vrracing

iTrader: (1)

RETed suggested a new topic thread since the wild goose I was chasing with the T2 coil turned out to be a phantom menace. So here we go...

JDM S5 Tii full rebuild with Pineapple template porting. All new seals and gaskets. New vacuum lines. Still using the NA emissions systems (ECU, AFM, APS). I have all the 370 parts available.

The car originally had a surging idle. Timing and TPS adjustments fixed that and it idled beautifully.

Then we did some "final" assembly including rerouting the throttle cable and installing new Mazdatrix plug wires and new NGK plugs (correct ones of course). Also connected the air pump pipe to the cat, put the undertray back on and put the snorkle on the air filter housing.

But then it wouldn't idle unless we gave it gas. And if we took it for a ride it wouldn't accelerate unless you fed it throttle super gently. We backed the Air Adjustment Screw all the way out of the BAC and it idled. Badly.

The timing is spot on (all except T2 obviously! ) We have spark so there is one part of the equation.

The TPS is spot on. As noted before we'd performed the full resistance check and all was well. And it is still good because with the ignition on but not running, there is one LED on the TPS checker. Press the accelerator and the LED immediately goes out.

The ISC had no effect. So I unplugged the BAC. Now it idles and does so smoothly. However, it won't accelerate.

Reading one of the recent threads got me thinking about the CEL codes. So I went and checked them. We have:

* 08 - Airflow Meter (AFM) - Basic Fuel Injection and fixed timing (Cripple mode)
* 30 - Solenoid, Split Air Valve
* 31 - Solenoid, Relief Valve
* 34 - Solenoid, Bypass Air Control (BAC) Valve
* 38 - Solenoid, Accelerated Warm-up System (AWS)
* 40 - Solenoid, Auxiliary Port (6PI) Valve
* 41 - Solenoid, Variable Dynamic Effect Intake (VDI)

34 makes sense since we unplugged the BAC.
38 makes sense because it's a JDM Tii so no AWS
40 and 41 make sense because we are still using NA emissions system but the Tii doesnt have a 6PI or a VDI solenoid.

08 AFM is interesting. We're still using the NA AFM so that should be kosher. And it worked fine with the NA a few weeks ago before the swap. Cripple mode sounds a lot like Limp mode. Hmmm...

30 and 31 I have no idea.

We plugged the BAC back in and reset the codes. The only one that changed was the BAC. The rest returned. Guess I have more research to do tomorrow.

RETed suggested a vacuum leak. I guess we could have knocked something around when we were pulling and replacing the TMIC while rerouting the throttle cable. We were golden before the throttle cable reroute. I checked with an unlit torch but didnt find anything. I might get more aggressive tomorrow.

btw, here's a youtube video of it idling badly. The Corksport Catback doesn't reproduce well on youtube video. I'm gonna have to get one of those Vibrant super-quiet 3" resonators I saw Aaron Cake all excited about.

I think that the root cause is the AFM. The other things are explainable by where we are in the swap process and the AFM is the only Input item in the list. It seems reasonable to assert that the others are dependent on the output of the AFM for their operation.

So we'll start with the AFM tomorrow. If yall have other ideas or even just confirmation that I'm on the right path, I'd love to hear em.

Thanks,

Jim

arghx

iTrader: (3)

You need to pressure test your system for vacuum/boost leaks. Don't go any further until you do that.

www.boostpro.net/prodtester.html sells one, but it can be easily made out of home depot parts. You'd be surprised how easy it is to miss a leak.

And the codes 30 and 31, split air and relief solenoids, are emissions solenoids used for the airpump. I imagine you removed these.

vrracing

iTrader: (1)

That's interesting. I'm guessing that's only used from the compressor on back though it would seem logical you'd have to plug the exhaust because it would seems like one of the rotors would have the exhaust port open.

It wouldn't seem like it would work on the intake piping though since those parts would have suction on them while the rest of the engine would have positive pressure.

So why would you think an air leak would cause the AFM to throw a code?

Oh, and we have all the emissions intact including the air pump and rats nest.

vrracing

iTrader: (1)

Ok, we've eliminated a code but it still doesn't wanna go.

We replaced the vert ECU with the 370 and replaced the NA AFM with the 370 AFM. I'm not sure why that matters since according to the FSM they should read the exact same thing. However, the NA AFM would spike to 1000 ohms right when you pushed on it and then drop back down to what you'd expect as it when in. The rest of the ohms were fine except that initial spike.

So with that change the CEL code 8 went away

We're left with:

30 - Split Air Solenoid Valve
31 - Solenoid Valve (Relief)
38 - Solenoid Valve (AWS)
42 - Duty Solenoid

Reading Dokta's S5 N/A -> J-spec TII swap write up, it appears that the JDM S4 Tii's do not have wiring for the Split Air Solenoid Valve. So I'm guessing you swappers just ignore the 30 code.

