Jeremy Z28

iTrader: (5)

Okay guys. As you can see, I am new to the board. I just recently purchased an '87 Camaro LT with an LG4 carbed V8. I bought it knowing it was gonna be a project car. So far, I have had the brakes redone all around the car with new everything, alignment done, and also a good tune up - all belts replaced (were squeeking when I bought the car), timing checked, etc.

Now, on to my question. After the tune up, the guys down at the shop I took it to advised that the carb needs to be rebuilt, and that the EGR valve needs to be replaced. The car has some trouble starting up sometimes (mostly when the car has been sitting for 7+ hours), and the car also will die after it finally starts up after it's been sitting, and will also "hesitate" (I punch the gas, but takes the car a second to get going) - all of these problems leading to the carb. The car will also "ping" when it is idle and when I punch the gas real quick - leading to the EGR valve as it is not opening and closing properly. Now, my question - I am trying to squeeze as much power as I can out of this car, so do you think it would be wiser to just go ahead and rebuild the carb, or I would I be better off buying a new Edelbrock carb or something else of the like? If the Edelbrock offers more torque/hp I am cool with that, even if it more expensive or I need to replace other parts in order to install the new carb. Oh yeah - they want $480 + tax for the carb rebuild and EGR valve replacement.

Second, does anyone know where to find any good performance parts for the 305 carb motor? I have looked around on the web and can't find much for my motor - mostly the TPI stuff is what I see. The only things I have seen so far are the March Pulley Kits and the Edelbrock headers from ThirdGenResource.com - but that place seems to sell their stuff a little overpriced, or is it just me?

Last but not least, what exhaust brand/system do you recommend for the most aggressive sound and performace for my carb 305? A buddy of mine has a '92 TBI 305 RS with a Magnaflow that is the sweetest sounding thing I have ever heard. A guy I was talking to at a Muffler shop said Flowmaster was the way to go, but most of the Third Gen Camaros I have heard with Flowmaster setups seems to "pur" more then they rumble, and rumble is more what I'm looking for.

Anyways, thanks for any input you can give me guys - I really appreciate it.

88Camaro350

480$+ tax is crazy. You can buy a new 600cfm edelbrock or holley carb for well under 300$. And EGR valve replacement is VERY easy. IIRC (car no longer has it) it is only held on by 2 screws. Just remove the vacuum lines going into it, unbolt it, then bolt the new one on and hook up the vac lines. The EGR valve is about 20-30$ at your local parts store.

I would just go ahead and buy a new carb and EGR valve if it was me. If you want to run a holley carb I would recommend getting a new intake as well. Since those "Q-jet to holley" carb adapters look very restrictive.

As for exhaust on a 305...I would do this.

Edelbrock TES headers (350 TPI model with a 3'' y pipe)
No cat or a high flow cat
and a hooker catback

I love the hooker catback. Sounds great and doesn't pop and sputter like flowmasters do when you let off. The edelbrock TES header system would be perfect for a 305 but they are really to small for guys with built 350s. Because they have small 1.5'' primary tubes that step to a 1 5/8''. When I get around to it I will installing a set of 1 3/4'' SLP headers.

BTW: You mid as well go ahead and replace your fuel pump also. It could also be part of your problem. Since the pinging is either from timing (you said you checked so I'm assuming its ok) or lack of fuel. (or to high compression or carbon buildup but im assuming his problem is fuel related)

A stock replacement pump from your local parts store is CHEAP. In the area of 15-20$ for a mechanical pump and very easy to install. (DAMN you guys with your mechanical pumps my block doesn't have a mechanical pump provision )

Once you get all that done then its time to get to real modding

five7kid

iTrader: (14)

Welcome aboard.

Your pinging problem is most likely due to the EGR valve either not opening or the passages being plugged (my factory manifold passages were plugged after 135k miles - cleaning them solved my pinging problem). That's assuming the timing was properly set during the tune-up. The starting & hesitation problems may be fixed with a carb overhaul, although the 7+ hour thing may be the fuel bowls draining because of q-jet galley plug leakage - a common problem. Putting a non-computer controlled aftermarket carb on is, IMHO, silly (and bordering on stupid).

