I repalced the engine in my 1990 tracker. it has been great for 5K then Sunday it started loosing power it only hits about 55mph adn 4k rpm. I replaced the EGR the cat, added a header, free flow exhaust and the O2 sensor when I did the motor. I tried a new fuel filter, the intake is clear, plugs looked ok, can't find a vaccum leak, Timing is good, and I'm thinking it is a clogged Cat. It sounds/feels like it is starving for fuel/air or the exhuast is restricted. Are there any unique ZUki things or have I missed something. Thanks for the help. J

I repalced the engine in my 1990 tracker. it has been great for 5K then Sunday it started loosing power it only hits about 55mph adn 4k rpm. I replaced the EGR the cat, added a header, free flow exhaust and the O2 sensor when I did the motor. I tried a new fuel filter, the intake is clear, plugs looked ok, can't find a vaccum leak, Timing is good, and I'm thinking it is a clogged Cat. It sounds/feels like it is starving for fuel/air or the exhuast is restricted. Are there any unique ZUki things or have I missed something. Thanks for the help. J

If you think it's your exhaust (cat) unbolt the new header at the collector of your new exhaust and wire the exhaust up out of the way. Fire it up and head out on the road. If it's fast again, you've got a clog. Oh yeah, you may want some ear plugs.

Look at your plugs, and see what they tell you. Golden brown = good. black = rich. white = lean.

Did it suddenly loose power? Within a mile or so or after a couple of tanks of gas 200+ miles? If sudden, you may want to check cam timing, you could've slipped a cog on the belt...

Those are some good starting points to look at...

Good Luck, Eric

Tried the plugs they look great no errosion or fouling. I remember someone writing something about injctector or fuel pressure regulator beong troublesome. I hate to run loud but they may be they answer. Thanks if you have anyother insite please speak up. j

It won't be that loud.  You'll just sound like one of the little rice racers with a fart pipe on it.

Yea I guess all 1600cc can't be too bad. I just hope no one see me and thinks I have converted to CARS.

Don't know much about it but have heard of people having problems with a clogged carbon canister.

If you rev it up to 4k+, what happens at the tailpipe?  Do you still have a good flow of air?

Are you positive about the timing?  Could the distributor have gotten loose?

Does it have throttle body injection?  Can you see the spray from the injector?  It should be conical.  Some here have said their's isn't, but mine is pretty much a perfect cone.

It has good power until 4K?

ive got a 94 track fuel injected where would i look to see if i have a nice cone comen out the fuel injectors

Timing is perfect, I see spray but not conical, It has no power to 4k then it just tops out of power. I can see dust movenet but I need help to test flow, or I need a hand throttle. How much does and injector cost, how hard to rebuild? Thanks for all the ideas keep em coming some one will hit it.  

I see spray but not conical,

Apparently, that's common.  Injectors are expensive from parts stores, but you may be able to pick one up cheap on eBay (I just sold a throttle body with injector, fuel pressure regulator, and throttle position sensor for $40).

I can see dust movenet

I don't understand this?  {edit}  Ahhhh, you mean out of the tail pipe!  Yeah, it'd be good if you had a helping hand.  Maybe a broom handle on the accelerator pedal would reach.  If not you might try tying something onto the tailpipe that would give you an idea of the air coming out.

I need help to test flow, or I need a hand throttle

Actually, it'd be a good idea to test the fuel pressure.  You could hook up a fuel pressure gauge before the throttle body.  You should be able to work the throttle linkage from the engine compartment by hand.

I was also wondering how is the compression?
Have you adjusted the valves?
Was this a rebuilt engine?

ive got a 94 track fuel injected where would i look to see if i have a nice cone comen out the fuel injectors

I'm not familiar with the FI on different years. If the '94 has multi-port injection (an injector for each runner) then you can't see the injector spray.  If it's throttle body injection, like my '90, then you can remove the air intake tube from the top of the throttle body and see the injector and its spray pattern by looking down the throttle body while the engine is running.

A restricted exhaust is easy to check with a vacuum gauge.
Hook to manifold vacuum, start engine, note reading.
Rev up enigine and hold it, note reading. It should drop
when you hit the gas but come back up. If vacuum does
not come back up your exhaust is restricted.
Hope this helps, Samwise

 :DThanks for all of the help, I'll try these things this afternoon. I learned one more thing yesterday the large hose from the egr to the valve/filter above the egr keeps blowing off the bottom of the filter. I checked the vacum ports on it P Q and bottom it holds a vacum when air is applied to the bottom and P is plugged. The VSV sem to have power and work too. ANy more ideas?

A restricted exhaust is easy to check with a vacuum gauge.
Hook to manifold vacuum, start engine, note reading.
Rev up enigine and hold it, note reading. It should drop
when you hit the gas but come back up. If vacuum does
not come back up your exhaust is restricted.
Hope this helps, Samwise

Hey that's a good idea. Thanks... Even with a clogged exhaust it still would come back up but be real slow right? I mean the engine is still pumping air even though it's restricted.... Anyway, thanks for the tip that's much easier than dropping the exhaust.

-Eric

And, if it gets real clogged, the cat will glow red after a long drive(been there ).  But yeah, just take it off and go for a ride before you let it go that far.