Wade Nelson

Yes, that will work.

Couple of things 12" (not psi) of vacuum at idle isn't NEARLY enough. That's an indication of a REAL problem, like a broken valve spring, MAJOR vacuum leak, COMPLETELY clogged exhaust system, timing chain off a link, SOMETHING major. Vaccuum that low tends to indicate major mechanical problems with the head. Your "Tachs gone wild" above 3000 rpm sounds more ignition related to me, like your distributor pickup is failed or the toothed reluctor has a crack in it so at higher rpm's the ECM is seeing a very invalid signal. A crack in the reluctor can be damn near impossible to see without bright lights, etc. Your best shot is to put an oscilloscope on it and WATCH the signal above 3000 rpm and see if it goes to hell. Did you test the FPR as I suggested? If the diaphram is "holy" then raw fuel is pouring into the intake manifold directly from the FPR. That could easily explain the rich condition, although it should favor the two closest cylinders. I'm still leaning towards a failed TPS, connector, or wiring because its failure modes explain SEVERAL of the symptoms you describe. Very similar to a 4-Runner I owned with a failed TPS, erratic idle, lack of power under load, hesitation /stumble, misc.

Take your car to a mechanic with a smoke machine and smoke the manifold to find your leaks. (They only apply 1-2psi) Alternately, find a heavy smoker to exhale large amounts of tobacco smoke into the brake booster line. Then check the brake booster itself. You may need to do both engine cold ' engine warm to detect a manifold gasket leak that seals up when the engine iscold. A vacuum leak should be causing your vehicle to run LEAN, not rich. the 280 doesn't have an 02 sensor, right? So the things telling the ECM how much fuel to inject include: Air flow meter Coolant temp sensor Throttle position sensor Signal from distributor telling ECM rpms Could you have been dialing the AFM the wrong direction? No, I don't think advanced or retarded timing would cause your engine to run rich. Since the 280 does NOT have a catalytic converter, I would EXPECT it to blow a certain amount of soot on startup when the Cold Start Valve is practically flooding the engine with fuel. But your plugs should clean up within 3 minutes of hitting the highway. What happens when you try and start it with the CSV disconnected? Are you positive you replaced the CTS and not the GAUGE sender? Unplug the other one and see what the gauge does. Aren't the Aux Air Valve and CTS connectors the same? Do you have them swapped? Pull the hose off the fuel pressure regulator and plug it witha golf tee. Now put on a fresh piece of vacuum hose, longer, and try sucking on it with the engine running, see if you get any rpm change. Or "Tee" a fuel pressure gauge in and watch that while you suck on it. If you get a mouthful of gas, well, spit it out, and then go buy a new FPR. If your idle won't remain steady, I would STRONGLY suspect your throttle position sensor is either failed or out of adjustment. The ECM isn't getting the signal TELLING it your foot is completely off the pedal. A failed TPS can definitely cause rich running, because the ECM is being told it's under load when in fact it's actually loafing. So there, I've talked myself into throwing a new TPS on it, or at least testing the old one throroughly with a DVOM, per the Fuel Injection Bible. (you've already downloaded and begun memorizing that, right?) That should keep you busy for 3-4 hours. Get back to us with what you find.

I don't see how backfiring could knock the timing off. Please elaborate. (I intend to sell this response to Click and Clack, so....be careful!)

http://www.classiczcars.com/forums/thread46866.html This is a fairly good thread on the topic, also search on "hard starting" and "hot restart" to find others.

Quit screwing around on Internet forums and take your car to an auto electric shop. People get paid good money to diagnose auto electric problems, and deservedly so, IMNSHO. The range of possibilities includes: A failed alternator Miswired alternator Bad wiring and/or connector to alternator (likely) Bad main engine and/or body grounds Bad B+ wiring to fuseblock, failed fuseblock, miswired fuseblock Bad B+ to alternator connection Bad ignition switch (likely) Some combination of the above. It sounds to me like you have multiple overlapping problems.

drop me a PM if you've got the wrong manual also. Or just need an '83 manual, I can pick up an '80 on Ebay.

