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-   -   86 TII swap won't start, but really wants to. (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/86-tii-swap-wont-start-but-really-wants-887302/)

HAILERS 02-17-10 05:58 PM

2 Attachment(s)
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.

MastrChase 02-17-10 11:43 PM

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.

satch 02-17-10 11:57 PM

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

MastrChase 02-18-10 12:10 AM

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)

HAILERS 02-18-10 06:39 AM

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.

HAILERS 02-18-10 07:34 AM


Originally Posted by HAILERS (Post 9813118)
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?

MastrChase 02-18-10 07:59 AM


Originally Posted by HAILERS (Post 9813118)
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.


Originally Posted by HAILERS (Post 9813156)
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?

HAILERS 02-18-10 08:39 AM

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.

MastrChase 02-18-10 10:29 AM

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.

HAILERS 02-18-10 02:16 PM

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?

junito1 02-18-10 02:17 PM

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.

junito1 02-18-10 02:19 PM


Originally Posted by HAILERS (Post 9813821)
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?

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?

MastrChase 02-18-10 03:33 PM

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

HAILERS 02-18-10 04:05 PM

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.

junito1 02-18-10 07:45 PM

Best of luck to you bravepotato.

Im interested to find out what the problem is.

MastrChase 02-18-10 07:55 PM

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.

MastrChase 02-19-10 02:51 PM

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?

MastrChase 02-19-10 06:31 PM

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?

MastrChase 02-20-10 04:25 PM

Help?

satch 02-20-10 04:30 PM

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.

HAILERS 02-20-10 05:10 PM

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.

MastrChase 02-20-10 05:59 PM

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).

HAILERS 02-20-10 07:04 PM

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.

satch 02-20-10 07:51 PM

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.

MastrChase 02-20-10 11:08 PM

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.


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