Finally getting some highway time on my 87 duke for the first time since i bought it last year. Im new to fieros and still have a lot of questions. Ive done a tune up on the car, new plugs, wires, and fluids. However the car feels like it is severely starved for power and is consuming lots of gas. The previous owner knew this, but i thought it was due to the fact that she was only running on two cylinders (one spark plug wire was melted in half, and another one wasn't even installed, and the o2 sensor looked factory original) i did a compression test on the engine when i bought it and all four cylinders passed no problem.

It takes FOREVER to accelerate in this car from a stop to normal highway or even city speeds, and going up any slight incline i have to shift from 5th to 3rd just to make it up hill. Also, leaving a stop light, it poofs out a noticeable amount of blue/white smoke but doesn't do it while driving and the oil quantity still looks good. The fuel consumption is tremendous and the exhaust smells kind of rich. Almost half a tank in 70-90 miles. Sorry for wall of text, so let me summarize:

Is the lack of power normal for this 2.5?
Should i be having trouble accelerating like this or maintaining speed on hills?
What could be up with the smoke output upon leaving the stoplight, without oil consumtion?
Could the outrageous fuel consumption be an uncalibrated gauge? i don't wanna run out of gas on highway to check...

I'm getting good fuel pressure on a new injector. Could these problems be a clogged catalytic converter? Mine looks like it is the original one from the factory 25 years ago, and the exhaust note sounds kinda rough at idle. almost "lawn-mower-ish."

Again, sorry for the long story, but i just wanted to give you guys as much information as possible to help me try to diagnose this.

Yes it could be a clogged cat. Take out the O2 sensor and see how the engine runs.

If that doesn't improve the performance try this - Electrically unplug the MAP sensor (the green three tower plug) and see if that shows a marked improvement on performance.

Youre saying remove the o2 sensor, not just unplug it? let it get up to normal temp while im trying this one test at time? Also how will replacing the catalytic converter with a "test pipe" affect my exhaust note? Anything would probably be better than how it sounds now.

Yes removing the O2 sensor. It will make a big leak in your exhaust. If the problem is that your exhaust is plugged past the O2 sensor, power will improve. This is only as a test. Removing the O2 sensor is the easiest way to give a temporary bypass to the cat/muffler.

[This message has been edited by phonedawgz (edited 04-12-2012).]

blue/white smoke?
Smoke only off the line? May mean intake valve has dead seals.

full time too? May mean above and/or a coolant leak.
A few places can inhale coolant and pass compression test.

If you think a coolant leak then likely needs a cat after you fix the leak. Coolant will kill a cat. (both kinds... Dogs and people to.)

Also check that TBI is reaching WOT.... Stretch throttle cable can be a major power problem.
See my cave, DIS and 700tbi 4cyl engine section. Throttle cable in general engine

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Make sure the EGR is closing all the way also, If it is sticking open it will cause a vacuum leak and poor gas mileage.

Just something to check.

Common issue on 87 dukes.

Any codes?

[This message has been edited by mike-ohio (edited 04-12-2012).]

quote Originally posted by mike-ohio: Make sure the EGR is closing all the way also, If it is sticking open it will cause a vacuum leak and poor gas mileage. Common issue on 87 dukes.

This EGR is on many GM engines... All Duke Fiero, Not just 87.

AZ has OE style EGR. Avoid Generic ones.
Covered in emissions in cave...

It isn't poofing blue/white smoke all the time, only at take off from waiting for an especially long traffic light. It doesn't do it at all during short or momentary stops, and i don't notice any smoke while driving (as safe as it is to drive while staring at the back of my car...) Someone where i work has suggested possibly bad oil control rings as an alternate or additional problem to the valve seats? the cylinders would still pass compression test, but might allow for oil into the chamber to build at long idles.

No codes are getting thrown.

Would it be better to replace or just delete the cat?

Also, could/should i delete the EGR? i have read that dukes don't care much or at all if one gets deleted. But, couldn't that hurt MPG or performance. Not that my performance could get much worse.

I'm a little worried to do to the check with removing the o2 sensor. Seems like that would allow hot air to just blast my firewall where a couple of important things seem to to be routed.

Kinda sounds like it is choking on too much fuel? Any idiot lights on? An o2 sensor that is bad should usually give a code, and would cause too much fuel to be used.

Also wanted to note removing the 02 sensor and driving will blow hot air on electrical wires won't it? Phonedawgs is experienced, I just wanted to make sure that is what he said and is safe?

I would cut the cat out. You could always splice it back in, or if it was the prob you'd bneed a new one anyway.

