Street legal

vince v · 07-29-04, 10:22 PM

I bought my first vette around nine months ago, an 86. I love this car. I brought it in for state inspection and it failed. Found out the air pump was disconnected and had no cats. The engine has a high performance cam (don't know much about this) and performance chip. The idle was rough and high (1100 - 1200 rpm), the mechanic said I needed new fuel injectors. Also replaced EGR switch and valve. He replaced the chip with a stock chip from his 89.

I got a temp inspection, good untill Nov. The idle dropped to 800 - 900 with better mpg and higher performance. I changed the coolant and t-stat (160 deg), performance improved a little.

A few months later the high idle is back 1200 - 1300.

Does anyone know the cost of new cats and what is involved in installing them. Also, will this help the idle.

Thanks

Moonunit 451 · 07-30-04, 12:23 AM

Quote:

Originally Posted by vince v

I bought my first vette around nine months ago, an 86. I love this car. I brought it in for state inspection and it failed. Found out the air pump was disconnected and had no cats. The engine has a high performance cam (don't know much about this) and performance chip. The idle was rough and high (1100 - 1200 rpm), the mechanic said I needed new fuel injectors. Also replaced EGR switch and valve. He replaced the chip with a stock chip from his 89.

I got a temp inspection, good untill Nov. The idle dropped to 800 - 900 with better mpg and higher performance. I changed the coolant and t-stat (160 deg), performance improved a little.

A few months later the high idle is back 1200 - 1300.

Does anyone know the cost of new cats and what is involved in installing them. Also, will this help the idle.

Thanks

Hmmm, Where is the chip that came with the car? Is there any way you can find out what cam was installed, and any other performance mods? Frequently the chip is burned to match mods installed.

Cats will not help your idle. You should check the TPS, or have it checked. There is a detailed proceedure for this posted by plumbcrazy I believe in one of the top 5 posts here.

Who is "the mechanic" and what qualifications does he have to work on your car?

vince v · 07-30-04, 08:11 PM

Quote:

Originally Posted by Moonunit 451

Hmmm, Where is the chip that came with the car? Is there any way you can find out what cam was installed, and any other performance mods? Frequently the chip is burned to match mods installed.

Cats will not help your idle. You should check the TPS, or have it checked. There is a detailed proceedure for this posted by plumbcrazy I believe in one of the top 5 posts here.

Who is "the mechanic" and what qualifications does he have to work on your car?

The previous owner said after he installed the new one, he pitched the orginal chip.

I'll search for plumbcrazy's procedure.

I know now that my mechanic wasn't qualified to work on my car.

The car is running real rich.

Thanks for the info.

vader86 · 07-30-04, 08:39 PM

The first thing you need to know is what cam is in there. Before doing anything to the chip. The chip itself does control the idle quality and the A/F ratio, so it is possible that it isnt set for your cam.

Check the TPS, remove and clean the TB and IAC. Hopefully that will fix the idle. Otherwise youll need that chip reset for the cam before you start throwing money in it.

If you want new cats, you can check out Random Tech or Car-Sound.

vince v · 08-19-04, 09:52 PM

Sorry, for not replying. I removed and cleaned the TB and IAC. That helped a little. I replaced the 160 t-stat with a new 195 degree. I noticed an exhaust leak at the exhaust manifold. I replaced the gasket and disconnected the battery to dump computer memory. The car is running better than ever. I guess the exhaust leak was causing the O2 sensor to read a lean mixture, therefore dumping more fuel.

Question, really need help with this one. I bought an EGR temp switch, had a code 32. There's a plate bolted where the temp switch should go. What's with that. Is the EGR valve working?

Thanks

oldace84 · 08-20-04, 12:22 AM

Check it out!

1987Silvervette · 08-20-04, 02:15 AM

Im sure your mechanic was more than willing to switch your chips. he screwed you in a sence. I hope he gave you soem green for that chip......good luck

taegdh · 08-20-04, 09:47 AM

I would almost bet that the guy who modified the engine, removed the EGR and the Temp Switch. EGR valve you would find under the plenum, looks like a mushroom between the 5 and 6 cylinders.

You should get ahold of the previous owner and get all the information about the engine you can. There should have the spec sheet for the cam, or atleast the manufacturer and model number, from which you can get the specs. Also see if he punched it out, replaced pistons, (Higher compression), or changed the Fuel Injectors. You'll need to know all all the mods that were done, you can get some eprom reprogramming done.

You can buy aftermarket Catalytic converters, just make certain that you have them heat shielded so you don't melt the floor. You'll probably need two. If he just bypassed the AIR injector pump, it probably is still hooked up the the exhaust manifold. You should look see if the CATs require air from that system or not.

Also: Check out the October 2004 Chevy High Performance Magazine. They had a pretty fair and easy to understand article in there about programming the eproms.

vince v · 08-20-04, 03:35 PM

Hey taegdh, thanks for the info. I'll contact the previous owner and the Chevy High Performance Magazine.

jdenn47 · 08-20-04, 09:48 PM

I also have a 1986 Vette and assume I have a L98 but not sure if I have a ZR1.
Is a TPI Intake Air Foil, ($30) or Induction Power Coupler, ($50) worth the cost ?
John

Edmond · 08-20-04, 10:19 PM

Quote:

Originally Posted by jdenn47

I also have a 1986 Vette and assume I have a L98 but not sure if I have a ZR1.
Is a TPI Intake Air Foil, ($30) or Induction Power Coupler, ($50) worth the cost ?
John

The 86' would have the L98. The ZR-1's are from 90-95 with the LT5 engine.

The air foil might give you 1 or 2 hp. The coupler is just a waste of money.

I thought that the vehicle could pass emissions without the pup cats? As long as it was tuned correctly and the main cat was there; the vehicle would pass emissions.

corvette66 · 08-21-04, 01:16 AM

This may sound goofy. im no expert. but how could he have no CATS? unless they were cut out and replaced with test tubes. Or maybe it has the "off road" system. But sounds unlikely

virdtoy · 09-11-04, 11:31 AM

go back and check out Alex's exhaust shop in Bridgeport,Pa he'll set you on the right path. tell him Vird sent you.

vince v · 09-12-04, 07:51 PM

Quote:

Originally Posted by virdtoy

go back and check out Alex's exhaust shop in Bridgeport,Pa he'll set you on the right path. tell him Vird sent you.

Thanks Vird, I'll do that.