getZ

Does anybody have any info on how an O2 sensor fails. How as in what does the O2 sensor do when it is bad versus what makes it fail. I'm looking for a way to diagnose a bad O2 sensor besides replacing it.

I'm pretty sure it's not getting fuel then. As far as the AFM, I know it will stumble and ran crappy but it will try to turnover at least. The Throttle position sensor is not really a sensor but a switch (at least on the later zx engines) so I don't think that would hurt a startup either because if it open or closed the computer wouldn't really care. It would still fire the injectors, but maybe at a different pulse width. So going back to the injectors again. My 81 turbo motor had a resistor pack from each injector that tied them all to 12 volts. They were all red wires in a bundle that went to a connector. You can also measure each injector and see that you have voltage there (I'm not sure what the exact voltage was because it dropped something over the resistors but I would guess it is something over 9volts. What year is your engine?

Maybe you should back up a bit. Does it turnover, stumble and try to fire or is it cranking without ever trying to turnover? I thought you already established it wasn't firing the injectors, no?

if it fires up with starter fluid, you probably have spark so it's probably not the ecu or CAS. Nissan uses a pull up resistor to 12 volts on all the injectors that tie into a common point. Not sure if all L-28 motors have this, but mine had a resistor pack that connected all the injectors to a 12 volts source. The injectors are always connected to 12 volts. The ecu simply grounds the injectors to fire them

Making a sump is really simple. It basicly a box or even less that that cut from sheet metal. Mine's has only three folds from a sixteen guage sheet of metal with two bungs welded into the back although I run the pickup from the stock location.

Dude, calm down and kick the dog or something. Ranting and raving will get you no where except banned from the forum. I worked a tech support phone line for a couple of years and I am used to hearing people get frustrated. It's also important to realize you steer the direction of the call. If you give misinformation or bad hunches to the person on the other end of the line he will go the wrong direction. I'm used to people saying "I checked that and it's good." Usualy I have to ask "what do you mean by good and how did you check it?" Nobody is getting paid to scan the forum every day and every hour so be patient. We don't all live to support the forum. First things. Isolate each part of the car before you go on. Make sure you have gas and spark and go from there. Stop revisiting the parts you covered already unless something changes or is intermittant. Make sure your connections are solid. I prefer to solder almost everything to connectors instead of crimping them. We start with fuel: You said you had fuel before so I assumed you had a pressure guage hooked up to the fuel rail and now you are asking about fuel again. Do you have pressure to the line when cranking the car and how many psi is your guage reading?

Making a sump is only half the battle. You still need to attach it. If you can't fabricate one, you can pay somebody to do it. Another option is to either run a cell or use a tank from another car. Do a search on fuel cell or sump. I personally made my own sump copying sombody elses design. It's really simple, a flat sheet of 16 guage metal with a few cuts made into it, folded into a partial box then welded together, then shaped to sit flat against the tank. Mocking it up in cardboard make a pretty good model before you cut up the sheet metal. Being able to weld and cut metal is almost a prerequisite to a successful hybrid unless you want to pay a premium for sombody else to do it or have very good friends who can do it.

Before I recalibrated it was reading around 20. Hit the calibrated button for a couple of seconds and it recalibrates to 20, so whatever happened on the first reading seems to have been a fluke. I started to adjust the idle mixture screws (this is for and edlebrock performer 750) and the o2 sensor stays around 10.4-10.7 until both screws are only around a quarter turn all the way clockwise and I set the A/F around 13.0. This confused me because I thought those screws were air jets and not fuel adjustments. I almost have them closed off (only a quarter turn from fully clockwise) yet the car got leaner? Hmmm....where was that edelbrock manual now. At least that was good to know. My car is failing emissions.

I stumbled across that website last night. There's a lot of good information on that forum. It should make for a good resource.

well......the instructions are pretty simple. Plug it in, turn it on, let it warm up (it has a warmup countdown), calibrate to atmosphere and attach sensor head to the car. I will probably call the manufacturer in the morning. It might be okay the way it is.

yes it is an LM-1 http://store.summitracing.com/partdetail.asp?autofilter=1&part=INN%2D3723&N=400587+115&autoview=sku What do you have to do to recalibrate, remove the 9 v battery?

Anybody ever use one of these wide band O2 sensors? It's the one Summit Racing sells. I let the thing run through it's self calibration to atmosphere and then hooked it up to the car. My issue is without the car running the sensor is saying 10.6%. It seems to respond with idle mixture adjustments (this is for a carburated car) from 12.7 to 13.7 percent while leaning the idle adjustments so it looks to be working, but 10.6 with the car off? What gives?

