z or bust Posted April 1, 2007 Share Posted April 1, 2007 Ok I have an 82 280ZX N/A and just swapped the stock intake manifold and throttle body to the N42 non egr manifold and the 240SX throttle body, but when I turn the car on it won't idle and below 2000 RPM's it makes a popping noise in what sounds like the 5th and 6th cylinders. Once I get it up to 3000 it seems to run fine but the RPm's slowly go from 3000 to 4000 without me doing anything. I'm not sure if it has to do with the vaacum advance on the distributor or any other vacum problems just because that had to all be bypassed with the install of that manifold. Please help me i'm totaly stuck. Quote Link to comment Share on other sites More sharing options...
big-phil Posted April 2, 2007 Share Posted April 2, 2007 I'm not sure about your problem, but..... Your from Maine aren't you? Thats where I was born. I could tell from your Sig that says "WICKED" Prescott thats in Maine right? anyway...on with your problem, its sounds very vacuum related to me. Quote Link to comment Share on other sites More sharing options...
z or bust Posted April 2, 2007 Author Share Posted April 2, 2007 Yeah thats what I was thinking possibly the Vacum advance on the distributor. Actually its in arizona. My friend is from Maine thats where that one came from. The funny thing is is I don't even have that 300 anymore. Yeah this is stressing me out cause I can't figure it out. I'll try the advance though. Quote Link to comment Share on other sites More sharing options...
aarang Posted April 3, 2007 Share Posted April 3, 2007 Is the distributor vacuum advance hooked to ported vacuum? You can't run it directly to the manifold. Depending on what throttle body you have, you can run a vacuum line directly from the distributor to one of the small vacuum ports on the bottom of the throttle body. The distributor should see no vacuum at idle, only when you move the throttle should anything be happening. Also, be sure to bypass the thermal valve in the thermostat housing. Aaron Quote Link to comment Share on other sites More sharing options...
PapaSmurf Posted September 29, 2007 Share Posted September 29, 2007 I'm having the exact same problem, the timing has to be advanced way high to start and run but I hear that poping noise too. I thought I had not bolted the exhaust manifold on right because it was loud but I checked it and it's fine. 2-3k rpm the noise goes away. I am however running SUs and I'm running the vacuum line directly from the port on the carb to the distributor (which I've always done to great success) Quote Link to comment Share on other sites More sharing options...
z or bust Posted September 30, 2007 Author Share Posted September 30, 2007 Yeah i dont remember what my problem was but it was something stupid and simple. anyway this is an old thread lol i've already finished my turbo coversion, drove it for two weeks and decided it was fast enough do now i'm swapping in a 350. but good luck i hope you figure it out. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted March 24, 2008 Share Posted March 24, 2008 Hey guys, same problem. Put on the 75 intake manifold with the 240sx TB [the small vacuum idle pipe on the bottom of the TB]. I am not using a spacer, I mounted the TB upside down and ran cable throttle linkage. My engine won't idle and I'm also occasionally getting the popping noise on 6. It will run fine up higher in the RPMs but I dont think my Fuel pressure regulator is getting enough vacuum, the fuel line from the rail started to baloon!!. Can you guys tell me what you did to fix it? I thought I hadn't closed up a vacuum port and I had a leak but I guess you guys ran into this too. Any help would be awesome. I'll look at the distributor today for the vacuum line, but I don't remeber seeing it. Quote Link to comment Share on other sites More sharing options...
Careless Posted March 24, 2008 Share Posted March 24, 2008 maybe your FPR is stuck closed? have you tried to free it or check it using an air compressor and some extra hose layin around? I just did this on an EGR vacuum valve over the weekend and solved the Toyota Previa's 2000rpm cutout problem, which was associated with the TPS as well, once EGR was repaired. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted March 25, 2008 Share Posted March 25, 2008 The Fuel pressure regulator is new, and I can feel the gas flowing through the return line. I took a 75 Non-webbed manifold and shaved of all of the bolt holes, there is no EGR or anything on it, I just have the brake booster line and two vacuum ports that I'm using one to run the pressure regulator. I havent hooked the TPS back up, but that shouldnt affect it at idle, right? The engine idles at about 500. Could this be a vacuum leak at the manifold to head connection? My roomate suggested last night if I don't have proper crankcase vacuum it could also run poorly... any of these sound familiar? [Also if I force the A/F mix rich by pushing the flap open on the AFM it doesnt do anything which makes me think the Mix isn't lean] Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted May 21, 2008 Share Posted May 21, 2008 If anyone else has this problem, [i fixed this months ago] check your injector seals. I put new ones on and the problem was fixed. Quote Link to comment Share on other sites More sharing options...
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