soundwavetsunami

Ok, for the background. I got a freshly rebuilt 88 TII longblock off of stuff here on the forum a couple months back. I removed the emissions components to try and solve a vacuum issue I was having. My emissions removal was successful and it produced sufficient vacuum, but it still wouldn't start. It would crank over, catch for a second, but then die out right away. So then I go to check over everything and make sure nothing was wrong. I capped up a vacuum hole I missed and tried it again it. It cranked and was firing, but it seemed as if to not be getting enough gas. Now I tried the other ECUs I have laying around (88 NA and 88 Jspec TII). Same thing happens again. So I re-double checked everything, made sure the battery charger was on, made sure my hackjob of a resistor pack was still in and made sure my fuel lines were ok and not mixed up or anything. Now I go back to crank it and now I don't get any spark. I've checked with an inductive timing light (I know they don't always work for our cars, but it was worth a shot) on all four wires and I even did the lights-off-look-for-arcing test just in case I was completely missing the noise or something. But still nothing.

I removed the starter and tested it to make sure it's not drawing too much for the coils to fire. But it's fine (I got it 5 months ago anyways). I go back to put it in, but I break this flimsy connector when I was getting on the ground. Its about 7 inches long, it connects to a white one prong connector that is attached to the body wiring harness near the oil level sensor. its a black square with 0.07/250, R 17 G, .H: , and a bizarre triangle shape on the top. It looks like its supposed to ground something, but I can't remember what.

Anyways, I disregard the grounding-lookalike for the moment and I put the starter back in. I try it again to see if maybe it decided to fix itself while I was gone. Still nothing. So I head back to the engine bay to try and think about what it could be. It was then I noticed that the grounding wire that runs from the top of the bellhousing to the firewall right below the VIN code was getting extremely hot. My basic electronics class tells me that that this means that there's too much current running through that wire but I can't manage to locate the problem.

My dad has helped me look over everything and with troubleshooting. He's gotten just as sick as I have of spending hours looking in the engine bay and trying to find answers. But he's gotten to the point where he's telling me to just pull the engine out and go over everything at once. I mean, it would be easier to fix the oil leak that way (both inlet and outlet to the turbo are leaking pretty bad), but that's too much work for my tastes.

So now I come to you, the rotary gurus, looking for the following answers:

What could be causing the initial inability to start?
What systems should I test to get spark back?
What systems should I test period?
What is the connector that I explained in my 2nd paragraph?
What does said connector do?
What could be causing the bellhousing ground wire to get so hot?
Where does the twinscroll (I believe this is it) actuator vacuum line go?
Where should I connect the vacuum opening on the end of the secondary fuel rail?

I'm sorry that those last two weren't really accounted for in my story, but I just need a little clarification on them. Thank you very much for any help anyone can provide.

Billy.

RETed

First, confirm the coils are firing or not.
These things have a hard time firing most inductive timing guns.

Pull the spark plug wire ends off the spark plugs and place them near a known, good ground source.
I tend to pop the black rubber covers off the driver's side strut tower and use the studs as a convenient ground spot.

Crank the car over - do you see spark?
A friend comes in handy here.


-Ted

soundwavetsunami

Ok, i'm gonna try it tonight and see what happens. It used to spark when I had the cables off and I could hear and see the arcing before. But I'll still check again tonight. Thanks Ted.

prjct87rx7

iTrader: (7)

would your coil still fire if the ignitor is bad? maybe just weak as hell?

RETed

No.
If the ignitor dies, the coil will not fire.
Ignitors are either working or dead.
I've never seen an "intermitently" working ignitor.


-Ted

soundwavetsunami

ok, I just checked it using your plan of attack Ted. Still nothing. Does anyone have any other answers to my questions in the first post? I need this car to get to work (ironically enough I work at a mazda dealership) and I start soon so I really need help here.

Oh, and new question: What's the difference between the coil and the ignitor? Because I've noticed that both trailing and leading coils both say "coil and ignitor" on them. I'm a little confused between the difference.

RETed

Ignition no spark - it's narrowed down to ALL coils / ignitors are bad (highly unlikely), wiring (most likely), ECU, or CAS.


The ignitor accepts a relatively low power signal from the ECU and amplifies it for the coils to fire.
Think of the ignitor as an amplifier.
Mazda integrated the ignitor (module) into the base of each "coil pack".
The leadings have one ignitor.
The trailings have two ignitors - one in each of the metal base of each trailing coil.


