Looking for lost power
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
Looking for lost power
When I put the pedal down to the floor the car screams but it doesn't seem to move like it used to (couple of weeks ago).
I think I get better acceleration from 3/4 throttle than from full throttle.
Any tips on what I should look into would be appreciated.
So far this year the car has new:
plugs
wires
rotor
Cap
Fuel pump
Fuel filters
Flushed and painted inside of gas tank
Flushed fuel lines
MAF sensor
MAF sensor was the most recent change. And timing wise was the closest to when the power went away.
I did notice a puff of smoke (light coloured) on start up from the drivers side manifold, possibly from under the heat shield.
Thanks
I think I get better acceleration from 3/4 throttle than from full throttle.
Any tips on what I should look into would be appreciated.
So far this year the car has new:
plugs
wires
rotor
Cap
Fuel pump
Fuel filters
Flushed and painted inside of gas tank
Flushed fuel lines
MAF sensor
MAF sensor was the most recent change. And timing wise was the closest to when the power went away.
I did notice a puff of smoke (light coloured) on start up from the drivers side manifold, possibly from under the heat shield.
Thanks
Last edited by 87 rag; Jul 31, 2004 at 05:44 PM. Reason: forgot something
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
Okay,
Maybe you need more info.
85 000 Miles on car, not many in the last couple of years until I bought it.
No codes showing.
I'm going to check my tranny fluid level and look for vacuum hoses that may have come off or cracked.
The exhaust leak may be tough to find but I will look into that as well.
Problem is it does not appear to be leaking from where the manifold attaches to the block.
Is it possible that this leak could throw off the o2 sensor?
What else should I check?
Thanks
Maybe you need more info.
85 000 Miles on car, not many in the last couple of years until I bought it.
No codes showing.
I'm going to check my tranny fluid level and look for vacuum hoses that may have come off or cracked.
The exhaust leak may be tough to find but I will look into that as well.
Problem is it does not appear to be leaking from where the manifold attaches to the block.
Is it possible that this leak could throw off the o2 sensor?
What else should I check?
Thanks
Last edited by 87 rag; Aug 1, 2004 at 08:25 AM.
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
No one has added a word of advice but I see people are reading it so I will go on.
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I remove it and go with a straight pipe?
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I remove it and go with a straight pipe?
Last edited by 87 rag; Aug 1, 2004 at 05:51 PM. Reason: need to add something
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
No one has added a work of advice but I see people are reading it so I will go on.
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I just remove it and replace it with a straight pipe?
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I just remove it and replace it with a straight pipe?
Burning Brakes
Joined: Jul 2004
Posts: 956
Likes: 0
From: Mesquite Nevada
Originally Posted by 87 rag
Okay,
Maybe you need more info.
85 000 Miles on car, not many in the last couple of years until I bought it.
No codes showing.
I'm going to check my tranny fluid level and look for vacuum hoses that may have come off or cracked.
The exhaust leak may be tough to find but I will look into that as well.
Problem is it does not appear to be leaking from where the manifold attaches to the block.
Is it possible that this leak could throw off the o2 sensor?
What else should I check?
Thanks
Maybe you need more info.
85 000 Miles on car, not many in the last couple of years until I bought it.
No codes showing.
I'm going to check my tranny fluid level and look for vacuum hoses that may have come off or cracked.
The exhaust leak may be tough to find but I will look into that as well.
Problem is it does not appear to be leaking from where the manifold attaches to the block.
Is it possible that this leak could throw off the o2 sensor?
What else should I check?
Thanks
Originally Posted by 87 rag
No one has added a word of advice but I see people are reading it so I will go on.
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I remove it and go with a straight pipe?
I checked the tranny fluid and the vacuum hoses, everything seems normal.
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going? I thought that the cats got hot and glowed red when they were blocked.
Could this rattle cause power loss?
I have no emission testing where I live, should I remove it and go with a straight pipe?
Race Director
Joined: Jan 2004
Posts: 18,726
Likes: 710
From: Bergen County, NJ
I'm not the expert but, when changing the MAF, they recommend changing the Burn-off & power relays. Did you do that??
Or put the old MAF on see what happens [since that was the last thing done before you 'lost power'].
Or put the old MAF on see what happens [since that was the last thing done before you 'lost power'].
