Hello all, recently put on a new intake with an edelbrock carburetor. My problem now is that when I put it in gear it almost dies and will if I don't give it gas. I'm guessing it's a vaccum leak but don't know which lines go where. There are only three ports on the new carb for vaccum lines and there are a bunch of random lines that don't connect anywhere right now like the 4 coming out of my firewall in the middle. Which lines are important? I'm trying to simplify it as much as possible. Also took out my ac compressor and don't know what to do with the lines that were connected to it other than just taking most of them off is that fine as well? Do I need to plug those up?
Noahg...I see at this point-in-time you have 44 views with no assistance offered. I would imagine it may have to do with the limited amount of information you have provided. The best practice would have been to label all vacuum lines before you removed them. Bottom line if the vacuum ports to your carburetor and intake manifold are all plugged off and your carburetor is adjusted properly, your engine should at least idle assuming no vacuum leaks between the heads, intake and carburetor. Based on what you have written I must assume both the intake manifold and carburetor are new to your engine? Personally I prefer to replace one component at a time and then test that component. At this point we do not know if you have an intake to head vacuum leak, carburetor to intake vacuum leak, external vacuum leak or the carb is misadjusted or faulty. Please fill us in on the details of the installation and whether or not each component is new or just new to you. Pictures showing the vacuum lines close up and at a distance may also be of benefit. Good luck with your project!
The four lines exiting the firewall are for heat/AC operation, as long as disconnected not source of your issues.. At this point in time(40+ years after the fact) those will 99.9% cause a vac leak if connected... All that's really necessary for good engine operation is connect ported vacuum to advance diaphragm on dist, everything else can be plugged off... At least till drivability issues are worked out...
Krazy Comet, I may have made it too complicated. Unless of course, Noahg still has a problem once your suggestion is applied! Enjoy your day!
Rick I didn't mean to sound like your suggestion isn't valid, just wanted to mention(in a roundabout way) most of the maze of vacuum lines aren't really necessary... Problem could still be there, beside vac leaks, bad/wrong PCV, low idle speed, incorrect idle mixture, late timing etc can all cause similar issues...
yep.. due to problems through the years, nowadays I ALWAYS cap everything off on manifold and carb to eliminate possible leaks and variables that can bite me in the proverbial ass while I'm foolishly chasing my own tail around in circles trying to figure out what went wrong. Assuming the car was running perfectly fine before the swap.. and assuming you didn't reinstall the distributor a "tooth off".. I believe you may just have some basic adjustment issues going on here. Did you remove or move the distributor at all during the swap? Ideally, most shouldn't be doing this type of swap without a timing light and vacuum gauge because you're just flying blindly into a storm that can blow your damned wings off if you get it wrong. As Tom mentioned too.. be sure the vacuum line is connected to the distributors advance pot. That will allow the advance pot to add more timing as you crack the throttle open to accelerate and keep the motor from struggling to smoothly rpm and falling on its face. Otherwise the factory curve is about as lazy as a 29 year old living in his mothers basement. lol If you want to quickly play about and see how much more timing than the factory settings would have you believe is necessary.. more of what spark advance this motor would PREFER to see at idle?.. simply run the distributors vacuum pot to FULL manifold vacuum source(NOT the ported source mentioned above). This will add advance at idle too whereas the ported source mentioned above will only add more spark advance once the throttle has been opened enough to expose that ported or "timed" orifice within the carbs main body. Easy to try.. easy to see(and hear).. easy to reverse back to the original ported vacuum source previously mentioned.
Krazy Comet, I didn't take your response as a negative. Both you and groberts have far more experience than I at diagnostics.
Thanks everyone. I'll try to plug up some ports and see if that helps. I'll be working on it in a few days and hopefully I'll be able to try a few of these different things. I'm going to be buying a timing light as well so I'll check that. I did mark the distributor when I pulled it out and it should be in the same place although it could be a tooth off. I don't think it's fuel because I can get the rpms up pretty high without a problem. Yeah for all I know it can be the carb as well, I bought it used and just rebuilt it but it seems to be functioning fine and all the internals looked in good shape, plus I replaced most of the stuff inside.
Alright everyone I've been having an issue with my starter ever since I did the swap and can't make any progress. It will try to crank over once and then just clicks. I bought a new battery and sanded most of the connections with no luck. It seemed to be working fine before the swap so I don't know how the intake swap would cause this. Any ideas?
Could be the starter is defective or gone south. Did you replace or have it tested? As far as AC lines; I removed mine as they were to old to be used w/ my R134 conversion/upgrade. You can plug them if it makes sense to you -- I didn't plug mine.
I have not replaced the starter yet so I'll probably do that next. I've plugged the ac lines so that's done. I don't see it being anything other than the starter but I don't know why it stopped working almost completely after the intake swap...
Noahg, I don't see any mention as to the condition of your battery cables/ground cables or solenoid. I would do one of three things: 1. Replace/clean the cables and see if that fixes it. (I probably would do this first) 2. Replace the solenoid. (I have heard a whack from a hammer sometimes fixes it) If you don't want to spend the money first, go to #3. 3. Pull the started and bench test. If bad replace, if not see #1 & #2. Micah
