You need to check your timing first off. An 86 has a knock sensor and you should NEVER hear audible knock if the timing is set reasonably close. Overadvancing the timing and relying on the knock sensor to "save you" is a bad way to go.

Disconnect the timing wires (4-wire plug coming out the back of the distributor to the harness going over the trans bellhousing) and set it to 6* BTDC for starters. 0* is the stock setting but 6* will almost always provide more power without any knock on an LG-4.

See if that helps before you do anything else. You need to figure this out becuase I think it is part of the reason you are so far down on power.

Also, the secondary side of the computer controlled QJet can be modified for much better performance. Replacing the stock vacuum pull-off with a quick release one from Edelbrock helps. Setting the air valve tension spring for 1/2 turn from zero tension instead of the stock 3/4 turn will also help. Replacing the junk stock CH secondary metering rods with a set of DR rods will also help quite a bit. Email me if you need help with any of these carb mods.

A good tune-up of plugs, wires, cap, rotor and getting someone to scan the computer to check for any trouble codes or bad sensors is also a very good idea on a car this old. Never seen one this old that didn't have at least 1 sensor out of whack.

 

Thanks guys, I will look into all of these things. I too only run high octane because I feel NO power with low octance fuels. I regularly run a bottle of booster just to maybe add a few mpg because I do alot of commuting. But my mileage is starting to suck. This car used to get awesome mileage when I first bought it. Even though it idled like crap and needed a good tune-up, it still had more ***** got better mileage. Its just pissing me off. I have tuned the car several times since I bought it. I don't know why it would do this.

I did think about getting a chip burned for better spark and all that. Does anyone know if when I bought a 350 and swapped it in, would I need a chip? The 350 will wear everything my 305 had,. all the old pollution crap, unless I can find new stuff. But it will have headers, intake, cam, better ignition, 3" exhaust, and some other goodies.

Does anyone know how much NOS I could safely run on a carbed smog legal 350? I was thinking a 75-100 shot just for the track here and there. Not for a steady source of hp. Well thanks guys

Will

Merry Christmas!

 

how old is that motor? how many miles on it? really, unless thats a newer motor/newly rebuilt.. i wouldnt try to run nitrous. im sure u can run a 50 shot fine if its an older/high milage block, but i wouldnt suggest it. if ti is newer.. maybe a 75 shot. usually use basic NX kits go for about $500.

 

Thanks guys

As far as the NOS, I was going to use that on the 350 I am gonna build. That motor will either be a very low miles donor, or a fresh rebuild. I was never gonna use now on the 305.

Also, the my motor is stock 86 Lg4, just to clarify.

There are to codes, im looking into them.

I know about the carb nods, but I need to know where to get the rods and the edelbrock part you spoke of!

Thanks guys

Merry Christmas

Will

 

Will,

Damon is THE man when it comes to tuning LG4s! He helped me immensely and is one of the REAL good guys on our forums

You can trust what he says.

 

D Nickle??? We spoke over a year ago. He sent me tons of info on how to tune my carb up and so on. I just need to find the parts and get to it. My main project is getting my car painted and the interior replaced. During which time I planned on building a 350. But I wanted to spice up the 305 just a tad, get her running better, for the time being. Thanks for the help guys, I appreciate everything

Will

 

No to be rude or anything but a 305 is a lost cause in the first place. If it was TPI then maybe I'd think about it, but not a 305 with a quadrajet. Instead of spending cash on trying to run 15's just save the money towards your 350. My friend spent outrageous amounts of money to get his 89 GTA to run times as fast as mine.

 

I hear what you're saying bro. I was mainly talking about the mods that would carry over to my 350 yet benefit the 305 right now. like better tuning for the carb, and little things. I am not trying to be super fast with a 305, the 350 will take care of that. I just want a healthier motor to get me through the next year or so. But I appreciate it. I know how the 305 gets ragged on, but for whats its worth, a good little motor. Its never done me wrong. Thanks guys

Will

 

Thanks for the kind words, guys.

The rods you can buy from Edlebrock. Buy a "G" hanger while you're at it. Local speed shop is the place to go to order. However, if you run into a problem just call "The Carb Shop" in Ontario, California (not Canada). 909 area code I think- don't have the number with me. You'll have to call information. If they don't have a set of DRs then get a set of CPs- they're the same specs.

I think running a scan on the computer is a really good idea. By the time the ECM actually sets the "Check Engine" light on these cars something's already VERY far outta whack. And once the light is lit the ECM runs the car in "limp home" mode with very rich mixture and almsot no spark advance. It's a guaranteed 30HP drop as soon as you go into limp-home mode (plus mileage takes a big hit). Even if it's not, a simple Vacuum sensor that's hosed up or a TPS sensor that's shot can really cause some power loss and possibly dirvability probmems.

If the engine hasn't started burning oil or eating coolant at the same time this power loss started the basic mechanicals are probably still OK.

 

Well guys, heres what went down this weekend. I hooked up my timing light and couldn't believe what I was reading. Timing was set somewhere around 18*. I guessed because it was off the timing marker completely. Someone told me that 13* was stock timing, so I went a little lower, around 10-11*.

One thing I noticed though after doing this, is that the car seems to just lag. I mash on the gas and it is really slow to pick up, it gets there, but it is a really slow and steady rise through the gears and power band. What gives? I am guessing I need to adjust the spark curve. How do I do this. Would one of those performance chips be a good idea for now?

Also, I ran a scan and two codes were stored. One was for the mixture control solenoid. It says that to check for malfunctions, you should use an ohm meter and if it ohms out at below 10 ohms, its faulty and needs tom be replaced. So I put the meter on and it ohmed out in the high 20's . This should be ok? THe other one was for EGR I believe. I tried moving the vac diaphram, and it feels kinda tough to move. Might I need a new EGR valve?

Just wanted to run this by you guys. I really wanted to check my timing forever now, but to me it feels like it actually hurt performance. The car used to have a little heat to it once it was fully warmed up and what not. Now it feels fery mellow, and call me crazy, but a little louder too.

Thanks guys

Any help at all

Will

 

Something to consider - stock harmonic balancers tend to "drift" as they get older. The timing might not be anywhere near where you believe it to be.

 

Then how does one go about adjusting the timing??? Trial and error???

 

Honestly - buy a new harmonic balancer. You will be able to use it on your 350. Don't know if it will work for you, but in a pinch w/o a timing light - I've held the throttle to 3,000 RPM & advanced the timing until it stumbled, then backed it off a little and tightened the distributor hold down there.

 

Well, it seems after all that my timing was retarded in the first place. Here is exactly what happened. When I checked the timing first off, it read way off almost what would be considered 14*-18*. But when I disconnected those 4 wires, it was below 0*, so I set it up somewhere around 8-10*. Plugged the wires back in and checked the timing and everything was cool. The car feels like it has a little more umph than it did before. Now I just have to see if I get any change in mileage or anything.

Does this make sense to you guys? Did I do it right? Ever hear of a stock motor just being retarded like this before? To the best of my knowledge no one has ever messed with the timing, at least not as long as I have owned it. It feels like I gained some power. Now I just have to tackle the SES light codes.

Thanks guys

P.S. I doubt that the dampener has moved much at all. I have seen balancers that were out of whack and you could see rubber showing or other signs of wear......