No start when hot?

[NiGMa]

Hey guys, after having solved my non-starting issue I wanted to point out the problem to everyone in a seperate thread, hopefully it will be helpful to some. =)

I refer to this thread: http://www.supramania.com/forums/showpost.php?p=1387428&postcount=29

PROBLEM: Car doesn't start if driven long enough for engine to reach operating temp, will only start when cooled down a bit, usually 10-15min depending on ambient temp. Will crank fine, but not fire.

SOLUTION: Replace the EFI Main Relay!

I had this problem gradually get worse over the last 4yrs, it originally only happened in summer but then starting doing it all year round.

It was hard to diagnose because you could only test things in that 10-15min window.

I am thinking because my car is one of the oldest MKIII Supras(manu. date Aug 86) and because its spent it time in the harsh Australian climate, that I have stumbled across a problem many may start having soon.

If your having this type of issue, try shaking your main relay, this would temporarily solve my problem, and check if your relay is hotter than seems normal. Don't bother with the TSRM test for the relay, it will pass it when its outside of the 10-15min window, or shaken around a bit.

Hope this will help some guys.

I have taken alot from this forum, so I'm trying to give back a little. Thanks =)

 

[supraduper]

great thread, i am sure it will be useful to someone at somepoint... this is the kind of post that make forums work...

my only suggestion, is make your subject line something you would search for when having this problem

like "no start when hot"
"cranks no start when hot"
"no start issue"

but seriously, good info

 

[NiGMa]

Ok thanks, yeah I didn't like the title... I'll go with "no start when hot" =)

 

[supraman508]

refresh my memory,but where is the main relay agian?

 

[NiGMa]

refresh my memory,but where is the main relay agian?

Errr... good point, it would be better to call it the EFI Main Relay. I'll update the first post.

Its located in the main fuse/relay box behind the battery.

Thanks

 

[carfanatic89]

The EFI fuse is it the fuse block behind the battery. The EFI main relay is mounted on the left side of engine bay ontop of the strut tower

 

[NiGMa]

No, thats not it, its here:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=BE&P=14

Its B on Junction Block No.2, its called the "EFI Main Relay"

Not sure what the one on your photo is.

 

[supraman508]

No, thats not it, its here:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=BE&P=14

Its B on Junction Block No.2, its called the "EFI Main Relay"

Not sure what the one on your photo is.

thanks NiGMa

 

[carfanatic89]

my bad, sorry your right, Thats called the fuel pump relay.

 

[supraman508]

I have the same problem cause i have a code 11 that pops up and the engine won't start rite up after she's been driven and engine is hot.I messed with the EFI main relay when the engine was cold and she started rite up.sometimes when the engine is cold she won't start up rite away at all.I guess if i replace the main EFI Main relay it might make a difference.

 

[NiGMa]

with mine, I noticed a difference even when the engine was hot and wouldn't start, all it would take was a little rattle of that relay and she started up fine. =) And if that solves your prob, I'd get a new one.

 

[supraman508]

with mine, I noticed a difference even when the engine was hot and wouldn't start, all it would take was a little rattle of that relay and she started up fine. =) And if that solves your prob, I'd get a new one.

I'll chek E-Bay asap.