FEOA Forums banner
1 - 4 of 4 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter · #1 ·
After about 15 minutes of really, really hard driving, my engine just sort of crapped out. It still runs and revs fine, but the faster I go (or if I'm going uphill) it looses more and more power. It just kind of drops the revs as if the limiter was telling it to stop, but it does this somewhere around 2-3k rpm at 5th gear. I know it's not a direct engine problem because it revs just fine in neutral, and I can bring it to the redline in 1st, and almost 2nd. Just the faster I go, the less torque I have.

It's got a new cat, new head and exhaust manifold gaskets, new sparkplugs and wires, new belts (timing, and I think it's called the control belt?) as well as new fuel, oil and air filters. My original guess was that my hard driving missaligned the timing belt, but a mechanic said that wouldn't happen. There was a leak in the exhaust manifold, that was fixed by replacing the gasket... my guess is that the O2 sensor was out of sinc because of the exhaust and needs to be reset before full power can be restored. Another mechanic also suggested that I have a bad water cooler or something.

Do you guys have any idea what might cause a general torque failure at high speeds? Any help would be greatly appreciated, thanks.

By the way it's a 2nd gen 1.9.

-Blueshot
 

·
Registered
Joined
·
874 Posts
At 2-3k in 5th gear about how fast are you going???? And by low tourque what exactly do you mean????? I don't want to insult anyones intelegance here, but in 5th gear there isn't goint to be that much torque to begin with du to the gearing of the tranny. I usually shift into 3rd from 5th if I am going to try to pass or gain any speed in a concideraably short time. I personally have never had my engine (1st gen 1.9HO) over 3.5-4k in 5th, and I was pusing it to get that far. The cop that pulled me over when I was doing it said I was goin 94 at the time. That is a different story on a different post though.

As far as the "missalighned" Timing belt goes I think what you are looking to say is it may have jumped a tooth. This is known to happen on high mile, worn out, or missadjusted belts. And it usually infact results in a difference in your performance. If the Timing belt was recently replaced you might want to double check the alighnmet of the timing marks on the cam pulley and the head with the #1 Cyl at top dead center. Knowing from experience they are a bit haard to get dead on, so the new belt may have been installed a tick off. That would affect performance across the board though.

The O2 sensor doesn't "Sync" with anything It produces its own voltage signal to tell the computer what needs to be done witht he mixture. There is no way to reset the O2 sensor, but the Computer can be reset by disconecting the battery for a few minutes. This may help or may not. You may want to check for stored trouble codes before you do this, then check again after driving a few days.

As far as the "watter cooler" goes the only thing I can think of there is the radiator. The only way it failing would cause TQ loss is by the engine overheating to the point where it almost want to melt down.
 

·
Registered
Joined
·
2 Posts
Discussion Starter · #3 ·
Thanks for replying! In response to your question; I don't have a tacometer, so I'm just guessing on the rpm from past experience driving cars that do. By torque I'm just referring to the engines ability to pull the vehicle during exceleration or up an incline. Going downhill it's hardly noticeable.
When I'm in 4th or 5th gear (at a reasonable speed for the gear) there will be almost no positive response from the engine if I floor it. Instead it sort of coughs like it's about to stall and actualy feels like it's dropping below 1000 rpm. It will do this too when I go uphill. My new top speed is around 70, and this is after flooring it for a good 4 or 5 miles.
As for lower gears, 1st, 2nd and 3rd, it doesn't cough like 4th or 5th, but there is a noticeable decrease in power. I used to be able to peel rubber going into 2nd, but now I can barely peel into 1st :-/
I took a look at the O2 sensor today to find it was actualy loose (unscrewed) so I tightened it back up, but there wasn't a noticeable change.
Question: How long does it take the O2 sensor to adjust to a change in the exhaust? Could it possibly take a few days of driving before it will return to peak performance after having fixed a leak in the exhaust manifold gasket? Could there possibly be damage to the sensor from it being loose?

Thanks again for any help you can offer!

P.S. What do you mean by stored trouble codes?
 

·
Registered
Joined
·
874 Posts
Once the O2 sensor warms up it will react instintaniously to changes in exhaust oxygen content. If the O2 sensor is more than 70000miles old you might just concider changing it. As far as stored trouble codes Go Here for a list of codes and definitions, and how to recall them from your ECU. Basicly find the test connector under the hood. mine is near my dip stick (but mine is also a 1st gen scort). there should be a big trapazoid looking connector and a singe wire connector next to it. Hold the big connector with the small end up, and stick a paper clip into the connector on the right, then plug the single connector to the other end of the paper clip. Don't worry about connecting a test light or volt meter like the description says unless you want to read the code while under the hood. The code will flash on the dash board. Most cars flash the check engine light. I'm not sure about the 2nd gen Scorts, but mine acctually flashes the shift indicator. Make sure you read through all the sequences on the link I posted before you try to get the codes. you will have to jump through a hoop or two. After you get the codes if any, clear them as described on the site, and drive for 10-20 mins. driving a long streach of open road or freeway is the best thing to do. After that, come back and check the codes again. Also keep an eye on the check engine light while you are driving to see if it comes on at any time. If it does try to remember everything you are doing at that point in time, i.e. speed, are you accelerating, decelerating, cruising or stoped, is the engine bucking or ideling rough, how long have you been driving, basicly as much information as you can pertaining to the car and the way it is reacting. When you get home, wheather the light came on or not check the codes again, if you haev any new ones, or any came back, post them here and I'll see what I can figure out.[/url]
 
1 - 4 of 4 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top