Stats on the enemy: From "HOT ROD" April 05 "SVT VS STI" Mustang Cobra curb weight..........3,665 pounds test weight..........3,530 pounds weight/power ratio 9.05 lb/hp (as tested) quarter mile.........13.30 seconds at 109.0 mph (altitude corrected) I didn't see what altitude they were running at.

The way I see it from what others have done. You have several options. Weld the spider gears together which is like running a home made spool (I'm not a big fan of this, although I've heard of a few people with this setup.) I also don't like a spool on a street car. Find a r200 lsd. They are hard to find and pricey if you can find them. Find a later model r200 off an 86 300xz with the bigger ring gear bolts, I think they were 12mm, with that you can find a new limited slip from DTS that will work (this is what I did). This gives you a bit of flexibility with gear selection. I landed up putting in a 3.9 gear set. Pay the bucks for a Quaiffe diff for an r200 with the 10mm bolts. Adapt a limited slip from DTS to your diff with ring gear spacers. This I know nothing about. I almost went this route, but later decided against it. I make references to DTS because I only know of two limited slips made for the r200. Adapt a VLSD from a Q45 onto you car. There are adapters available or you can make your own adapter. I'm sure I missed some options, but that is what I could come up with. By the way, the DTS unit is packaged by somebody else, but I couldn't remember who it was. Rumor is that it is actualy made by Nissan.

Anbody run the Dynatech Powercats? It's about the only ones that will fit under my car without taking a muffler out. They're pretty small, under a foot long with a 4 inch diameter in the center section. I've heard some of the higher flow cats don't really work that well as far as emissions.

There's a few guys running the vintage air stuff on this forum and several write ups about their installation. That's probably the way I'm going to go one of these days....after I get my car through emissions.

Aside from replacing the whole computer. I couldn't find a way to get around an ignitor. I did at one time use an msd 6AL to simulate the computer input. Ground the white wire and you get a good healthy spark that is audible. You don't even have to use a plug out of the engine. You can hear the plug in the engine. If there is gas in the cylinder it will turn the crank slightly.

"off topic but i must say that there is a reason why the fast drag cars are RWD and not AWD... RWD owns AWD at the drag strip AND at the road course, the ONLY time AWD is better is on non paved surfaces and rain or snow" Wow, you could start another thread with that statement. Iron heads make more power than aluminum heads in an apples to apples comparison not counting any kind of porting. The heat retained by the iron keeps energy. Heat is energy. Comparing the L-98 to the vortec isn't really a fair comparison. You have about 10 years difference in technology. The vortec head was developed from the reverse flow LT-1 and made its way back to the standard v-8 after the LT-1. The runner design gave both good low and high rpm flow. The take off on that runner design led to a total redesign of the small block and the birth of the new LS type engine with the tall cathedral style runners.

I suspect something is wrong with the regulator. I had a similar problem with my 81 turbo motor in my 72, but I landed up putting a small block chevy in and the problem went away. Well okay, obviously I didn't put the engine in to fix an electronic problem. It was just something I decided to do. The alternator I have now is a one wire with an internal regulator and the rest of the stuff is still the same, fused link, wiring, etc

what kind of voltage are you reading across the battery while the car is running. It should be over 13 volts right after you start it up.

Any of the digital stuff they have would be adaquate for automotive stuff. They have really come down in price in the last few years. I have some stuff at work I was looking to get rid of. It's some older philips and tektronics stuff. PM me if you are interested. I can give you model numbers etc.

It works about the same as a ratchet shifter. Except with electronic tranmissions you can also change how hard the system shifts. Where are you going to find an tiptronic tranmssion for a small block chevy?

Speaking of dry cell batteries.... I had an Optima red top on my camaro that is now in my z. It would sit for six months and still start up in the camaro. Once after a longer time period then that I had to recharge it. It went all the way down to zero volts and recharged without a problem. Now this Exide (Checker) dry cell I had, died once with my turbo motor and could never hold a charge again. If it was just bad luck, I don't know, but I would not buy that Exide again.

On my first few rides out I didn't have the hood latch installed. It kind of works like a speed governor. Start getting above 50mph and the hood starts to lift. At about 60 it is about 6 inches open...time to slow down.

I'm not sure if you are thinking that a 3000 stall suddenly grabs at 3000 rpm, like dumping the clutch. If you are, it doesn't quite work that way. It's more like it slips really bad until you get to 3000 rpm, kind of like a transmission that is slipping all the time. Automatics are usually kinder to drivetrain parts. Seems like the first thing to go is half shaft u-joints unless you upgrade to CV joints. Some of the really fast guys even break those.