Rumnhammer

I just checked the Autometer website on the bouncing problem, make sure your dip switches on the back of the tach are properly adjusted for 6 cylinder operation, it comes from the factory set for 8 cylinder. Chris Rummel

Do you have the IAC valve hooked up? ie all the plugs pluged in around that? Did you recheck the timing? For the Tach, are you using the Autometer adapter 9117? you should be able to have it work using that. Although I'm going to try the yellow/blue wire which is the tach signal not the yellow/lavender before I invest in the adapter. According to the Autometer website, the cars that need an adapter are coil on plug like this engine is, but this is for the most modern engines that either don't have a tach out or the tach wire is Multiplexed meaning more then one signal is going to the cluster through it. Since the tach signal is dedicated on this one i think it will work. If It doesn't it's not a big deal just means I'll need to get the adapter, but I like to see for myself, before dropping eighty bucks on the adapter. You might want to check the connection for the water temp signal, the one that goes to the ecu, it's the one with two wires make sure it's plugged in. Try using the dianostic trouble shooting in the back of the manual. if you can find a link on here somewhere, it's outlined in a pretty simple if then style format, Hope this helps. Chris Rummel

I'm still going to try it, using the ecu signal, did you have the dip switches properly thrown on the back of the tach? What adapter did you use for the autometer tach? Chris

I have the tach sitting on the dash to go in, and I'm going to run the tach wire from the ecu, really no reason not to, since the Autometer tach will take it's signal from that source just fine. I know that when I had my 240z back in the day (20 years ago) and I added a jacobs ignition to it the stock tach stopped working until I used an adapter, but the autometers are supposed to work using the stock ignition signal without an adapter. by the way the tach wire is yellow with blue stripe not lavender, L is used in the nissan schmatics for Blue, and I think it was just posted wrong. sounds like an ignition problem, to me. Maybe the people that set the timing didn't tighten up the cam angle sensor bolts enough and it moved messing up the timing again. Chris Rummel

I would say yes to that except that the hard lines on the 280z and the stock skyline are the same 5/16 diameter, so I don't think that is the reason. The walbro, that is commonly used (what I used) is greater volume not greater pressure (although you can get them with both) so I wouldn't think that is it either. I think more likely the cause it because most people don't incorporate the FPCM listed in the wiring diagram under RB25DET only. controlled by pin 104 on the ECM, this was not on my clip and if you get the engine and trann on a pallet you most likely would not have it either. I believe this varies the voltage to the pump, to help control the volume. Since I ran separate lines in 10 gauge the pump will be doing some serious flow. I think if I have this problem, I'll try a restrictor in the line going to the regulator. Other reasons why you could be running rich could be the ecu is in limp home mode, that could cause the type of richness and runablity problems you are having. Usually the main cause is a malfuntioning MAF, check that out and see that it is working properly. An ecu in limp home mode runs like you describe, "very rich and will not let you build revs. You said in your other post that Garage 112 added the regulator and adjusted the timing, I think the timing adjustment is probably cleaned up most of the backfiring and poor running. If it started running rich after again after you added the tach then most likely something in the ignition is amiss, since you didn't mention that you touched the regulator, but it started running rich again. anyway there are some suggestions for you to try. good luck Chris Rummel

Maybe you used the wrong wire for the tach, on mine the one for the tach is yellow/blue not lavender, I know for sure I traced those wires several times. Also there are other wires that ARE yellow/lavender coming off there maybe you got the wrong one hooked up. First thing I would try, would to actually use the wire from the ecu instead of whatever you tapped into for the tach adapter, as long as you flip the correct dip switches on the autometer it should work useing the ecu source. You may have tapped into the ignition the wrong way because you problem sounds like an ignition problem. Why do you need to use an aftermarket fuel pressure regulator? if all your stuff on your engine is basically stock, and you stock regulator is working correctly, you shouldn't really need a different regulator to make the engine run right. Maybe your stock regulator was messed up. if you just took an engine out of one car and put it in a different one, it shouldn't have made an aftermarket pressure regulator nessary. Chris Rummel

