Ongoing issues with starting

[SevenMKIII]

All perfect, none were blown and I had replacements on hand just incase.
Could a bad CPS or it's wiring have this effect? I read that if the tach needle doesn't jump when you are cranking it is the CPS? True? False?

 

[suprabad]

If fuel pressure is good, and you've replaced the tps, double check the timing. Begining of the thread you mentioned setting the timing I think, double check it. If it's too far out, it won't start.

 

[SevenMKIII]

I can't set the timing back to 10* BTDC because it won't start. I checked base timing and it's spot on. Crank at 0 and cam gears both at 12 o' clock. It has to be something with not getting power to the coilpack, the the IGt signal isn't getting sent or something.

 

[SevenMKIII]

What is the first thing to look at when you are not getting spark at the plugs? I'm using the stock ground wire to the head, I may move that to the chassis ground off of the battery, the connectors look fine, I haven't traced the wires back but I don't see them being a problem. When I pulled the motor and unwrapped the entire wiring harness and checked all of the wires and retaped and covered them...I don't want to pull it apart again.

 

[ATL88Supra]

ok its your cps check the wires all the way to the igniter pack on the drivers side its silverish then check the cps its self, question have you done a head gasket job ? you might have put the cps in wrong i did the same thing when i did mine

 

[SevenMKIII]

I did a complete rebuild. I know the CPS is installed right, I set the timing to 10* BTDC with it like four weeks ago when I was able to start it, then I had the TPS issue and I bought a new one, adjusted it to TSRM and somewhere in there it stopped starting. Like I said, I'd rather not rip up all the taping I did a few months ago before putting the motor back in, that will be last resort. I also purchased the ignitor from a member. The CPS looked fine and worked flawlessly before, and I bought a new plastic cover and seal for it as well. I'm worried about the wires to the CPS, they are pretty stiff. But I still have a weird feeling that it may have something to do with the ECU based on it throwing one random code only once, and it did it twice more with two different codes but never again has it thrown a code.

 

[SevenMKIII]

Seeing as how there isn't a turbo Supra in a 60 mile radius (probably) I get all of my help and info on here, I know some of you guys have some advice for me. Please take a few minutes to read my problems and share what you know :cry: My friend is coming over tonight, he works at a family-owned shop here in town and I don't think he knows much at all about Supras, or imports for that matter, so I'd like to go know where to start...

 

[SevenMKIII]

I think I found the problem:

Checked the resistance of the wires on the CPS, one was 236k ohms one was 230k ohms and one was like 400 something k ohms...Dead cps.

Is there a way to clean/replace just the wires to have them work better or do I just need to find a good one?

 

[SevenMKIII]

Installed new CPS, still won't start. Could it be the ECU? Look back at first post please, updates there.

 

[3p141592654]

I did a quick read through, and you have fuel but no spark it would seem.

If you pull the CPS and rotate it by hand with the ignition on you should see the plugs fire.

If the CPS is bad it should set code 12 after cranking. Do you have code 12?

How reliable is your wiring on that side of the engine. The heat and age can cause the wiring to become brittle leading to open circuits, but any problem there should set code 12.

The igniter is grounded through the mounting bracket. Any corrosion there can cause trouble. As a quick check, run a test lead from the bat negative to the igniter housing with alligator clips or whatever you have on hand.

 

[SevenMKIII]

I assumed I have fuel because it is pressureized still and when I cracked the feed line gas trickled out under pressure. Any other way to check?

Wiring is, well, hard and brittle as anyone would expect. Just pull the CPS out, leaving it plugged in, and rotate it with the keys at the 'On' position and I should see spark? I'll have to try that after work.

Before when I tried, last night or a few nights ago, after cranking it wouldn't throw any codes. But when there are no codes the CEL is supposed to blink quickly with no stops, showing there is nothing stored. Mine doesn't illuminate at all, showing no codes but not that there aren't any by blinking either.

I'll try running a wire with a clip or something connecting the Igniter to the neg- side of the battery at the same time.

Thanks for the response!! Any help is appreciated.

 

[3p141592654]

When you turn the ignition on does the CEL come on?

 

[SevenMKIII]

Pretty sure, it worked a few weeks ago. I think somewhere in this thread I was explaining how it threw random codes one day after another but they never came back.

