86 TII swap won't start, but really wants to.
 

Alright, so my friends and I have swapped an 87 TII into my 86 'se'. All went well, except it won't start.... You've heard this before right? I've searched and found some good tips, but am still stumped and now HAVE to have the car out of the rented garage by Wednesday MORNING. I'm on a super tight budget for this swap and don't want to throw the money away on towing. Plus those more knowledgeable then me are busy and most aren't rotary buffs anyway.

So, the engine is turning over but not starting. It really wants to and started twice but only for a minute. The first time I killed it, the second time it died when I gave it gas and had used starter fluid. Though we've used started fluid over and over and its not starting.

We've tested these so far: the fuel pump(NA till the FD gets here) IS sending fuel to the end of the line, the plugs and wires are sparking, the engine is not flooded, the engine sounds like its good, the fuel injectors have been tested and work. And I've got an open downpipe and nothing else yet, we even reversed the fuel lines to see if it was a jdm engine with no luck.

The engine has all the emission stuff cut or blocked off so I do have some connectors not connected. The engine was rebuilt 20k miles ago. I've been in constant contact the the seller and he's garunteed it to be good though I have not done a compression test.

My mechanic friend used a Noid Light on the primary injector connectors and only one was working. Then it the bad one worked, then it didn't..... Then it turned over and almost started.

I'm thinking of running fresh wires to the injectors from the ecu (N332) to test if its the ecu and/or the harness. But I drove the car into the shop 2 weeks ago. Speaking of ECU I'm using my N/A harness and cut the 1R wire and taped the ends off (I hope I didn't misunderstand the directions). The ecu hasn't been tested.

There was probably 2-5 gallons of gas that sat for 7months to 1.5 years. I can't remember, lol. It also has 2 gallons of 100 race gas and 3 gallons of 93 in it. Could it be that there just isn't enough good gas in there? I'll be putting in another 6-9 gallons in tomorrow.

I checked the grounds in the engine bay (one on the fire wall and one under the intake manifold), and checked that the boost sensor vac line is connected. Though it is my NA boost sensor. Maybe I missed a major ground or vac line that'll stop it from starting? Also as far as I know the CAS hasn't been messed with. Certainly not by us. I've checked my EGI fuse and though it looks old, its not brocken and as I said, I drove it in 2 weeks ago on the same bad gas.

Man, I'm tired and frustrated. I'm sure there are a few other details, but I'll post them as I remember.

Thanks for all the help in advance guys and gals. I'm still searching the forum to see if I dig anything helpful.

.... Do the A/C lines have to be hooked up? the two lines that connect into a bracket thats inbetween the AC and PS? I'm wracking my brain thinking of more details that may be pertinent.

Sometimes a cold engine will be hard to start IF the ECU is not seeing the START signal from the start circuit OR if the water thermo sensor on the back of the water pump housing isn't connected up.

Missing either of these two items will result in toooooo litttttle fuel being injected on a cold engine being started.

Remember, fuel during START is not determined by the afm, but by an internal start fuel map inside the ECU.

Pin 3B gets the start signal IF the key is HELD to start. So get the meter out and backprove 3B and see if it's getting batt voltage when the key is HELD to START. Black wire with a Blue stripe on the small ECU plug.

Also 2I on the middle plug should read 1-3vdc on a cold engine and if it reads 4.5 to 5vdc, that indicates it is not connected up. All plugs connected up and backprove 2I. Green/White wire in the middle plug.

I'm still using my NA boost sensor. Do I need the turbo sensor? Would this stop it from starting?

No. But the ECU not seeing the START signal or the waterthermo sensor not being connected to the ECU wiring will cause poor starts.

The wrong pressure sensor will effect idle plus other engine speeds.

Buy a can of starter fluid. Spray for three seconds and no more into the air filter assy. Start the engine.

I've started turbo engines with non turbo boost sensors and non turbo engines with turbo boost sensors. NOT a player during START. The AFM is also not a player during a stock RX start.

I found today that the water thermosensor (switch?) wire is cut. I've been looking in the FSM. Does it connect to a e-fan? Or into the wiring harness? The FSM says something about an e-fan, but HAILERS you're saying harness, which makes more sense.

try switchin the Injector wiring..I made that Mistake and it Stumped me for 3 months.
is the AFM hooked up?..how are you Sprayin starter fluid in it?

