Whats wrong with my car!?!?!

[jordoug]

I have a 1994 Lumina Z34 with about 98000 miles on it. The car is supposed to do 0-60 in 7.5 stock. I have Flowtech Afterburner Mufflers and a Fram Air Hog Air Filter in my car but it only does 0-60 in about 9.5 to 10 seconds! I have taken my car into the shop several time and I found out the cam timing was off but that was all. All I know is that the car does not launch at all, the first 30 mph go really slow and then it takes off. Also, sometimes it will hesitate around 2000 rpm and it will not go anywhere. My only guess is that it is something to do with the spark plugs but I have no idea. Please let me know if you have any ideas at all about what the problem could be!

[85_305]

I have a 1994 Lumina Z34 with about 98000 miles on it. The car is supposed to do 0-60 in 7.5 stock. I have Flowtech Afterburner Mufflers and a Fram Air Hog Air Filter in my car but it only does 0-60 in about 9.5 to 10 seconds! I have taken my car into the shop several time and I found out the cam timing was off but that was all. All I know is that the car does not launch at all, the first 30 mph go really slow and then it takes off. Also, sometimes it will hesitate around 2000 rpm and it will not go anywhere. My only guess is that it is something to do with the spark plugs but I have no idea. Please let me know if you have any ideas at all about what the problem could be!

First off, you need to stop mag racing. Mag's are almost NEVER right, and depending on which magazine it is, they are more than usually import-oriented and favor them (thus, lean towards) imports more than American cars.
Second, how are you measuring your 0-60? Your watch? Your SOTPM (seat of the pants meter), g-tech? Track??
My 3.1 was the same way though (well my auto anyhow..) complete DOG in first gear. Second was quick. Third and fourth got even quicker. Now my 5spd 3.1 GP, THAT was quick to 30. But that car REALLY started pulling in fourth. Same w/ my 3.1 '93 sunbird; very quick to thirty and every other gear, but REALLY gets moving in fourth.
I still, to this day, have not found out why first is a dog other than the fact that my tranny (4t60) was geared towards the highway. Yours may be the same.

[jordoug]

I'm sorry but I don't know what you mean by mag racing. But as for the 0-60 timing I have been using stopwatches and I have tried it many times to make sure my times were accurate. All I know is it is supposed to do 7.5 stock and mine does 10 seconds.

[bszopi]

There is no way you can accurately measure 0-60 with a stopwatch and the spedometer. It could just be your spedometer is lagging the actual speed of the car. If you look at when they test for 0-60, they have a very accurate wheel hooked up externally to the car, which is then hooked up to a computer to time the event. No way you can re-create that manually.

[IsaacHayes]

For example my speedometer is dampened some how. It just does not move fast like the tachometer does. Accelerating and it lags behind. Same for slowing down. I can come to a complete stop and the speedometer will be reading 25mph and still falling.

[jordoug]

I may not be able to accurately read my 0-60 with a stopwatch but I do know it is very slow up to about 30 mph, when I step on the gas nothing happens, it just accelerates slowly for a little while and then it takes off. Sometimes it does not do this but usually it does. Also I have timed my 0-60 by looking at videos I have made and using the second counter in the video.

[85_305]

I'm sorry but I don't know what you mean by mag racing. But as for the 0-60 timing I have been using stopwatches and I have tried it many times to make sure my times were accurate. All I know is it is supposed to do 7.5 stock and mine does 10 seconds.

Inacurate...

I may not be able to accurately read my 0-60 with a stopwatch but I do know it is very slow up to about 30 mph, when I step on the gas nothing happens, it just accelerates slowly for a little while and then it takes off. Sometimes it does not do this but usually it does. Also I have timed my 0-60 by looking at videos I have made and using the second counter in the video.

And even more inacurate.
Mag racing is reading what Magazines have to say and then believing every word they say to the book

[bszopi]

One more thing to note... 98,000 miles. I'm sure the tranny isn't acting as quick as a brand new one.

But to go back to your real question, since you mentioned spark plugs, when was the last time you changed them? How about the fuel filter? Possibly the injectors are getting old.

Either way, NEVER expect a car that is 13 yrs old, even with a new muffler and a replacement air filter, to perform as well as a brand new car.

