Car Won't Start When Warm
- Thread starter LoveX1/9s
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ng_randolph
Bjorn H
Stock for an '86 is 3 wires; one red and two brown. The fourth wire in the first photo is probably a "brown wire mod" (<- search).
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LoveX1/9s
True Classic
Interesting. The previous ownner told me I had the brown wire mod. If true, I'm going to look for the 4th. Mine is a 85.
LoveX1/9s
True Classic
What on earth is this? My car doesn't have one... You have to open the picture to see it in the yellow oval. Actully, I do have one. It was hiding but I have a square cut out on my transmission... I see others have a cut out but does anything go on it, over it, etc.?
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ng_randolph
Bjorn H
Perhaps not; there isn't one brown wire mod, but one idea with a multitude of interpretations. The PO may have implemented a different version of a brown wire mod.
ng_randolph
Bjorn H
Your first and second photo show the clutch slave cylinder. There is a rectangular cutout in the bellhousing a little closer to the engine (your third photo); this is to see the TDC mark on the flywheel. You can see the 0°, 5° and 10° marks at the edge of the opening (corresponding to TDC, 5° and 10° before TDC), From the factory there would have been a black plastic plug in this opening, many of these plug have gone missing over the past several decades.
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LoveX1/9s
True Classic
Thanks on both posts.
LoveX1/9s
True Classic
And yet another issue that really is an issue. I found this red wire to nowhere. It's pretty dinged up in spots. It's part of a red and blue wire that I haven’t traced through yet. It's hard to tell from the photos but it looks like they are meant to go to the same spot from under the dash. However, along the way, the red side is cut off. The single red and blue wire looks like it continues to the fuse box. Will trace it through but does anyone have a hint to get me to the right place and what is this for? The pictures need to be enlarged. Some of the pictures make the blue wire look like it's just blue but it's indeed blue and red as seen in the picture in the far right. Unless they got squished together through the years, the single red and single blue and red wire looked like they were meant to be paired together... The blue wire in the middle picture is actually blue and red stripped as shown in the pic on the far right.
I see a light blue red to a light switch but frankly, I have no clue and why a red wire too?
Of course, if it's blue red, its for the electric antenna switch which is no longer on the car.
And since, I'm fishing if it's light blue red, it's for the thermo time switch. Perhaps an ahha moment... Or the air flow sensor. Honestly, I don't know if it's blue or light blue but that could be it too. It would help if I knew wht I was doing or looking at. LOL.
I see a light blue red to a light switch but frankly, I have no clue and why a red wire too?
Of course, if it's blue red, its for the electric antenna switch which is no longer on the car.
And since, I'm fishing if it's light blue red, it's for the thermo time switch. Perhaps an ahha moment... Or the air flow sensor. Honestly, I don't know if it's blue or light blue but that could be it too. It would help if I knew wht I was doing or looking at. LOL.
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kmead
Old enough to know better
You should have three.
Someone likely did the ‘brown wire mod’ which adds another power wire to the ignition switch from the main junction. It is a very poor solution to band aid a different problem which is that the switch can’t handle the existing electrical load though the existing contacts. Adding more power improves this for a while.
The solution actually needed instead of adding another wire’s worth of power is to offload the switch by using relays for the major loads.
That is a discussion for another time after your car is working properly
A plain red and a plain blue wire likely was added by someone for another purpose. They don’t look like typical period Fiat/Bertone colors.
If the red wire is cut, does it have power? Is there another half you can find which is within reach of the cut end? Is the blue cut or continue on somewhere else? Can you follow that forward to the far end and then back to wherever it goes to?
myronx19
True Classic
100% agree. The ignition switch becomes the choke point.
LoveX1/9s
True Classic
Still can’t find where the red wire connects. It’s actually a standalone wire. Didn’t find the other end of the broken part. Found a blue wire that turns on the fog lamps I think. And some broken wires and some unconnected wires. The red wire that’s dinged goes up into the dash. There’s a mother one that looks abused but not sure if it the same one. Also found some breaks that maybe for the radio. Have to pull it to see. Please tell me I don’t have to take the dash out to trace it or do I?
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ng_randolph
Bjorn H
The wires in the first photo are definitely not stock and look like speaker wires. If you unwrap the tape on the wires in the second photo, you will probably find phono plugs (RCA plugs), so used for an audio system. In the fourth photo I see a blue splice inside the console; definitely not stock. The insulation on the red wire in the fifth photo looks like it has overheated and melted at some point, so it would be a priority to find the other end of it and remove the wire completely.
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LoveX1/9s
True Classic
Still can’t fine where the red wire connects. It’s actually a stand alone wire. Didn’t find the other end of the broken part. Found a blue wire that turns on the fog Kathy’s I think. And some broken wires and some unconnected wires. The red wire that’s dinged goes up into the dash. There’s a mother one that looks abused but not sure if it the same one. Also found some breaks that maybe for the radio. Have to pull it to see. Please tell me I don’t have to take the dash out to trace it or do.
That said, the ignition was replaced and the junction block is missing and the thick wires are spliced together so I’m guessing the wires to the ignition switch fried at one point.
