Engine Loses Power

[RickS]

First, my name is Rick. My wife and I both picked up a couple firebirds just so we could join this website. ;) But really.. they are hot looking cars!

My wife's car is a 1996 firebird with the 3800 Series II and manual tranny. We test drove it and it ran wonderfully. I checked it out and all seemed ok. No major oil leaks, no smoke, no rapping or tapping. It did have a Check Engine Light. I checked and it was a P0441 (Evaporative Emission Control System Incorrect Purge Flow) I looked under the hood again and found a line unplugged that ran to the EVAP Purge Relay. I fixed that and reset the code. Fixed that problem. We drove it home. Insured & registered the car, and then I drove it to work the next day, on the way into work I put in gas at the local station that I always use and finished my drive to work (about 2 miles) and the ride was smooth.

When I got out of work, I started the car and let it idle a moment while talking to a co-worker. It idles fine. I got in and took off. As I was accelerating I felt the engine bog down at about 2.5 to 3k RPM. I shifted and it was worse. I pulled over and the car idled fine. While in neutral I punched the gas a little when it hit 2 to 3k RPM, the car would spit, sputter and bog down.

I put some dry gas in and let it sit, assuming it was possibly a burst of water in the fuel. I rocked the car a bit and let the car idle for 10 minutes. That didn't resolve the issue.

I checked again for Check Engine Codes and there were none. I unplugged the EVAP Purge Relay again to see if that was faulty, and perhaps why it was unplugged. It made no difference. (It did set a 'pending' P0441 code, which I expected)

I crawled under the car to check for red hot or bulging catalytic converter, that seemed fine.

I have searched/read the posts here and many people who had similar issues stated the issue could be the fuel filter, fuel pump, coil pack, wires/plugs, or a plugged cat. Sadly, the threads I found were not resolved or the original posters didn't make a conclusion post.

I assume that if it was misfiring from bad plugs, wires, coil, etc.. I would get a Check Engine Code, correct? I assume the cat would give a code too? So, at this point it leads me to assume it's the fuel filter and/or fuel pump?

Any opinions or ideas before I tackle this?

Rick S

[cam98aro]

Re: Engine Loses Power

sounds like a clogged fuel filter to me

it would run really rough if it were a misfire

[RickS]

Re: Engine Loses Power

I pulled the fuel filter and replaced it with a new one. Still didn't work. The car ran, just didn't have much power.

I decided to see if I could limp the car to the mechanic (about 20 miles) and it made it 8 miles. The check engine light started to flash on and off, and the temp started to rise. I pulled over and let it cool. There were 2 codes.. one was P0300 (random/multi misfire), the other was P14XX (I dont recall the code). I pulled the dipstick and the oil was a quart low (it was full a couple days prior) but the oil looked ok (no water). I pulled the oil fill cap to add a quart while I allowed the car to cool and noticed a little white foam and a few drops of antifreeze on the inside of the cap. Once the car cooled I checked the radiator and there was no oil in there (but the water/antifreeze was rusty/dirty and due for a flushing)

At this point I assume it's a head gasket or perhaps a head. I assume the seller doctored it with something so it would drive (it started, idled and ran fine) when we picked it up. We got about 12 to 20 miles out of the car before this happened.

Tomorrow a flat bed is picking the car up beside the road and taking it to my mechanic, who will try a compression test and if all else fails we will pull the heads off and take them into the machine shop.

On a bright side, my v6 engine (not my wifes, described above) is back from the machine shop, freshly rebuilt from the bottom up. Hopefully in a day or two, I will have my 97 firebird on the road.

Any other ideas or suggestions for my wifes car?

Rick

[winnipegcamaro]

Re: Engine Loses Power

i also have the same problem. i am brining my car in tomorrow for a diagnostic test and maybe well see if they can find out, but ive been reading and looking as you have and am still inconclusive. when i rev my power also cuts out and bogs down as u said, i have ordered my magna flow cat and was soon goin to order msd wires and ngk plugs, but i cant find shipping to canada for them :(. but if they figure out the problem ill post it tomorrow maybe it can help you or your info can help me :).

[RickS]

Re: Engine Loses Power

The car will be delivered to my mechanic today, but he will be unlikely to mess with it right away. He is still putting the engine back in my car (which I just had rebuilt) and I am unsure what other projects he has going, though perhaps since I am a good customer he will bump my wife's car to the top of the list.