Like switch the two primaries with the two secondaries? I could try it but when my friend used the noid light on the secondary lines, they weren't on either (which to my understanding is normal sense they're not firing on startup).

well... heres some food for thought on the NA boost sensor 0 vacume is 5 volts, on the turbo sensor 5 volts is about 14ish psi . so when u try to start the car might be doing fuel cut to the rear rotor. untill u get into decent vacume then the ecu wouldnt freak out.


try starting the car with the boost sensor competly unpluged?

well i just read what hailers siad and he seems to know quite alot so maybe thats not it.

The water thermo sensor is on the back of the water pump housing. Has two wires and usually is a green plug.

Personally, I'd go to HARBOR FREIGHT and buy a cheap digiatal meter for ten to fifteen bucks and get familiar with it. Then backprobe the ECU wires at 3B and 2I. The 3B to make sure it shows batt voltage when the key is HELD to ON and the 2I should read approx 1-3vdc with a cold engine. IF 4.5 to 5vdc is seen......then the plug is off the water thermo sensor or the wires are broken at the water thermo sensor.

Buy a can of starter fluid and spray no more than three seconds into the air filter/snorkel, then start the engine.

And or go to the small plug on the ECU with you digital meter. Neg meter lead to a known gnd point. Key to ON. Small plug off the ECU and probe the light green wires on that plug. All light green should show batt voltage proving the circuit is good from the main relay thru the injectors plug to the ECU.

I guarantee if you remove the elect plug off the boost sensor on a working car, the engine will start each and every time. As for how well it runs is questionable, but remember..........there is a default value for that sensor is it's disconnected.

Does this car have a solenoid resistor package bolted to the area below the air filter/afm assy? Is it connected to a large round plug with five wires?


The water temperature switch on the bottom of the radiator has zip to do with starting and the water temperature sensor has zip to do with starting the engine.

Listen to HAiler.
I have personally had an engine that wouldnt start because of the water temp sensor on the water pump housing was broken off. I had accidently broke the water temp sensor clip. The car wouldnt start. I though it wasnt important to start it. I got mad till i bought the simple little sensor.

Put it in and she fired instantly.

FIX the temp sensor first. I think it around 10 bucks. +-

It ended up being a pinched ground wire to one of the fuel injectors. It started, ran rough under throttle and died at idle.I drove it out of the storage init then started it a few times and held it at about 2.5k. Then took the uim off and tapped up the pinched and exposed ground..... and now it wont start again.

I'm sure I'll have to figure out the vacumm mess to get it to idle smoothly.

I do have two questions. My "Add Collant" light & buzzer keep going off and were going off before the swap. It that the sensor at the bottom drivers side of the rad.?

And also, what is the little sensor (I guess) that is next the coolant fill? Thermostat sensor?

The one wire sensor that causes the low coolant to go off.......is on top of the radiator. That wire is looking for a gnd signal to turn off the buzzer/light. Gnd it while it's buzzing and the buzz/warning will go ...off.

The water themperate SWITCH on the bottom of the radiator effects the air bypass solenoid and is emissions related. Just attach the two wires to that switch and all will be taken care of related to that problem. Does not effect idle/running of the engine once the engine is warm/hot.

That particular sensor is for the factory electric fan.

I think I meant a pinched power wire to the injector. Hailers, I'll try and buy the digital meter tomorrow and test it. I just don't understand why it would just start up like that, and now won't.......

yeah the default value for the boost sensor is 4 psi if its unpluged.
reason i wonder is when cranking the car that sensor is reading 0 vacume. so tahts showing the ecu 14 psi which is fuel cut mode to the rear rotor. so could that be making it even harder to start if its only fueling 1 rotor? ( it might not even check taht when your just cranking it to start so i dont know)

i have had cold start prolbem swhen my water thermo sensor became disconected before

I did type alot but yes! go with hailers, hes a genius, he's helped me out with alot

I'll try unplugging the na boost sensor for shits and giggles. And yes, I'll listen to Hailers too ;)

Okay.. so I tried to backprobe the ecu at the pins you said Hailers, but I think I realized that the pins aren't numbered/lettered like I was lead to believe. So, now I have to figure out how they are organized. And the wiring diagram in the FSM in nuts. I cut a wire just before the ecu, so I could "reuse my NA harness" as a buddy told me, and now if I don't actually know the order, I could have caused my own problems, lol. Anyway, busy now, thanks for the help so far. More tomorrow.

You look at the plugs with the plugs attached to the ECU.

You look at the wire side of the plugs.

They are numbered from the right side moving left. You do it in a up/down fashion.

