It has to be the fuel pump... Right? (98 SL2)
 

Hey, everybody. So I'm lost at this point. I've done hours of research, replaced everything I can think to replace (IAC valve, air filter, fuel filter, fuel pump relay) and used a bottle of fuel injector cleaner that I got at AutoZone. I've even removed and SUPER cleaned the throttle body. I did an oil change just two weeks ago and so far NOTHING has helped. At this point, I think it MUST be the fuel pump, but I thought I should pose the question somewhere and see if I could get some suggestions/advice.

What it's doing is this:

When I first start the car, it'll idle sporadically and REALLY low (around 300-500 RPM). If I do nothing, it dies and then becomes impossible to start unless I start with the clutch AND the gas pedal on the floor. Once it restarts, I rev it up to around 3000 RPM (which sends out white smoke from my tailpipe that REEKS of gasoline) and hold it there for a few seconds. Once I let go, it'll stay running and idle between 1200-1300 RPM. Also, the longer it sits, the harder it is to start. (i.e. If I run into a gas station to buy a drink and it's off for 5 minutes, it'll start ok, but even then, it'll start and idle around 2000 RPM for a second or two before it slowly makes it's way down to 1200 RPM. But on the other hand, if I let it sit for the 10 hours I'm at work, it'll do all this **** again.)

As for driving, it'll run and it's still getting me from "A" to "B", but it's much harder to go from a dead stop to moving forward than it used to be, the acceleration feels sluggish, my gas mileage has dropped dramatically (I used to get ~28mpg and recently I've been getting an average of ~19mpg), and just recently it's been sputtering every once in a while while I'm stopped at a stoplight. And the last thing I feel I should mention is that my service engine light isn't on.

Anyways, sorry if that's a lot to take in, I just wanna make sure that I don't leave anything out.

Other problems that I don't think are relevant, but I'll right them down in case I'm mistaken:

- The airbag light will come on my dash about every other time that I start my car
- The windshield wipers don't always stop when I tell them too
- I just got done fixing a charging issue with my car (the belt tensioner broke and wasn't spinning the alternator fast enough to charge the battery)

My car is a 1998 SL2, fuel injected, manual transmission, with just 127.5k on it. It's starting to bug the ever-loving crap out of me though, so if any of you have had a problem similar to this, or even if you can just offer some advice... It'd be much appreciated. Thank you.

Since your fuel smells like gas, start with the basics. Check your fuel injectors first. It sounds like you've got one or two leaking. If that's a throttle body engine, maybe it's the fuel pressure regulator. Raw gas in the exhaust is not a good sign. Get a fuel pressure tester from Autozone and hook it up. I THINK your fuel pressure should be between 40 and 50 psi. If not, then perhaps it's a bad pump. I think it may be a faulty injector or relay even, but not the pump, but I'm not a mechanic. Get some other opinions before jumping on anything I've said.

If you regular idle when fully warmed up is higher than 950 and is rough. that would indicate a leaking intake manifold gasket, but as far as I know, this is an issue with SL1 engines, not SL2.

The other thing that pops out at me is the engine coolant temperature sensor (ECTS), but you should be getting a service engine soon light. Another thing is the fuel pressure regulator. If you can run this all the way to 6500 rpm in a low gear (2nd) at full throttle without it missing a lot, then the fuel pump is good.

You may not have a service engine soon (MIL) light, but have you had it checked for pending codes? Pending codes don't stay very long so you would need to read the codes right after having the issues above. Most codes are called two trip DTCs so they don't set the MIL light until the second occurrence of the DTC on the same or next drive cycle.

The code reader will also show if all the monitors are being checked.

Take the time and go to the new member area and give yourself a proper introduction. While your at it open the USER CP go to signature and add your first name, location, and car info.

My 99 did that to it was the temp sensor one I changed that it started running smoother and the idle when warm came down to around 900 and it starts without any problems.

idle problems on this model car are historically relate to the engine temperature sensor. The one at the end of the cylinder head on the drivers side. It single handily causes the greatest amount of problems. And while I am not one to say go to the dealer for parts, this one I do. The long and short of that statement is GM screwed up the installation of these things and aftermarket never go the right part in stock. So find a GM dealer that will sell Saturn parts (they all are supposed to I think but I'll bet only a few do.) Try a Chevy dealer first, they seem to be more popular than not.
When you find one by a new temperature sensor and ask about the connector repair part which is a replacement for the connector, you may or may not need it but if you have one that is cheap insurance.
As to is it the fuel pump? That is why I bought a fuel pressure meter for fuel injection. Knowing the answer to that question up front keeps you from spending a ton of money on parts you don't need.

You can certainly check the fuel pressure, it would be a good place to start. I'm inclined to agree with Rubehayseed about the fuel injectors though. The first replacement set went into my SL1 around 130K if memory serves. And if it smells that strongly when you restart it, it's definitely getting fuel. You say it won't idle, but does it misfire at all?

I'm going to come down on the side of the engine coolant temp sensor as the problem child in this issue. The ECTS reads the engine temp, then adjusts the fuel/air ratio accordingly to get the best mileage/performance. If the sensor fails, then the car becomes a gas hog, and is also difficult to start.

Second on my list would be the throttle position sensor ( TPS )

I wouldn't check anything.........I'd just buy more parts and change them. Start with the head lights.

My, my, my...........:D