Subaru/ hot start problem

[tea2]

Subaru Impreza 2.2 L '96 refuses to start when engine is hot on inconsistent basis, it has never done so when the engine is cold [fall, winter spring or summer]. So far dealer and independent mechanics have tested the full pump, the compression, the coil [replaced then without result put back in the car], placed on scanner, driven it with scanner connected to system, replaced the timing belt, removed, cleaned, inspected and moved the injectors, replaced the ignition wires, checked for leak in intake, checked continuity of injectors to computer, verify for corrosion on terminals and still the problem is there. Anyone has a suggestion?

[Kartelli]

main relay? if the car just stalls in hot weather, might be worth a shot, and is a reasonably cheap fix (80 bux TOPS)

Honda's have this problem all the time

[tea2]

Thanks for the tip K, I will look into it.
I must add that the problem is not a hot weather problem only althought it happens more frequently when it's hot. t-2

[Punk]

:) Check three things...vapor lock in the fuel lines....or.....check the starter........or........believe it or not, you may need a new battery...I'll explain this one...
My father had a car that...during the summer, the battery would act like it's dead.......changed the battery..never happened again.:banghead:

[tea2]

Thanks for the suggestions P., both the battery and starter are O.K. but I will take a look at the fuel line. Visiting Montreal, I stoped at a Subaru dealer and described the problem to a mechanic with 25 years of experience working on these cars. He immediately suggested the heat sensor since they oxydise and send wrong signals to the computer. I will install a new one when checking the fuel line and let you know about it.

[bighead2267]

keep us update!!

[tea2]

Hi,
I changed the engine coolant temperature sensor without result [as suggested by a SUBARU mechanic with 25 years of experience working on these cars], the car still will not start occasionnaly when hot. I guess the next step is to get rid of this piece of subaru TRASH, definitely NOT AN OTHER SUBARU since 6 mechacis can't figure out what's wrong with it and the company when contacted about the problem will not be of any assistance.
Buyers beware!

[StupidWade]

This is a common problem for DSMs as well, I did a quick search and came up with this suggestion, which may or may not help.


"2) Change your vaccum hoses, especially the one going to the fuel-pressure regulator. Sometimes this one leaks and creates problems for the fuel-pressure regulator."

Good luck. I know (and obviously you do, too) that this problem is hard to fix.

[tea2]

Thanks for the suggestion Wade, they can definitely dry out without showing any sign, I also drive a '62 MGA 1600 MK II and brake hoses are notorious for doing the same. Will keep you posted.

[tea2]

The problem has been solved and I am posting it for anybody who may come across this particular problem: check the knock sensors [2 on the Subaru]. After replacing them the engine is running like the day the car was purchased, thanks to all in my quest for the holy faulty sensor. R.