The small plug on the left of the ECU is shown in the attached jpg along with the ECU plug on the far right. The Middle ECU plug is not shown but is in the wiring diagrams where I got this attached jpg.

You can unbolt the ECU from the mounts to tilt it in a upward direction to access the wires/pins easier when using a meter. The ECU does not need to be grounded for it to work (I mean its case does not need to be grounded).

Awesome Hailers, thanks so much. That clarifies it well. Is the middle plug on page 50-26? EM-31? Thanks. I'll test it shortly, but I really want to find out if I cut the wrong wire. I was told to cut 1F. But I thought the top row (all the way across right to left) was 1, bottom was 2 and was A-Z (right to left). So that means I cut.... the middle plug, top, 4th from the left-most end of the plug..... lol. Probably important.

So each plug has A-B, from right to left and the plugs are 1-3 from right to left. So 3B is the third and smallest plug, 2nd wire on the top row, from right to left. Then 1F would be the first, right most and biggest plug, bottom row, 3rd from right to left?

You probably know the answer now but pin 3B would be on the bottom row and first pin on the right most position and thus located under pin 3A. The pin just to the left of 3A would be pin 3C. You are correct about the location of pin 1F.

Oh right, duh, haha thanks a lot satch. So what I was "1F" (I actually ment 1R) is wrong, I cut 2K the twin scroll turbo solenoid valve wire. I'll put that back, lol. I guess with a butt connector. Then cut and tape off the real 1R and test 3B and 2I. Man I was all kinds of confused. Thanks everyone for straightening me out. I can't tell you all how much it means :) I was looking in the wrong area in the FSM, this is the right section, (thanks satch) http://www.teamfc3s.org/main/factory...TEMS_TURBO.pdf

Anyone remember anything else I need to do to make my NA harness work with a N332?

Any luck on the swap running? Tis wednesday..

The pages called CONTROL UNIT are found in the FUEL AND EMISSIONS section of the FSM. The attached is from a 86 FSM. Turbo control unit values are different. See FSM for you version.

Sometimes what is wrong with a given car is totally different than what I might think it is 'cause there's a unknown that has not been mentioned or noticed.

Power is getting to 3B (got up to 1.00, is that high enough?) and 2I got up to 3.2x. I haven't reconnected 2K or cut 1R. Also the battery wasn't fully charged but it was turning over and trying to start. Does the battery need to be full?

To use my NA harness, do I just need to cut 1R (like I was told), or do I need to re-route a few wires (like compare NA diagram to turbo)?

I'll test the pins again tomorrow to make sure I got the correct readings.

(Also, I haven't tried disconnecting the boost sensor yet.)

Looks like these pins/wires are different from NA to Turbo: 1R, 2B(?), 2K and 3D.

Are any of these significant? Do I need to switch any of them. 3D is the fuel inhibitor switch on NA but the fuel pump resistor relay on turbo, important?

Thanks again gang.

Did you install a starter from a TII in your swap?

No, I installed just the TII motor with NA clutch/flywheel. I am still using (or trying to use) my NA tranny and rear end. (Though I do have on and the TII tranny too)

When you probe 3B and hold the key to Start, you should see the same voltage the starter is seeing which would be a voltage drop down to ??? 7-9vdc. So the 1vdc indicates something is wrong imho.

Three volts on 2I sounds normal for a cold engine.

I'd just depin 2K and 1R from the ECU plug. I wouldn't cut 'em. IF for some reason you can't depin 'em, then cut 'em several inches from the plug so you can splice 'em back together again someday if needed.

Have you ever altered the starting circuit in any way in the past?

Not that I can recall. So... 3B should be seeing 7-9dcv? And it should be dropping as I'm trying to start the car? Could my starter be dying?

Voltage should only show up on that wire if the key is HELD to START.

I'm not sure if you should see some stray voltage on it without holding it to start. By stray voltage I mean something like a volt or so. ''

The only reason you don't see batt voltage on 3B when the key is HELD to START, is because the starter is dragging the voltage down to around 7-8 volts when the starter is turning over.

I don't see the starter dragging the voltage down to just one volt like your seeing. I might look at one of my cars today to see if there's some stray voltage on 3B without the key being put to Start. Maybe if I"ve time.

I'd get a can of starter fluid and spray for three secondssand no more, into the snorkel of the air filter and start the car and try to keep it running with the pedal til the engine gets warmed up and then try to start it again.

Sometimes if there is a large air leak, like a major hose off, then the enigne won't stay running.