Modding a pan that bolts up and making a pickup is still easier then fabbing up an entire oilpan. I'd still go that route, even if it was for an RB26. Chris Rummel

Well the wiring is pretty much done, I got the regulator deletion sorted out, the alternator wires sorted out, got the new fuel pump relay run, all the fuel pump wiring done, fuel pump mounted, and the fuel tank back in today. also got all the fuel lines done. I hope to get the pics up when I get a spare minute. Only one problem today, the driveshaft needs to go back to the driveshaft shop, as they made it too long, I followed the instructions on the website, but I don't think the metal collar on the back of the RB tranny was taken into account. I want to finish the rest of the wiring (stuff to the gauges and putting in the boost controller) and then I should be able to get the pics up. Chris Rummel

There is no interference at all, since they bolt to the block not the oilpan, FWIW if you get your pan from the Nissan dealer in the sticky, It's pretty reasonable pricewise and far easier then making one. Why bother fabricating one if there is a bolt on solution thats reasonably cheap?? Unless you want greater capacity or more baffles or something I wouldn't bother. Chris Rummel

Hey all, I found an old posting by Zcarnut on how to find the S post. Using a multimeter set on OHMs check both posts with the black probe to ground on the alternator body. The S post will be more ohlms then the L, and on the RB25DET wiring up to the alternator the S post is an aqua green color. With that sorted, on to the voltage regulator bypass! then pretty much done wiring. Chris Rummel

I believe the Autometers are adaptable for various signals, I know the speedo from them uses either a hall effect (square wave) or stock senders using a sine wave. My friend just ordered both for his car so we'll see how it goes. How did you do your voltage regulator bypass? because that is where I am now. my wires going up to the regulator only had 5 wires so I'm going to run a signal out from the hot when on for that one. Chris Rummel

Ok, I've decided to sort out the external regulator mod, the way I had it per the Zcar creations was totally wrong for a 75 280z, in this car the wiring is much more similar to a 260z in that it has the stupid shunts and the wiring at the voltage regulator is similar. My wiring going up to the regulator only had 5 wires and wiring it like it was had the yellow wire going to a green wire that tested postive for going to ground! I'll be connecting the yellow to the white and the white/black with the diode to a new hot when on wire I'll run out from inside the car, and that should take care of the regulator, I'm just leaving the shunts alone, since as long as they work, I'll leave them. I'm taking pics so the path will be smoother. Chris Rummel

Ok, I hit a couple of snags, first is the differnce in the wire color on the RB harness plug at the alternator, it seems to be that the S post wire on the RB is Aqua green instead of the white with red stripe, I think that is nearly sorted, but now I have a second problem. I followed the instructions for the external regulator bypass from Z car creations but when testing my yellow Z car wire that attaches to the S post I found it to have continutiy to ground!!! That is not right! so looking around for info on the external regulator bypass now. After following the instuctions from that link, I had the yellow wire going to 6 on there, which goes to ground after going though a condenser, my connector didn't have a white and blue wire at 6. The second problem with the bypass wiring is that there is not a wire coming out of my #1 connection there is a wire from regulator side but nothing on the harness side, so which 2 get connected with the diode???? I found a post from Bastaad525 that has yellow and white connected, and white with black connecting to black with whitestripe for the diode, but i don't have a black with white stripe wire? FWIW this car is a 75 280z from California, so the wiring is more similar to a 260z then anything else, soooo i think the yellow and white connection is good, but what do I connect the white/black with a diode to??? the white/black goes to the L post on the alternator if I have to run a wire from somewhere else to go to this i will I just don't know what. Chris

Are you measuring the voltage at the fuel pump, and it is 5 volts? you may need to run a dedicated 10gauge wire for the fuel pump if that is the case. I'll be posting this after I get it done. Chris Rummel