Some one added a ground from the cam cover to the body. It’s wasn’t a great job, came undone so I removed it. I wonder if I should add one back in and do a better job. That was taken off years ago at mid west bayless request. There were a few crazy grounds added. I saw that some one grounded to the oil pan and that has since fallen off.
That said, the ignition was replaced and the junction block is missing and the thick wires are spliced together so I’m guessing the wires to the ignition switch fried at one point.
Yeah. So it looks like I may have to undo the dash to trace it through. Could t find where it went on the fuse box side. But I did see a wire that didn’t look good under the dash. Not sure if someone replaced it or not at this point. I don’t even know what it does.
Some one added a ground from the cam cover to the body. It’s wasn’t a great job, came undone so I removed it. I wonder if I should add one back in and do a better job. That was taken off years ago at mid west bayless request. There were a few crazy grounds added. I saw that some one grounded to the oil pan and that has since fallen off.
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kmead
Old enough to know better
Leaving a ‘dead’ wire, meaning one that has no current, will not hurt anything. Just test it to see if it has current in any mode. I would pull your radio to see it or some of your other oddball wires end up there.
Removing the console is easy to do and would allow you access to some of the standard ways people pass wires around under and in the dashboard area.
The power distribution junction block has been a problem area for many over the years if folks have overloaded the circuits or if for some reason there is corrosion on the contacts which increases resistance. Resistance ends up creating heat which melts the plastic and creates more resistance etc etc. Yes your ignition switch may have been replaced but that distribution block issue is a different issue generally unrelated or related due to someone overloading a circuit downstream of the switch.
The X electrical system is from the end of one era of wiring design where they didn’t use a lot of relays. If you look at a Miata which started production as the X was ending production, there are many more relays to deal with the loads from the various systems. Adding relays to take the load off of singular points like the ignition switch is good practice: starter, lights, wipers, HVAC fan, power windows (yes I know there is a relay there but the load still goes through the ign switch as it is currently designed). Once your car is sorted out with many of the mods applied by others removed you can if you wish add some of these, or not if it is all working properly
On more modern cars the ignition switch is the trigger for many relays, the same with the majority of the switches in the car so very little current is run through the actual switches which preserves the switches and can provide more power to the actual accessory. Modern cars do this as well plus the system communicates back and forth amongst the components on a system referred to as CANBUS, not something to worry about on an X. My Honda Element uses CANBUS and dozens of relays, the electrical manual is an inch and a half thick with a second nearly 3” thick manual to supplement it for testing processes. Good thing its electrics are reliable…
There should be one ground from the engine/transmission assembly to the body. That ground goes from the drivers side end of the transmission to the body. It should either be a bare braided copper wire object or some have replaced it with a heavy gauge insulated wire. In either case removing the wire and cleaning the contact points on the body and the transmission is a good thing to do to ensure a good electrical connection. When reinstalling using some dielectric grease is a good thing to do to protect it or a conductive grease (used in electrical panels) could be used.
Previous owners are confounding with what they did or some ham handed mechanic did to quickly ‘fix’ something and brutalized the system in the process.
LoveX1/9s
True Classic
Can a bad fuel pump blow a fuse? Noticed that I wasn’t getting current to the fuel pump. Fuse was blown. Has current now but still won’t start? Bad coil in the pump perhaps?
Can spray in starter fluid to get it going but it sputters down. Will get an new filter and pump and I hope that does it.
Can spray in starter fluid to get it going but it sputters down. Will get an new filter and pump and I hope that does it.
kmead
Old enough to know better
No fuel, no go…
A fuel pump could blow a fuse if it was clogged with rust/particles from a gas tank full of guck. It is a good idea to put a ‘coarse’ filter in front of the pump, there is a thread in the Best of Xweb around installing one inline.
The pump can be cleaned as it has an internal filter which could be blown out, it isn’t removable.
Have you tried removing the line from the pressure regulator and running the pump to see that you have flow through the fuel rail? This would be the fuel return line from the regulator to return excess fuel to the tank. I would remove the line from the pressure regulator, add a short section of line into a fuel can from the regulator and force the pump to run.
LoveX1/9s
True Classic
I haven’t tried that but I should see if my tank is good. Car doesn’t have a pre filter but I ordered one today along with a pump and filter. There was no full pressure in the line to speak of. I’m finding myself rechecking what others before me claimed they did. :-(. Either a new filter wasn’t put in 3 years ago (paid for one though) or it gummed up.
kmead
Old enough to know better
Glad you are back on the road.
Adding a ‘coarse’ inline filter ahead of the fuel pump is cheap insurance. Inconvenient to change as you want to run the tank down as removing the hose will empty the tank. The first time I changed mine I had about 1 gallon of fuel (which I did strain and reuse) go into a low Rubbermaid bin, there was a fair amount of grit. The next time there was very little. The good thing is over time you will likely need to change it less often as you will have caught the majority of the particulate matter in the first few changes.
At some point you might want to pull out the fuel level sender and have a look inside the tank to see if it is rusty or has other guck built up in it.
In the meantime, do enjoy your car and congrats on making through a travail.