As to performance, the LG4 is limited by the following (and basically in this order): air cleaner, exhaust, cam, heads, ignition. After that, you can add torque converter, gears, and intake manifold.

What you do:

Air cleaner - the single snorkel thing is a killer. Either find a factory L69 dual-snorkel cleaner (getting harder and more expensive to do), or fabricate one (there's a tech article on the Board about how to do that).

Exhaust - If you buy any aftermarket part made for an LG4, consider yourself cyber-slapped. The Exhaust forum discusses this regularly; the best course of action is to get '86-'90 TPI single-cat application high flow parts. My recommendations would be Hooker 2055 headers & y-pipe, Catco 9118 direct-fit high-flow 3" cat, and whatever cat-back you think you like (but for the same application above).

Cam - get a computer-compatible roller, like Crane Compucam 2032 or Comp Cams equivilent.

Heads - either port the stock heads per Standard Abrasives Do-It-Yourself-Guidelines and install 1.94" intake valves, upgraded valve springs to match the cam, and screw-in rocker studs; or World Castings S/R Torquer 305 aftermarket heads and port them (already have the rest of the good stuff).

Ignition - the stock ignition control module and coil are weak and prone to failure. I used Accel upgrade parts, others are available. This may also fix your starting/hesitation problems.

You'll need a higher stall torque converter to allow the engine to get up into the cam's power band. If you go with the 2032, figure on at least 2500 stall. Gears - 3.42's are a good compromise between performance & economy.

I like my intake manifold, but it doesn't have the exact bolt pattern that your heads do. If you go with the World heads, that problem is solved by getting the '86-early style heads (you can still use your centerbolt valve covers). Or, elongate the center-two bolt holes on each side. I wouldn't bother with the Edelbrock Performer, it isn't much if any better than stock. Port matching the stock intake would be cheaper and probably yield as good if not better results than the Performer.

So, how's that for more than you wanted?

five7kid

iTrader: (14)

The '87's also had an electric in-tank pump.

88Camaro350

That sucks. Getting the tank out is kinda rough.

twistydick

dont know if you have one near you, but advance auto parts has rebuilt cc carbs for 269.99.thats what i got.had probs with my first one, whover bench tuned it at the factory didnt check the mcs, but they replaced it with no trouble and my new one runs great.youd almost think it got injection(the way a qjet is, when tuned right)480.00 is straight up retarded, u can brand new for that

five7kid

iTrader: (14)

The $480 was stated to be carb rebuild and EGR valve replacement. Considering remove/install and adjustment time, that isn't that unreasonable (I wouldn't pay that, of course, but for having it done, it's in line).

Now, if they guaranteed that the EGR would work when they got done, it's even more reasonable, because most likely the intake manifold will have to be removed in order to clean the passages - if it's anything like mine was, that is.

fb305svs

my intake was BADDDDD too when i repaced my egr in myold 86-

cgb

What he said lol..

Seriously, more than 80 percent of the time, whenever I see / hear of a "EGR problem" it's NOT the valve itself. It's the passage UNDERNEATH that valve on the intake manifold. This becomes choked with built up carbon and clogs the passage.

Remove the EGR valve and look inside...

As for the carb...they are NOT hard to rebuild for the normal DIY, but you have to pay attention to DETAIL.

IF you want to attempt to do it, I personally would recommend the following :

1. Rochester Carb book by Doug Roe
2. Factory manual for your car ( GM manual not Haynes or Chilton ) it has the correct settings for the computer controlled specific components, plus the manual is worth every penny when doing anything that you're unsure.
3. You'll need the proper tools to adjust the various settings, check with NAPA they make a kit that comes with the needed tools...and it's not expensive
4. Carb rebuild kit
5. Bucket of carb cleaner, a clean work surface and some patience.

1. $15 new
2. $10-$30 used
3. $10-20
4. $40
5. $10


OR you can find someone to send you carb to so they can rebuild it, but this is less exact than adjusting everything while running on the car.

The hard start condition ( as mentioned ) is caused by the gas in the carb leaking out of the carb when it sits for an extended period of time. When you rebuild your carb, this is an easy fix, you can epoxy the plugs to fix this.

