My car used to be respectably fast for a 305, I had gobs of low end torque and high end power to match. After installing edelbrock tes headers specifically for my car along with a brand new catco and all new piping my car ran like crap. Yes the headers leaked. Even after I put on the soft copper gaskets. Next we bought new gaskets and rigged the two of them up into an "unleakable" super gasket and cranked them down and topped it all off with locking bolts. After driving to Arizona from Wisconsin I am not pleased. I have about 20% of my original power and my gas milage went down 75%. What is going wrong with my baby?

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91' red RS convert.
71,000 miles
89' IROC hood
red Z-28 16" rims
potenza re730's
MSD ignition
MSD coil
K&N fiter
350 ported polished heads
hypertech chip
flowmaster 40 series cat-back

 

Sorry, I don't have the answer to your question.

But, I would like to ask you a question.

How was the install with these headers?

Did you have the motor in or out at the time?

I have a 91 RS vert as well, and I'm going to be taking the header plunge very soon. Just trying to get an idea of how the install is going to affect my weekend.

This is our daily driver so having it up on blocks for a week is not an option for us.

Thanks.

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91 Mystic Teal RS Convertible (1 of 5,000+ made in '91)
Stock 305 TBI, Auto Trans, Stock Rear End

Stereo
Nakamichi CD-35z, Infinity Kappa Series 4x6 & 5 1/4" speakers, Fosgate 12" sub in a custom box, 200watt amp for the sub.

Future Mods & Add Ons

• Infinity Basslink
• Hooker Headers
• 3" Exhaust using Flowmaster 80 series muffler
• MSD Ignition
• K&N Filter
• Some Suspension Improvements

 

My suggestion to you is if you haven't already bought the headers, don't do it. THere are many other cheaper mods that do a lot more for you and are less of a hassle. After reading my story I can't believe you still want to do it but here it goes: If you are a novice mechanic like me this will take you a full day and night of working. I started by lubricating all nuts and bolts then I removed the factory cat and y-pipe. WHile the car is in the air mark and dissconnect all plugwires and plugs. drop the car and remove steering shaft after dissconecting all the airbag equiptment. remove alternator support bracket, take out OE manifold, install driver side header. Passenger header is a real pain. Take off allheater hoses and move ac out of the way, remove valve cover. take out manifold put in header. THis job is a bitch I spent nearly 1000 dollars on all new exhaust components and my car now drives slower. But hey its your car.

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91' red RS convert.
71,000 miles
89' IROC hood
red Z-28 16" rims
potenza re730's
MSD ignition
MSD coil
K&N fiter
350 ported polished heads
hypertech chip
flowmaster 40 series cat-back

 

i have done the tes header swap on my 92 305 RS with alot of help and supervision of a fellow board memebr fomr here...not sure what his ID is on here thou...but I saw a pretty nice sized gain with the headers....you might wanna ge ta chip,,...i know that helped a good bit as well....

the install is a SOB....its tricky but doable in a day or 2...the bigest hting is getting the old bolts off...there are Tabs that hold them in...and that is a pain...the other pain is sliding the headers into plce..

 

Took me 6 hours total to swap on my TES headers, 3" y-pipe, 3" catco cat and some new 3" piping.

jacked the car up maybe 15" on 4 jackstands, one per corner. I dont have AIR...maybe that helped. its not hard at all, just a little time consuming.

 

Did you put your plug wires back on right? It is very easy to cross them or have one burn up if it is resting on a primary tube. All TBI cars will gain power with a header install so you must have something mixed up. Did you plug in the O2? Headers will cause these cars to be slightly out of tune and they can benifit from some chip work. However, you should still see gains with the stock prom.

 

Something didn't get back together correctly. Or, you've really confused the TBI.

You might want to check with the guys over on that forum for their crack at it.

 

well headers are worth the time and effort it takes to get them on, not that i have anything against Edelbrocks TES, but i know someone who has them on his F-body, just the task of getting the spark plugs out/in and keeping the plug wires from touch the primary tubes is a task in itself, i ended up cutting a 3/8" slot in the side of the socket, like the o2 socket, just so i could get it on the plugs. I just recently put on my camaro, Heddmans shortie headers no problems there but then again i dont the A/C box or A.I.R. tubes in the way. total install time was 2 hours w/ bare block in the car, no heads, still a work in progress.

ShiftyCapone said it all, Chip tuning, its your best bet.

 

after every mod i do, I reset the computer

 

He apparently posted just before I put in my plug for him.

 

Ha ha beat ya to it. It says that we posted at the same exact time. You are probably the one that took the post so long to go through...jk

 

On my way down to AZ from Wisconsin, I fouled a buttload of plugs through the mountains. Change your plugs out, I gained about .8 in the quarter just by doing that!

Tony

 

I had the tes on my 92 when I had it. The install is a SOB as others have said, but the improved performance was worth it. I burned up a couple of plug wires on the 'maiden voyage', so maybe that is what is wrong. Also make sure all your sensors are hooked up and not broken. I broke one of mine.

This was quite a few years ago when I did it (in '94) so I wasn't the best mechanic then, but it took me about 2 full days to do it. There was a lot of figuring out what to do. There weren't all these type of boards to go to for help either, just the crap directions from Edlebrock! You def have a problem because they will help the LO3.

Good luck

 

Just for kicks unbolt the cat and drop it out and try driving it again. If it's welded in, disconnect the exhaust at the headers, and tie it up out of the way. If you disconnect the headers tho, make sure the exhaust isn't directed at any lines, wires, or sensors. Maybe by some chance you got a defective new cat, and it's not allowing any gas to flow through it. You can also tell it's functionality by it's temperature, although I don't remember exactly what the rule is Maybe someone else can help out with that.

Also, use a pyrometer to check the header tube temps. Great tool, and they're cheap now too Craftsman has a laser model that reads up to 700 deg. and accurate to within an inch or so for $40. I don't have one yet, but it'll be one of my next toys... it'll instantly lead you to a problem of cyl's not firing.

Like the other guys said, make sure you have o2 plugged in, make sure plug wires aren't mixed up, make sure your wires aren't cross firing or shorting to ground. Also might want to pull the plugs and see what they are telling you. Headers should definately not sap your power, it HAS to be something done wrong on the reinstall.

Does it idle ok?

Good luck tracing the problem, and let us know how it turns out.

EDIT: If you routed the plug wires to close to the headers, you could have easily killed them that way too. Even if you can't physically see any burn marks you could have fried the conductor inside of them. Do a resistance test on them...

2nd EDIT: Just realized that the original post is three years old, so it probably isn't gonna help out the original poster any