i have searched the forums and have not found my exact problem, so im making a new thread.

i installed a performer manifold on my 76' cutlass and have had nothing but problems! my car ran perfect before the manifold swap and now it idles very rough. i thought it was due to the egr blockoff, but i put the egr back on and still the same problem? also it seams like there is water getting on the gasket for the blockoff plate/egr valve?? is this normal?

my quadra-jet was re-built around 12 years ago and i have never had a problem with it. i sprayed the quadra-jet down with carb cleaner when i had it off the car just to clean it up. now the choke is working fine but when it warms up it idles very rough, and unless i rev it pretty high it sputters and eventually dies then spits gas strait up in the air! im figuring its time for a re-build but i dont have the cash rite now just wondering if you guys could help with any suggestion?

 

Did you pull/move the distributor? The obvious answer is that you have a major vacuum leak. PCV and brake booster hoses re-attached?

 

no sir, no change in timing or anything. as far as vacume lines, brake booster, ect. i put everything back the way i found it.

 

Was thinking that too. But check to see whether your install on the intake is good. If it's not sealed down right, it could be sucking air from an improperly seated manifold gasket. And you said there was coolant in your EGR?? That chamber should be dry. If you've got coolant in there that's a problem. This sounds more and more like a improper manifold gasket. Check your oil - is it turning milky colored? If it is, your getting coolant in the oil and you'll have to change oil/filter too. You might have to pull the intake and check your gasket. See if anyone else chimes in on this theory before you do it. There are lots of good tech guys on this forum.

Are you using all your old vacuum lines, or did you plug some off? If you plugged some, make sure the seals are good. I'm still thinking you have something wrong with the intake gasket. If it was running perfect before, the only thing that makes sense is the areas you disturbed.

 

Sounds like an intake gasket problem to me. Coolant & unmetered air.

 

yesir i agree, im thinking i messed up the carb by spraying it down with cleaner? there is no coolant in the oil, and i replaced all of the vacume hoses with new ones and put it back the way i found it, nothing capped off.

 

Keep in mind everything in the carb is made to handle fuel so it is very unlikely that a carb specific cleaner would damage anything. Did you ever tip the carb completely upside down when it was off the car?

 

yes i did, is that bad??

 

It can sometimes cause the needles to come out of their seats inside the carb.

 

1) Put a vacuum gauge on a intake manifold port or the Carbs PCV port and measure the vacuum.
2) Rebuilt the Carb. Peruse other threads about Carbs, Idling, and such to get ideas about how to do it.

 

^^^^^yesir i have tried everything else, im gonna try the vacume gauge tomorrow and then a rebuild if necessary. thanks for your help guys!

 

Put the iron intake back on and throw away the edelbrock.

 

Definitely double check the intake manifold gasket. Rebuilding the carburetor should help too. You should be able to get a carburetor rebuild kit for under $20.

 

Let us know what the Manifold vacuum is before re-installing the Intake Manifold. Regardless of the vacuum I would rebuild the Carb.

 

ok i got a vacume guage and hooked it to the pcv port, i got a STEADY reading of 19-20 and a reading of about 15 when i opened the throtle. so im assuming the vacume is not an issue? please correct me if im wrong.

also the car ran and accelerated 100% smoother with the pcv disconnected, and ran rough again when i connected it. so ill be taking a trip to the parts store in the morning for a new one. im hoping this will be the fix im looking for. ill keep you guys posted.

thanks again everybody!!

 

OK, outstanding vacuum pressure while idling, but the open throttle vacuum pressure is really high. It should initially drop to 5 psi or even lower and then slowly rise.

Running the car without the pcv mean you are sucking in lots of air. Pull a plug or two. I bet your plugs are really oily, and you are running real rich, too much gas.

I would say you need a Carb rebuild, and or wrong size main jets (toooooo big).

 

well like i said i never had a problem with the carb for the past 12 years so i think the jets size should be ok. i adjusted the carb to compensate for the rough idle, so im gonna try to re-adjust it tomorrow with the new pcv

 

I'm confused. You hooked a vacuum gauge to the PCV port? The tiny little vacuum gauge nozzle hooked to the giant vacuum line port?

Makes me want to verify what you mean by "pcv disconnected". Do you mean you pulled the PCV valve out of the valve cover port, without removing the valve from the vacuum line? Or did you remove the valve from the vacuum line, and either plug the open line or leave a giant vacuum leak?

When it is running smoother with the PCV disconnected, do you mean the valve is still connected to the vacuum line but not pulling in crankcase fumes (just fresh air), or did you completely remove and plug the PCV vacuum line?

I'm only asking because the phrasing seems odd. I've never seen a PCV line that was small enough to plug a vacuum gauge into it without some effort making the hose sizes match...