Also...I'd start by running a couple of cans of Seafoam or GM top engine cleaner through the engine...this will help remove ALOT of built up crud that might be contributing to the pinging / hesitation problem.

Jeremy Z28

iTrader: (5)

As mentioned above, thank you very much for the info guys - it is much appreciated. It's great to have a source of honest answers to turn to.

The pinging problem has been solved, as the lines have been cleared - EGR valve was fine.

On to the mechanical problems again...

1. Now, the damn carb - during the day, it's great. I went to work the other day, came out six hours later, and just turned the key - she started right up. I retract the 7+ hours thing that I said earlier, it's when the car sits overnight it takes me a few minutes to start up. During the day for some reason it seems okay, I can let it set however long and it will start right up.

So, the morning is the only time the car is hassle to start up, and it will also hesitate and die most of the time if I press the peddle down hard enough. It this just the carb needing to be rebuilt, or is it something else now, that the cold of the night is causing?

2. Here is something that I am still yet to get a straight answer for. I am not sure if it is my gauge cluster going out, or a loose connection, but my three small gauges (they make a small "pyramid") located between my speedo and gas meter (remember it's the LT - no built in tach) they are completely f00ked up. When I turn the key just so it only in accessory mode, 2 of them will light up. And for those not familiar with my particular setup, my three small gauges do not use needles, they appear to be digitalish and are supposed to light up red. Now, when I start the car, for a split second the third one that didn't light up with turn on for a second, but as soon as the car starts up, ALL three turn off completely, and I highly doubt it is "supposed" to do this - am I right? The only other "weird" thing regarding my gauge cluster is when I go faster in MPH, my fuel needle will slowly start to creep up more and more. But as soon as I hit the brake, it will creep back to its normal spot. I heard this pretty common for Camaro's due to the geniuses that designed the gas tank. My original plan was to put a 115 MPH or even a 145 MPH gauge cluster from an 85-88 Camaro that had the built in tachometer and used the needles instead of the digital readout of the oil, etc. BUT some guy I was talking to at a shop that sold original third gen clusters said this was not possible, and I would have to add extra sensors to the engine to even get some of the gauges to work. Is that true? If you didn't see the info below my user name, I have an '87 LT that reads 85 on the speedo, has three digital readouts for the oil, etc and the fuel gauge is in the spot where the tach should be. If I cannot put one of the 115/145 MPH gauge clusters, guess I'll have to stick with what I have and mount a tach to dash or what not.

3. I have been reading around and doing my research, and I see that some other carb people have also had this problem. Sometimes when I first start my car, mostly in the morning, the car sounds like it's running a high RPM - my car does not have a tach (YET), but I am no dumbie (or at least not that big of one) and it is definately running higher then it should for idle. But as soon as I shift it into a R, D, whatever - THEN it sounds normal. I read there is a screw that needs to be turned on the carb to adjust something? Not really sure there.

4 Last but not least, when my car is idle or going slower (10 MPH or so), there seems to be a rattling noise - almost as if it were pinging while idle. It doesn't seem to make this noise if I am driving 20 MPH or faster, or maybe it's just that I can't hear it going that speed. I know it's probably a long shot, but anyone have an idea about this?

The same guy at the same shop said to bring it in and he will take a look at everything I am describing above, but I would hate to be jacked out of some more money by them if what they're telling me most likely isn't the correct thing, OR if it's simple enough to fix myself. Thanks again.

fb305svs

#'s 1 and 3 sound like choke adjustment issues- simplest thing to check is for connection to the supply wire, and to make sure it backs it self off as the engine warms up (check for this in the morning before u go to work- pull the air cleaner top, and base if u want, and check to make sure the choke flap is closed all the way- ifit isn't, u need to adjust it. secondly, start the engine, and watch the plate- it should open slightly after start and as the engine warms up, should back off, allowing the engine to return to a normal speed idle. Engine speed can be changed 2 way through the choke- high idle cam lever which is activated when the choke is i believe more then 50% engauged, and because of the impedeing restriction caused by the choke plate- check for operation of the system, thats a good place to start.

#2 - are these guages or "dummy lights"? im not horribly familiar with the LT's...