I read your post on it, which is why I was thinking the white with red stripe is the S post. I think the RB26DETT wiring is a bit differnt from the RB25DET because the other wire on my plug is aqua greenish not blue and white. please look anyway, basically I need to know on the plug is it the front plug connection or the back. Chris

anybody? anyone who has done this swap please look at the plug as it goes into the alternator and see which wire goes to the S post or at least let me know which post is the S post. On the top of the alternator the picture shows this (S/L) but that has the white with red stripe wire going to L, which does not seem right, from what I've read others post on here that it goes to S? Please look at your car and respond, this is the last wiring thing I need, and then I'll post pics with all this so everyone will know. Chris Rummel

Ok, really quick question on the RB25DET alternator there is a little diagram on the top that shows the S and the L with an outline of the plug, only problem is that it does not seem to jive with the wire color on the plug. So quick answer I need ASAP is There are two wires in the plug that plugs into the RB alternator one is white with red stripe and one is a aqua greenish color. Which wire is to the S terminal????? I'm wiring in the Yellow Z car alt connection and taking pics so this confusion won't happen again! I checked the manual for the RB and nothing! no pics on here of the RB alternator either! My assumsion is that the white with red stripe is the S, can anyone conferm this?? Chris Rummel

Not a problem, I like to lend a hand to my fellow gearheads. got almost all the way done the wiring today. About the only thing left is the connections at the alternator. So far my largest problem is space, fitting that fat RB tranny harness in there is a Bitch! I stripped off a few of the now useless chassis connectors and the power steering connectors and also some of the hard plastic covering to make manipulating the harness easier. I added extention wires with quick disconnects for the connector that is way up in there behind the IAC valve, that thing was hard to get to before I put the manifold on the engine, now it is impossible to get to, so I had the forsight to add these wires to make it easier to get to and connect, glad I did too, because I even had to add a middle extention to the ones I already made before. I worked some REAL magic getting the connectors and relays and about 2 feet of wire stuffed up in the small area next to the clutch pedal, I'm still kind of supprised it all made it up in there!! I made a small change to the wiring of the hots, the instructions have the black/red fat wire and the fat red wire both going to the fat red and white ign on and hot wire. I sent the black and red main ignition wire there, but the ECCS relay backup wire and the backup power/ memory wire for the ecu pin58 I connected to the fat red wire that goes straight to the battery, this was the main power wire for the stock fuel injection harness, so it seemed perfect to use for that same purpose on the RB harness. I wanted to make sure that pin 58 wire went to an always hot connection also because when I get the power FC in there it states that on some engine swaps the memory wire for the ecu is not connected properly and the ecu blanks out when ever you turn off the ignition. (my friend with the SR20 swap is finding this out now and having to run a wire so I made sure I did it while I was in there) I did have one brain fart today, I forgot to get the lavender water temp out wire out of the bundle to run up to the water temp gauge, I figure I have 3 courses of solving this, first pull my bundle down from the space with all my connectors in and pull that one wire out, vampire tap right at the ecu connection, or run a separate wire vampired off the wire at the sender in the engine compartment and attach it directly to the temp sender wire on the z harness. We'll see which one I'm most up for when I scope it out this week. I also found I had to move my isolator connection up higher on the fender well, to properly postion the tranny harness. Getting there I suppose. Chris Rummel

I used a thin bladed regular screwdriver, and using a rubber mallet I gently tapped the screwdriver in at one end, just enough to get through to the inside of the pan, then I tapped on the side of the screwdriver pushing the blade forward, cutting the sealant. When you get far enough along, you can use the screwdriver to gently pry it down the rest of the way. good luck Chris Rummel