Race Director
Joined: Jan 2004
Posts: 18,726
Likes: 710
From: Bergen County, NJ
Originally Posted by 87Clwy
Could be the cat is going. If you can hear something rattling around inside it, it probably means the 'honey comb' inside is breaking up. Could be partially blocked, which would mean it wouldn't necessarily glow red--but could be part of your problem.
I know because it happened to me.
Melting Slicks
Joined: Jan 2003
Posts: 2,167
Likes: 0
From: What did the 5 fingers say to the face? SLAP!!
Originally Posted by 87 rag
I have a rattle in the main cat and it is not a loose cover. Does this mean it is going?
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Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
I may have a cracked manifold,
I see the exhaust come out from under the heat shield on the drivers side when I start the car.
It will be a pain to check but I will look into it.
I did not replace the relays with the MAF. I saw that I should have after I changed it. I suppose I still should.
The rattle will kill power...
Is it possible that the rattle will create back pressure and cause exhaust to leak out of a manifold seal on start up?
Thank you for all your input.
Nothing for a day, then bam.
I see the exhaust come out from under the heat shield on the drivers side when I start the car.
It will be a pain to check but I will look into it.
I did not replace the relays with the MAF. I saw that I should have after I changed it. I suppose I still should.
The rattle will kill power...
Is it possible that the rattle will create back pressure and cause exhaust to leak out of a manifold seal on start up?
Thank you for all your input.
Nothing for a day, then bam.
Burning Brakes
Joined: Jul 2004
Posts: 956
Likes: 0
From: Mesquite Nevada
Originally Posted by 87 rag
The rattle will kill power...
Is it possible that the rattle will create back pressure and cause exhaust to leak out of a manifold seal on start up?
Thank you for all your input.
Nothing for a day, then bam.
Is it possible that the rattle will create back pressure and cause exhaust to leak out of a manifold seal on start up?
Thank you for all your input.
Nothing for a day, then bam.
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
I will inspect the manifold.
Sunday night I took the car out and it seemed pretty good.
Not 100 % but I would say 90 or so.
I was happy just being able to drive it.
On the highway on the way home the engine light came on for a couple of minutes and off again.
Got home and used the code reader, code 45.
Seems to be in the area we were talking about.
I thought this was a good thing because it finally told me where to look.
Problem is, I shut the car off and Monday morning it wouldn't start. Turns over, won't fire. If I give it gas it will fire but as soon as I let go of the gas it won't idle, just quits.
I'm about ready to put it on a flat bed and have it taken to a shop but the $$$ that will cost compared to figuring it out myself.
Please help.
Sunday night I took the car out and it seemed pretty good.
Not 100 % but I would say 90 or so.
I was happy just being able to drive it.
On the highway on the way home the engine light came on for a couple of minutes and off again.
Got home and used the code reader, code 45.
Seems to be in the area we were talking about.
I thought this was a good thing because it finally told me where to look.
Problem is, I shut the car off and Monday morning it wouldn't start. Turns over, won't fire. If I give it gas it will fire but as soon as I let go of the gas it won't idle, just quits.
I'm about ready to put it on a flat bed and have it taken to a shop but the $$$ that will cost compared to figuring it out myself.
Please help.
Le Mans Master
Joined: Feb 2002
Posts: 7,858
Likes: 2
An exhaust leak in front of an oxygen sensor will throw them off, yes. Enough to effect performance for sure. It will cause the sensor to think the exhaust is lean and so the ECM will attempt to compensate by adding fuel, i.e. you will run too rich. Also check how tight your coil wire fits. Although my '95 uses difference ignition setup than your 87, I have found the fit of stock GM wires to be not so great-- kind of loose. I put a slight crimp on the end of my coil wire that attaches to the terminal on the coil, which made it fit much more snuggly.
Thread Starter
Drifting
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
Thanks guys, sounds like I need to address the exhaust situation before I can tell if something else is wrong too.
I should be able to at least tell what is wrong, then I'll decide if I can fix it myself or not.
I was thinking about some 2149s, Didn't feel like spending the money just yet but I'll do that before replacing a cracked manifold with another manifold.
Thanks again for all your help.
I should be able to at least tell what is wrong, then I'll decide if I can fix it myself or not.
I was thinking about some 2149s, Didn't feel like spending the money just yet but I'll do that before replacing a cracked manifold with another manifold.
Thanks again for all your help.