It's just that one TRAIT of a ECU not seeing the start signal or not seeing the water thermo sensors output, is for the engine to be difficult to start and keep running til the engine gets warmed up. After that point, the engine will start almost normal as long as the engine is fully warmed up.

To clarify, I got ~1dcv on 3B while cranking. Are you just wanting a readng while it's all the way on before cranking? Also, I don't know if it matters but I have low impeadence injectors and am going to put in an fd fuel pump to replace my stock na pump. When I crank, I smell gas, but it's not starting.

Out of curiosity, could you cut the connecting end off of the wires that lead to an injector and splice in another connector from any other harness? The clip were all brittle and crumbled so we did transplant a few of those clips wight the same injector clips that fit from a 300ZX's harness.

Do you have spark? IF you have a spare CAS attach it to the harness. Key ON. Spin the bottom gear on the CAS by hand. You should see spark from the plugs or at least hear the sparking. Do you?

The one volt puzzles me. Even if the ECU does not see the start signal it'll use the afm for fuel.......just be not enough for a cold start but after a while the engine should *catch* and start up.

Sure you dont' have a hose off somewhere? Like off the BAC?? Or the brake booster feed line off at the engine?

wow. Your using HAILER for all hes got=) heh.

well you could pull out the spark plugs and smell them to see if they smell like gas. THis should indicate that the primary injectors should be working.

The impedance of the injectors has to match the ecu. as in s4 injectors with s4 ecu.

1988 TII is the exception being an s4 with high imp injectors.

You should teach him the easy way of checking for spark? SParkplug wire and screwdriver sitting ont he strut tower and look for an arc?

86 harness and 87 engine and ecu, all reportedly low impedance.

Well, sparkplug and screwdriver etc is fine, but IF a person has a spare CAS and he attaches it to the harness and spins the bottom gear with his fingers with key ON, he'll see spark and the advantage is that the battery does not get worn down by the starter and the spark will be larger due to there being nothing to drag the batt down. Plus there's no wear on the engine that's spinning over and over and over with no starting of the engine.

Plus he can stand there at the engine bay closer to the area of the spark. Plus if he pulls the small white plugs off the two coil assy and spins the CAS with the key to On, he'll be able to hear the primary injectors clicking as he turns spins the bottom gear of the CAS.

Just wrote this to explain why I suggested he might connect a spare CAS if he has one.

Best of luck to you bravepotato.

Im interested to find out what the problem is.

Thanks junito1, I am too, lol. I think Hailers is on to something. Its probably not starting b/c it doesn't realize the engine is dead cold.

Anyway, I'll work on it more tomorrow. I have to clean it out (I have the TII tranny and a bunch of other parts in it from having it towed), then I'll probably put the FD fuel pump in it and charge it up and retest 3B and 2I.

I have an NA CAS, but thats the best I can do.

Okay so I have my battery being charged by another car and when I retested 3B when ON but not cranking, it reads 0.03. When CRANKING it reads 9.0x.

2I reads 2.7x at ON and 2.8x at CRANKING.

Its also possible that the spark plugs have fouled by now. I should probably replace them with new ones. I still need to replace the fuel pump with the FD pump. And reconnect 2K.

Do I need to do anything with the pins that are different from NA to TII? Like 2K, 2B, 3D?

Fuel pump in. 2K butt connected together. 1R pulled out. Same reading as earlier for 3B and 2I. Still not starting. I'm guessing 3B is the issue?

Help?

Are you 100% sure the fuel lines are connected properly?

"My mechanic friend used a Noid Light on the primary injector connectors and only one was working. Then it the bad one worked, then it didn't"

Why not focus on this issue until it's not an issue? And as far as your Cas is concerned why are you assuming it's okay? Your car is not starting therefor you shouldn't assume anything until it's up and running.

I agree with the above.

You really need to see if you have spark or not.

Where is your old engine?????????????????????????????????????????? and its CAS?

Fuses that make the engine run are the Engine fuse in the interior.......and the two EGI fuse in the engnine bay.

If the Main Relay pulls in you know the Engine fuse is good. IF you pull any of the elect plugs off the various solenoids on the left side of the engine and you have batt pwer on the Black/White wire of any of those connectors, then the EGI COMP fuse is good (plus it agains confirms the main relay is good and the engine fuse is good). If you pull the small plug off the ECU and the Black/White wire has batt power, then the EGI INJ fuse is good.

If you connect a spare CAS to the harness on the engine and spin its bottom gear with your fingers with key ON, you should hear the sparkplugs sparking and the primary fuel injectors clicking proving the ECU and CAS and wiring are good.

