robertjame

Im sorry if I was confusing, using a transmission from another manufacturer (toyota) would require much much more fabrication then what I have mentioned. Such as changing bell housing, using a different pressure plate, and bearing. Switching transmissions from auto to 5spd may in fact be as simple as just swapping them. This is often not the case, as I said before in manufacturing an engine the spec of how the crank should meet the transmission is offen transmission specific. AkA auto or 5spd. Some manufactures make all there crank shafts to the same spec, AkA they will plane and bore the end of the crank to accept the input shaft and pilot baring for an manual transmission even if its in an auto. But often they dont waste the production cost of milling every crank in this way, only those that need it, AkA for the 5sps. All Im saying is be prepared for some difficulty and make the needed adjustments. And yes there in no bearing in the auto trans, the torque converter bolts to the flex plate. In the manual the mating is done by the clutch disk being gripped by the flywheel and pressure plate, the input bearing being needed because the input shaft is longer then that of the autos. The auto's is only 2 inches long and the manual is some 6 or more. This isn't plug and play here, I have done this all on my own before and helped friends do it across 3 manufactures including a Nissan 240sx witch was the worst. Please no one take offense, this is just my view, its not hard to do just harder then say changing out a bad clutch disk. Rob

I did this conversion on a 1998 Audi A4 1.8T, its not so bad. Things to know/look out for are reverse lights, your HB's harness might not be wired for a clutch peddle or for reverse lights. This wont hamper your conversion, you just wont have curse controle or reverse lights (no big, curse controle on HB's sucks pretty bad anyway). Second is if its a hydraulic clutch you might need to mod your master cylinder to accept your new clutch lines. Some cars have a totally separate oil tanks, but some share it. Last would be your flywheel/flexplate/crank situation. This is the primacy location of f#$%ed up conversions. First off gett a high quality clutch kit, spend some money now so you wont have to do this again next year. Make sure you have the flywheel as well, some kits just give you a new disk and pressure plate. The thing to remember is many manufactures predestine motors to go into an auto or a manual before they build them. The machining on the back of the crank can change some times widely from type to type. Bolt depths can be different as well as the surface and bore on the rear of the crank. All theses things are easily dealt with if your looking for them. Make sure your bolts dont bottom out, make sure your flywheel sits flat and very very flush, and make sure your crank accepts your manual transmissions throw out bearing. The trick I found when my conversion hit a wall with the bearing was to get a new bearing, one that instead of sitting inside of the bore in the crank was placed in the center of the flywheel itself after I planed down the crank shaft a little. My last note would be if you dont have a trasmission jack get one, the HB's 4x4 trans if very large and very heavy. Some say its an easier job to pull the whole motor/trans to accomplish what your trying to do. Good luck and look forward to pictures.

Fixed, new ECM and ajustable fuel regulator set to 5psi. This approach works but dosent offer any increase in performance from the injectors with out the ECM being remapped. Once I do that I can crank the PSI up in the 30's. Thanks again guys.

If your unaware of torque spec or how to pay attention to over tightening then you shouldn't be working on sensitive equipment. There are advantages to both studs and bolts, both points are valid but in my opinion using bolts is easier because of the close quarters on the vg30 to the wheel wall. Pulling the header over the studs is much much more difficult then simply lining it up and sliding the bolts in. Buy a torque wrench and learn.

Thanks, its merrily a tide over till I can map the ECM, thanks for the search tip by the way, ton of info out there about how to map Nissan ECM yourself, although I probably will still mail it off to get it mapped. Its very extensive to do yourself. Im going to have an upper intake modified to have a larger air well + a Q45 throttle body. I'll have my commuter mapped to include all of that + a new exhaust by summer next year. Ill try and post pictures of stuff as I go. Thanks a lot for your help guys, I'm new to posting on here but been a daily reader for over a year now. Great to be a part of the forum. Robert Johnson

I ordered an ajustable fuel regulator to bring me back to the fuel pressure I need for the 300zx injectors, now as you said the computer will lean them out a little but not enough. But cant I also lean them out a little more as well by reducing the line pressure farther then the stock spec for the 300zx injectors? If the computer is running off 180cc @ 43psi and I currently have 400cc @ 43psi and need to take it down to 36.3 psi to run the spec psi on the 300zx injectors. Cant I go farther still and drop the fuel pressure to 20-30psi?? Just till I can afford to get my ECM mapped for the new fuel capacity. Thoughts??

FSM for the pathfinder says 43psi is the correct pressure for the pathfinder injectors, i have 300zx injectors and the FSM for the ZX says the rail should be kept at 36.3psi. The correct mixture depends on the pressure and the pulse, if the pressure is to high the pulse will put out more gas then the ESM requested. I think this must be it, either I need a 300zx regulator or an After Market Ajustable one to get me in the market of 36psi.

Ok so today my new ECM came in, I hooked it up fired her up, she ran much much better, still not right but way better. I checked for a CEL and there was none, I checked the voltage coming from the ECM to the temp sensor and it was 2.2v. Perfect. So I unplugged the fuel pump relay and BAMB!!! Perfect idle, 600rpm smooth, it's been weeks since it's idled without stumbling. It would rev all the way to 5000rpm super strong, then it slowly ran out of gas, started stumbling, then died. When the fule pump was plugged in it ran a little rich (like before it was F@#$ed up) and was missing. So I know the injectors and timing are good thanks to that great 5 min of strong engine, but maybe the regulator or fule pump are messing up. I have 93 400cc Nissan 300zx injectors with my 94 pathfinders fuel reg. I havent checked the fule line pressure yet but I'll post pictures of that soon. Maybe an aftermarket ajustable fuel reg?? Thoughts??