#4 - Rattleing noise could be anything from an exhuast leak to a rocker arm. Can you hear it at idle as well? check the heat shield on the cat, use a mechanics stethscope or put your ear up near the valve covers to listen to the rockers... (carefull of the accessories!) some noise is normal, louder individualised tapping is not. unlikely that you need to adjust a rocker unless there is some other sort of problem with the lifter or cam lobe... possible though i suppose.

Hope this gives ya a little insight, im sure there will be many more replies!

five7kid

iTrader: (14)

Digital instrumentation, huh? According to the Tech Data on this board that was one thing that the LT did not carry over from the Berlinetta. But, perhaps the digitalness was different.

Typically, instrumentation is supposed to go full-scale when you put the ignition in the start position - this is to prove that it is "working". Sounds like yours has problems in the "run" position, so that should help direct your hunt.

This sounds like a perfect reason to get a factory repair manual set for your year. I doubt there is any shop out there that would be willing to tackle this for a pre-arranged estimate, and I doubt you'd be very happy with the bill if you told them to work on it until they figured it out.

Jeremy Z28

iTrader: (5)

I'm pretty sure that they're the "dummy lights" as someone else I talked to referred to them as "Idiot lights." LOL - no clue what any of this means though. (guess that's why they call them dummy lights...) If I still had a digital cam I would snap pics - hopefully will get it back soon. Does it mean they really have no purpose / don't work? I'm guessing this means that I cannot put a 85-88 115/145 MPH gauge cluster?

Thanks again for all of your replies. Where is a good place to pick one of these up - some stores, online resources, etc. I searched eBay and came up with this. Too pricy or is that about right?

five7kid

iTrader: (14)

I had a mental picture from your description of LED "gages" that would light up progressively as the value increased. If they are indeed "idiot lights", the operation you described sounds normal. They should only come on when there's a problem with the system they are "monitoring" (as in when the engine isn't running but the ignition is in the run position) and when starting.

Switching from gages to lights requires changes in the engine sensors or sending units. The lights use switches, the gages use senders. I'm not totally sure about the cluster change, whether the dash wiring would accomodate either type. I believe I've heard that the wiring didn't change, just the from/to hardware.

That's the manual. Price is high, but that's actually less than what they cost new (more like $95). I thought there were typically at least two books, one for mechanical and one for electrical, but I haven't thoroughly researched that. Sounds like this one at least has the electrical schematics.

ss400hp

Wrong!!!! The fuel injected models did but the quadrojet LG4's do not, mine has the standard mechanical pump and I have owned the car since it came from the factory. Mine is an 87 by the way, as far as the carb goes, change it, do away with the computer because it doesn't do much anyway other than emission control and fuel/air mixture, etc... I gained several hp at the rear wheels by changing intakes and the carb, went with a edelbrock 600. Don't change it if you live in California..

ss400hp

Also, my 87 has a tach and all mechanical gages from the factory, you probably could find one and just swap things out.

ljnowell

Thats kind of a crappy way to put that. But, I dont think he is as wrong as you may think. I have taken the pump out of the tank of a few 87's that had the mechanical pump on the block and the electric in tank. All of them were carb'd. Maybe someone already removed the one from your tank?

bulletboy29

My 87 had one.

ljnowell

I am pretty sure that they all did. None I have seen didnt have both pumps. As far as ditching the Qjet, I wouldnt it. Have it rebuilt or buy a reman. Unless you are going crazy with heads and cam that carb will work great. If anyone gained loads of HP from changing thier Qjet, they either dont know how to tune one or just needed some work on it.

85Blackbird

http://www.i-5automotive.com/page5.html

i had a very similar problem with my old q-jet, since its computer controlled, it is very hard to replace with just ANY carb i want.

when my mechanics quoted me two days to rebuild the carb, i said **** em, i'll just buy a new STOCK one. hahaha they laughed and told me i'd pay upwards of $600 for a stock rochester qjet, and would spend at least a few weeks worth of calls to find.


well mr, plasma sword, for about $285 you can get exactly that for real cheap.
http://www.i-5automotive.com/page5.html

a great reman better than new stock carb.