Bogging with anymore than 1/4 throttle

This has been an issue since I bough the car. Any more than 1/4 throttle and it's LOSING power. I can actually feal it. I've tried changing plugs, wires, filters (including air), PCV, cap, rotor... Just did a head gasket (didn't end up needing it...long story) and last time I checked the compression it was good. I"m driving about 60mph and like an old lady times 10. I mean, I accelerate so slow it's almost dangerous. I'm getting 38 with a 1.0L 5-spd and thats BEST CASE. It has no power to pull itself up hills (mainly because I can't accelerate past 1/4 throttle) and I also checked the fuel pressure which was dead-on-balls. I've sprayed the hell out of the intake temp sensor and the throttle body with carb cleaner and checked/adjusted the timing to about 5*. I'm out of ideas here. No check engine lights and I'm sure it works because if I pull the intake temp sensor it'll throa CE light for a while then go out. I dont have any brake drag, good cooling system with a new radiator and thermostat and a brand new exhaust from the last cat---back.

I'm out of ideas!! I've got a 4cyl and it's a rocket compared to this pig. The 4-door 4ycl gets the SAME MILEAGE... SOMETIMES BETTER than the 3cyl 2dr PLUS it's got about 4x the power.

One other thing I'm seeing is if I stomp on the pedal it has a delay before it winds up. It's not instant like the 4cyl. This car is even slow accelerating downhill (I'm completely serious).

Any ideas? I'm seeing posts about o2 sensors and MAP sensors but those are all serious money and I dont want to be into this car for anymore than I have to. There's nothing worse than replacing parts you dont need! Just getting it to where it is (road worthy (windshield, transmission, clutch, tires...endless)) has been an expensive project.

Any tips would be great.

Thanks, Scott

Sounds like air is getting in where it should not (vaccum leak).

Are you getting the same result when you pull the throttle cable from under the hood? (I ask, so that you can eliminate any mechanical problem with the pedal or cable)

It sounds like a few different problems that could be happening. The easiest to check is perhaps a blockage in the exhaust(aka plugged catalytic converter). It could be the case since it's still the old cat on a new cat-back system. It's not too un-common at all on older cars, and will cause exactly the problem you're having right now. Try disconnecting the exhaust at the manifold(yea, it's gonna be loud) and see if the engine revs freely. The 3 banger should give you pretty decent throttle response. Also, you may want to see if your TPS is calibrated properly. It could be mis-adjusted, or just dead. A used TPS isn't hard to find. There's plenty of guys on here who probably have spares from old dead motors lying around :lol: .

You know I initially thought it was clogged cat because it felt and sounded like it just couldn't dump the air. I later had a break in the exhaust where to does a 90* and heads under the engine (due to bad motor mounts and horribly rotten plumbing) and while it was cracked... which was pretty bad, it still didn't have power. In you experience do you see more cat problems with the one @ the engine or the lower one?

When I had the exhaust fixed I specifically asked for the cats be to be checked but I thought that required it to either be removed or holes drilled in either side to test flow? Neither was done. Infact, I dont think they did anything. 26,000 miles later I'm still driving this slow pig and the mileage has gotten even worse over the last 2 weeks.

I'll pull the exhaust this weekend, piss off my neighbors and give it hell. Hope this turns out to be the problem. if it is, there's no way to clean a cat is there? Replacement only?

If it is a pre 96, I would just gut out the cat. I did on my 92 gmc jimmy. You can put it back on and have great air flow through it. I am having about the same problem only mine is running too rich!!!!! I am going to gut mine this weekend. I am also going to run all new vaccuum lines too. Hope this helps.:grinyes:

If it is a pre 96, I would just gut out the cat. I did on my 92 gmc jimmy. You can put it back on and have great air flow through it. I am having about the same problem only mine is running too rich!!!!! I am going to gut mine this weekend. I am also going to run all new vaccuum lines too. Hope this helps.:grinyes:
LOL, I was about to suggest that. Stick a long screwdriver in the pipe, shatter the element, then dump it out. If they do e-testing where you live, replace it. It will get quite a bit louder without the element in the cat though. The cat does a pretty good amount of silencing. In my experience, I've never worked with, or seen a metro with 2 cats. Is yours a late model metro?

