Performance lacking in my 1994 SHO

[alphaseinor]

I have a 1994 SHO
Automatic
AC... blah blah blah....
120,000 Miles.

I picked this car up for $500 in a police auction. (has new blisteen shocks and brand new aquatred 3 tires... Ford (Sony) 10 disk cd changer, leather in perfect condition, worth $500??? I think so...)

I have driven many SHOs and this is a very slow SHO (0-60 in about 10-12 seconds).

The car wants to smoke when at idle, but not while acellerating. it does not smoke at startup.

I am assuming the previous person did not ever do anything to this car other than an occasional oil change. the paint is flaking, and is cracked on the roof by the sunroof, and the hood only. there is minor hail damage.

I think the catalytic converters may be clogged due to the smoking problem. From my previous experience with my 1984 dodge colt turbo, the catalytic converter would explain the lack in power.

Since I have never worked on a SHO, where should I start. After I have all of the problems fixed, what performance modifications are there for this car?

The automatic transmission is the original for this car and is starting to partially shift and then slam into the 2nd gear. I will probably replace versus rebuild due to the lack of decent automatic shops here in town. Any suggestions?

Top speed is about 120 MPH. I have taken my mom's 5 speed SHO when new to 140.

The check engine light will pop on if driven cross country, stopped, shut off, started, driven hard, and then cruise at 60. The light will shut off in about 1 second. Where is a good place to get a code scanner, is there a manual way of doing this?

Brakes are warped (figures...), any suggestions other than the crap OEM stuff?

Thanks,

Brian Hague

 

[alphaseinor]

oh yeah,

smoke is coming from the exhaust, and is black.

it's not a lot of smoke, but it is smoking...

 

[FOSHO94]

bad head gasket perhaps

 

[yamahaSHO]

FOSHO94:
bad head gasket perhaps

No, it would not be a bad head gasket. A bad head gasket would allow coolant to get into the combustion chamber and coolant does not leave black smoke. When you combust coolant, you will have a white smoke. If the smoke is black, it sounds like it is running rich.

If you are looking for a code scanner, you can buy one at Auto Zone or go find a paper clip. You might want to look into a 60/120k tune up. Your cat problem could just be part of your problem. You have to single out other causes by completely going over the motor and all of its sensors and electrical connections.

 

[svtman]

Read your codes here - all you need is a jumper wire:

http://www.midwestsho.com/codes.html

As far as the black somke - that means a rich condition. Your codes will probably point to the culprit. As far as the ATX - they say Doug Lewis makes the best ones. The stock brakes on the 96 can be retrofit to fit your 94 with a simple kit - makes a fair difference they say.

 

[projectSHO89]

Cat's probably. Head gasket failures are rare on these engines. You are not exhibiting any symptoms of a blown gasket.

If the engine mixture were overly rich, that would explain the black smoke, bad cats, and a CEL.

Cel codes can be pulled with nothing more than a paperclip. See the FAQs at www.shotimes.com www.midwestsho.com or visit http://dalidesign.com/hbook/eectest.html

A rich mixture is most commonly caused by a bad thermostat, bad temp sensor, leaking injector, or something else that upsets the computer.

BTW, the total in my signature is WAAAY understated...

Steve

 

[luigisho]

The mileage indicates you are due for an expensive maintenance routine. Run a search in this section for 60k service (atx cars get it much later-around 100k). You can check it out on http://www.shotimes.com too. If you do suspect cats an exhaust shop should be able to perform a backpressure test to check air flow. I'm sure if it was not cared for there are quite a few parts that should be replaced- starting with the timing belt.

 

[alphaseinor]

I found documentation on the 100K and 60K maintenance done early (95k and 50k respectively).

I get the following codes

136 - (running code) Oxygen sensor not switching/system lean Left or Front HO2S.

175 - (memory code) Oxygen sensor not switching - system was at adaptive limits - Left or Front HO2S.

189 - Fuel System was lean at part throttle - Left or Front HO2S.


I see a pattern... smoke, lean?... maybe the computer is reading lean, but running it rich to adjust out of lean condition?

Should I replace the HO2S?

 

[projectSHO89]

Front O2 sensor is dead.

Probably why the engine is running rich. Note: the code says lean because that's what the dead sensor is still reporting after the mixture was enrichened to the limit.

Bet the front cat is bad, too, by now.

BTW, you never indicated under what conditions you were seing the black smoke. If it's under heavy acceleration, then it's noremal to a point.

Steve

 

[alphaseinor]

The smoke starts becoming visable about 30 seconds after starting the engine. heavy accelleration *LOTS* of billowing black smoke. I heard I should replace both O2 sensors, can I get away with replacing 1 until friday?

The smoke is black, like an out of tune diesel. Smells like my '65 Mustang.

I just removed the 'cone' from the inner fender, it'll now smoke the tires as well... smoke from the front and the rear... Cool!

Hi ** hi **... it's off to Autozone we go...

If the cat is bad (will be checked on monday) which Y pipe would be best? I don't have emmissions, so... anything goes.

 

[luigisho]

You can get away with anything you want since it still runs. If you want to replace one now and one later-sure. I would try to get 2 new ones on there for peace of mind in knowing those are new and should be trouble free for some time.

New y-pipe? I'd get the Sho Shop or Performance Plus models to get better exhaust flow. I like my SS pipe, but others have had delayed delivery problems with them to put it mildly. Look around and make an informed choice before you order stuff like this.

 

[svtman]

Yeah - definetly replace the failed O2 sensor quickly. Replacing the other one is a judgement call. I had one fail and I replaced that single one. Why - because I tested them both as per the instructions on www.shotimes.com and the other one passed (the computer was right!) Unless you want to replace parts that are working...