-Ted

soundwavetsunami

Well I've already checked the CAS and I did check the coils. All were within spec. So that leaves wiring. What should I start checking now?

And I'm still looking for the following answers; anyone who knows any possible solution (not just Ted ), please help me out:

What could be causing the initial inability to start?
What systems should I test period?
What is the connector that I explained in my 2nd paragraph?
What does said connector do?
What could be causing the bellhousing ground wire to get so hot?
Where does the twinscroll actuator (I'm pretty sure this is it. It's a hard vacuum line that runs from the near the exhaust manifold that runs to a metal canister underneither the TID) vacuum line go?
Where should I connect the vacuum opening on the end of the secondary fuel rail?

HAILERS

You need to connect a vacuum source to the fuel pressure regulator on the end of the fuel rail. The path for that vacuum WAS from an angled nipple on the lower intake manifold located near your oil injectors. A piece of vacuum tube connected that angled nipple to a metal nipple that ran to your FPR solenoid (orange electrical plug on it). Then from the FPR solenoid it traveled to the FPR itself thru a metal nipple.

About that ground that gets hot. I'd say you battery to chassis/engine ground is not on good. The batterys neg cable goes.....from the battery......to a ground point below the left strut tower......on to the long bolt on the starter. So you have two places to look. Below the left strut tower and the cables connection to the long bolt on the starter. Sometimes its not on the long starter bolt. It might be on one of the bellhousing bolts above the starter.

Got a spare cas? Pull the connector off the cas installed on the engine and put that connector on your spare cas. Turn the key to ON. Spin the spare cas's gear with your fingers. You should see a large spark if you have one of the LEAD coil wires pulled out of its bore and laying just outside its bore in the coil assy. Or you can lay a sparkplug wire on the fender if you want to do it that way. If it sparks, then there's nothing wrong with the ignition circuit IMHO.

That square black thing is a capacitor for the oil pressure gauge. The car should start and run without that being connected. BUT there is another one of those located under the trail coil assy. It's for the coil's. How important? Got me. Never pulled it off to see if it effected the running of the car. I somehow doubt It would.

That long metal line on the twin scroll actuator? It goes to the twin scroll solenoid on the vacuum rack on the left of the engine. It's green in color I THINK. Look. Get a good cigar and light it up. Pull a vacuum line off the twin scroll solnoid. Blow smoke into the line. The smoke should exit the other end if you didn't block it up. Where the smoke exited is where you need to connect a piece of vacuum hose to the long metal pipe on the twin scroll solenoid.

I'm confused. Does this engine ever run? Ever?????

HAILERS

Also. The grounds for the ECU is located on top of the rear rotor housing. It's no where near the ECU. It's on a *ring* terminal on top of the rear rotor housing. It has two or three black wires on the ring and a bolt going thru the ring to the housing. So...did you connect this ring terminal to the housing? Go look. It's under the upper intake manifold. Some people claim they can see it without removing the upper intake manifold. Goody for them.

soundwavetsunami

Ok, awesome HAILERS. Unfortunately I'm leaving for West Virginia later today and will be gone for the weekend, so I'm just going to get a list going of stuff to do when I get back. I swear that if you help me get my 7 running I'll like... give you a cookie or something.

Anyways.

I knew about the FPR nipple and where it was supposed to go, but the directions on rotaryresurrection for emissions removal says to plug the angled nipple and run all the vacuum sources from one of the nipples on the firewall side of the UIM. I did this- I'm running the FPR nipple and the pressure sensor from the 3rd (out of 4) vacuum nipple down on the UIM. I checked the vacuum from this source and it's reading neglible amounts of vacuum (1-2 in. hg.). In fact the entire engine is only pulling about 9-10 in. hg. on startup in total. So if I'm going to route the FPR back to where it belongs do I need to hack the rats nest up to get the orange plug? Because I remember reading in (IIRC) DaleClarks post about emissions removal that there's absolutly no difference between it being on or off.

For the grounding... when you say leftside do you mean drivers side or passengers side? I'm pretty sure you mean drivers side because routing rather beefy grounding cables from drivers side to passengers side to drivers side again doesn't make much sense. I just need clarification on that because I've spent more time under the hood than in the seat. And on my car the 2nd ground you talk about does go to the long bolt on the starter. It's just that the yoohoo before me crossthreaded the bolt with some random nut and now the nut won't go back on. So I've got the ground wire on there but it's not tight in any sense of the word. Does that sound like it? It does to me. But now I have to find a similar bolt and nut to go put it on properly. If you happen to know the specs on that bolt and nut off the top of your head... that'd be lovely.

