Power Cuts in and out on long drives

[saturn009]

I have a 2001 Saturn SL with about 90,000 miles on it.

After about a two hour drive on the freeway, the power cuts in and out, but never kills the engine. It doesn't happen on short trips. Once it starts to happen and I stop for a couple minutes, the problem dissappears and doesn't come back until I drive it for a little while longer. No service engine soon light has ever came on.

I have changed the fuel filter, spark plugs, air filter, had it taken in and they replaced a bad intake gasket and set wires. I have also used injector cleaner, but the problem is still there.

Any suggestions?

[RC1488]

Replace your Engine Coolant Temperature Sensor. Use the search button to find a video i posted to change it. Your resin one is stock and cracked. The ECTS controls many subsystems of the car including air/fuel mixtures.

Clean your EGR and throttle body. Pay particular attention to the Idle Air Control Valve.

Does the SES light turn when the key is in the RUN position? Sometimes the bulbs burn out

[saturn009]

SES light isn't burnt out. It still lights up before engine is on.

I will try the engine temperature sensor and see if that fixes it.

[saturn009]

Engine temp sensor didn't fix the problem. Still sounds like it isn't getting gas correctly.

I replaced the serpentine belt as well since it had a cut in it.

I have uploaded a vid of what happens.
http://www.youtube.com/watch?v=ZZwlVxwfw-4

[RC1488]

Clean your throttle body.

When this problem occurs, turn the car off the back on again. If it goes right back to normal its possible the TPS is faulty.

[saturn009]

The throttle body was pretty dirty. I tested the TPS and it worked just fine. The SES light should have came on if the TPS was the problem anyways.

I think the only thing left to check would be the catalytic converter which is next on my list of things to check.

[saturn009]

Isn't the Cat converter. Only trouble codes that come up are O2 sensor and coolant level.

Maybe an intermittant fuel pump or EGR?

Any suggestions are appreciated.

[RC1488]

Only trouble codes that come up are O2 sensor and coolant level.

[/quote]

What are the codes specifically.

[saturnspeed_12]

your crankshaft position sensor could be on its way out. referencing long trips causing the problem, that does sound like a fuel pump problem. the extended drive causing the pump to overheat. but usually with that, you will have a bit of trouble starting the car. may take a second longer then normal, or several seconds to start.

[saturn009]

Don't know the exact codes. It was brought into a mechanic and thats what I was told.

The only trouble I've had when starting the car recently is probably because of the cold weather here in Minnesota. It starts normally when in a heated garage.

It would be nice to know for sure if it was the fuel pump since the whole tank has to come out for that fix.

[RC1488]

Originally Posted by saturn009

The only trouble I've had when starting the car recently is probably because of the cold weather here in Minnesota. It starts normally when in a heated garage.

CPS failures are usually temperature dependant. However its good or bad. As in the car will not start or the car will start. I have not seen the CPS cause issues with symptoms where the car hesitates or lack of power...it just dies when the CPS fails.


You need the SES code referring to what o2 issue is present. Go to autozone/advanced auto to get it. A good ECTS will put the car in closed loop fuel delivery in which case, fuel delivery is based on data from the o2 sensors (front and rear).

[saturn009]

The closest autozone/advance is an hour away, probably would take longer with this car. It is hard for me to get a hold of someone who could get the codes for me unless I want to pay for them.

Recently, the car acts up in less time. It will only take about a half an hour or less of freeway driving for it to happen. Another symptom that just started to happen is when first starting the car, it did take a couple more turnovers than usual to start on the first start. It is a warmer day today. It also felt like it does right before it acts up and then it went to a normal idle and ran fine. I couldn't get it to do it again on startup.

Would it be worth a try to replace the fuel pump?

[TheBigfut]

Have you tried dropping the exhaust and letting it run? From personal experience it sounds like either the Cat is getting plugged or somewhere in the exhaust would be my first guess. The second guess would be that its something in the fuel system. when was the last time you changed the fuel filter? added dry gas or line conditioner? changed the air filter?

[RC1488]

Originally Posted by saturn009

Would it be worth a try to replace the fuel pump?

I highly doubt it. Its rare when s-series fuel pumps cause issue...and when they do they just flat out die.

Untill you get those codes your going to be putting tons of money at the car untill its fixed. Its worth it to pay someone to get the codes. Should cost like 10 bucks if that since it takes about 30 seconds.

[SC2ner]

hit up advanced auto or pepboys or something like that and they will check the codes for you for free. Like RC said, do not diagnose with money.