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..