Toyota Celica Supra Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
118 Posts
Discussion Starter #1
10 minutes after cold start my car died while I was driving normally. I noticed 5 minutes before it died that the idle dropped down to 500rpm then went back to normal in one second. Then, driving at 3k rpm, my car shut off and I smelled something burning coming from the car. Not sure where it was burning but it smelled like it was from the front of the car. It smelled like someone lit electronics on fire in my engine bay while also burning rubber. While I was on the side of the road I cranked it and it acted like it wanted to start up but would die at around 200rpm-100 rpm. After a few cranks it didnt want to start up at all and just kept cranking.

Here's what I have done/checked:
I have spark to the spark plugs.
I can smell fuel in the engine bay after cranking/giving it some gas (thus, I think that its getting fuel).
I jumped the connector under the AFM and heard a fuel pump in the engine bay turning.
I sprayed started fluid into the throttle body and tried to start the car up without the intake on but I got no signs of any combustion.
I took the timing cover off and saw that the timing belt is good but I havn't checked to see if the timing is correct. The chance of it skipping more than 3 teeth to me is almost impossible.
 

·
Registered
Joined
·
2,042 Posts
Coil melt down? Fuel, spark, compression/timing.

From experience and androcidal evidence from reading the forums over the years coil is suspect...
check for spark again, paying close attention to maximum spark arc distance, there is a simple tool to check for this, probably something your local parts store has on a loan/rent basis. Looking for better than 0.06" (60 thousandths) of spark arc distance.

fusible link still good?

HTH

let us know what you find...

will
 

·
Registered
Joined
·
118 Posts
Discussion Starter #3
Hi.

Timing is good (see pics).

The coil gives off a good spark (i think, i could see it during the day time). The spark plugs spark i couldnt see in the day and only saw it at night. The cap and rotor are 2.5k miles old.

I pulled the plugs to do the compression test and the plugs were good and WET with fuel. My head was rebuilt 1.9k miles ago and before rebuild had 165 psi compression. This morning it had 135 psi compression all across. Not sure if this was after the rebuild or after this whole thing. Still, it should start.

Do you think a bad AFM, ECU, or distributor signal to ECU could cause this.


Sent from my Samsung Galaxy S10+ using Tapatalk
 

·
Super Moderator
Joined
·
8,159 Posts
I would check your fuel pressure.
 

·
Super Moderator
Joined
·
10,344 Posts
Fuel pump is my top suspicion too looking at your symptoms. Though the smell isn't typical of fuel pump failure, but failing idle and nearly starting can be. I would do the AFM jumper again and stick your head under the gas tank and listen to it run. A healthy pump will have a soft and consistent high pitched whirr. If its oscillating, or in general sounds stressed or unhappy, its likely the pump is done (do you know how old it is for sure, how many mile on it?). A pressure test at the rail is the best way of course, but generally you can tell just by the sound.

A flaky almost dead igniter is possible too, apparently they are going on people a lot these days, though I've never actually had one fail on me. Would explain the smell.

Only other things I would suspect considering the smell is the fuzable links at the battery, though you really shouldn't have spark if those go.

I suppose the distributor dying could do this too, but did you do your spark test with a lead coming off the distributor or the one off the igniter?

Once you've eliminated those, you're pretty much left looking for random fried wires that shorted out and fried relays under the hood (unless the smell was really strong in the car).
 

·
Premium Member
Joined
·
5,492 Posts

supra_toy

Registered

Joined Apr 9, 2003
2,034 Posts
#2 3 days ago
Coil melt down? Fuel, spark, compression/timing.

MAKE your own spark tester. Grab an old sparkie and bend the side electrode WAY over and crimp on a 2 -4 ' long 12 gauge lead with a medium-sized alligator clip on the end for the ground.The blue spark should jump all to way down the center electrode,just get out of the way.This won't work in bright sunlight-needs to be dark.

The TSRM can help.
MK2 TSRM On-Line (NO SPARK)
Pick up coil,ignition coil resistance,Igniter and some head scratching time.Last resort: plugged in a working coil/igniter.......WTH?

