jjanitor

Hi,
I have an 86 Tran Am with a 305 carbed engine with an H coded engine. I have looked high and low for the EST connection. Only thing on my firewall is a red wire with a connector. I have looked up by the hood hinges and followed the wiring harness around looking for it. I could really use some help.

RBob

iTrader: (1)

For the large cap distributor, electronic carb'd engines, look for a 4-wire connector near the base of the distributor. The 4 wires exit the distributor, goes to this connector, then continues on to the EFI harness.

Unplug that 4-wire connector to open the EST/BYPASS.

RBob.

jjanitor

Thanks RBob. I had to pull the intake and have been hunting for that elusive brown wire.I know exactly which connector you are talking about.

RBob

iTrader: (1)

Understandable, the single wire EST/BYPASS connector is for EFI engines. In the case of EFI the ECM requires the other signals in order to fire the injectors.

With a carb, not so much.

RBob.

jjanitor

Hey RBob,

I spent some time on the car this afternoon and set that distributor up. Wow- The cars running like a champ. I bought the car new and it has 48,000 miles on it. It has never been in the snow and the body is perfect and clean (Ie never been hit). The intake manifold seals were starting to leak oil so I decided to take the top of the motor off. I also replace the valve covers and their seals. Interesting the valve covers were starting to rot. I replaced them with factory OE. The EGR valve was plugged on one side and I cleaned it out. I also replaced the plugs but they didn't look terrible. The plugs were original and over 30 years old.

I changed the wires and cap along with all belts, hoses etc etc. The car still had all original belts and hoses.

My next question is what would happen if I disconnected the air pump? The pump is starting to make a little noise. I don't have to deal with emission because the car is driven less than 5,000 miles a year.

Thanks for all your help,

John

zed-028

Air pump can be disconnected without any issues and will take about 20 mins tops. The bit that takes forever is deleting the tubing that runs to the cat as you can only get at it from under the car 1 bees dick of a turn at a time. The bolt that holds it to the passenger head is also the grounding point for the Electronic Spark Circuit so you might as well clean the area up a little while you have it off.

deleting the tubing on the headers is a little trickier. I originally grabbed a steel threaded cap and put it over the ends where the check valves were and used some high temp loctite to seal it shut. eventually i nipped them off at the headers, used a tap and die set and threaded some rod into the holes.

There are only a couple of electrical connectors and the little black box dealio after that. Havent had an engine code from it at all and the belt for it (not serpentine) just slips off as it drives nothing else.

jjanitor

What about if I just pull the belt off? I really don't want to hack this car up at all. The car has four belts, one serpentine and three V belts. The outermost belt is the one that drives the air pump.

jjanitor

I also have torches and can remove the tubing if need be.

jjanitor

Also too, how good are the factory exhaust manifolds on this car? Would putting in a set of headers help me at all. I know this car has low horsepower and I don't want to put $400 into it for a three horsepower gain.

Any thoughts?

John

sofakingdom

iTrader: (1)

The "H" engine (LG4) is altogether WEEEEEEK. But, of all the things making it that way, the exhaust system is probably THE WORST.

Changing to headers won't revolutionize it all by itself. Think of that as more the foundation for everything else. NOTHING ELSE will do any good AT ALL with the factory exhaust still there.

Get a good quality set of headers. Spend what it takes: DO NOT just slap on the cheeeeeeepest thing you can find that nobody went to jail for printing the word "headers" on the box. Have them ceramic-coated. DO NOT get "universal" ones: get a set SPECIFIC TO THIS CHASSIS. Avoid anything that bolts up to the stock LG4 exhaust: anything that does that, will preserve THE bottleneck, which is, the tiny Y-pipe and I-pipe size. Get a setup for, say, 88 TPI 350; NOT LG4.

I'd suggest trying to find a set of SLP headers, which of course are no longer made so you'll have to hunt for used; or, Dyno Don's setup. (visit the exhaust forum and look for that user) The BY FAR best deal is stainless headers with ceramic coating: they will last MANY TIMES as long as any form of mild steel ones, and will radiate not much more heat into the engine compartment than manifolds. Get a setup with 1¾" primaries and 3" collectors. Then get a 3" cat and any of the 3" cat-back systems that are available. I have the Hooker one, which is OK, kinda loud to my taste but not too bad. Not near as bad as Blowmaster for example. DO NOT try to get a muffler shop to build a "custom" system!!!! You will spend more money that way than just buying a boxed system, and it almost certainly won't fit as well or be as easy to maintain.

On the motor you have, should be worth around 25 - 30 HP. Won't radically transform the car, but will improve torque at all RPMs and will let the motor produce meaningful power at higher RPMs; might even make to 3500 RPM or so before it craters, instead of the way it is now, with peak torque at around 2000 RPM and steadily falling off as RPM increases from there.

Next mod should be a better cam. Don't go too radical. A choice that is well and widely known to work well in the LG4 is the Comp XE256.

Next thing after that should be gears: you probably have 2.73s now, 3.23 or 3.42 WILL radically transform and revolutionize the car, once those other 2 things that limit the engine RPM to idle speed have been cured.