[This message has been edited by 2.5 (edited 04-13-2012).]

quote Originally posted by blacknblue: 1.It isn't poofing blue/white smoke all the time, only at take off from waiting for an especially long traffic light. It doesn't do it at all during short or momentary stops, and i don't notice any smoke while driving (as safe as it is to drive while staring at the back of my car...) Someone where i work has suggested possibly bad oil control rings as an alternate or additional problem to the valve seats? the cylinders would still pass compression test, but might allow for oil into the chamber to build at long idles. No codes are getting thrown. 2.Would it be better to replace or just delete the cat? 3.Also, could/should i delete the EGR? i have read that dukes don't care much or at all if one gets deleted. But, couldn't that hurt MPG or performance. Not that my performance could get much worse. 4.I'm a little worried to do to the check with removing the o2 sensor. Seems like that would allow hot air to just blast my firewall where a couple of important things seem to to be routed.

1. Smoke points to intake valve seals. Any smoking will cause problem w/ the cat.

2. maybe but if cat is bad... muffler could to block to from parts of dead cat..
Fix the cat after fixing smoking problem. New cat will not cause power loss, lower MPG, etc...

3. 87&up likely will hate you. EGR is a dumb item but ECM Ignition timing expect EGR to be there. A test: sandwich a section of a pop can to block EGR. OEM style EGR can only block 1 hole but should help to see... Just a scape 1x2 in and loosen the EGR, sandwich (start at TBI side), tighten...

4. Yes, running engine long w/o O2 or crack pipes can fry wiring etc. Be very careful w/ that test. Should show if helps or not very quick.
Needs to warm the engine?
pull out sensor cold and put in back a bit loose
warm up the engine then shut off
Carefully remove o2 again. (tip, Duke's exhaust manifold cools fast...)
test.

And again... check that TBI is reaching WOT.... Stretch throttle cable can be a major power problem. I had this problem in the past... W/o mod'ing the cable, I chose to mod the pulley. (auto trans... Doesn't mess on engine end of throttle cable. Still not sure if I like it but mod the pully is reversible...)
See my cave, DIS and 700tbi 4cyl engine section. Throttle cable in general engine

[This message has been edited by theogre (edited 04-13-2012).]

Thanks everyone for the help so far, been so busy this week i haven't had a chance to test the EGR yet. As far as the intake valve seals are concerned, what exactly am i looking at? Removing the head and having it rebuilt? I've always heard to never put a fresh head on a tired bottom end, or else rings and other parts in the bottom end area would fail quickly. Previous owner claimed that the engine was rebuilt 20-30k miles ago, built never produced any rebuild paperwork, so this was likely just a gimmick to help her sell the car (i was gonna buy it anyway.) Also is it safe to just hacksaw everything in front of the catalytic converter aft off? I'm super broke until next weekend and due to an unfortunate set of events, i'm depending on my gas guzzling fiero as a daily driver right now for 40 mile round trips to and from work. so to summarize:

1. is it safe to have my head rebuilt and reinstalled on an engine with a (probably) tired bottom end? Even if i drive very cautiously from now on?

2. is it safe to just hacksaw my entire exhaust off right in front of the CAT and drive it daily 40 miles for a week?

3. Thanks again everyone, and Ogre, i will take a good hard look at that throttle cable and EGR this weekend before i commit to myself to CAT or head rebuild

I know this seems kinda to simple but on 2 out of the last 3 Fiero's I have owned the gas pedal was bent. They were not reaching WOT and the cables seemed to b fine. I grabbed the pedal and pulled straight up it takes a little bit of pressure and you will feel it move if this is the case! Both cars exhibited a lack of power as you state im just not sure about the gas mileage thing. One would assume no WOT better mileage so just my 2 cents. And yeah I have removed my cat and EGR and actually gained a few MPG and some power 84 SE duke. There are no emissions in maine and antique auto does not need inspection.

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If it works take it apart and find out why

quote Originally posted by theogre: AZ has OE style EGR. Avoid Generic ones. Covered in emissions in cave...

I have to use a generic-type EGR on my setup (SD4 valve cover, etc.). It works just fine and passes emissions. The OEM type is too big, and won't fit.

Just went and did a good general visual inspection of the EGR, vacuum is routed to the correct port on the throttle body and has no leaks, or deteriorated areas on the vacuum hose. Looks the original one from 1987, i'll be replacing it on payday.

As far as the CAT... since i'm super broke this week and relying on the car as a daily driver (and gas is super expensive), would it work for a week to just delete the entire exhaust starting before the cat? Or how about this: Could i get the old drill out and drill a good sized hole in the bottom of the cat, facing the road to relieve some pressure from the system for a week before i can get to exhaust shop?

make sure your IAT and engine coolant temp senors are functioning as they should before you start drilling holes and **** in your car- clogged cat is a tremendously over-used diagnosis on this forum.

Found the problem. Upper coil pack was burned out. If it happens again, does anyone have a good part number for the ignition coil control module?