jmead

this is thwe chevy forum, this belongs somewhere else, you'll probably get more replies in the V6, or toubleshooting areas

I know you can get a general indication of how a car is running by "reading" the spark plugs. Unfortunantly, I couldn't find any sites with a detailed explination of just what to look for, so I'll let the experts at HybridZ take a look. I'm not sure exactly how old these plugs are, but they probably have around 3k miles on both sets. They are layed out such that the plug furthest on the right was the plug closest to the driver. This set it from a 1970 240z with dual SUs. I'm guessing this means the carb towards the driver is running rich, and the carb towards the front of the car is running lean? Any simple way to adjust this? (links maybe). My manual covers carb disassembly, but not tuning. This set is from a 1976 280z, fuel injected. I'm guessing this means that the engine is running rich in general? Any way to correct this? The car is stock, I haven't messed with the injection to cause it to go out of tune. Thanks for any suggestions, ideas, professinal opinions, etc. Sorry for the large pics, but I wanted the plug ends to be easily visable.

I see what you guys are saying, and it makes sense. There would be a few flaws: First, it lengthens the overall depression of the pedal. This may be desirable; I guess it depends on what you want. Personally I would prefer a system that only decreases the force necessary, thus allowing more accurate control. And second, it would be difficult to "tune". If you wanted to change any of the characteristics, you would have to design a new "cam". There may be a way around this, but not any simple ones that I can imagine. And thirdly, well, I dunno, I knew there was something else but I lost it. It looks good through. I'd like to see if anyone pulls this off. Pics are necessary, of course.

Sorry that I can't help you with the specifics, but it sounds like a great idea. I've wished for this very thing many a time. It wouldn't be hard to do, but it would be hard to do simply and reliably. I'm interested to see what ideas hybridz comes up with.

I've got a 350 w/ stock heads. They're a little crusty, and could use some work. I've got a chance to pick up some bare 283 "POWER PACK" heads cheap. This would allow me to choose the parts I want and build up the heads, while still having good working heads (hopefully) that I don't mess with. Will the 283 heads fit a 350 no problem? Anything I should consider before buying? Just want to know if they will work. Thanks

I was just going to learn as I went along, but if you guys think they're worth the cash I'll try and pick a few of those up. The engine is rebuilt already, so I think I'm just going to leave it, but I would like to know what to check for if i decide to open it up further to make sure everything is how it should be.

Well, its nothing special, but I've got big plans for it. Here is the intake I pulled of it. Sucker is heavy, I weighed it at over 40 lbs! And here is the TH350 that came along with it. This is the first engine I've ever been inside. So far I've removed the intake, exhaust manifolds, and valve covers. It doesn't look so complicated, I think I've got everything figured out.

wow

Yes, there is a vac modulator on the transmission (I believe). This means it is a 350, correct?

Thanks for those links Mike C. Based on those pictures, I'm nearly positive it is a TH350. So I've got a 3 speed auto, no overdrive, however freshly rebuilt (or new, he wasn't sure which). I'm tempted to just use the TH350, but based on other memebers experiences I think I'm going to try and find a 700-R4. I noticed one of the yards around here was having an 'any transmission you can find for $40" promotion, so maybe this is my chance to pick up a better trans cheap.

I picked up the transmission that will be going along with the chevy 350 that I'll be getting tomorrow. I wasn't sure exactly what kind it was, other than it was "heavy duty" and "brand new". I was hoping for a 700R4, but I'm pretty sure that it isn't. I'm having trouble identifying it. All that I've found on it so far is "T5" stamped in two different places. I don't have any problem figuring out its a T5 then, but its and automatic. I was under the impression that T5 were standard transmissions, and all the info I can find online suggests the same. Is the such thing as a T5 automatic? If not, where should I look for more markings (its pretty dirty, I had to clean it off just to find the T5). Is this a decent transmission for a swap? Anywhere I can get any more info on it? Thanks..

nobody has any ideas?

