential for wonky fuel pumps. Any problems starting the car in the morning or ater it has sat for an extended time?

sier 05-02-2004 02:54 AM

First of all, thanks for all the replies.

I will try the gas cap/dish washer trick (it cant hurt anything).

And yes, my car *always* has a problem starting in the morning or when I leave it sitting for more than a few hours. It will crank and crank and crank, but no start. Count to five, and the car will start fine. Occasionally, it still wont turn over, so I simply count to five again.

Do the fuel pumps get clogged easily or something?

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