For the spark thing, I'll have to pull the old CAS from my NA block, but at least I know it works. So I just detach the connector and hook up the old one and spin it? Sounds easy enough.

Oil gauge capicator? Meh, I think that can wait as long as the car will start without it. The thing is is that I can't remember for the life of me where it came off of. I know it connects to a one pin plug right by the low-oil sensor, so I doubt it's the one for the trailing coils.

The tube that I think is for the twinscroll used to hook up to the rats nest, but since I removed it I'm not entirely sure where it went. So now the tube that I'm talking about starts between the end housing and the downpipe. It's right behind where the EGR used to be. It's also directly below the FPR nipple on the secondary fuel rail. It runs straight down then hooks under the downpipe and goes towards the front of the engine and hooks up to a bizarre canister looking thing that's right under the turbo. And Tsk Tsk Tsk Hailers! I'm 17- still not allowed to smoke. Whatever. I'm not even sure where I'm supposed to blow smoke into. Am I going to have to just hook the hardline that I'm talking about to a vacuum source or am I supposed to get the green plug off of the rats nest and run it like it should?

I've already checked the ECU ground before. It's still snugly connected right there on the rear rotor housing. So that's one thing that's not wrong. Yay.

And to answer your final question. No. This engine has never run on its on. It used to be able to run on starting fluid, back when it had spark. And it came extremely close the one time, but it just didn't feel like it was getting enough gas to make it. It was firing, just not enough. But right after that it stopped sparking. I'm pretty sure I've got a short somewhere. But other than that, I've been getting the same results no matter what-- Cranks for a few seconds, catches, sputters out and dies. And it's really starting to **** me off. But just for reiteration (and maybe a mistake I made reading a month so back), for the resistor pack, its supposed to be 6 ohms to each injector, correct?

Thanks for once again leading me in the right direction.

88and93

You definately need to fix the problem with the starter bolt/ ground. After that check for 12v at the main relay. The coil/igniters are only connected to the ECU and the main relay. As has been previously mentioned the chance of both coils dying at the same is not likely. These main relays don't last long and you hope it isn't the ECU. Good luck.

soundwavetsunami

Well I haven't checked the main relay yet. But I do have more than one ECU and have tried swapping it out with an 88 NA and a 88 jspec TII all with the same results as my 87 TII ECU.

soundwavetsunami

Ok, I spent some time out in the garage today.

I checked the CAS as per HAILERS suggestion. No spark.

Checked the main relay. According to the Haynes manual it's fine.

Didn't get around to fixing the crap with the starter long bolt.

I got frustrated and busted out the multimeter and started backprobing the wiring harness at the ECU. I've only done plug 3 and here's what I've come up with:

3A good (ground)
3B 12v (starter switch)
3C 0v (rear primary injector)
3D 0v (fuel pump resistor relay)
3E 0v (front primary injector)
3F 0v (rear secondary injector)
3G good (ground)
3H 0v (front secondary injector)
3I 2v to 2.25v (main relay)
3J good (battery)

So I've got good grounds to the ECU and that's about it. 3B is probably what's causing my bellhousing ground wire to get hot. I didn't have my resistor pack in, so that might explain my lack of power to injectors.

zerrorx7

i kinda had the same problem while ago. while twice to me

one was my air flow meter which had one of the wires broken inside, and if thats not good then u wont get fire

next is the main relay which must be tight against the frame. try using another one if u do have one or just go to a junkyard and pull one

HAILERS

Usually if there is no spark, the first and second thing to check are the 80 amp Main fuse in the engine bay fuse box then the ENGINE fuse in the interior fuse box.

If those are good and you have 12v at the small, white, two wire connector at the LEAD coil assy (the black/yellow wire, not the other), then I'd check with a voltmeter for approx 4-5vdc at the boost/pressue sensors connector. It would be the brown/white wire you'd check to see if you have 4-5vdc. I picked that connector because it's easily accessable, nothing to do particularly with the sensor itself.

Take to heart the remark about the afm. There was a fellow recently who found he had spark when he disconnected the afm plug but not with it connected. It must have been dragging down the Ref voltage out of the ECU. No ref voltage equals no spark ever and ever.

I've never seen that afm problem myself, but then I don't see any other cars than my own.