I bought a new PCV valve for my 280ZX from Rock Auto. Standard kinda PCV, threaded on one end, hose barb on the other. Only problem is I can't find any place to put it on my engine. The PCV hose from the valve cover to the intake manifold, well, it apparently doesn't thread into either end! I can't find any place for it except my glove box! Is the PCV integrated into the 90 degree elbow going into the valve cover? Did Rock send me the Rong part?

How's the job search going? Did you check out the book I suggested?

How about some follow-up? Did you get this diagnosed / fixed? Please share so others can benefit.

A day after FINALLY getting my new injectors installed and working, what I'm noticing ON MINE is: A) A lower, smoother, idle. (Probably MORE due to all the vacuum leaks I sealed in the process, like cracked PCV hose, old rigid hoses on thermovalve, etc. I actually had to dial up the idle a bit. New injectors a lot quieter. C) Throttle response --- ahh, not enough change for me to discern. D) BAM! Starts instantly. I also replaced the CSV, and when I tested the old one, it wouldn't click. That probably has a LOT to do with it. E) I haven't put a gauge on it yet to see if it's holding pressure better, but it sure seems so. F) I'm hoping for an added 1-2mph improvement due to better cylinder balance. This job took about 3 times as long as planned for with one of my new injectors failing, having to replace injector connector wires, etc. Kinda like labor, hopefully the baby makes it all worthwhile. I sure did miss driving my Z for two weeks!

With ethanol more pricey than gasoline these days it's unlikely the government will MANDATE E15. A little ethanol (E5-10) gathers water, boosts, octane, and results in more complete combustion because of the oxygen it brings to the fireball, DESPITE the lower energy density of E10 gas vs non-alcohol-added. More than a little is of no benefit to any of those worthy goals and only lowers MPGs further.

Here's a cheap trick I found. Extend your tailpipe 8-10" beyond the end of your rear bumper. Yes, you will trip, catch your legs / pants on it every time you go around the rear of the car... Above about 35mph, ALL of the noise is being spewed out behind you, and you kinda "outrun" it. The car gets a lot quieter. I've done this on muscle cars, sports cars, all sorts of cars that I wanted a free flowing exhaust but not quite so much noise at mid and higher rpm's out on the highway, but a nice roar in town.

How about posting a followup of what your mechanic found?

Here's more info. One of my six new injectors failed, first fouling plug #1 (and giving me HORRIBLE gas mileage) then sticking open and hydrolocking the motor. One "symptom" was at idle, the exhaust note sounded funny, even though there was no engine miss. It was like it went pop pop pop in time with one cylinder firing, due to all the extra fuel in the exhaust. Hopefully no head/gasket damage was done, I'll find out pretty soon here. When I removed the fuel rail AND injectors I could see #1 going drip, drip, drip. I removed the #1 injector and sprayed it out with brake cleaner onto a fresh paper towel. The ONLY thing that came out was the tiniest sliver of rubber. Apparently while installing the injector hose onto the fuel rail, it "shaved" a tiny bit of rubber off the hose, despite my use of lube. Or else that bit had been floating around in the fuel rail ever since some other hose or fuel filter replacement. I tried "clicking" the injector using a spare resistor pack, and connecting it to the battery. It wouldn't click. Neither would my OLD cold start valve. In contrast, one of the OLD injectors happily clicked. So there must be a second bit of schmutz actually clogging the pintle. Next I'll try using compressed air to blow out the failed injector from the nozzle end, and try to re-click it. This time I went ahead and replaced broken injector connectors, and replaced the three hoses on the thermoswitch accessible only once the fuel rail is removed. All were hard as rock, of course. By first cutting them in two, and THEN slitting them lengthwise, I managed to remove them from the plastic nipples on the thermoswitch without breaking any of THOSE off. Hurrah! I also replaced the injector pedestal that was broken, for which I previously didn't have a replacement. Except now there were TWO broken ones. good thing I grabbed THREE at the junkyard. Right now the hood is up, and I"m waiting for FedX to show up with my replacment injector. I've already cleaned everythign under the hood I can find to clean, so....