Alright...got my car running smoothly, now it turns out I've got a transmission problem. It turns out the vacuum line that connects to the manifold was loose, and leaking vacuum, causing the transmission to lurch at certain speeds depending on the throttle position. I re-attached the hose securely, and the car is much smoother, but it will still ocasionally lurch around during a shift. This is mainly at high speeds (45+). What more can be done to fix this? Is it possible the hose itself is leaking? What other parts could cause this to happen? I've read something about a "vacuum modulator" in the tranny. What does it do? I've got a 76 280z, auto tranny, stock. Thanks for any input

I guess I'm going to replace the dizzy with a zx model.... But there is some NEW INFO This is kind of strange...while I'm driving, esepically after accelerating, it will buck as I've said. This is when the gas pedal is released slowly to come to cruising speed. But, if I take my foot of the gas as fast as I can, IT DOESN'T DO IT! Why could this be? It almost sounds like a transmission problem to me.... I would think it should be worse the faster I decelerate, but that isn't the case... Any ideas?

I'm not sure about the igntion timing...I was figuring that somebody would suggest that (it make sense that the only way it would fire out the intake is a serious timing issue). I don't really know much about that area of my car. I've never had my dist open or off, still have the stock coil, same wires....etc. Any suggestion on what to check out specifically? And yeah, I know a filter is a good idea. The only reason I'm running it without a filter at all is because I just completely re-finished my tank (inside and out), and flushed all the lines of any old gas. I wasnted to eliminate as many potential problems as possible, filter seemed like a logical one. I'm pretty sure the TPS switch is correct. I've made sure it is set to idle when at idle...I can't be sure it is at WOT when its at WOT, but it must be close. The problem could be TPS I suppose, it just seems odd due to the nature of the problem, I think it dies at 5-6k no matter what, if I'm in neutral and steadily increase the throttle until its that high, or just a quick press, does it either way. Thanks for the suggestion, I'll check that. (I need two people though, so its going to have to wait for now)

IT WAS A VACUUM LEAK IN THE BRAKE BOOSTER! denny411 - you've earned yourself at least $5 for that! I hadn't even thought of the brake booster. I removed all the hoses and covered them, but same problem. I didn't see the point in trying the brake booster too, but I did....and that (pretty much) fixed it. There is still a problem though. Off idle it still backfires a little, and when I get very high on the tach (around 5-6k) it bounces all the way to redline and dies. When I turn the key off and back on, it does starts and runs fine, but it will do the same thing over again if I hit 5k (or sometimes lower, it has done the same thing at 3k before....just it happens almost everytime when I hit 5-6k) Any ideas? Does this sound like AFM? It does to me...but ECU sounds good too. Let me here those ideas. The problem is only half fixed (but that is a whole lot better than not fixed at all). Also...yeah, the SBC swap. That was the plan the whole time. Only not quite yet. I'm building up everything I need first. I've got the headers, fan, and I bought a chevy 350 and 700R4 (just haven't picked them up yet). My plan was to rip the engine out this winter when I couldn't drive the car anyway. But I also told myself that if I couldn't get this engine running again smoothly for under $100 I was just going to start the swap a little sooner.

OK, thanks for the replies. I'll have a few hours to myself to go screw with the car ina little while, and I'll go try the suggestions. The fuel pump is OK, I think. I had a kink in the hose that went between the gas tank and fuel pump, but I found a 1/2" 90* hose connector and that solved that problem. I've cranked it over with the fuel line disconnected, and some fuel came out....I assume that means it is working. I'm not really sure if it was operating at 100%, all I was looking for was to see if it worked at all. Also, the filter was clogged, i think. I removed the filter and I'm using a straight piece of hose right now, just for testing. I'll be replacing the filter ASAP.