Is the valve the old plastic valve, or a metal valve? I've seen the plastic ones disintegrate internally, causing a massive vacuum leak.

 

I had a 1990 Buick Estate Wagon with the 307 SBO that ran horribly with the PCV hooked up. The rings were worn because it was a high mileage engine. Whenever I hooked up the PCV it had so much blowby that it caused the engine to stumble and the idle to suffer.

 

Yeah, we used to get those in the tuneup bay now and then. We'd show the owner what the real problem was, do the tuneup, then adjust the carb for best idle with the PCV in. Pull it out and they would run very lean, but we could usually get them through the emissions test... As long as we told the owner what the situation was, they really couldn't complain.

It'd be nice to see a picture of the water on the EGR gasket. That would be my first concern, if it were mine.

 

i disconnected the pcv vavle hose from the carb (the 5/8 hose on the left side of the carb) placed the vacume guage on the carb. (the guage has a 5/8 adapter) and started it. the car will not run without one or the other connected. the pcv valve is metal and ive never replaced it in 14 years so its time.

 

Last night I only had a few minutes to reply, and I didn't express myself very well.

OK, about the PCV valve and port: regardless, whether or not the PCV valve is connected to the PCV port, it should not immediately affect the performance and vacuum produced by the Engine. If the PCV valve is plugged that just means more air will enter the Carb via the Carb's barrels. Just logically reason it out.

If the PCV valve is plugged it will create additional pressures in the bottom end of the engine. The PCV valve and the breather filter on the other valve cover allows the bottom end of the engine to breathe, and that is about it.

To test the PCV valve: start the engine and just leave the hose and PCV valve connected to the Carb. Pull the valve out of the Valve cover. If you feel suction on the PCV valve it is partially working. Then turn the PCV valve around and place to against the hose. If you no longer feel suction, the PCV value is completely working as designed. That is how you can test it. You can also test the PCV valve by blowing into both ends, but oil tastes like crap.

When you take a Carb off, which has not been rebuilt in many years, (and I consider 12 years [many]), you move the crap contained in the Carb about and that can fall into and block important fuel or air passages.

Did you pull a plug or two? Were the plug(s) oily? I still don't understand the vacuum you measured when you opened the throttle. It should initially drop to 5 or less psi, then rise. In last message I mentioned slowly, but time is relative, so slowly to me maybe fast to you. The point is, the vacuum should not drop and then immediately swing back to where it was.

Re-measure the vacuum and tell us what it is when you open the throttle. Continually look at the gauge and make sure it drops and then rises. I would also peruse the threads about Carbs and idling, (for ideas). I replied to recent threads concerning these subject. You also should change the fuel filter.

 

^^ thanks for taking the time to help me! you were right it wasnt the pcv (oh well only $3) i pulled 2 plugs and no oil or gas, the electrodes were dry. im getting a REAL strong exaust smell and i noticed smoke coming from the other valve cover breather that smelled like exaust?

from the other threads i have researched it sounds like im running lean? how would i fix that?

i re-tested the vacume and it reads 20 on idle and it did drop to about 7or8 with the throttle open then raised up pretty quickly.

 

First replace the Fuel filter. If that doesn't help then you will have to rebuild the Carb. Sorry, but it seems like that is your only choice. Since you replaced the intake manifold you may also need to replace the main jets with bigger ones. You stated that it is running lean after warming up, which means either fuel passage(s) are blocked, clogged fuel filter, or wrong size main jets.

Check out the Internet and see if you can find other recommendations for main jets with your Carb and Intake Manifold. Rebuilding the Carb is not hard. The Carb cleaner with parts basket in one gallon can runs about $25.00. The gaskets about $25.00, and Carb float about $30.

Use this site to see other Threads about Carbs. Also utilize the Internet and read about Carb rebuilding. Study diagrams and understand what goes where before you start. There a weight above the check ball, so don't lose it when you tear the Carb apart. When you put the Carb back together make sure you place the upper Carb body, directly square on the middle Carb section. There is a power valve and associated needle assemble, and if you don't drop the upper section directly down square onto the middle section you can bend the needle or Power value assemble. I've done that before, so I know.

 

OK, the vacuum you measured is fine. The smoke you see coming from the Air Breather filter probably only happens when you open the throttle, or crank the engine over. This 'smoke' is caused by lack of vacuum pressure [that is created by the engine] temporarily dropping or is not present when you first start the car. This lack of vacuum causes the PVC valve to close and the engine's bottom-end pressure to escapes out of the Breather. That is why Smog laws specify that the Air Breather filter be vented into the Carb Air filter, but we will not go there. All of the above just means that what you see is normal.

I would 'guess' that the exhaust smell you mentioned is burnt oil, but I don't know what you are smelling. Excess blow-by can be determined with a compression test. Have you run a compression test on the engine? If so, detail how you did it and the numbers obtained.