S4 NA to S4 Turbo II Sprak problems
 

Ok, s4 gxl na converted to a s4 TII. After all it has been done and everything hooked up we are getting strange spark issues. It will spark once while the key is in the crank position and then no spark for the rest of the crank until the key is shut off and then retry to get the same one spark.

Also the car has no tach movement while the car is being turned over.
I looked over the service manual and tried to trace it all out but the only thing I can figure is that the ECU is bad.

Anyone else have any ideas?????
Thanks

Put your non turbo ECU back in and see if the thing starts/sparks.

It should if the cas is connected up.

What combination of harness are you using?

Have a working meter?

Yes, have good meter, and good na ecu. Guess that should be an easy way to see if I get spark.

The passengerside harness is S4 TII also.

swapped ecu over to the na ecu and still only one spark and only one pluse of the tach.

Anyone??????????????????????????????????

you don't have a crappy connection at the coils do you?

Go to the boost sensor. Put the meter on the brown/white wire in the plug.Turn the key to ON. You should show approx 4-5vdc. Check that.

It's assumed that both EGI fuse are good in the engine bay and on the interior fuse box the ENGINE FUSE is good.

All main fuses under hood good. All fuses under dash good. Will do the boost sensor thing.......standby

Here's another thing that is helpful. IF you have your old non turbo CAS: Pull the plug off the cas on the engine and put that plug on your non turbo (spare) cas. Turn the key to ON only. Now spin the non turbo cas with your fingers and see if the sparkplugs/injectors are firing. You might have to pull a sparkplug wire just out of the LEAD coil assy to see it spark. Should spark much larger than what you normally see because the starter is not turning when you do the above.

The idea behind checking the brown/white wire at the boost sensor is this: The ECU has a reference voltage it puts out. IT goes to all the sensors but it also is required for the ECU to produce a spark signal to the coils. So if there is no 4-5vdc on the brown/white wire, then the ECU internals are also missing that 4-5vdc signal i.e. no spark today.

The boost sensor is just a good place to look for that ref voltage, that's the only reason to look there. One meter lead to a good gnd and the other to the brown/white wire, meter on dc volts and there you are. I'd prefer the plug off the sensor. Easier.

Thanks, will have to check those spots tomorrow or saturday, as the car has been pushed back to the back and battery pulled out.

Lets hope it is an easy fix so he can drive this car again and get it out of my yard.
Thanks

Ok, checked all four wires here. The brown/white has 4.99 vdc, two have 12v and one was ground. I have not done the cas trick yet due to not havig a extra cas here.
Anymore ideas?
Thanks

No new ideas here. IF you have the voltage on the brown/white wire at the pressrue sensor then the ECU should have the ref voltage to do the job.

Check for 12v at the small, white, two socket plug on the LEAD coil assy. It should show 12vdc. Don't mess with the other wire in that connector.

If you have it there then you should have spark. I recommended the CAS thing because sometimes the spark will be real weak because the battery is low and the starter is sucking up a lot of juice. IF you had a spare cas and just spun its lower gear with the key to ON and starter not tuning........you get a larger spark, verifying that there is nothing wrong on the spark side of things.

Swapping in a turbo emissions harness (the one on the engine) and using a non turbo front harness (the one that the emissions harness connects to inside the car) does have some adjustments to be made for things to work right, but spark shouldn't be one of them.

AH, HA! You said two wires on the boost sensor had 12v. Should not be so. The brown/red wire should NOT have 12v. What is happening is the NEW turbo emissions harness has not been modified properly and is backfeeding 12vdc from the METER fuse (memory) to the ECU pin 2B and the boost sensors output wire that is brown/red. You need to fix this someday soon.

You probably don't have a water temp gauge working either. That's due to some wiring changes that need to be made to the NEW turo harness at either plug X-15 or X-16.

BUT I don't think these are the reasons you don't have spark.

The CAS plug is on the cas. The coils are connected up just as they were before the conversion. You have ref voltage on the brown/white wires. AFM is connected up. ECU plugs are on. Both X-15 and X-16, the two other large plugs on that NEW emissions harness are in place.

EGI COMP nd EGI INJ fuse are in place in the engine bay. The ENGINE fuse is good? Right? It's in the car fuse box. It HAS to be good. But if you can hear your fuel pump run then it is good. So you ask yourself if you can hear the fuel pump run with the key to ON and the fuel pump check connector jumpered with a piece of wire. No fuel pump running in this condition means the ENGINE fuse is popped.

You need to take care of that 12v on that brown/red wire at the boost sensor. It might help. Although I doubt it is causing the no start problem BECAUSE I've read of others who had not taken care of this problem and their car ran. Just a false boost sensor reading at the ECU which screws up things very well thank you.

Do yourself a favor.

Find the plug on the EMISSIONS harness that has that 15 sockets on it. It's a dark yellow plug. You had to mess with it when you put the turbo emissions harness in your car.

On the EMISSIONS side of that plug, as shown in the attached jpg, remove the BrR (brown/red) wire from the socket. Put some tape around the wire end once you get it out. That act will prevent the ECU from getting a wrong signal from the boost sensor.

Then reinstall that plug where you found it.

Just in case. You remove a wire from the plug by looking in the mating end of the plug. You'll need a small, really small jewlers screwdriver. You press down the tap you see inside the plug and at the same time pull on the wire to extract the wire. You need something the size of a tooth pick, but a tooth pick will be too weak, that's why I suggested a jewlers small common screwdriver. Most auto stores or supermakets carry a case of them for what? five bucks or so.

Thats funny you said the water temp gauge because when the key is turned to the on position it slowly climbs to the max position and the buzzer goes crazy!

Well, since we have alot of problems with this car is there a number where I can talk to you live? I would love to get his car out of my garage / yard and he really needs his car back. Trying to help out a friend turns into a 5-6 month nightmare!
Thanks
Chad

Ok, found the Black/White wire you were talking about. The na was BW and the turbo was brown/red.

I removed that wire and checked the voltage at the boost sensor again to find this:

4 - wires

Brown with white stripe -- 4.97 vdc
Black -- ground
Black with white stripe --12.2 vdc
Brown with red stripe -- .591 vdc

Still have not been able to do the cas thing yet and still looking for the water temp thing to fix that.
Chad

Thats great about fixing the boost sensor wiring.

Now the water temp gauge. Here's the deal. The wire on both turbo and non turbo coming from the SENDER is Yellow/White.

The only problem is, the turbo Yellow/White is in a plug called X-16 but on the NON turbo car that Yellow/White is in a plug called X-15.

What this means to YOU, is you need to find the Yellow/White wire in the X-16 plug (on your NEW emissions harness) and extract it and MOVE it to the plug called X-15.

THere is already a wire there in the X-15 and it's Light green/Black. Remove that Lg/B wire and cover it with some tape and tie it to the harness. It's a useless wire. Install your Yellow/White wire in that socket. It should be on the very end of the 13socket plug.

See the attached jpg where I show a red arrow showing to move from *here* and intall *there* i.e. at the end of the arrow.

The gauge will work now as a water temp gauge.

Does this car have power steering??

Your probably starting to see why when I did my swap I kept my original non turbo harness. It's easier. Much easier.

You'll figure out later that in order to make your alt work right, you need to run two wires from the alt plug to the plug called X-15 and install those two wires where you see the letters BW right above WB standing for black/white and White/black respectively. On the alternator the two blades in the jack on the alternator form a *TEE* shape. The top of the tee is where the BW wire comes from and the bottom of the *TEE* shape is the White/Black wire.

Someone should have LONG AGO made a sticky for how to use a Turbo Emissions harness in a Non Turbo car. Shoud have been archeived.

There's other ways to make the alt work right. Just run a wire that represenst the Black/White wire to the METER FUSE in the interior fuse box. The W/B wire would be run to the CPU plug and spliced to the White/Black wire there. You could run those wires anyway you want to, to get there.

No spare CAS. Not a big deal.

Pull your CAS out of the engine but leave the plug on it.

OH, and before you do that, turn the crank pulley til the LEAD mark is aligned with the fixed pointer.

Now, turn the key to ON. Do not turn the starter at all. Just key to ON.

Pull one of the LEAD coil wires just barely out of its bore, or pull the wire off a LEAD spark plug and lay on the fender near a strut tower nut/bolt.

Rapidly spin the bottom gear on the CAS. You should see a large spark.