For 31 the solenoid, the blue clip's locking catch was broken off so we're not sure it it was on well. I sprayed some contact cleaner on there and we'll try it again later. In case the solenoid is bad, can I just grab one off the NA? Are they interchangeable? I'll cut that blue clip off and put the one from the JDM harness on there.

We dont have AWS on the JDM so I'm guessing we ignore 38 as well.

And I'll have to pull the Duty Solenoid connector off the JDM and splice it on to the 6PI wires to make 42 go away. But it doesnt seem logical that would cause our problem.


I think this weekend we'll:

• go step by step thru all the ohm tests for the emissions control pieces
• make all the HD runs to try the pressurization system arghx suggested.
• pull the two air intake pipes and tape them together with X-treme Tape just to make sure they seal and seal well. Check the ends for cracks while we're at it. Probably wrap the outer ends with the X-treme Tape as well.
• I think we'll also flush the fuel injector complex
• do a compression check
• check the TPS yet again
• and then pull the cat out and try it without any possible back pressure. The exhaust is all new but we're running out of problems.
• and finally I guess we'll pull the UIM and pull the injectors and shoot em with carb cleaner. They were professionally cleaned during the rebuild.

If you can think of anything else, I'm all ears.

Jim

vrracing

iTrader: (1)

One other thing, are the NA and Tii filter boxes the same? It seems like the Tii air intake hose wants to point down quiet a bit and not line up horizontally.

RETed

None of those should affect how the car runs...

If you get stuck, I'd start back with the basics.
Fuel and ignition timing.
If possible, try and confirm the fuel pressure is within spec.
Double check ignition timing to make sure it's within spec.


-Ted

vrracing

iTrader: (1)

Thanks, Ted. That confirms my suspicions. I have a fuel pressure gauge though I'm not sure if it still works too well as the methanol from the sprint car tended to dry it out. As I recall from the FSM it looks like you just put a tee in the incoming line. Shouldn't be too hard to manage.

I was wondering if maybe the turbo froze up. As I noted before, once we did the timing and TPS, it ran great. Then the next day after we did that final assembly (snorkel, plugs, plug wires and throttle cable rerouting) when we started it a puff of blue smoke came out and it was boggy. It really feels like the engine is either constipated or has asthma. When the cat clogged up last year with the NA engine it behaved very similarly though not to the same degree. I'm going to pull the intake tubes anyway to seal em up with the X-treme Tape so I can give it a spin then. It spun really nice with no play before we installed it but it's 20 years old and sat in a junkyard so who knows.

I was also wondering if maybe when we'd glass bead blasted the UIM, throttle body and all the air/fuel tubings that maybe we'd gotten some in the lines and it's settled on top of the injectors. We'd plugged them but you never know. On the other hand, when I did the test to see which fuel hardline was the input (on the JDM Tii's it is the front one btw) we flushed a fair amount of fuel thru there. Plus we ran all that time during the timing and TPS setting. And once we got those right it seemed to run very well.

We'll pull the plugs and check em out side by side. Plugs are after all the windows into an engine's soul.

btw, is there a standard test for vacuum? I was thinking it would be useful to put the vacuum gauge on the vacuum port for the OMP and see how much we're pulling. (yeah, I'm fishing!)

Thanks for the info and advice. I do appreciate it.

RETed

The engine will run fairly well even if the turbo is jammed solid, so I doubt that's the culprit.

Glass bead...uh, that could be bad.

Idle vacuum with stock ports when ignition timing (5-degrees ATDC) and RPM's (750RPM + or - 50RPM) are in spec should be about 18inHg.


-Ted

vrracing

iTrader: (1)

I think the glass beads are a real long shot. I feel like I'm moving out of the probable and into the possible on my diagnostics. Next stop, the twilight zone!

I'll have picts of the plugs mapped by location shortly. That may tell us something.

I could take off the UIM and put the NA injectors in. They leak a bit though not so much that the NA flooded, but that'd confirm or deny if glass beads did happen to get into the fuel hardlines. I dont know how an injector works so I'm not sure what the impact would be if beads did get in there. Would they jam or would a hard spray of carb cleaner move em out?

vrracing

iTrader: (1)

Got pictures of the plugs.





I dont see anything obvious. It looks like maybe the #1 rotor is running a little leaner than the rear.

Thoughts?

Molotovman

iTrader: (49)

I know you said timing is spot on. Are you %100 positive it is? My car did the same thing aftrer I put a reman in and my timing was off due to a bad CAS stab. Line the yellow mark up with the stud and pop the blind cap on the CAS. Make sure it's where it's supposed to be.

RETed

Slight color variations, but nothing out of the ordinary.

