Car Problem

[RyanbabZ71]

Ok 93 Ford Escort with a 1.9L. Been running great getting 28-29 mpg back and forth to work. Yesterday started it up after work and the rpms shot up and went down and the car almost stalled. Kept doing it. Finally got going and the car ran good until I hit a stop light then it would rev up and then almost die. Kinda started surging too when letting off the gas. Today when I started it (didnt drive it today) I noticed back smoke coming out the the tailpipe.

 

Any ideas?

 

 

Thanks!

[Black02Silverado]

How many miles are on it? I would look at the O2 sensor. Black smoke means running rich. Might be the EGR valve as well. I'm not a ford person. I can ask a guy at work who is a ford guru.

[RyanbabZ71]

84K miles

 

Thanks!

 

My only thoughts right now are fuel pump or cat converter???

[Black02Silverado]

Talked to the guy at work. He said to see if there are any codes, Auto Zone and Advance Auto can read it for you for free. Then it can be a bunch of things. Engine temp sensor, if it is off it will make it run rich thinking the engine isn't up to temp, throttle position sensor. O2 sensor, EGR valve, how is the air cleaner? A clogged cat would make it loose power more than anything.

 

From talking to him it sounds like this is a common problem with that perticular vehicle. He has been working on an 89 doing the same thing and has changed out everything but the computer. It is still doing it but not as bad.

 

Sorry I couldn't help any more than that.

[RyanbabZ71]

Thanks for the help. I talked to someone and they said it may be an 02 sensor and they have had a similar problem on a ranger pickup. We will see.

[RyanbabZ71]

Changed plugs and 02 sensor still didnt help.

 

I am leaning towards the tps because at idle the car will be at appx 100 rpms then it will go up to 2000 by itself then back to 1000 then to 500 and almost die. It has died recently but starts right back up

[Guest chevydeerhunter]

Any ideas? 

 

 

Thanks!

 

<{POST_SNAPBACK}>

 

 

 

 

Ummmm....it's a Ford?

 

Seriously though, maybe a vacuum leak?

 

Too fast an idle speed. If an engine without computerized idle speed control is idling too fast and refuses to come down to a normal idle speed despite your best efforts to back off the idle speed screw or air bypass adjustment screw (fuel injection), air is getting past the throttle somewhere. Common leak paths include the carburetor and throttle body gaskets, carburetor insulator spacers, intake manifold gaskets, and of course, any of the engine’s vacuum fittings, hoses and accessories. It’s even possible that leaky O-rings around the fuel injectors are allowing air to leak past the seals. Another overlooked item can be a worn throttle shaft.

A rough idle or stalling. A performance cam with lots of valve overlap can give an engine a lopping idle, but so can a vacuum leak. A really serious leak can lean the air/fuel mixture out to such an extent that an engine won’t idle at all. An EGR valve that’s stuck open at idle can have the same effect as a vacuum leak. So too can the wrong PCV valve (one that flows too much air for the application), or a loose PCV hose. The rough idle in these cases is caused by "lean misfire." The fuel mixture is too lean to ignite reliably so it often misfires and fails to ignite at all. Lean misfire will show up as elevated hydrocarbon (HC) readings in the exhaust—enough, in fact, to cause a vehicle to fail an emissions test.

Hesitation or misfiring when accelerating. This may be due to a vacuum leak, but it can also be caused by a weak or inoperative accelerator pump in a carburetor, dirty injectors, or even ignition problems such as a cracked coil, worn spark plugs or incorrectly gapped plugs.

An idle mixture that defies adjustment. When setting the idle mixture adjustment screws on a carburetor, the idle speed should start to falter as the adjustment screws are turned in to lean out the mixture. If the screws seem to have little or no effect on idle, you’ve either got a carburetor problem or a vacuum leak.

[RyanbabZ71]

Well i replaced the throttle position sensor today it brought the RPMs back down to a constant level doesnt "search" back and forth as much like it did before between 500-2K rpms.. Finally was able to pull off the codes and 1 was for the TPS and the other was for the MAF voltage above the max. I think I will try and clean before i buy a new one.

 

I know its a ford but I get double the MPG of my truck so back and forth to work its nice to save some $$$.