Wont start after driving for a while..

maxaud

Active member
freddie":3rsdl2di said:
By the way there is a fuel pump cut off wire at the MAF. (no air flow = no fuel flow)
Know what wire color that is?

I've been leaning more towards vapor lock myself but will entertain all options.
 

alltracman78

Active member
185s don't have that, their ECU controls fuel pump shutoff.

As a mechanic, my first thought hearing the symptoms is coil.
But I don't have the car in front of me.

Next time it won't start shoot some starting fluid in it and see if it fires up. If not you're looking at a fuel problem.

If it is fuel most likely either filter, pump or control. Control is easy to verify; when it won't start disconnect the pump and put a test light in the connector. If you have light the control is fine, if not, something's wrong in the EFI system [probably ECU or COR].
Filter is easy to change and is good as preventative maintenance anyways.
 

maxaud

Active member
Coil has been replaced and so has the fuel pump.

A shop sprayed some fluid in and got it to start so suggested I replace the pump. Still had the problem afterwards. I can hear the fuel pump running too which would lead me to believe the powers is getting to it.

Where is the filter located on the st185.
 
Fuel filter is located on right hand side of the engine right below where the cruise control box is. You will see it in line if you follow the fuel rail where it starts going underneath the car. This at least applies to the usdm alltracs.
 

alltracman78

Active member
IIRC Homologation cars don't have cruise control. :)
It should be under your intercooler overflow bottle. Down low by the bottom of the L strut tower.
Just follow the fuel supply hose.
For some reason a lot of people have trouble getting this off. Loosen the bracket for the filter, get a wrench on the nut for the fuel line [make sure it's on there GOOD; if you round off the nut it becomes a PITA]. IIRC you can knock off that little bracket on top of the filter [holds the supply line in place] and then put a socket on the nut on top of the filter. Bump it with an impact gun. Don't go crazy, it's not a lug nut, you just want to bump it loose. Or if you're not feeling the impact gun try with a rachet. If find this much easier than using a wrench on the top or the bottom.

A factory pump you shouldn't hear running, a walbro you probably will. But only if the engine is cranking or running.
If the pump is working the control is obviously good. I doubt all 4 injectors [or all 4 resistors or controllers in the ECU] are not working at the same time. Unless the wire that feeds the resistors has a bad connection.
Start with the easy [filter]. Then move on if that doesn't fix it. :)
 

maxaud

Active member
Yeah, no cruise control on the RC.

It does have the larger Walbro pump.

Thanks guys. I'll start there and see what I can find.
 

88_ST165

New member
Sounds like vapor lock to me... But anything could be going on. I had a 93 Camry that did a similar thing. After it was hot I could turn it off and it would fire up right away, but if I waited 5-10 min it would crank for a good 6 sec before it would start.

Maybe have a look at the TPS? may be out of spec? who knows!? my 89 GT-S Celica had some funny starting issues with a bad TPS.

maxaud":xhz5btpe said:
Bringing this thread back to life. Been a while since I've been on.

STILL having this issue.

Basically, if I drive any long distance or if I drive the car for longer than 30-40 minutes and I shut it off it wont want to start. Simply turns over and doesn't even sound like it's trying to start.

Was told it may be vapor lock in the fuel system but I still encountered the issue with the fuel cap off.

Seems to be fuel related instead of spark.

Any other ideas as to what this may be?
 

FC Zach

Active member
Your symptoms sound similar to an issue I had November, 2015. It was an intermittent issue that was difficult to diagnose. . (well, for the most part I was too lazy to find the problem until I was forced to while stranded). I too thought it was a pump. I had spark but no fuel. .

FC Zach":1ds6rt0a said:
Last November I diagnosed and repaired an intermittent engine stalling issue (and no start) when my Celica left me stranded in a store parking lot. I suspected it was a fuel pump issue but it was in fact a fuel pump relay that caused all my headaches, I was grateful it was this simple and that I didn't have to pull the tank and replace the pump :)
22163604614_6ed482ff0f_z.jpg

I started an emergency help thread and from the help I got there I was able to get the car running. Try this next time it wont start:
FC Zach":1ds6rt0a said:
Found that I was supposed to bridge terminals Fp and +B. . . did that and car runs. If I disconnect the jumper wire the car cuts off.