I will keep you posted.

Rick

[chevy the kid]

Re: Engine Loses Power

it's the intake gaskets. Once there were changed there is no water on my oil cap.

[95redslp]

Re: Engine Loses Power

i was just giong to suggest what he did... could be the intake manifold gasket i hear they are a problem.

[RickS]

Re: Engine Loses Power

How do you test/check for a bad intake manifold gasket?

Rick

[Moses]

Re: Engine Loses Power

note: I'm not an expert, if any of my info is wrong and someone else knows better, let me know.

The intake manifold gaskets will usually leak and mix coolant and oil. However, there are some leaks that leak out air.

Mainly it would seem as if you're losing compression the motor needs, and bogs out around your RPM range. If you still have it, and a gauge to check the compression in the cylinders with, do so, that will point to either the head gasket ( if you're losing a lot of compression ) or the lower intake manifold.

I can't be positive, I've never had to change any of the gaskets on my motor yet...knock on wood.

I'm at 205,000 miles.

[insaneABOT]

Re: Engine Loses Power

Well you are right about water being in the oil; another thing that you can do is to open the radiator cap and rev the car to see if the water forms bubbles if so expect to have a bad intake manifold gasket or head gaskets that are bad.

[Moses]

Re: Engine Loses Power

Well you are right about water being in the oil; another thing that you can do is to open the radiator cap and rev the car to see if the water forms bubbles if so expect to have a bad intake manifold gasket or head gaskets that are bad.

Yeah, but it could cause air to be sucked into the coolant system which is bad. =(

[LETZRIDE]

Re: Engine Loses Power

i also have the same problem. i am brining my car in tomorrow for a diagnostic test and maybe well see if they can find out, but ive been reading and looking as you have and am still inconclusive. when i rev my power also cuts out and bogs down as u said, i have ordered my magna flow cat and was soon goin to order msd wires and ngk plugs, but i cant find shipping to canada for them :(. but if they figure out the problem ill post it tomorrow maybe it can help you or your info can help me :).

summit racing is where I bought mine they shipped to me here in Toronto, ON

anyways...I had a intake gasket leak and I had oil mixing in with my coolant, Im still trying to get it all outta my system, PITA to try and clean it all out...I know I heard of a way to check if its the heads without a compression test...take the rad cap off and let the car idle and see if any bubbles rise...if they do then you introuble, but I would get a compression test done just to be safe before you spend big money...coolant mixing in with your oil is a HUGE PROBLEM definetly dont drive the car until that is fixed.


as far as the car bogging...I can only guess a missfire...I get a random one myself sometimes trying to figure it out...gotta take a closer look when weather warms up again.
But things to look for would be cracked/burnt wires, broken spark plug, correct firing order...those types of things...otherwise I would say cat (but you said its fine)

[RickS]

Re: Engine Loses Power

My mechanic checked the fuel pressure from the fuel pump and that seems fine. He did a compression check tonight and all 6 cylinders, they vary from 140 to 147 psi in each cylinder.

Is there a way to check the intake manifold gasket specifically? I will recommend removing the radiator cap and revving the engine while watching inside the radiator for air bubblers to my mechanic tomorrow.

Rick

[RickS]

Re: Engine Loses Power

The plugs look normal, no moisture. The oil (dipstick) didn't appear to have any moisture. The oil fill cap does seem to have some moisture, but could be just condensation from prior to us purchasing it.

If the car is left at idle, it idles fine and does not over heat. It doesn't give any codes. If I rev above idle it hitches and bogs down. It did overheat and flash the Check Engine Light, as I mentioned above, when I tried to drive it to the mechanic. The codes it gave were P0300 and P1406.

As mentioned in my last post, the compression test on the cylinders yielded 140 to 147 psi in the cylinders which appears to be fine. This would lead me to believe the block, heads and head gaskets are not the issue.

I pulled the cap off the radiator and revved the engine. It bogged down as expected, but there were no air bubbles surfacing in the radiator.

Any other ideas?

Rick

[RickS]

Re: Engine Loses Power

things to look for would be cracked/burnt wires, broken spark plug, correct firing order...those types of things...otherwise I would say cat (but you said its fine)

The wires and plugs look fine. Firing order is correct. The cat does not glow or bulge. If I have the mechanic disconnect the exhaust before the cat, will there be enough back pressure for the car to run correctly? (just long enough to see if it bogs down when revved)

Rick