IF you spin the engine over with the starter and see the tach needle make small bumps as the engine spins....that more than less proves all the above are good.

You've lost spark sometime since you first had the engine actually startup. Why you don't have spark now is a good question. No spark is usually a blown engine fuse or one of the EGI fuses gone bad.

My old NA engine and its attached CAS are here at my house.

The injector connector issue was resolved once the wires was unpinched and taped. Though it doesn't hurt to double check, your right.

I'll watch the tach next time I try and start it. (Real soon)

I might as well replace all those fuses anyway. Most of them are have a little green on the bridges. But I drove the car in with the old engine, then a few yards on the new engine. That all doesn't make sense.

I'm no good at this mechanic stuff yet, but this is the scenario: 86 NA was sitting for about a year with about 3-5 gallons of gas in it and a dead battery. I charged the battery and it all but started right up. I drove it into the storage unit/garage, pulled out the old engine and put the new one in. I bought the 87 TII motor from a fellow forum member "yomomspimp06". He said the engine had been rebuilt 20k miles ago and had run as soon as 2 weeks ago (now 4 or 5 weeks ago). This engine has most if not all emissions removed and blocked off. When we took the NA motor out, the NA tranny was left in the car, but the starter was taken off. It was put back on after the swap. I had also cut the wire going to pin 2K (a mistake , I thought it was 1R, b/c I'm using my NA harness) It wouldn't start. I put 3 gallons of 100 racing gas in it and older 2 of 93. Someone came and tested some wires and found a injector power wire was pinched and was exposed because of the TMIC bracket. The TII engine has started six times out of about 30 attempts total. The last time, after unpinching an injector power wire, I drove it out of the garage and parked it. Then immediately started it up another 3 times, each time I revved it at about 2.5k working the gas through. Each time, if there was no throttle, it died. Then during the same day, after going to wal-mart and taking the UIM off and taping the previously pinched wire off, it will no longer start. I had it towed home. Since then, I've tried retaping it, installed an FD fuel pump, pulled 1R out and butt connected 2K together. I've tested 3B (and got a dcv of 0.03 at ON and 9.0X at cranking) and 2I (got 2.7x at on and 2.8x at cranking).

1R and 2K shouldn't have been causing the present problem.......so that's out.

Getting 9vdc on 3B means the ECU is getting the Start signal required for the ECUs internal fuel map. Not required for spark....just to let the ECU know your starting the engine.

The 2I getting 2.7vdc cold means the water thermo sensor is doing good.......and it also means the ECU has power going to it in that it's making ref voltage.

Since you took the upper intake off to repair a pinced wire things have gone south in a bad way. Large to huge air leak perhaps...somewhere. Like BAC air hose off or turbo intake duct off at the turbo or brake booster hose on the back side disconnected.

I'd leave the CAS in the engine in place, but attach your non turbo CAS to that harness and key to ON and spin the bottom gear on the CAS and the sparkplugs should be heard to crackle and the primary injectors click. You do this without spinning the engine with the starter. Just key ON and spin the bottom gear on the spare CAS. You do this to keep the battery fresh and also so the starter will not drag the batt voltage so far down as to not be able to tell if the sparkplugs are really sparking. Saves wear and tear on the engine and battery and you can do this in the middle of the night so as to not disturb the neighbors.

On a series four turbo intercooler there is one small hose on the aft side and one on the right rear of the intercooler. Either connect them up or plug them for sure.

Make sure the BAC's air hose is connected up to the turbo outlet hose. Make sure the blow off valve in the TID is inplace and conencted at both ends. Make sure the small checkvalve is pluggged into the TID. Make sure the afm elect plug is on.

I'd do the CAS thing mentioned right now first of all. Any time of day or night. Little or no noise to be made doing that.

Earlier you claimed a wire to an injector was "pinched." If this pinching prevented the proper current from flowing through the wire and creating continuity, then unpinching the wire cannot possibly guarantee that the connection will be complete for the best it could accomplish is temporary at best. If the pinching severed the wire then unpinching the wire is only an attempt to bring two halves together. This is not an acceptable fix. More is required.

Satch: Yeah, you're right. Though the wire wasn't cut in half, I know I should probably use a butt connector with heat shrink. Really I need to solder it together, but I don't have any experience doing it. I could buy the supplies and practice I suppose.

Hailers: This process of elimination is exactly what I need from someone who knows way more than myself. Thank you. I'll try these / track these down tomorrow.

Thank you both for keeping an eye on my thread. I REALLY appreciate it.