I went through ALL of the steps and found out that the ECU somehow unplugged it self.1.6 hours of diagnostic time,6 minutes to get the ECU plugged back in.:mad:

Can you borrow a coil/igniter from a 'Cali' forum member?You need that pair,anyway.
My extra is in my LR cubby ,double-bagged.NOT for sale.If you were closer,you could borrow mine!;)
 

·
Registered
Joined
·
118 Posts
Discussion Starter #7
Hi so I have done some more testing and have some more to do. Thank you for the help guys. I've eliminated timing, fuel, and compression from the equation. The spark from the coil is really good. I need to double check the spark to all the plugs. I have a spark plug tester and will do it tonight. I was able to find someone with a lot of spare 5mge parts here in socal and got a spare distributor.

What does the wire that comes out of the distributor do? I feel like its making an okay spark but maybe something is wrong with those two wires. I also was thinking about the ECU. Let me eliminate spark from the equation first before I dig into electrical things.
 

·
Registered
Joined
·
118 Posts
Discussion Starter #9
Update: swapped ECU, swapped distributor, checked injector resistor... no luck sigh


Sent from my Samsung Galaxy S10+ using Tapatalk
 

·
Super Moderator
Joined
·
10,344 Posts
Try following the process in the TRSM above as described. Random part swapping rarely fixes the problem I find.

Again, how does your fuel pump sound? A clogged fuel filter is a possibility too. If you can get a good fuel pressure reading off the rail that will put that question to rest.
 

·
Registered
Joined
·
360 Posts
from cars in past ive had 3 things have been the issue were cars stops running while driving

Alt
fuel pump
engine blows!
 

·
Premium Member
Joined
·
5,492 Posts
5 ways for the engine to die: (besides granading the engine @ 10,000 RPM)
Spark.
Compression.
Fuel.
Timing belt (compression).
Alternator failure(with some warning).
 

·
Registered
Joined
·
118 Posts
Discussion Starter #14
Ok so I figured out the issue. It was a coil/igniter that had a weak spark coming out of it. Put in another one and it fired right up! The 6th cylinder that would sometimes stop firing was most likely due to the plug wire popping out.
 

·
Registered
Joined
·
205 Posts
Congrats on your repair. You threw us off when you said you had a good spark.You should see a spark under daylight conditions in a shadow. Thanks for the update.
 

·
Premium Member
Joined
·
5,492 Posts
Plug wire popping out. My new NGK wire set did not set the dust boots to the correct position. I had to use silicone spray to slide the boots just right,so the dust boot was just touching the spark plug cavity and not in too deep to pull the
wire off of the sparkies.If the boot is not just right,it may allow crap in there to cause a weird misfire.

GOOD! You had another coil/igniter!Don't leave home with out one spare set..My spare fuel pump is coming today.
 

·
Registered
Joined
·
118 Posts
Discussion Starter #17
Plug wire popping out. My new NGK wire set did not set the dust boots to the correct position. I had to use silicone spray to slide the boots just right,so the dust boot was just touching the spark plug cavity and not in too deep to pull the
wire off of the sparkies.If the boot is not just right,it may allow crap in there to cause a weird misfire.

GOOD! You had another coil/igniter!Don't leave home with out one spare set..My spare fuel pump is coming today.
To be more clear, it was just the coil that was replaced. This made me wonder, how could a coil go bad suddenly? I looked at it and noticed that is was starting to rust from the inside and there was corrosion where the ignition wire goes into. Still confused though. Wouldn't the problem gradually appear instead like an on/off switch? I don't want to be constantly worried about the car dying while I'm driving. I just hope it wasn't some electrical issue that killed the coil somehow and will kill my next one as well.
 

·
Super Moderator
Joined
·
10,344 Posts
Probably wasn't your coil, was probably the igniter. Pull it apart and have a look inside. One problem we are seeing with these cars now they are really truly old, is the igniter circuit board depends on an insulating white electrical paste to transfer heat from the board to the case of the igniter, which or course has fins on it for dissipating heat. The problem is, that paste has dried up now. If you pull it apart you'll see that it is probably all dry and crumbly, so the igniter circuit boards are starting to fry themselves. Simple preventive maintenance on an original igniter is to just replace the paste.
 
1 - 18 of 18 Posts
Top