I got about 80% of the wiring done today, got a lot of good shots of the wiring, This really is not too bad as you guys will see when I post the pics only about 5 or 6 wires coming off the white connector and I intigrated a plug under the dash for a couple of wires so I didn't have to go up to the ignition switch for those, litterly plug and play that. I also cut out the isolator connector from the skylines main fuse box and mounted it on a bracket so I can run the big hot from the skyline tranny harness right to it, and the other side goes to the big battery connection hot. Since my friends car is using the Greddy intake manifold, I also found that I need to lengthen the wires for the two connectors that go to the IAC valve, got shots of that too. I spliced the Z lower harness that plugs in, into the lower RB harness, and I ran the rest of the main harness through the firewall to the stock Z ecu location, and it will be a bit tight for room in there, but I;ll get it right. Man, you really burn a lot of brain calories doing the wiring, I spent most of the morning just separating the harness and double and triple checking the lines seeing what goes where on the harness with the multimeter. I took a couple of progress shots so you can see how intimidating the spagetti mess is before you sort it. Then took some shots showing how much simpler it is after you do it. Believe me this will be much easier, to understand after I post this stuff, I found that before doing it, I was overthinking this wiring, hopefully this will make the wiring easier for others. Even though this guide will be for a fuel injected 280z the wires are the same as far as hooking up the ecu so regardless of the Z car you have, this will be easier. I should have the pics up some time early next week. Chris Rummel

I think it is because if you don't make notes or take photos while you do it you are just glad to have it done and get it started. I'll try to take as much detail as possible, I'll note the power and ground hook ups, the attaching of the tranny wiring to Z car wiring, and I'll be doing the wiring of the fuel pump direct from the battery, though a relay to the fuel pump using 10 gauge wire for the power delivery and I'll show how I did it. That should cover pretty much all the wiring, execept the alternator external regulator convertion and that has been covered good enough already. Hopefully it will become a sticky for others. Chris Rummel

I got the tranny mount done today on the swap, I went the L28 stock tranny mount onto the RB isolator mount route. This seems to be the easiest route with the least amount of fabricating, you just need to fab the "ears" and mount them to the tranny tunnel a little bit back from the stock possition. I had brand new poly bushings for the l-28 tranny mount so that cinched the deal. Was not that hard supprisingly the hardest part was spot welding all around the base to the tranny tunnel. I made the ears and the base out of 1/8 inch steel so welding it to the 18 gauge floor was a little dicey, and there was no room under the car to wear the welding helmet so I had to place the mig head and just shut my eyes for the spot welds, turned out pretty strong, but just for added intsurance I drilled through the floor and the mount and then added a second base of 1/8 inch steel as a backing inside the car then though bolted the whole shebang, No way that puppy is coming off now, I won't be affraid of making a lot of power with it now. Now on to the wiring, probably do that this week and I'll be posting pics so it will be easier for those that follow. Chris Rummel

I'll be doing my wiring on the car probably next week, I'll be photo documenting as I go so hopefully this will put new info out there to make it easier for those that follow. FWIW I'm doing an RB25DET into a 75 280Z, but with photos it should make it even easier regardless of what Z car you have. Chris Rummel

I agree on the harbor freight tool comment, I have quite a few HF tools, but I limit it to very simple things like hammers , benders, presses and the like. Steer clear of anything with electricity involved from HF, I bought a heat gun from there and got it home turned it on and flames shot out the end with electrical sparks, It proceded to burn up in my hands. I took it back and they replaced it, but I was sure to test it in the store before I took the replacement one home. HF is also great for buying stuff you throw away after use anyway like cheap acid brushes and latex gloves. I also don't buy ratchets or wrenches, there I value my knuckles too much to trust HF stuff for that. Chris Rummel

I plan on doing it like you describe, I want the plates in there to add extra strength where the ears weld to the tunnel. My friend is getting a new carpet kit so the old stuff will be pulled out and I'll use dry ice to freeze the tar on the inside of the car to shatter it and remove it, I'll still have someone inside the car with the squirt bottle. I'm using a set of the Brad B mounts so engine placement should be close to what you have, since most people are fabbing there own mounts there will be a lot of variance, so I still want the measurements just to get a rough idea how big to make the ears in advance so I don't spend a bunch of time crawling under and out from under the car, if that makes sense. Chris Rummel