Yes presumable till it runs out of gas, I think it runs better when the fule pump is unhooked because the injectors are being told to run to rich. No fule pump with open injectors (pulsing excessively) works better then way to much fuel... Im guessing. So what im wondering is whats causing the rich condition? The computer is putting out almost twice the voltage as spec to the temperature sensor. First off i dont know if thats right or what could cause it. Is the same voltage problem recurrent in other parts of the system? I have a new ECM on the way but will plugging it in risk burning it up too?

So I messed with the car some today and heres what I got. First I couldn't get the car to start and stay running without a little help from the throttle. So I checked the cap and rotor, wires and plugs, the voltage to the coil was around 10v +\- The coil fired through every wire to every plug, removed from the head with a good visual spark. So I checked the fuel pressur by squeezing the inline, it was firm and fule was flowing. So I checked to see if all the injectors were firing by touching each one with a flat balde screw driver to feel if it was clicking. All were very obviously opening and closing, so I unplugged them one by one to check there harness voltage, all came up in the market of 14+ volts. So my ignition system from start to finish seems to work fine. All my injectors are getting the correct voltage and seem to be operating fine. So by mistake I found out if you unplug the fule pump relay the engine seemed to run better. Still missing and stumbling though, I could slowly rev it up to around 3000rpm, it would go higher but wasn't happy and I wasn't pushing it. So I checked the voltage of the temp sensor and it was high, to me to high, 5+ volts. So theres something not right there, the + and - lines come from the ECM, no other bodys manage the sensors voltage. So that points to an ECM problem. I purchased another ECM on Ebay yesterday so Ill have that soon, will see if that dose it. Thoughts??

Yes it is the one for the ECU not the dash, It is throwing code 13 and I know the sensor is good. I have two, one new, one old both measure the same amount of resistance. Now there is a small amount of resistance added to the circuit at the ECU witch is expected due to the added resistance of the wire. What I dont know is how much. Is it to much causing the ECU to read the engine as very cold? Causing it to go in to a "cold start" mode where it dumps gas? Dose anyone have the resistance specs for temp sensor+the wire at the ECU block? Ill take some pictures of my reading and let me know if it seems wrong.

Ok so I guess I should begin at the beginning, 6 months ago my 1994 Pathfinder SE-V6 4x4 AUTO Vg30E was put down to remove the heads to drill out broken exhaust studs and for replacement of the lifters and cams (lack of top end oil and increasing clicking of lifters). The heads were repaired, all new gasket kit installed and she ran like new. 4 Months ago I installed a throttle body spacer and an intake manifold spacer/thermal block and E3 spark plugs. Great increase in performance with no failures. 3 months ago I installed a Street Fire MSD Ignition System with a new cap and rotor. Amazing low end power gain. So the next step was to replace the coil, wires and injectors. Heres where I lost control of the situation, I installed a highly modified fule rail from a 93 300zx witch on idle ran a little rich but ran very well at any point on the open throttle. I installed an MSD HVC 45000V street Coil with MSD wires. Now the wires I ordered didn't fit, so while I waited for some extra parts to correct this problem I left 3 of my old Bosh wires on cylinders 2, 4, and 6. I knew the coil would burn them out very shortly but I did it anyway. Now this set up worked very well for about a week, but the engine went down as I was trying to wire in a 4000cfm dual electric fan. Now that I've done extensive research I know how stupid what I did was but its to late now. I wired the relays in with the ECM's temp sensor. BURN!! dumb I know. Immediately there were problems, I reversed what I had done, looked into how its really suposed to be done, ordered the after market temp sender that mounts in the radiator and wired it up. Still no change in engine performance. It was missing like crazy, running so rich theres a black spot in my driveway. So I continued to back track. I tested to continuity of the sensor, then the line, then the line and the sensor and nothings wrong. so I checked the plugs, 2, 4, and 6 were fouled black. So I checked there wires, dead all three (the bosh wires). So I replaced them with the MSD wires and cleaned the plugs and test fired them, all were good. I reinstalled and no change. I checked the cap and rotor, good signal all the way through. I un-hooked the MSD box and coil, re-hooked my old coil and no change. So I tore it all down and switched to my old fule rail with no MSD box or coil, no change. So I checked compression on all 6 cylinders and were solid. So I checked for vacum leaks and there are none. No rotten rubber, no broken seals. Its slowly gotten worse so now it wont even stay running with out help from the throttle. The timing is dead on 15. Im at a loss, I think it might be ECM but now Im broke and have a very expensive POS in my driveway. The comp is throwing code 13 temp sender may be open/grounded/or fault, but the temp sensor has been replaced since all this happend and the line isn't broken or grounded. Fault in the ECU itself? What about the oxygen sensor? Unhooking g the MAF just kills it. Then if you restart the engine with it unplugged is acts the same with out allowing hi rev. Maybe the Throttle Position Sensor? Or the Cam Shaft Position Sensor in the bottom of the Distributor? Thoughts?? Pictures will be up by the weekend.