Imagine one of your exhaust valves being stuck open WHEN the spark plug fires. The fuel/air mix not just in the cylinder, but also in the exhaust manifold is getting ignited. That's what your backfire is. It could be a broken distributor gear or bent valve, jumped timing, blown head gasket (allowing fire from one cylinder into the next one) etc. Compression / vacuum testing will point you in the right direction to look. The fact that you recently replaced your oil pump SUGGESTS to me something wrong with your distributor drive, like a broken tooth, whatever. I don't think your repairs are going the be cheap.

Sounds to me like it has jumped time -- timing chain has jumped one or more teeth on the sprocket. Have you done a cranking compression test? Or checked vacuum while cranking?

Down south here we put 'em up on blocks. Seems to deter all but the most determined thieves.

I'd pull you plugs and make sure you're not hydrolocked. That'll make a really loud bang when you crank. And it won't start. Pull the plugs, crank it, and see if it cranks normally. Have someone else crank it for you and see if any fluid gets ejected from any of the plug holes If you have a blown head gasket that would explain the hydrolocking AND the blown water pump seal. If it's truly JUST an exhaust backfire, then I'd look for an air leak @ the exhaust manifold gasket or downtube.

Four or six mil clear polyethylene sheeting from the hardware store and a hot glue gun. It's removable, and the hot glue is very easy to work with. Apply it to the film, NOT the cold sheet metal body.

Instead of insulting you, allow me to try and answer your question. The front brakes do 80+% (appx) of the braking work on MOST cars. However, the way most brake systems are designed, the fronts don't engage until AFTER the rears have begun to engage. This results in a weight shift to the front --- the nose dives a little bit. This puts even MORE weight on the front tires, allowing the front brakes to perform even MORE braking work before a skid begins. If you've ever driven go-karts, you know that locking up the rear wheels tends to make the rear end swing around --- something you desperately want to avoid, especially in a Z, which may spin and "swap ends" on you. Whereas locking up, skidding the fronts TENDS to result in understeer --- you scrub off rubber, speed, and energy as the front "can't make the corner." If you're lucky, you regain traction BEFORE going off the road. Furthermore, once the front locks up, by letting off the front brakes, you can trade braking energy for cornering energy. Think of a pie, you can apply various amounts of traction to either cornering OR braking. Which is why you brake on the straightaway BEFORE you get into a corner, so you can have ALL your traction available for cornering. The "circle of traction" is a concept you really DO need to understand before you start aggressively driving sports cars, if only to keep yourself alive. Manufacturers have long found that cars which understeer are GENERALLY safer for consumers than those that OVERSTEER, and slide the rear end around. I'll stand back and let all the "experts" clarify, correct, argue, etc. at this point.

I suspect I have the 3.54. In my car, what I find is for coming OUT of a corner, 3rd gear is too high. If I downshift to second coming INTO the corner, I have to rev it too high to match rpm's, and my 200k mile synchros just aren't up to the task. So what I've BEEN doing is stomping on the brake AND the gas and leaving it in 3rd. But my RPM's are too low to pull away quickly. I SUSPECT I'd like the 3.7 or even a 3.9 simply because of where 2nd and 3rd would end up, range-wise. (Higher RPM's in 3rd at the same speed) I find for passing, I really have to go down to third. Fourth just doesn't give me the accelration to get the job quick enough, not up here at 6000' altitude, with appx. 15% power loss. With the 3.7 I might be able to "only" go down to 4th. So do you want a quiet, comfy cruiser, or a hells-bells cornering and passing machine. I probably have it all backwards, but you get the gist of what I'd prefer the gearing to be. A few hours going back and forth between two cars, one equipped with each ratio, and you'd instantly know which you'd prefer.

For anyone following this thread, NOTE that this upgrade is reportedly for 240's only. The later z-vehicles supposedly have a bigger or better fan. From the discussion I see that the upgraded (Honda) fan has an air channel that blows cool air onto the brushes. That will make them last a LOT longer, both by staying cooler, and getting rid of any carbon / copper dust. That's a feature on many Toyota blower motors that is NOT on the 280ZX blower motor. It can be a channel or a little hose, but it needs to transport air from a high pressure area to the brush area. What I"m saying is: Don't leave it disconnected!

Umm, can you provide more information, like WHICH Honda blower, out of WHAT model? Is it available from RockAuto? Is it three screws, two wires, and you're done, or is modification of the base necessary? Or point us towards a post which provides this info? Thanks.