Mine's a 96. You know... the middle one might be the second muffler. Thinking back to when it was on the lift, I dont recall 4 cavities under there. Maybe I'm wrong about the 2 cats. What are the implications of gutting out a cat on a 96+? My state (NH) is supposed to be doing emissions soon but they will definatly be pretty relaxed. That, and the amount of emissions the metro gives out, I can't imagine I'd fail no matter what I did.

One other think I just remembered, I was picking up a couple doors for another car project at the yard a few months back and stuffed them in the Metro. Of course they didn't fit.. they were fullsize coupe doors (Dodge Neon) and I ended hanging them out the hatch. This was the first time I ever drove with the hatch partially open and the entire drive all I could smell was rich fuel. It was definatly coming from me. It wasn't stinky eggs, it was unburnt fuel. Dont know if this helps the hypothisizing??

Sounds like you're runnin really rich to me. Unfortunately, you can't gut your cat. There's an o2 sensor down there too. You'll need to replace the cat :( Since yours is an OBD-II, the ECU relies a lot on the oxygen sensors. You could have faulty sensors, sending the computer into open-loop mode. Could be running so rich it's drowning itself. That would explain the poor throttle respose and fuel mileage too. When you disconnect the cat, you're gonna get a check engine light most likely. Check the cat.. If that's ok, I'd check the adjustment of the TPS, and perhaps replace the o2 sensors. They're usually good for 50k anyway. If you have over 100,000 on them, they're definately due. Also, a bad o2 sensor over time will pretty much destroy the cat too. Perhaps you have a few issues going on.
Oh yea, that second "bump" in your exhaust is just a resonator. Basically a pre-muffler.

If you go back thru my older threads, you'll see that my '93 Metro 3 cyl had that same
throttle business that "DieInterim" (Blake) likes to call the "sweet spot".

My engine did that and eventually stopped running. I changed the MAP and the one O2
it has in the exhaust manifold. Didn't help.

My Metro is sitting in the driveway with the TB halfway off waiting for decent weather
for me to get back at the damned thing.

I just wanted to say that this problem of your's seems to be quite common with Metro's!
Quite a few threads in this forum about "bogging down"....
I, too, would like to know how this happens. Is this an Engine Confuser Module (ECM)
problem?

BTW - HOW does one "calibrate" the TPS - that thingie on the opposite side of the TB
that rotates with the throttle and has a Potentiometer within it?

HOW?

DoctorBill

PS - when I bought MY '93 Metro from a Montana guy, it had no Catalyst! Straight pipe
to the muffler! Loud.

i had same problem in a 94 and thought i had replaced everything that might have solved the problem but it still bogged down and didnt want to go over about 60 mph. fuel pressure checked fine but when i pulled the return line off while engine was running nothing was coming out of it. fuel pump was pumping pressure but no volume, replaced it and its been running fine ever since

PS - when I bought MY '93 Metro from a Montana guy, it had no Catalyst! Straight pipe to the muffler! Loud!

There's an o2 sensor down there too. You'll need to replace the cat Since yours is an OBD-II, the ECU relies a lot on the oxygen sensors.

In 96' downstream O² sensors were introduced, so like zuke said, you gotta have a cat. Too bad. Cats are okay, as long as they are maintained or replaced regularily. Years ago I had my cat cut out, just to avoid these problems (no emissions testing in Alberta! :grinyes: ) It is louder now, but now too much. Glad I kept the resonator though! While I was at is, I had the muffler replaced and larger pipe (same as the exhaust manifold size.) There was a definite pickup in power!

My 3 banger (95) only bogs down going up long hills on the highway.

Jai

I know Interim hates me posting Teamswift links :screwy: But here's some good info on adjusting your TPS.
http://www.teamswift.net/viewtopic.php?t=19119

And on that subject, if most people on here take a look in the FAQ section there, just about any question that you could possibly have is already answered there. And there's a lot of cool tips and tricks there too.

Jai, I feel ya on the no cat thing, lol. I had a straight 2 1/4" pipe coming right off my header, no cat, no resonator, to a straight-through Thrush turbo muffler. Standing behind it idling, I could feel the asphalt shake. It's not bad with the top down though. But with the top up, you can barely hear yourself think at 70mph :(.

Does it have the problem when you first start it up also?