Guest mikedick6969 Posted May 18, 2006 Share Posted May 18, 2006 I got a mostly stock 75 Z. Is it worth the upgrade?? Not just for power, but reliability as well. I just got the car, and wanna give it a refreshing piece by piece. Thanks in advance! Quote Link to comment Share on other sites More sharing options...
blake culp Posted May 18, 2006 Share Posted May 18, 2006 I would say it depends on how your stock system is running, if it is running good and you seriously are not looking for more power now or down the road i would keep the stocker. If the stocker is starting to give you problems, you could get a megasquirt installed and running for the price of replacing a few parts on the stock system. With my old turbo system, it would run good one day then like crap the next, which i found to be really annoying. Now it runs reliably and good day after day. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 18, 2006 Share Posted May 18, 2006 Well I just bought it from my brother. It ran on the way to the storage where it sits now, but I went to start it and there are fuel problems already. I still havent been able to get it goin, but im waiting for the next paycheck so I dont have to swipe the wifes battery everytime I wanna make an attempt. About the only thing not stock on it is the 78 El Camino 80 amp alternator on it. I have an L28 from a 78 280 that I wanna build up and throw in there this winter. So yeah, Id like to add a bit more power to it in the future. Quote Link to comment Share on other sites More sharing options...
HizAndHerz Posted May 19, 2006 Share Posted May 19, 2006 From my somewhat limited experience, the things that go bad are typically in order of frequency: 1) Corroded connections (injectors, sensors, fuse links) 2) Leaky or clogged injectors 3) Worn out or clogged up fuel pump 4) Rust or varnished gas tank 5) Worn trace on AFM circuit board (usually easy to fix) 6) Bad temperature sensors 7) Bad relays 8) Previous owner's hacking The stock ECU seems to be very reliable. I've got a stack of good ones in my garage. I blew up the only one that is bad. A lot of the stuff in the list above has to be fixed even when changing FI systems. Even though I plan on "upgrading" at least one of our Z's to MegaSquirt in the future, I've found it valuable to test and then refurbish, rebuilt or replace all the components in the stock system. My Z's ran like crap or not at all when we got them, but have been completely reliable since going through the above list of components. If your engine isn't running right for some unknown reason or multiple problems, trying to get MegaSquirt running would probably be a major hassle. Don't expect MS to be able to diagnose fuel pressure or electrical problems. It will tell you about sensors and connections to some extent, but those things should be fixed first anyway. If you were certain it was the ECU that was toast, it might make sense to convert. But then again, working ECUs can be had for cheap. Just my $0.02 Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 19, 2006 Share Posted May 19, 2006 My cousin believes its the temperature sensor. One can be had at my local auto store for 15 bucks. The one right by the heater bypass. I will surely go through that list though. The injectors and fuel pump are new, and we checked the gas tanks contents as well. Im gonna also do that AFM refresh thing too. If I had megasquirt, I could get rid of that AFM. Is that true?? Thanks for walkin a newbie through this hizandherz!! Quote Link to comment Share on other sites More sharing options...
mobythevan Posted May 19, 2006 Share Posted May 19, 2006 If I had megasquirt, I could get rid of that AFM. Is that true?? Yes. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 19, 2006 Share Posted May 19, 2006 Excellent. Thanks for answerin that moby. I thought I read that somewhere, but I couldnt find the article. It would be nice to ditch some of that older hardware and bring the Z up to the times. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 20, 2006 Share Posted May 20, 2006 Temp Sensor just ordered. Ill have it tomorrow. Then to see if its fit enough for the upgrade. Quote Link to comment Share on other sites More sharing options...
v8260 Posted May 20, 2006 Share Posted May 20, 2006 keep us updated. i had the same question. only thing mine has is headers and an intake. One of my buddies said that if i switch im almost guarantee better gas milage being that he was saying the FI systems back then had flaws and were pretty primative to todays FI. im going to go turbo eventually so im going to go megasquirt but i was gona convert to megasquirt before turbo. let us know what u end up doin. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 20, 2006 Share Posted May 20, 2006 Will do! Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 20, 2006 Share Posted May 20, 2006 Well just tried the temp sensor. No go. Guess ill try a couple more things before I just sell the thing and get something newer and better than a Z. Got the megasquirt priced out and ready to order. Just waiting on another check. If this junky Z wont run I may just slap it on my 02 Cougar. EDIT: Sorry. Just a bit pissy. Had the heater Bypass hose blow up in my face when starting it. Split right down the middle. Quote Link to comment Share on other sites More sharing options...