[Emc209i]

jordoug,

Timming can be a serious if it is off. Most of us Fiero guys know that by shifting the exhaust cam a meer 13* back, the car will pull MUCH harder up top and less on the bottem end. That's in a 2700 pound car. Now being that you are in a W body, you would feel a difference (ergo lack of power) much more. 13 degrees is a tiny difference over stock, and if thats an intentional shift in the right direction. If your car's timming is off (say it jumped a tooth) by only a little, performance could be seriously hindered. I would be sure to have a new timing belt on the car and the timing set up right. I have also heard talk of lessened power from a worn timing belt. I'd certainly have it changed at this point. If you drop the belt while trying to make it run hard you might not have a Lumina any more, it may be in the yards with the other countless 3.4 DOHC motors with broken belts. Go from there man.

It may also be a sensor, so you need to throw a ALDL reader on it to make sure you are getting things like correct MAF readings, cam sensor pulse, TPS reading etc etc.

-Paul

[85_305]

One more thing to note... 98,000 miles. I'm sure the tranny isn't acting as quick as a brand new one.

Eh that would be the least of my worries. GM had it right when they made their early 90's tranny's for these cars.

jordoug,

Timming can be a serious if it is off. Most of us Fiero guys know that by shifting the exhaust cam a meer 13* back, the car will pull MUCH harder up top and less on the bottem end. That's in a 2700 pound car. Now being that you are in a W body, you would feel a difference (ergo lack of power) much more. 13 degrees is a tiny difference over stock, and if thats an intentional shift in the right direction. If your car's timming is off (say it jumped a tooth) by only a little, performance could be seriously hindered. I would be sure to have a new timing belt on the car and the timing set up right. I have also heard talk of lessened power from a worn timing belt. I'd certainly have it changed at this point. If you drop the belt while trying to make it run hard you might not have a Lumina any more, it may be in the yards with the other countless 3.4 DOHC motors with broken belts. Go from there man.

It may also be a sensor, so you need to throw a ALDL reader on it to make sure you are getting things like correct MAF readings, cam sensor pulse, TPS reading etc etc.

-Paul

I didn't realize that the 3400's were kept going by belts instead of chains??

[Emc209i]

I didn't realize that the 3400's were kept going by belts instead of chains??

Which is why at this point you need to stop trying to help him because you clearly have no understanding of the motor at question. Have you ever considered that maybe we aren't talking about a 3400?

You don't have to be an expert but for God's sake cut all of the mag racing trash. He clearly stated that the motor has hesitation problems down low. At this point he is trying to find out what is wrong with the motor, not to prove or discredit 0-60 assumptions. "Please let me know if you have any ideas at all about what the problem could be!"

Back to the problem at hand.

I thought about this some more today. From your post it sounds as if you have recently aquired the car, being that you are performance checking it now at 98,000 miles. You really need to do a tune up and at least change that belt before it breaks. GM recomends it be changed every 60K miles. if you have no idea if the belt has ever been changed you may regret not doing it immediatly.

As mentioned below; change the plugs, wires, and fuel filter. Run some good injector cleaner through the system if you don't want to pull up the fuel rail to clean the injectors by hand. It is also a good idea to change transaxle fluid while you're at it. The catalytic converter can also sometimes cause excessive backpressure. Make sure that the power steering pump has fluid and isn't causing drag. When you make your runs also make sure you do it with the A/C disengaged.

Your description of lagging power doesn't match anything other than timing in my book. If the others were bad you would have diminishing power. These motors aren't VVT so it just sounds like the bottom end is bogged down by bad timing. You really should spruce up the motor though; they are high mantainance after all.

What the guys are saying about 0-60 timing is that the speedometer isn't always accurate. So no matter how accurate your timer is there is almost always variation in the speedo readings and actual speed. Its not that big of deal though, you shouldn't be in the 9-10's, the LQ1 is stronger than that.

[Emc209i]

Look here:

http://www.youtube.com/watch?v=sGgldDEfcBE

At about 20 seconds in he "guns" it from a stop. He isn't really getting on it though. I've watched a 1995 Monte Carlo spin through first, so he isn't really getting down on it (you'd hear the tires chirp).

If you time it, it takes him about 7-8 seconds to get to and beyond where 60mph should be in second gear.

[jordoug]

So, ideally my car would be running like that or at least close to that.

[jordoug]

I have been looking around and it lookes like my engine has a timing chain, not a belt, does that change anything? By the way, thanks a ton for everything you have done so far!

[Emc209i]

You are posting in the DOHC section. This section is for the 3.4 TDC/DOHC engine(aka Z34). If you have a 3400 motor you are posting in the wrong section. If it really is a Z34 it has both a chain and a belt. The chain drives the intermediate shaft. That shaft drives the belt that raps around all four cams. There may be slack in the chain also.