awd92gsx Posted November 4, 2005 Share Posted November 4, 2005 OK...I'm out of ideas... After putting on my new heads and intake whenever I put the car in Drive it simply wants to stall out and die. Also, if I give it more than about 1/2 throttle, it backfires through the carb and wants to stall out unless I let off of it. I tried a new carb, I just tried resealing my intake manifold, ignition advance is good (set at about 12 BTDC - changing this doesn't really make alot of difference.) Checked and changed the throttle body gaskets, doesn't appear to be any leaking around the carb. When in park/neutral it seems to idle "ok" and seems to rev up just fine...but, as soon as it's put in park it wants to die. I'm completely and utterly out of ideas. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted November 4, 2005 Share Posted November 4, 2005 Do you have your spark plug wires on right? So it only does it when there is a "load" on the engine? Guy Quote Link to comment Share on other sites More sharing options...
jbc3 Posted November 4, 2005 Share Posted November 4, 2005 Still sounds like a possible vacuum leak. I had a car that acted the exact same way and it turned out to be a cracked intake manifold. I didn't find the problem until after I had replaced every gasket twice and bought a carb, returned it and got another because I thought it was bad. It was an 86 Jeep Wrangler. The idle was a little high in neutral when I got the engine back together, but I mistook it for a poorly adjusted throttle on the carb. So I adjusted the carb so it idled at ~800. Same symptoms you are having. Good luck, Jody Quote Link to comment Share on other sites More sharing options...
Cal Poly Zmanaustin Posted November 4, 2005 Share Posted November 4, 2005 Still sounds like a possible vacuum leak. This gets my vote too. If you have spark and decent fuel pressure (bad gas or something intermitant clogging the filter) then it sure sounds like a vacuum leak to me. Good luck. Quote Link to comment Share on other sites More sharing options...
boodlefoof Posted November 4, 2005 Share Posted November 4, 2005 I agree, sure sounds like a vacuum leak. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted November 5, 2005 Author Share Posted November 5, 2005 Yeah...it sounds like a vaccuum leak to me as well...I just can't seem to figure out where it's coming from... I bought one more set of intake manifold gaskets (good thing Chevy parts are cheap!!) and some different sealant. I don't know why I would be having so many troubles getting the intake sealed up right...but...I seem to be having them. Quote Link to comment Share on other sites More sharing options...
LS1 Z Posted November 5, 2005 Share Posted November 5, 2005 Going back to vac leak.. If you put your hands over the carb, does it smooth out? Did you shave your heads to where they doesn't match up with your manafold? Just some ideas on a vac leak. JOEY P.S. Your comment on backfiring. Sounds lean. or Timing chain not off. It's very easy to have the firing order off, with 5 and 7 swapped. Seen it many times. Hoped I helped! Quote Link to comment Share on other sites More sharing options...
getZ Posted November 5, 2005 Share Posted November 5, 2005 If you are the same person writing from the Desert Z forum. I tried explaining some points to you but you I guess you understand what I was telling you. I hope you don't get offended because I would really like to see you get that car running again. An EGR valve does not go from the caruretor vent to the intake manifold. EGR stands for Exhaust Gas Recirculation. It's an emissions device used to reburn gas coming out of the exhaust. It goes from the exhaust manifold to the intake manifold NOT THE CARBURETOR. On the 280z engine it is mounted on the intake manifold with a tube that goes down to the exhaust. Yours is designed to be mounted on the exhaust not the intake with exhaust into the center and manifold connection on the side. I would pull off all the emission stuff you got on it, plug it up and make sure it is running correctly before you reinstall all of it again. If you need a bung welded on the exhaust for the EGR, I can do it for you for nothing, but I live in the east valley. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted November 5, 2005 Author Share Posted November 5, 2005 I must not've seen that post...I'll go back and check... Technically, on a 1G SBC the EGR is routed through a port in the cylinder head into a chamber into the intake manifold and then rerouted to the intake charge. The vaccum port is routed from the carburetor, to the thermoswitch back to the EGR. The standard 1G SBC setup is mounted solely ON the intake manifold, rather than some of the later setups being mounted between the exhaust manifold and the intake In any case, it's blocked off at the moment until I get it running right...but, my Dart heads don't have the exhaust port going to the intake for the EGR anyway, so, it's not functional anyway...but, I need it for visual. If you are the same person writing from the Desert Z forum. I tried explaining some points to you but you I guess you understand what I was telling you. I hope you don't get offended because I would really like to see you get that car running again. An EGR valve does not go from the caruretor vent to the intake manifold. EGR stands for Exhaust Gas Recirculation. It's an emissions device used to reburn gas coming out of the exhaust. It goes from the exhaust manifold to the intake manifold NOT THE CARBURETOR. On the 280z engine it is mounted on the intake manifold with a tube that goes down to the exhaust. Yours is designed to be mounted on the exhaust not the intake with exhaust into the center and manifold connection on the side. I would pull off all the emission stuff you got on it' date=' plug it up and make sure it is running correctly before you reinstall all of it again. If you need a bung welded on the exhaust for the EGR, I can do it for you for nothing, but I live in the east valley.[/quote'] Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted December 4, 2005 Author Share Posted December 4, 2005 Just an update: I found one problem...I had two cam lobes worn completelydown on my cam...so, I ended up putting a higher lift cam in it (262/272) from Summit. Also...and I think this has been my problem from the beginning. My new cylinder heads allow the inner plugs (3 & 5 / 4 & 6) to contact my headers... So, aside from heatwrapping my headers (which I will do if necessary)...any other suggestions? I've considered getting the shorter spark plugs ACCEL sells...I'm open for suggestions, though. In any case, 1st gear is useless now, even through my 245's. Quote Link to comment Share on other sites More sharing options...
Psykovertible Posted December 4, 2005 Share Posted December 4, 2005 jeg's sells wraps made of kevlar or something like it in the form of spark plug boot protectors that are pretty nice. if you still have issues after the cam you can try the joe pyro method and carefully spray brake-clean around the intake to see if it changes idle at all. at least you boosted the cam in the end so that will make you happy. Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted December 4, 2005 Author Share Posted December 4, 2005 Well...it runs fine until the boot melts and it starts arcing against the header...(fortunately I kept my old wires)...so, I think between header wrap and the plug protectors, I'll be ok. Quote Link to comment Share on other sites More sharing options...
80LS1T Posted December 5, 2005 Share Posted December 5, 2005 The wire protectors will not work if they are in direct contact with the headers. I have them on my LT1 and it still melted the wires when they were in contact with the header. I now have a different header so it doesnt make direct contact with them so its not an issue any more(this was before I made my drivers side header and switched my passenger side to a regular block hugger type header). Guy Quote Link to comment Share on other sites More sharing options...
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