OK, this is how it works. I'm getting pretty annoyed, car doesn't work, and I don't know how to fix it. I've posted a few threads, but I've just been getting the same replies. I've very thankful for everyones help, but I figure if I add some incentive maybe I'll get some more suggestions and some more detailed responses. Basically, the person who tells me how to fix my car gets $10. If there are multiple variations of the same suggestion, the person with the most detailed and informative response gets the prize. $10 (or more, depending on how much help I need to get this going) will be awarded through either paypal, or via $10 money order. My problem: Car doesn't run right, and often, at all. It used to run a little rough, backfire occasionally during hard acceleration off-idle, but now it is much worse. I've replaced the AFM (twice), both times with used units that were supposed to work, but none of the 3 I've had in the car have been tested with any other. I've also eliminated the possibility of a vaccum leak (I think), the hose between the AFM and intake is fine, no holes, rips, and I've replaced the clamps. I'm also fairly confident it is not a ground issue. I've tested everything with a multimeter and everything seems to be grounded to everything else. It used to not start at all. Last time I tried, it would start after alot of cranking, idle very roughly, ocasionally backfiring out of the intake (blew the intake hose off once, could see the flame), and then die. If I give it gas, it just backfires more, but sometimes it will rev up all the way to redline and behave as it would normally, and then go back to sputtering. Car is a 76 280z, K&N filter, no other mods (yet). So, what could it be? Wiring to the afm (how can I check/fix this?), timing, ECU problems? Let me hear your ideas

Ok, I've got a 76 280z Basically stock, had a 60mm TB with same problems (replaced it with stocker), and a K&N cone filter. That is pretty much it (for now) Also, for the gas tank. I drained it, washed it, cleaned it with a rust eating acid (metal ready), washed it again, dried it with hair dryer for 2 days, coated the inside with US standard fuel tank slealer, and as I let that dry I gave the outside 2 coats of POR-15.

...anyone?

OK, I posted before about a problem I was having. Sometimes car would backfire off idle during acceleration. Would run ok after that, maybe a little lacking in power, but driveable. Got a suggestion about a bad AFM. Got a new (used) one....same thing. Another...same thing. I took it off the road to fix the leaky gas tank. Fixed the tank, but now the car won't start. I can crank and crank, sometimes it will start for a second, run real rough and then quit, most of the time it doesn't even get that far. But I tried something out of desperation. With the AFM connected to the ECU, but not to the intake...same thing....but when I disconnected the AFM all together (both from the intake and the computer), it started and ran! Now, I didn't run it very long (no filter), and I didn't try to drive it, but at least it started. Now, what does this mean? Bad wiring? Something with the ECU? Did FI this old even have a "limp mode"? So...any suggestions? I love this car, but I can't figure it out...I really cant stand to have it just sit in the garage. Thanks for any input

OK, I posted before about a problem I was having. Sometimes car would backfire off idle during acceleration. Would run ok after that, maybe a little lacking in power, but driveable. Got a suggestion about a bad AFM. Got a new (used) one....same thing. Another...same thing. I took it off the road to fix the leaky gas tank. Fixed the tank, but now the car won't start. I can crank and crank, sometimes it will start for a second, run real rough and then quit, most of the time it doesn't even get that far. But I tried something out of desperation. With the AFM connected to the ECU, but not to the intake...same thing....but when I disconnected the AFM all together (both from the intake and the computer), it started and ran! Now, I didn't run it very long (no filter), and I didn't try to drive it, but at least it started. Now, what does this mean? Bad wiring? Something with the ECU? Did FI this old even have a "limp mode"? So...any suggestions? I love this car, but I can't figure it out...I really cant stand to have it just sit in the garage. Thanks for any input

why not just get a pair of the larger aligator clips (like the kind found on higher-wattage car inverters) and snap them right to the battery? It sounds like it won't be driven much so it wouldn't cause a problem not having the wires more permanantly attached. Also, I believe VW includes a solar charger with alot of their new cars, and consequently, there are alot of VW solar charges for sale on ebay. AFAIK they can be had for under $20 and should do the trick with only minor modifications.

Ok, well, I got my 60mm 240sx throttle body installed. Used aluminum spacer, already came with TPS and linkage, so it was basically just bolt-in. However, it seems there are some things that can no longer be connected. There is a hose comming out of the valve cover, it branches into 2 hoses, one goes to some sort of valve, and then into the old TB, and one just connects straight to the TB. My question is: What do I do with these hoses now that there aren't any provisions for them? Plug them up, leave them hanging, or possible install one of those valve cover breathers I've seen where the hose would come out? Also, the valve installed right behind the throttle body, what is it? I think its called the AIR regulator valve? What purpose does it have? Sorry about all the questions. And thanks for any help

OK, we've got the hose that connects the filter to the AFM, and then the hose that connects the AFM to the throttle body...anything else I should check?