Just bought a SHO, couple questions.

[nickvisel]

Hey all, new to the community and not a huge mechanic type, but I like to know how to learn the skills.

Last week I just purchased a 1993 SHO with a five-speed and roughly 200k miles (and no recent 60k tuneup as far as I am aware) for about 700 bucks, so naturally I have a power steering fluid leak somewhere, along with some small amount of oil burning somewhere, and the AC doesn't work but windows down is OK because I love the intake growl. Also there's a valve clicking somewhere.

Drove it home from LA which is about 400 miles so I had a good test drive, so after getting to know the car a little, I have some questions.

It doesn't seem to pull as hard as I remember my mom's 92 pulling. In general, it doesn't accelerate like I expect it should, and specifically, it seems to have a relatively hard time pushing 7k rpms in first and second gear. It seems like idle runs just a little bit rough based on the exhaust note, but I haven't trained my ears to SHO idling tendencies.

I'm wondering what the most common causes of the degradation in performance on the engine's behalf is, and what's the best way to go around finding and fixing said problems.

Since I don't live in Phoenix, I'm considering making the car catless but before I do that I'd like to see what else would help the car breathe better.

Thanks a lot!
Nick

 

[bubba]

Welcome to the forum!.... Sounds like you get started on the 60k... Is there any oil in the plug well? (most likely there is) and is getting the spark it could be! The tapping could be, could be just the injector's firing!...(but maybe somebody will give you a better idea!

Run your codes on there it's not hard and will give you a good starting point! This website will tell some of the stuff www.shotimes.com I wouldn't make it catless, you'll lose your bottom end...and she'll be a dog!

Other than that I wish you luck...and You should check out the website and pull thoughs codes man, and search,search,search...

 

[SHOmethewayhome]

so... where in AZ do you live?

i have a code scanner, and i would also strongly recommend doing a 60K maintenance interval.

 

[pitaSHO]

60k that car for sure. The power loss could be a number of things, but it could be clogged cats or plugged mufflers, especially if it's wussing out on you at the top. I have a catless y-pipe that I will be converted to catted just to eliminate the rasp. I have 205k on mine, too, and it runs really good; after I replaced a piston. Since it's from California and it's an MTX does it have the EGR system on it? That could be the source of your rough idle. I would also check for a vacuum leak. If it does have the EGR system on it check the back of the intake and make sure there are no little vacuum stems that are missing a hose. There is a guy here locally that has a 92 EGR car and he was missing a vacuum line off the back of his intake. I just put my finger over the stem on the back of the intake and the idle smoothed right out. I know there are a lot of guys in the Phoenix area that could give you the knowledge you need to do the maintenance. Rod bearings, for sure.

Welcome!

Chris K.

 

[nickvisel]

Thanks for the responses!

@Bubba Thanks a lot! I'm assuming it's really easy to check for oil in the plug wells. Any explanation as to why holing out the cats loses the bottom end a bit?

@SHOmethewayhome Prescott Valley, Arizona. I visit Phoenix pretty regularly when I have a registered car (which currently my SHO is not and I already got one ticket for that..)

@pitaSHO I do believe there is an EGR system on it, I just don't know where to look, or I haven't been paying attention. The airbox thing with the air filter has a rip in it, I'm assuming, since there's a bunch of tape over it and I think it makes a slight whistling noise from the air being sucked in. About the idle, it stays the same at 900~950 rpm, it's just that the exhaust sound sounds rough; it's not like the engine is idling roughly.

I'll be posting a video on youtube soon so everybody can see it.

 

[bubba]

You just don't have the power at the bottom of the rpm range is what I meant to say! Just on take off!...... Oh and you might want to do the rodbearings also!

 

[Phoenix]

Welcome in

 

[Vnuk1]

Welcome...

 

[SHOtimer]

Welcome!

Their are a lot of great AZ guys, here. Post in the AZ section and maybe you will be close to some of them.

http://www.shophoenixproject.com/maint.htm

^^^^will help you through the 60k service.

Doug

 

[nickvisel]

The spark plugs are definitely oiled. What does this mean I should be replacing?

 

[Schumacher609]

I would start with an upper 60k service.

Here is a guide on how to do it: http://www.shophoenixproject.com/upper60k/upper60k.htm

Familiarize yourself with ShoPhoenixProject.com too lots of good maintenance guides there.

Oh and welcome in!

-Mike

 

[platoribs]

Scour the shopheonix site it is your best friend right now. After you get the engine tuned up you can start shopping for suspension and various parts, cause you'll be replacing a lot of parts over the next 6 months.

If last that long you'll probably know everything you need to be able to open you own SHO service shop.

You might also throw in the rag and buy something that hasen't been flogged (if your has) hopefuly you won't also have a bunch of rust to contend with cause that just makes everything so much more entertaining... twist\snap, turn/snap, pull/snap... the list goes on and on...

...but don't get me wrong once you get it working like its supposed to, what a blast!:wave:

 

[nickvisel]

It's in pretty good aesthetic shape, and I haven't seen a lick of rust on the body or in the engine bay. Guess we'll find out when I get the money and tools to start the 60k service.

 

[Schumacher609]

Maybe someone that lives near you will give you a hand/let you use their tools? Then you don't have to spend money on tools just yet. Post in the AZ subforum and see if you can't find someone to help.

Just make sure you do the full upper 60k all at once. If you replace plugs and wires with out replacing the seals and fixing the oil leaks first, well it will ruin the plugs and wires quick.

-Mike

 

[victorymike18]

... The airbox thing with the air filter has a rip in it, I'm assuming, since there's a bunch of tape over it and I think it makes a slight whistling noise from the air being sucked in...

Can you give a little more detail on this, or a picture?

If there is a rip in the rubber intake tube (between throttle body and MAF Sensor) then you may be getting some un-metered air coming into the motor, which can cause rough running.

Regarding the lack of pull at the top end: With ~ 200k miles, the insides of the runners may be thick with grime. A good cleaning of the intake manifold can help free up some power lost over the years.

(Just my $0.02)

Mike.

 

[nickvisel]

Yeah, I had considered just doing the plugs and wires for about two seconds then read up on the whole upper 60k guide they had, and it occurred to me that I'm leaking oil, I need new gaskets and crap, so I abandoned the idea pretty quickly. I do have a mechanic friend who's been working on a 300ZX TT for the last year or so, so he's got a lot of tools, but I might need some special tools, so I will definitely check out the AZ subforum.

Thanks a lot for the suggestion!
Nick

 

[nickvisel]

Okay, well, I took off the intake manifold with relative ease, partly because all the support brackets were MIA. The runner gaskets look nasty, and the parts that I can see of the intake are definitely a little gunked up.

I checked up on the spark plugs. Facing the engine from the front of the car, the front ones have a little bit of oil in the wells, and two of the wires were replaced. The rear plugs were literally soaked in oil. I'm assuming gasket and o-ring changes will fix this.

What really has me worried is the brackets just not being there. Is this a big deal?

 

[SHOCarGo]

I had a Ford where it burned oil all the time, and it turned out to be valve guides. so if it where me, and if i was taking the heads off to do an head gasket. then i would go and get the heads cleaned, the valves re guided, and get the head shaved just a little to resurfaced it..

 

[SHOCarGo]

but i have a question are the 3.0 motor tolerances or non tolerances

 

[rubydist]

Valve cover gaskets, plugs and wires will make your new SHO run a lot better and stronger.

The V6 SHO motor is not an interference motor, but I still wouldn't want to let a timing belt break.