Guest lamar32 Posted February 18, 2004 Share Posted February 18, 2004 I think I read here that the msd won't benefit a 81-83 280zxt pcm please correct me if I'm wrong. My car has been running good but I've been fouling some spark plugs. recently I installed a walboro fuel pump and I think it's just spitting to much fuel, also I think my turbo is going there has been some smoke I pulled one of my intercooler pipes and there was a little oil residue. I have the turbo xs blow off valve that just vents to the atomsphere so I think oil has been escaping there as well. But can some one give the wiring diagrams for the msd 6a and there thoughts if is worth it for the pcm and if it really boost ignition. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted February 18, 2004 Share Posted February 18, 2004 Well, I think you know the problem is. You already got good spark but too much fuel. So won't you fix that first? Good FPR should stablelize the FP. My car never ran good without MSD, don't ask me why. I think because I didn't have enough timing when I took the MSD box out. Quote Link to comment Share on other sites More sharing options...
Guest lamar32 Posted February 18, 2004 Share Posted February 18, 2004 What is the best fpr to go. and can you give me the wiring set up for the msd. also can you use the stock rail with a new fpr. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 19, 2004 Share Posted February 19, 2004 Msd will benefit... most people will tell you they wont make any more power, and they may be right, but I'm along with yo2001, my Z cars have ALWAYS run NOTICEABLY better with an MSD installed. They start easier, idle smoother, especially when cold, have noticeably better throttle response, and do FEEL like they have pulled a bit harder. This was most noticeable in my turbo setup over my N/A Z's that I've had. I also agree though that you need to fix your problems with fouling or whatever first.... while an MSD may or may not help with that, even if it helps it's really just a bandaid covering up the problem. Take care of the problem first. Don't bother getting an FPR just yet. Running rich is 9 times outta 10 a problem with the EFI system, electrically, in my experience, but CAN be an effect of too-high fuel pressure as well. I just went thru this exact same problem, as a matter of fact, when I upgraded to an MSD fuel pump. What are you using as a return line? I was using the stock 240z return line which is WAY too small and restrictive and couldn't handle the new pumps flow, causing fuel pressure to skyrocket up to 60psi and the car to run like crap. Checking the fuel pressure is easy and cheap enough. You can get a pressure gauge from Home Depot along with all the brass parts/fittings you need for about $10-15, install that in the fuel line between the fuel filter and fuel rail. That will tell you right away if you're fuel pressure is a problem. Or an easier test is to just disconnect your return line and run it into a fuel-safe container and run the car for a minute that way... with the restriction gone the car should run noticeably cleaner. I had this problem and switched my lines around. On the driver side of the car there is a much larger hardline, which actually connects to the fuel vapor tank. I hooked my return line up to this, and in the back of the car I rerouted the hose from this to the stock feed line coming off the stock 240 fuel tank. You can do something like this or just run an all new hardline for your return. Adj. fuel pressure regulator will NOT help this though... it will not allow you to lessen the pressure any less than the greatest restriction in the return line, which is most likely the return line itself... you could back the FPR all the way out and it will have no effect... trust me on this. The EFI, unfortunately, is not so easy to diagnose. A bad sensor could definately cause you to run rich, especially the head temp or coolant temp sensor, these have a pretty big effect on overall fuel mixture. They are cheap and easy to replace so if you dont know their age or condition replacing them is probably a good idea. You can also toy with adjusting the spring tension inside of your airflow meter, tightening the spring leans out the mixture... very small adjustments made huge differences in the way my car was running. I can only imagine taht the spring in there loosens over time (which it's had 20 years of time in which to do so!) and as it loosens of course the car will run more and more rich. Also the possibility that someone has messed with it before you and screwed it up. Also... actually try this first (well first after checking if it's the fuel pressure)... seems to fix problems a lot of times with the EFI. Get a can of brake parts cleaner spray, disconnect all the wires of your EFI wiring harness and clean everything off. Quote Link to comment Share on other sites More sharing options...
Ben Posted February 19, 2004 Share Posted February 19, 2004 I have the turbo xs blow off valve that just vents to the atomsphere so I think oil has been escaping there as well. There's one over-fuelling issue right there. You are venting 'metered' air, which has been calculated & fuelled for. Disable the BOV & see how you go. A little oil film isn't always the turbo's fault, you could have a bit more blowby than standard. Fit an external catch can & see how quickly it fills (if at all). Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 19, 2004 Share Posted February 19, 2004 a little bit of oil film in the pipe between the turbo and intake manifold is actually pretty normal. Quote Link to comment Share on other sites More sharing options...
Guest lamar32 Posted February 19, 2004 Share Posted February 19, 2004 I'm using the stock feed and return lines from the 1972 240z. So let me get this straight there is another vapor fuel line that I should connect my return to. Also to check the pressure just connect a pressure guage right after the fuel filter b-4 the fuel rail with general plumber parts can anyone show me a pic of this setup. Thanks guys I appreciate all the nfo. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 19, 2004 Share Posted February 19, 2004 I may take some pictures of the engine bay today, I'll try to get a clear one of the pressure gauge setup. It consists of exactly five parts: the gauge itself (it's a water pressure gauge, I'm assuming used to measure sprinkler system pressure) cost around $7, an adapter to adapt the threaded part of the guage from 1/4 to 1/2, a three way tee (all three openings are female, threaded, 1/2), and two barb tips that the hose will go onto, 5/16" I believe, to thread into 1/2. They can all be found in the plumbing department of home depot. You can ask just about anyone there... just tell them what you're trying to build (and dont let them tell you it wont work for fuel, me and Jersey, another member, have been using these and they work fine, no leaks or anything), and they'll point out the parts you need. Oh and don't forget the teflon tape. Stock return line is WAY too small, that's your problem right there. I JUST went thru this exact same thing a couple weeks ago. If your car is a 240 (dont know how this applies to 260-280's) on the driver side of the engine bay, very close to the turbo, but against the wheel well and the frame rail, there is a hard line, about double the size of the stock return line. This hardline goes to the back of the car, and terminates right about where the other fuel lines terminate. From there, a rubber hose connects, goes up thru the passenger side rear, in front of the fuel tank, to the inside of the car, and that hose connects to the vapor tank. Here's what I did: I took the hose, the return hose that went from the fuel rail to the stock return line, took it out and got a longer hose, you'll need about 3-4 feet, 5/16" hose. Connected that hose from the fuel rail to the hardline on the driver side. Then, under the car, I disconnected that connected that same hardline to the vapor tank (leave it connected to the vapor tank inside the car) and connected it to the stock, small return line. I then connected a hose, from the larger vapor hardline, and connected that to the feed outlet on the fuel tank. If you connect it to the return inlet on the stock tank, that is also very small, and you will still have restriction. My feed now draws from the drain at the bottom of the tank, which is how most people set up their turbo 240's if they're using a stock 240 tank. Hope all this helps, if anythign is unclear dont hesitate to ask. Quote Link to comment Share on other sites More sharing options...
Guest lamar32 Posted February 20, 2004 Share Posted February 20, 2004 so I got all the stuff for the fuel pressure guage. And I figure I will just plumb in a new feed line and put the return on the old feed line I will see what the pressure is like when I do all that if the pressure is fine I will proably do the msd is the wiring for the msd basically just feed from the coil, or is there something special I hav to do, and do you guys think the msd is worth it. Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted February 20, 2004 Share Posted February 20, 2004 MSD is easy to wire. Six wires. Two replace the two that are already on the coil. Then the two that used to go to the coil, connect to two more from the MSD. Last two wires from the MSD are to the battery and ground. Hard to say if it's worth the money. Dont expect any more power out of it. But your car may run better, start easier, idle more smoothly. It also helps if you're running high high boost... enough boost to 'blow out' the stock spark... would get high end misfire. I would say, as it is, you probably don't NEED it unless like me you have a car that idles kinda rough or misfires at low revs. Quote Link to comment Share on other sites More sharing options...
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