Nismo280zEd Posted May 21, 2006 Share Posted May 21, 2006 lol i've had the exact same hose do that... right along the top edge right? lol. Megasquirt will save you time and money in the future. Right now you don't know why the car won't start... if you had megasquirt installed you can diagnose it and check everything one by one to find the source of the problem instead of educated guessing. Also as mentioned... nissan parts are expensive... megasquirt was designed for regular GM sensors... dirt cheap w/ lifetime warranties on them at most parts stores. Also.. the stock fuel injection was a nightmare of a rats nest. Atleast I think so. The MS allows you to ditch just about everything you see on that manifold except vacumn lines for your brakes, dizzy, A/c heater if you run it and the fuel rail. It's a much cleaner setup and your milege will be better once tuned. Ok now that that's said... I feel your pain from the hose so i'll be nice. First things first, when a car doesn't start immediatly check to see if it has spark. Use a spare spark plug plug it into a wire... put the plug on the valve cover and crank... if it sparks your ignition is fine... and it's fuel. If you have pulled a plug and found it wet... you have fuel or can smell the excesse fuel. Then you have an air problem. Even with bad temp sensor, afm etc the car will still initially spark and start. Check those first, then go through all the expensive parts. -Ed Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 21, 2006 Share Posted May 21, 2006 The car does spark, and start. My cousin set the AFM before I got the temp sensor. Now it pops and spits more than before when I didnt have the new temp sensor. Today were gonna go set the AFM. Its getting more than sufficient spark, so were also gonna take a fuel pressure reading today. Could be the screen directly behind the fuel pump since I just installed a fuel filter as well yesterday. That being said were gonna take another whack at it today. I soo wanna get rid of the old crud on that engine, thus why I was lookin at MS. Not so much a performance upgrade, but a cleanup of old parts, and a boost in reliability. Some of those parts are like 31 years old I suspect. Thanks for the input on the MS and my little problem Nismo280zEd. Im probably gonna try to get this thing running before I create myself another mess to deal with on the car. Quote Link to comment Share on other sites More sharing options...
spork Posted May 21, 2006 Share Posted May 21, 2006 Don't mess with the AFM unless you know for certain thats whats wrong with it. Many people screw them up by trying to adjust them. Rarely will the settings need changed! Just fair warning. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 21, 2006 Share Posted May 21, 2006 My cousins been adjusting the AFM on Z's for years. Its now down to not enough fuel we think. He's grabbing his fuel pressure guage from work tomorrow. We checked the immediate filters and screens, and they all checked out ok. Are there any screens in the gas tank on these cars?? We're probably gonna end up goin through the whole fuel system. The car now runs, but when we apply the gas pedal, it stumbles and makes a "whooshing" sound. This is when the car is not in gear or moving. Moving its a chore, as when we do apply gas, it has to be done slowly or the engine dies. Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 22, 2006 Share Posted May 22, 2006 Just got back from the storage. Word is theres a screen in the gas tank somewhere. No doubt plugged by the yellow gas in the car. We took the fuel pressure and it came out 10PSI. So we seem to have found the culprit. Any tips on cleaning out the fuel tank. Kinda runnin on limited funds or i'd be buying a new one, and all new fuel lines to boot. Quote Link to comment Share on other sites More sharing options...
HB280ZT Posted May 23, 2006 Share Posted May 23, 2006 Here is something that I did when I thought I had tank problems. On my 77 there is an inspection lid on the passenger side near the spare tire in the rear of the car. This lid gives you access to the fuel level guage. I pulled the lid and the guage to inspect my fuel tank. That is when i found out that mine was toast! Also at that time you can try to back flush the fuel lines with some compressed air. Hope this helps! HB280ZT Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 23, 2006 Share Posted May 23, 2006 Ohhh! Thanks a bunch. I thought I read something about the compressed air thing before. Any specific PSI to keep it under?? Thanks a bunch man!! Quote Link to comment Share on other sites More sharing options...
HB280ZT Posted May 23, 2006 Share Posted May 23, 2006 The only thing that I can say is to keep the pressure low 40-50 psi and make sure you have the other line pluged, ie if you are blowing out the supply line then plug the return and visa verse!! Also put something like a rag over the inspection hole just in case you get some fuel spray! HB280ZT Quote Link to comment Share on other sites More sharing options...
Guest mikedick6969 Posted May 23, 2006 Share Posted May 23, 2006 Ill probably empty the tank first. Im having a hell of a time locating fuel tank straps though........ Quote Link to comment Share on other sites More sharing options...
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