3p, I can't work on it right now unfortunately, I'm at work. I'll go over the list of things you said to check and get back with you.

To save some time later: If as I'm turning the CPS, the plugs do not get spark and it does not throw a code 12, what should I look for? I'll ground the igniter better off the bat. Just trying to think of all possible solutions.

VPC worked fine before the rebuild, I can unhook the GCC and see if that does anything, but I highly doubt that would change a thing.

I realize the ISC compensates for adjustment in the idle screw, but would that have any major effect on it? I don't even know where it's at right now (how far threaded), I moved it around a bit before.

Does no one think the ECU is at fault at all?

 

[SevenMKIII]

I finished soldering in a new set of male and female 4-pin plugs from Auto Zone a couple of hours ago, shrinkwrapped them and covered each in "liquid electrical tape" and put a wire loom over the whole bundle. Connection from the harness to the CPS is good. To be safe I poured another 5gal. tank of premium in it. Still nothing :cry: The tach needle doesn't jump like it's supposed to.

I didn't try measuring the resistence from the harness side at the CPS yet, it is pitch dark outside and I just wanted to get my plugs done. CPS is good, plugs are good, wiring is probably toasted and ECU I'm unsure about. Would it hurt to cut the CPS wires at the field harness and run new 14-16awg wires to the new plugs I put in tonight?

 

[3p141592654]

Did you confirm that your CEL comes on with the ignition?

If you really have a CPS problem it should set code 12 after more than 2 seconds of cranking.

 

[Burntz]

if you suspect the ECU so much, replace it, you've already done that to everything else lol

 

[SevenMKIII]

3p: No, for some reason the CEL doesn't come on now, jumpered or with the ignition.

Burntz: Care to loan me a good ECU for a day? :biglaugh: Ha where did you get your sig?

Well I have to run to Toyota on Friday to pick something up, and while I'm out I'm going to buy a few feet of 4-way Shielded wire and completely rewire the CPS. I have a field harness on my car so it will be easy to cut the four CPS wires out and re-wire them into my new harness to the plugs I bought yesterday. Any leads on where I can get shielded wire in a store? Toyota guy said they do not sell it at all.

 

[3p141592654]

You need to get that CEL on. Its the first thing to do. You are wasting your time with the CPS unless you know for sure you've got a code 12.

1) Check the EFI fuse.
2) If okay, measure the voltage between TE1 to E1 in the diag box with the ignition on, should be 4-6V (use a digital voltmeter).
3) If above okay, then ECU is getting power. Ground pin W of the ECU harness and confirm the CEL goes on. If not, the bulb is bad or the CEL wiring faulty.

The ECU is pretty reliable, they rarely fail unless the battery is hooked up backwards. Same with the CPS and other components. They rarely fail by themselves. The wiring, however, is often in bad shape especially on the hot exhaust side of the engine.

 

[Burntz]

3p: No, for some reason the CEL doesn't come on now, jumpered or with the ignition.

Burntz: Care to loan me a good ECU for a day? :biglaugh: Ha where did you get your sig?

Well I have to run to Toyota on Friday to pick something up, and while I'm out I'm going to buy a few feet of 4-way Shielded wire and completely rewire the CPS. I have a field harness on my car so it will be easy to cut the four CPS wires out and re-wire them into my new harness to the plugs I bought yesterday. Any leads on where I can get shielded wire in a store? Toyota guy said they do not sell it at all.

Do any jyards around you ave any mkiiis? also try to find someone around w/ a mkiii, and swap ecus to ceck

and click it, tats were it is lol

 

[SevenMKIII]

3p: :aigo: When putting everything back together I accidently had the large ground strap from under the fuse box (trying to remember) I think on the starter instead of the block and went to connect the battery and it didn't like that. Took it off and found my problem right away and switched it. Thing is, it was after all that had happened that my car was able to start and was running, and the CEL light was on.

EFI fuse is fine, I checked that the other day and I'll have to test the voltage at the diagnostic box when I get home or sometime tonight.

It's my brother's birthday so we have to celebrate that sometime. :sarcasm:

edit: Burntz: nearest I've found someone with a turbo Supra is in like Rockford, I'm not driving 3 hours to do a test :biglaugh: