No Start Problems

[radiod]

EDIT: I've left the first posts unedited so you can see where I started, and now where I'm going. After doing some more reading and thinking, I've decided to try and track down the real problem rather than do the relay mod which is essentially a band aid patch fix.

For reference...the mod I'm talking about:
http://www.supramania.com/forums/showthread.php?t=76403
TEWD Starting System Diagram:
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/manual.aspx?S=Main&P=038

It's got to the point where I'm push starting the car probably once a day on a pretty much brand new starter.

Just have a quick question about wiring this new relay in. I really suck with reaching in to small spaces and have a hard time getting to the starter. My question is do you think it would still cause me problems if I wired in the relay close to the firewall by pulling out the Black/Blue stripe wire out of the bunch in the harness just behind the intake manifold. I pulled the tape off and the wire is easy enough to get to there, but will having the old wire still between the new relay (to be placed between the intake manifold and the master brake cylinder) and the starter still have enough resistance to be causing me issues. I don't want to have to pay other people to do work I know I can do, just I really can't do it easily myself cause my arms are way too big .

If anyone else has any suggestions on how to get to the starter wiring easier, I'd be open to suggestions there too.

 

[Poodles]

Might want to read jetjocks posts in that thread...

 

[radiod]

Yeah, I never got that far and now that I look at the problem again, it is true that it's a mickey mouse solution to the problem.

At this point I'm at a bit of a loss as to where to go though. I know that the clutch switch is working correctly, because I can get the Toyota starter relay to click over every single time (and by moving the clutch in and out while the key is in "start"), and I know that I'm pretty much guaranteed that there will be a no start after some heat soak to wiring and whatnot under the hood. What portions of the diagram are actually under the hood? From what I can tell, after the starter relay it looks like it takes a trip through the firewall and pretty much straight over to the starter. The starter is getting power (you can hear and small click when you try and start it), but obviously not enough.

Biggest problem I'm having is when I go to TRY and diag more, it starts up fine on me (even trying to recreate it with a hot engine bay >_<) and when I really have to get out the door is when it decides to act up. Is there any suggestions of specific places I should look for a loose connection or high resistance?

 

[Poodles]

I'd check the factory relay. Also, you said it has a new starter, it might not be a good one (it's happened before).

 

[radiod]

Well after playing with it a bit last night it looks like I've lost all ability to start. I'll be taking the multimeter out next instead of the test light...need to get a battery for it first though >_<

 

[Satan]

I recently had some no start issues and can feel your pain. I would also suggest that you replace those things in the circuit, which can affect or contribute to the symptoms.

I replaced the Circuit Open Relay, EFI Main Relay, IGN fuses, EFI fuse and anything else that I thought could be the issue. Was ready to replace the ignition switch and associated wiring.

I took a look at the wiring diagram again and saw that the AM2 fuse was also in that particular circuit. I pulled/replaced it with another (I have several extra dash/body harnesses) and it started right up.

There was a small hairline crack in the wire of the fuse (I gues it had blown), but was not visible without some extra light and magnifying glass.

Long story short, is to not take everything for granted or assume that it's working/connected properly. It would have saved me alot of time, expense, and frustration if I had replaced everything in that circuit in the 1st place.

GOOD LUCK!

 

[radiod]

My starting problem is localized to the starting system (starter not turning at all), so one of the things I did in diag last night was pulling the AM2 fuse and jumpering acorss the posts, so unfortunately it's not going to be that easy for me.

 

[Satan]

^^ Ha ha.... I had to do that with the AM1 and AM2 once and the wires I used began to smoke/catch fire when cranking... What I was saying is to just not to assume that even the non-mechanical stuff is working as it should. Be careful and good luck.

 

[radiod]

Quick question, how much resistance is too much resistance between grounds? I've ruled out my battery terminal connections, but while I was testing resistance between different grounding points, I noticed that inside the fuse box (pulled AM2 fuse) I got 20(ish) ohms. between the battery and the engine though, everything seemed to be <2 ohms, which is acceptable. Resistance between the battery and the starter housing was 1.3 ohms. Voltage on the battery was 12.6V, voltage between starter housing and positive terminal was 12.6V, so no voltage drop there at all. When the ignition is put in to the "start" position, the voltage drops to approximately 12.3V.

So thus far I've basically come to the conclusion that the problem does not exist in the cable running from the battery to the starter. Is there anything I've missed in that area or would it be safe to move to testing points between the ignition switch and the starter?

 

[rustfarmer]

Sounds to me as if you have a bad starter solenoid or weak battery. Don't confuse voltage with amps, as you can have 12 volts yet so few amps available that the solenoid will click but still not spin the starter. You said you need to get a battery. Why? Could this be your whole problem?

 

[radiod]

Never said I needed to get a new battery. The battery is <6 months old and tests @ 800cca and 12.6V is a good sign for a healthy battery. The starter is pretty much brand new as well. And yes, the problem existed with the old starter (even after replacing contacts). Next step I'm going to try and take is measure the voltage drop/resistance at the solenoid on the black/blue stripe wire unless anyone else can come up with another idea.

 

[radiod]

I know it's been a while, but I ended up finally finding the problem. All my connections were good, turns out the new starter was faulty. Got another one under warranty and everything was good.

So for all you people out there with starting problems, don't go and do the "mod" to wire in that new relay. If I would have done that I would have hacked up part of my harness and still had the same starting problems. The problem is going to be a connection or something along the line, so rather than bypassing it all, figure out what it is and fix it.

 

[BOOSTEDSUPRA]

glad to see you got it fixed.:icon_bigg i never install anything untill its tested. never know what mood that particular person was in when the item you just bought was made, lol.

 

[radiod]

It worked fine for months before showing any sign of problems.