Hi, my name is zach and i recently bought a 2000 saturn sl2. Like ive heard about with these cars, mine has a stumble on initial acceleration but is fine once it is moving. What i have noticed is that there is no hesitation until the temp gauge gets to the 1/4 mark and as soon as it hits that it starts to stumble.
I recently changed the plugs and wiress, used ngk v power gapped at .040. The hesitation is still there but not as awful. Any suggestions? I checked the wires and the no 1 and no 4 plug wires are not mixed up. The only thing i know is that the motor was recently rebuilt (burnt valves) so it has all new gaskets and such. Any help is greatly appreciated. Last thing is that my ses light is on and last time i had it cleared it was saying the idle air control code. Came on again and havent had it read yet.

 

Moved to SLx section. No tech questions in the New Member Area please.

Please get the codes read and post them here as Pxxxx, not the description of the codes.

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Best plugs to use for this engine are the stock ones it left the factory with:

NGK NG5643 Copper Plugs, also known as NGK BKR5ESA-11 gapped at .040.
Simple, reliable, and concluded by 8 zillion people looking for a better plug to be best.
Ignition system likes it. Ignition system expects it -- not platinum, not iridium, not any exoticum.

Not sure about the "Like I've heard about with these cars" part. I've logged almost 500K on two mid 90's Saturn SC2s, and the few times they stumbled repeatedly, I figured out why and addressed it. A properly maintained S Series car runs and accelerates smoothly.

1) Try cleaning the throttle body w Throttle body cleaner (not carb cleaner). Be sure to get the back of the throttle plate clean. Pay particular attention to the small hole (inside the throttle body bore) near the throttle body entrance (in the bottom).

Work the throttle by hand from under the hood while spraying; you will need to give it extra gas as it will try to stall when you're spraying.

The way to thoroughly clean it is to remove it from the car.

Other possibilities but no need to jump the gun.

Manual/Auto?

Does it idle smoothly and at what RPM?

 

It idles normal around 900 rpm, its an automatic and it has 186k on the body but around 40k on the motor. Ill get the codes read and will post them. Ipl try the throttle body cleani ng and see if that helps

 

The idle speed for a DOHC Automatic in Drive w A/C off is 700-800, so you're running a bit high. This could result from a number of factors, so I won't start guessing until we get the codes back.

Definitely try the throttle body cleaning and pay attention to the passageway at the bottom --it's the idle air control valve

 

Sorry, but for some reason it will not let me reply to comments on my post so here goes again. I have a 2000 saturn sl2 automatic. 186k miles on body and around 40k miles on rebuikt motor. Car has hesitation on initial acceleration. I have changed the plugs and wires, no 1 and no 4 cyl are not mixed up. I have cleaned the throttle body. Only code that as showing was po442 and i cleared it. Any help is greatly appreciated. My number is 6363850241 as texting would be a bit easier as to help me troubleshoot. Thank you and happy mothers day

 

The only code that popped up was po442 evaporitve canister leak. I cleaned the throttle body thoroughly and that did absolutely nothing. Car shifts rough too come to think of it, it bucks and it reminds me of my stealth, but that turned out to be a fried computer

 

Merged your threads. Not sure what was going on with that, but fixed now.


Have you ever changed the ECTS (Engine Coolant Temp Sensor)? Original design was resin tipped and failed, leading to bogus temp readings and overly rich A/F mixes.

Replace with a GM sourced brass tipped ECTS and replace the connector at the same time About $50. Solder n shrinkwrap.

Not every part on a car needs the OEM replacement. The ECTS on a Saturn S car DOES.

Generics from AutoShmo do not behave the same (resistance vs temp response)
and this is what leads to incorrect A/F mix issues.

When a Saturn S series ECTS fails it usually fails open circuit, which is the equivalent of -40 deg as interpreted by the PCM. Since the ECTS V drop Value measured by the PCM never changes, the car runs absurdly rich and as the car warms up and goes into closed loop operation, this can lead to driveability issues since the A/F mix should be getting tweaked by the Front O2 sensor readings and the coolant temp, but it's just sitting there as though it is -40C.

One of the driveability issues seems to be a stumble or hesitation around 2K rpm. Not the only one, but has been reported by many owners. Bad ECTS can lead from everything to driveability issues, starting issues when cold, starting issues when hot, cooling fan not coming on when coolant temp rises (because the PCM thinks the coolant is at -40 so it never requests the fan on) and eventual overheating...etc

Since throttle body cleaning didn't help at all (surprised), ECTS is next recommended step as it cures many subtle and not so subtle issues and prevents many others down the road. the engine w 40K was obviously rebuilt, but only a Saturn dude would know the ECTS issues.

As for P0442 Small Evap Leak detected:

Ensure gas cap is tightly sealed and clean around the mating surface. You can use a TINY bit of vaseline on the o-ring in the cap to restore its ability to flex.
Get the code cleared and see if it comes back.

Also
Check that the vacuum line from the intake to the purge solenoid is connected.
Check that the line from the purge solenoid to the canister is connected.

High idle, we'll wait on the outcome of the above.

 

I read about that somewhere else how the ects's were faulty from the plant. As for the motor it was pulled from a totalled saturn with 40k orig miles yet somehow the previous owner managed to burn up a valve so the motor was rebuilt. I will definately replace that as the symptoms you described are what my car does, it will overheat if it sits because the fan doesnt always come on. Can i get that ects through a gm dealer?

 

indeed you can---must be an original resin tipped ECTS in there.
Surprised no one grabbed up such a low mileage engine before you unless it just hit the lot.

You'll be happy you did. And REPLACE the CONNECTOR. It costs more than the sensor and it seems stupid, but when the resin tipped ones go bad, they often leak right up the center of the sensor and onto the connector, which then corrodes, adding resistance to the circuit and screwing up the PCM's temp measurement.


Try a Chevy dealership first. They seem to have a clue as to what you're asking for.
Lemme go look up the GM part number and I'll edit this thread

GM part Number 21025106 (Believe it is AC/Delco) about $11 online--this may be listed as an AIR CHARGE temp sensor. The car does have one. It is the IDENTICAL PART. If you have to you can ask him for the 2 wire ECTS --it should be the identical part number but you never know.

Forgot -- I think someone makes an aftermarket connector harness for this (FINALLY)

Dorman 645-900 --but theirs is near $30 at Advanced and the dealer is not that much more. Or is it.?

Call and get a quote. The dorman harness should be fine

Remember -- it's a SQUEEZE connector

 

I really appreciate it man, i bought the car as a commuted cause my 83 elcamino gets about 8 mpg lol. Ive never owned a saturn but ive heard of their renowned reliability although i will say they have some reall junky interiors lol. I plan to do a tranny flush soon, and a couple mods to make it more to my liking. Out of curiousity, is there any safe way to crank up th e power of the 1.9 without damaging the motor or tranny?