Red
Freshman Member
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Posts: 7
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Short version: If anyone is near 333xx (Fort Lauderdale area, Broward Co. FL) I'm willing to pay a tech who has a scope and knows how to use it, to solve this problem.
IT IS NOT A SIMPLE RESTART/START ISSUE.
Long version:
I'm the original owner, 105k miles, '85 Toyota Corolla GT-S with their "VAST" ignition and EFI system. Last year the car played a new game when I brought it down to Florida. Runs fine, chews up the interstate without a hiccup, starts hot or cold and restarts on the interstate with no problems. EXCEPT.
When the car has been parked overnight, and the ambient temps are maybe 85F or above, the car will crank but not start. Happened last summer, and I was waiting for a tow truck to bring it into a shop when I said wtf, today has been cooler...and of course it fired right up. Worked fine agin until this June when things got hot again--same "won't start from parked" problem.
I'd rather hire out than invest in a whole scope system to track down the problem. What I've gone through, last year and again this year, is most everything that can be checked without a scope.
The fuel pump whirs, I haven't bought and installed a pressure gauge to confirm that pressure is adequate--but expect it should be OK if the car can do a thousand highway miles without a hiccup. "Should", I know, no assumptions just best guesses here.
The starting system: Tested and bypassed the AFM switch, the EFI main relay, both sides of the COR (fuel cutoff relay), all of these test OK and when bypassed, there's power going to the fuel pump as verified at the pump harness connector.
The engine will crank and fire--briefly--but I can't keep it running. I think that indicates the engine is starting on the NE signal and then dropping out when the ECU should be switching to the IGt signal--but in theory, if the ECu wasn't sending IGt, the VAST system goes back to limp-home mode on the NE signal and runs anyway.
The ignitor pack, with connections to the coil and two harness connectors, has been removed, opened, eyeballed and tested with ohmmeter to make sure there are no cold solder joints, no breaks in the harness leads. That's not a functional test but again, it is all I can do without a scope.
So maybe it is a fuel pressure problem, more likely an ignition problem, either way I need to find a tech (or buy the scope, ouch!) to dig further. The local dealer uses ODBC now for everything, he's got one tech who will gladly toil away...for somewhere between one hour and two days, they guess. No scopes left there.
This is not a simple "won't start when hot" problem. Trying to apply logic here: The car starts just fine when it is cool out--even if the engine bay is at full operating temperature, i.e. 170F++. So logically nothing in the engine bay "should" be the problem. Which leaves the COR and ECU behind the glove box, and the COR tests fine. Last week I stuck the ECU in the freezer for a couple of hours to cold-soak it, no joy. Then there's the fuel pump--but I'd expect that gets hotter when sitting in tank with returned fuel warming it up on the highway all day. Or not?
Anybody in the area up for a challenge? I'm going to start the week looking for a fuel pressure gauge that can be installed under the hood, to reality check that fuel pump. But again...if it did a thousand highway miles without a hiccup?
PITA, my tools are up North, the car & I are forced to remain down south for a good deal longer, and the car apparently isn't happy about this.
Paging Sherlock Holmes...
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