Quick&dirty test...
Remove the vacuum hose from the boost sensor and cap the fitting on the engine.
Does the engine run differently?


-Ted

vrracing

iTrader: (1)

I'll check it again but when I was chasing the wild goose on why T2 wasn't lining up with the mark I checked it a bunch of times. It's possible I didnt get it tight so it's worth the check.

vrracing

iTrader: (1)

Ha! i have no idea where that is. But my trusty FSM will enlighten me!

The TMIC and air intake system is all off right now. I'll give that a shot in the morning.

vrracing

iTrader: (1)

Where is the Boost Pressure Sensor? Is it the Pressure Sensor numbered 12 on page F 2-2? Why would that be the Boost Pressure Sensor if the NA has one; and the NA obviously doesnt have boost!

Btw, this is the Pressure Sensor on the passenger side wheel well in front of the strut tower

RETed

Bingo!

Wait, are you using a *turbo* boost sensor?
You cannot use the non-turbo "pressure sensor" in this case.
If you do try and use the non-turbo pressure sensor with the turbo ECU, you're going to hit overboost fuel-cut in a hurry!


-Ted

vrracing

iTrader: (1)

Hmmm... When we found that the NA AFM was jumping to 1k ohms right as you started to open it and then would drop down to match the expected curve, I swapped out the 370 AFM for the NA AFM and swapped in the 370 ECU. So yes, I am using the NA pressure gauge. Frankly I figured that since the NA and Tii AFMs have the exact same resistance check numbers, that the pressure sensors were functionally the same too. Learn something new every day.

I'll swap it out but I'm not hopeful!

vrracing

iTrader: (1)

And thanks, Ted. I really appreciate the help.

vrracing

iTrader: (1)

Ok, we went thru the entire air intake system and made sure everything was well sealed. And I put the 370 Pressure Sensor on as well. No change.

As ReTED suggested, I tried taking the Pressure Sensor line off and plugged it. But there was no change.

Here is a picture of how the vacuum lines are routed by the ACV in case I have it wrong. The FSM pictures are pretty useless.



I dont have the pipe that goes from the ACV to dump extra air under the fender. I didnt bother to hook it up this time as I assume it doesnt matter and to do it right I need to get another tube since the angle is different than the NA's tube.

Like someone fearing a colonoscopy because of what they might find, I went ahead and did the compression test based on the instructions from Aaron and Robinette. I didnt remove the Schrader valve (one way check) as Aaron suggested for two reasons. First, Robinette says you can just hold down the relief valve. the second reason is I'm not sure which to remove. My Penske compression checker has a schrader valve in the bottom (like the tip of the spark plug) and at the top by the gauge. So I just held down the relief valve and we did the test.

We go 95 with the needle wiggling on #1 and we got 115 with the needle wiggling on #2. If I let go of the relief valve the numbers just climbed. I think (hope?) that's good for a freshly assembled engine.

I'm thinking the next thing to try is to put the NA fuel injectors in there and see what we get. Or maybe I'll drop the Bonez cat out and try that.

Any other ideas?

vrracing

iTrader: (1)

Oh, and I think we'll go thru the whole fuel pressure testing regime. Gotta go pick up that 5/16th tee.

vrracing

iTrader: (1)

With the engine completely cold, I ran the compression test after taking the schrader valve out and both rotors bounce consistently but at barely readable levels. If I put the valve back in and hold the relief valve in just a bit I'm getting consistent 35 psi pulses. Of course, I have no idea how accurate this old compression tester is.

I have the tee to do the fuel pressure test regimen but I'll need to go get another pressure tester as the one I have doesnt scale to support fuel injection pressures, just carbs.

vrracing

iTrader: (1)

I also bought a 2" rubber cap (for capping off plumbing) and put a fitting for air tools in it. It fits perfectly over the AFM input. I pressurized it from my compressor with the regulator set to about 7 psi but there was no sign of leakage (except for a bit where my fitting went in the rubber cap).

I expected to see air flowing out of the brake booster vacuum feed line when I pulled it off but there was none.

Either way, we clearly dont have a leak on the air intake side.

vrracing

iTrader: (1)

I'm watching the Brickyard and was thinking about what could be causing the problem. Here's a theory...

I had the injectors cleaned and rebuilt by KGParts. But I was missing some o-rings, could have been the injector ones, could have been the bleeds. So I put some on from my Harbor Freight metric o-ring kit. If they were incompatible with the environment...

1+1=7

sounds like its timing


i know

you've already covered that
are you sure the crank angle sensor isnt 180deg off


itll run just like ****



my 1½ cents

good luck

vrracing

iTrader: (1)

I didnt recheck it but I will. I'm sure it isn't 180 degrees off because I lined up the dent and the mark when stabbing it.

Thanks!