To reinstall the cas, align the marks on the bottom of the cas and install. Rotate the CAS until it looks like the picture I've attached. See the two upper teeth on the CAS? Just above the 24 lower teeth??? YOu have to take the thin black plate off the top of the CAS to see this. Just two phillips screws.

Turn the cas until the upper teeth just cut across the edge of the two black coils in the cas. My picture is dark, so I outlined the two coils in yellow to try to emphasize that the top teeth should just cut the corner of the black coil. at least it should cut across the front coil . I guarantee the timing will be more than good enough to start a RX -7.

See attached jpg to see what I meant.

The only reason at all for doing this CAS exercise is to be really sure that there is no spark. A starter will drag the voltage waaay down and the spark sometimes is hardly visable. Just spinning the cas with your fingers with NO STARTER turning gives you a lot more voltage/ spark/ whatever. You don't have to spin the beegeez out of the lower cas gear to make spark. Just a good twist or steady turn.

I have found some info while searechingf for the water temp problem.

I sattes that I need to run wires for the alt and the water temp thru the firewall and add to the harness next to the ecu once I find the correct pin config.

Well hopefully the guy that was suppose to do this swap will come over and help me with these few problems and maybe the car will run.

Ok, well the spark is not weak, it is a very large spark then it shuts off while the key is being turned over.

Trust me, try spinning the cas by hand and see if you don't get multiple sparks when spinning. The cas install is not a big deal. You still have time today to do it. TAkes maybe fifteen minutes max to pull it and turn the key on and ...............

IF you still have the same results, try superstition. PUll the plug off the afm and try again. I've heard tales of how the afm for unknown reasons caused the spark to not spark. I've no idea why that would be the case.

And, are the coils firmly attached to the fender. Just basically tightened down. No cleaning required. Just trying to say if they''ve been moved from the original location they won't fire because the ignitor gets it's ground thru the coil mating with the fender metal. At the bolts/studs. Don't go making extra grounds for this. Just make sure the nuts on the studs are tight.

Just checked the voltage on the small white plug on the coil pack closest to the front of the car. No 12vdc on that plug at all!

The coil packs were never removed. The afm might be doing it....... hold on.
BTW - it is a brand new battery that I am running in my own rx7.

well the rain is here again.

The strang thing is the car just blew the 7.5 fuse. I replaced it and the shift light came on the dash lights and I hit the key again, and pop it went.


I wonder if the na harness would be alot easier to run. I could put that back in but not sure what all is needed to run that with the TII motor? I say this because the car had a small fire, very small when the motor was first put in due to no down pipe. It was put out in matter of seconds ( I am a firefighter ). The harness was opened and inspected but looked ok. Now I am wondering if it is not damaged internally since there is no voltage at the coils.

The car was pull started when the motor ran the first time.

Something else that might help

Anything and everything that was with the emissions has been removed.
The car has AC and PS. Running factory NA exhaust with a stock TII downpipe.
The car will get a boost controller, boost guage, upgraded fuel pump and a different exhaust later down the road if it ever runs again.

The stock airbox and TII afm, are being used with the TII pass side harness, TII pressure sensor, and TII ECU. Everything elase is stock na.

Darn. That's the METER fuse that blew. Hmm.

Try something if you have a spare fuse to put where the 7.5 METER fuse just blew. Pull the plug off the CPU, I said CPU not ECU. Then install the new fuse and see if it blows or not. I've a good hunch why it blew.

Meter fuse should not keep a car from running though. The engine fuse would. That fuse is next to the meter fuse. No engine fuse, no starty.

Look at the cover of the fuse box to verify what fuse blew. Look at the FAQ on this forum to verify that it was the METER fuse and not the ENGINE fuse. Please.

Right now as the wiring stands, there is a Brown/Black (BrB) wire in the turbo half of the X-15 plug that is mating with a White/Black wire in the front harness side of that plug. That white/black wire is going to the alt relay in the CPU.

You have to understand that that brown/black (BrB) wire in the turbo emission harnses is a GROUND wire. A ground wire that goes to all the sensors in the engine bay like afm. boost sensor, tps etc.

What this means, is, that as long as that BrB wire is mating with the White/Black wire in the front harness, the Idiot lights on the dash should be lighting up all the time. Even if the engine did start, whcih is not right.

That BrB wire nees to be removed asap, or when ever you get around to it.

Of course those light won't alight unless the METER fuse is a working.