Here's the thread:
http://www.alltrac.net/phpBB2/viewtopic.php?f=21&t=51010
 

maxaud

Active member
I actually replaced the relay too but I replaced it with a used one from a junkyard so it could be the culprit still. It does it get very, very, very hot.nthanks for the heads up.
 

maxaud

Active member
Was having the issue of not starting this weekend so I bridged the Fp and B+ in the diagnostic port and it started right up. Maybe it's the fuel pump relay but if it's going bad, I'm curious if there is something somewhere else that is making it go bad.
 

FC Zach

Active member
maxaud":2il3moje said:
Was having the issue of not starting this weekend so I bridged the Fp and B+ in the diagnostic port and it started right up. Maybe it's the fuel pump relay but if it's going bad, I'm curious if there is something somewhere else that is making it go bad.

It's definitely your relay. I asked the same question about the cause, this is the response I got:

yyonline":2il3moje said:
Usually it's just the relay that's bad. What usually happens is that something causes its internal resistance to go up (cracked solder joint, corrosion, etc.). When the resistance goes up, it generates more heat. Which causes more damage, which generates more heat, that causes more damage...etc. until it fails.

It's also possible that the fuel pump has high internal resistance which is causing too much current to pass through the relay and that's why it overheated. But the first scenario is more likely.
 

FC Zach

Active member
Forewarning, that relay is not cheap so be prepared to spend $90. . . unless you plan on replacing it with a "good" used part but you'll probably be in the same boat again.
 

FC Zach

Active member
Looks like any other relay, like the e-fan relay for example but rated for different load.

EDIT: I looked at mine while checking things under the hood last weekend. . . It's nothing like the fan relay, or any other relay. It's a completely different size. Also, it's the yellow one. . I say this because if it's getting excessively hot from too much resistance it will discolor and if like mine, it'll turn brown (as seen on the previous page).
 

underscore

Well-known member
In that case I'd just take apart the old relay and gut it, then wire it as the plug for a socket for a standard relay, allowing it to plug in without messing with the factory harness.
 

FC Zach

Active member
underscore":1ftvv62g said:
In that case I'd just take apart the old relay and gut it, then wire it as the plug for a socket for a standard relay, allowing it to plug in without messing with the factory harness.

That would be a great idea if you can find a suitable relay to put in its place.
 

alltracman78

Active member
FC Zach":3ep8gabm said:
maxaud":3ep8gabm said:
Was having the issue of not starting this weekend so I bridged the Fp and B+ in the diagnostic port and it started right up. Maybe it's the fuel pump relay but if it's going bad, I'm curious if there is something somewhere else that is making it go bad.

It's definitely your relay. I asked the same question about the cause, this is the response I got:

yyonline":3ep8gabm said:
Usually it's just the relay that's bad. What usually happens is that something causes its internal resistance to go up (cracked solder joint, corrosion, etc.). When the resistance goes up, it generates more heat. Which causes more damage, which generates more heat, that causes more damage...etc. until it fails.

It's also possible that the fuel pump has high internal resistance which is causing too much current to pass through the relay and that's why it overheated. But the first scenario is more likely.

High internal resistance in the pump would allow less current in the circuit and less heat at the relay.
The heat probably comes from higher resistance at the contact. Now if the pump had less resistance, that would cause more current in the circuit and more heat at the relay [especially if the contact is damaged at all].

A relay is a switch. Every time a switch opens and closes a tiny bit of material is "pulled" off one side and sticks to the other. You also get some "burning" on the 2 sides. So you're pitting and coating the surfaces with carbon every time the switch opens and closes. The amount of damage depends on the voltage, current, design and amount of use [opening and closing]. Same thing happens with your starter contacts.

Most likely the contacts are just worn out, causing heat. If they're worn out they also won't necessarily always work [like your starter contacts].

There is another option to the relay [specifically the high/low speed pump relay]. In the 5sfe cars there is no relay, they use a jumper so it's always on "high". It pulls right out and plugs right into our cars. Your pump will always be on "high". Not really a problem IMO. The jumper is in the same exact spot as our relay.
 

FC Zach

Active member
alltracman78":oh90gmeu said:
There is another option to the relay [specifically the high/low speed pump relay]. In the 5sfe cars there is no relay, they use a jumper so it's always on "high". It pulls right out and plugs right into our cars. Your pump will always be on "high". Not really a problem IMO. The jumper is in the same exact spot as our relay.

Thanks for this, this is good to know if it were to ever happen down the road. . next time I'm at the scrap yard I'll keep an eye out for a GT. This is something I'll keep in my emergency bag.
 
Top