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View Full Version : NEED HELP---> int no-start when warm/hot



b1pig
08-04-2006, 03:55 PM
Ok. I asked once in another forum. Tried the suggested fix.... no effect.

Here's the problem:
96 Legacy Wagon, 2.2 Auto, AWD. Cold start, no problem... yet. After driving a "short" distance, usually less than a couple of miles, after the car is shut down for 15-130 minutes, it doesnt start. The engine spins over freely, but does not fire.

The problem is intermittent, and it is hard to troubleshoot an intermittent problem. It did it 3 times with me while I was out of town in June. I had no shop manual, and no tools. Returned home, no problems. Last week, it did it to the wife. (ofcourse she's pissed). Today, it did it again. This time, she was in the car with a 2yr old, so now she's livid.

We bought the car from the local Subaru dealer. It was a single owner trade-in... or so we're told.

I posted this in 3 different forums, NASIOC, Legacy.org and LegacyGT. Only members of one forum came back with any response. 3 members suggested that the temp sender for the computer may be bad. I already had a bad knock sensor. I ordered and replaced both. Cleared the code. Test drove and all was well.

I replaced both sensors this past weekend. It did it's no-start thing again today, as mentioned with the wife. We probably spent too much on the car anyway... we both liked it. I can't have the wife stranded on the side of the road.

I can't replicate the fault at will, and I have yet for this to occur when I am there, I have tools and a shop manual.
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That said. I am asking for input on likely causes, known causes,etc. Here are a couple of ideas. It's hot. Very hot. Been in the 90s since we got the car. I initially thought that it could be vapor lock type thing, though rare in injected cars. Secondly, possibly either the fuel pump or the pump relay. Problem with both is that I was unable to locate the test port on the fuel line/fuel rail. I figure that would have given me a confirmation on one or the other.

Next idea was coil, ignition control or something. I didn't have a second set of hands to turn the car over while I checked for spark, the last time, so I am still considering any of these.

Car does not miss, skip or misfire at all.

My primary reason for thinking fuel delivery, was that the last time it did it to me, the engine sputtered, caught and then ran fine. Just as if it were getting a trickle of fuel, and then the presure coming up.

In Jeeps, the Crank Position Sensor is known to cause very similar starting/stalling problems. I have experienced this in an older Cherokee we used to own. In this case, the engine doesnt stall, it just wont start back up.

ok. I think I've explained this one as clearly as I can.....
discussion is open, folks.

Huffer
08-04-2006, 05:27 PM
So the starter turns, but it doesn't fire the engine?

b1pig
08-04-2006, 08:36 PM
you bet. just like reaching over and popping the plug wires off...

doesnt even try to fire.

you know how if you get enough fuel (especially with carb engines) the fuel will not fully ignite, but the engine will cough or catch? none of that. just spins... and spins ... and spins.......

then.... anywhere from 5-20 minutes later...
duh-duh-duVroommmmmmmmm......... http://smilies.vidahost.com/cwm/cwm/spin2.gif

belladonna
08-04-2006, 10:43 PM
are you getting a CEL?

Manarius
08-05-2006, 01:09 AM
Coolant Temp Sensor. Don't even have think twice. Warm start problem with lots of turning over = Coolant Temp Sensor.

b1pig
08-05-2006, 01:46 AM
Coolant Temp Sensor. Don't even have think twice. Warm start problem with lots of turning over = Coolant Temp Sensor.

replaced it this weekend. that is why I'm scratching my head, here. There are two. one for the gauge, one for the ECU, right? I replaced the one that is (supposed to be) for the ECU.

No CEL. No codes.

b1pig
08-06-2006, 11:05 PM
so... no other ideas?

:lol: boy, i'm loving this....
You know. When I get in my Jeep to drive somewhere, I never know if I'll be coming back in it or not. note the irony? :lol:

Huffer
08-06-2006, 11:50 PM
I would check the fuel senders... apart from that, I really have no idea.

belladonna
08-07-2006, 08:55 AM
so... no other ideas?

:lol: boy, i'm loving this....
You know. When I get in my Jeep to drive somewhere, I never know if I'll be coming back in it or not. note the irony? :lol:

has the suby actually left you hanging yet? :wink:

it's a heat soak problem or fuel i'm thinking...get someone to help you check for spark and fuel pressure. is your fuel pump priming when you turn the key over?

Manarius
08-07-2006, 09:58 AM
replaced it this weekend. that is why I'm scratching my head, here. There are two. one for the gauge, one for the ECU, right? I replaced the one that is (supposed to be) for the ECU.

No CEL. No codes.You replaced the one on the backside of the intake? It's small and just kind of prods into the cooling system.

b1pig
08-09-2006, 08:13 PM
hey, guys.

i can't hear the fuel pump prime. if it is, it is super quiet. no hum or whine.

as for the temp sender... yes. back side right side under the intake on the coolant tube. the larger one, I think. As per the Haynes Manual, it is the right one for the computer.... the larger one. Took a deepwell socket... around 3/4" or 17-19mm... something like that. dont recall the exact size.

I'm hoping to catch this thing in it's tempermental state with an extra set of hands so I can get to the root of the problem. When you say "HEAT SOAK".... you refering to the transfer of heat into the fuel lines? Potentially causing air bubbles to for in the lines? (vapor lock)

Also, did a scan of the manual, and didnt locate the location of the fuel pump relay(s). Help a brother out. :lol:

Huffer
08-09-2006, 09:13 PM
You should hear the fuel pump when you switch on all the accessories, all the lights light up, and you should hear "eeeeeeeeennnn" it only lasts about a second.

b1pig
08-10-2006, 01:26 AM
just went out.

I can hear the pump prime the system. Not that loud at all. It's barely audible under the rear floor with everything off and the doors shut... so yea, the pump is priming startup. Which is good, because if it wasn't, I was beginning to wonder how I'd be getting fuel pressure to run the car. :shock:

next guess is to start looking at the relay(s).