Help! Power Issue

[85redvett]

Was out for a quick drive today and hit the gas, engine rpms came up but power didn't seem to be getting to the ground. Tranny shifts fine. Noticed a different exhaust sound as well. Parked the car and removed oil filler cap, smelt it..smells like gas. Possible spark problem? Other ideas? I haven't checked for codes at this point...it just happened.

Thanks
Rick

 

[Schrade]

RPM boost suggests tranny.

Gas in oil does NOT.

Pull the FPR vacuum iine, and see if it has gas in it.

Check the dipstick - try to see if gas smell is as strong on the stick as on the filler cap.

Pull the EVAP vacuum tube that goes to the intake (should be at the EGR solenoid) (pull at the EVAP can), and see if it smells like gas.

Keep in mind that if gas is coming through FPR vacuum tube, and down through one or 2 of the holes (cylinders), it will also be rinsing oil back down the walls, and allowing it to warm up a little extra, withOUT oil protection!

 

[boomdriver]

sounds like a clogged cat.

RPM minus pulling power means exhaust restriction.

 

[Schrade]

sounds like a clogged cat.

RPM minus pulling power means exhaust restriction.

I think this is a winner. I think it would also account for fuel smell in V/C filler.

How about the stick? Does it smell?

 

[85redvett]

I think this is a winner. I think it would also account for fuel smell in V/C filler.

How about the stick? Does it smell?

Ya, the smell of fuel is strong. Either way the cats are coming off. Was planning to do it later but guess I'm doing it sooner...Tranny fluid looks good, full and no "burnt" odor. When just driving through the neighborhood it shifts as expected. Only an issue when I "give it" a little and it has a different exhaust sound. My wrench guy is a way for a couple of weeks so I'll have to wait to get the cats off.

 

[85redvett]

Problem Confirmed

Ya, the smell of fuel is strong. Either way the cats are coming off. Was planning to do it later but guess I'm doing it sooner...Tranny fluid looks good, full and no "burnt" odor. When just driving through the neighborhood it shifts as expected. Only an issue when I "give it" a little and it has a different exhaust sound. My wrench guy is a way for a couple of weeks so I'll have to wait to get the cats off.

I took the car into a local shop to have them do some diagnostics, they've confirmed the main cat is shot. I thought the 85 had just the one cat...FSM only shows one cat but this has 3, two pre-cats and the main. the main cat is the one that's fubar. Thanks for the help guys!

 

[boomdriver]

I'd try to get a new front Y pipe with no cats, and find a sympathetic shop that will install it, or see if they will take the old Y off and tell them its going to be an off-road car....

Its illegal to take cats off a car that came with them, BUT, your car DID NOT come with those pre-cats.Their books will confirm that. Somebody added those for some reason. Pre-cats came out in 87.
You'll be shocked at the difference without the pre-cats.

 

[85redvett]

I'd try to get a new front Y pipe with no cats, and find a sympathetic shop that will install it, or see if they will take the old Y off and tell them its going to be an off-road car....

Its illegal to take cats off a car that came with them, BUT, your car DID NOT come with those pre-cats.Their books will confirm that. Somebody added those for some reason. Pre-cats came out in 87.
You'll be shocked at the difference without the pre-cats.

I'm wondering if, because the car was manufactured for sale in Canada, if the pre-cats were factory installed to meet Canadian emissions laws at the time. I like the idea of removing the pre cats and I do have a guy that doesn't much care for Gov interference in our car hobbies....So... I expect it won't be a problem to rip'm out.

When you say "shocked at the difference without" are you talking about bottom end power?

Thanks for the comments/replies.

Rick.

 

[boomdriver]

Throttle response.
Right now it seems to rev ok.....but it takes a second. It hesitates just a bit.
Wait till the pre-cats are gone.
With the pre-cats it takes a little effort to get it to rev past 3 or 4000....just stepping on the pedal in neutral.
After a new Y-pipe is installed, a touch of throttle will get it to the same RPM, and lots quicker. Those tiny pre-cats are the majority of the restriction in the exhaust system.Mine "fell" off long ago.

Your thoughts on the Canadian emissions standards are probably right....I never thought of what GM would have to do to export to another nation.

 

[roger longman]

If I installed a "Y" instead of the cats in my '88 would it pass California emissions ?......Roger.

 

[boomdriver]

as long as the main cat is in near new shape.....yes, it will pass. I did it for several years.
we're talkin about tossing your current Y pipe with the pre-cats and getting a new Y that is a straight thru pipe to the 3" connect at the main cat.

 

[Schrade]

I took the car into a local shop to have them do some diagnostics, they've confirmed the main cat is shot. I thought the 85 had just the one cat...FSM only shows one cat but this has 3, two pre-cats and the main. the main cat is the one that's fubar. Thanks for the help guys!

Did they SHOW you how they 'confirmed' that the cat is 'shot'?

I think I'd rather pin the tail on the donkey, or spin the wheel of MIS-fortune, before I unloaded cash without a guarantee of a THE fix... ;squint:

 

[TedC]

Odd that your 1985 would have pre-cats. For the 86-91 vettes Eckler's sells an EPA approved front y-pipe with no precats and a single 3 way converter. So it is possible on these years to eliminate precats and still be EPA compliant. The 1984-85 front y-pipe they sell in either steel or SS says a reproduction of original and has no pre-cats. Front y-pipes changed in 1986 and are not interchangeable with prior years.

 

[85redvett]

Odd that your 1985 would have pre-cats. For the 86-91 vettes Eckler's sells an EPA approved front y-pipe with no precats and a single 3 way converter. So it is possible on these years to eliminate precats and still be EPA compliant. The 1984-85 front y-pipe they sell in either steel or SS says a reproduction of original and has no pre-cats. Front y-pipes changed in 1986 and are not interchangeable with prior years.

I suspect because I'm in Canada (Toronto) that GM had to meet the Canadian emissions standards and that might have resulted in precats on this 85. I can't imagine why anyone would install a new Y pipe with precats if the effect is negative on the cars performance...

As far as what did they show me to verify the cats are shot..well nothing except the guy that owns the shop has been a buddy of mine since high school (too long ago to actually type the years)..so I trust him. They checked fuel pressure, checked for codes, checked timing and I think some other things plus a road test. I'm not doing anything else with it until they guy who actually works on my car is back from vacation. I suspect it's true the cats are shot so the plan will be to replace the front Y pipe and get rid of the pre cats and go with a less restrictive main cat. However, I was planning no replacing the entire exhaust next year...so maybe I'll pull that ahead a year and do this year..we'll see.

 

[roger longman]

as long as the main cat is in near new shape.....yes, it will pass. I did it for several years.
we're talkin about tossing your current Y pipe with the pre-cats and getting a new Y that is a straight thru pipe to the 3" connect at the main cat.

Thanks boom, I'll look into this when I've sorted out my EGR problem......Roger......