Toyota MR2 Message Board - View Single Post - If it ain't broke --- don't fix it!

BillyDoc · 12-13-2008, 02:41 PM

MR2-MRnot. Well, it rained for two days and then I had some other work to do and couldn't get to it - - - but I just did. I rigged up a timing light with an inductive pickup tied to the back engine cover so I could see it in my rearview mirror and went for a drive. Unfortunately, when the motor died I still had a good spark. When trying to restart it before the mandatory waiting period, it also showed a good spark. After about 5 minutes it started up and I hustled home.

I did get something of a clue, though, that I had noticed before and forgotten. When trying to start it when it won't, when I let off on the key I can hear the fuel pump (I think) keep going with about a one to two second brrrruuuup then stop. It sounds like the fuel pressure is low and the pump is catching up. This is why I changed the fuel pressure regulator originally, I thought it must be sticking open or something so the fuel was just dumping thus causing the fuel pressure to be low. That didn't change anything, so I replaced the fuel pump next (and the filter hidden underneath and the one in the tank) --- and again no joy. When I tested the fuel pump relay it did test bad (bad contact) and I replaced that but the dying didn't change at all.

Ben, It idles just fine when it runs and I cleaned the throttle body too. I tried just disconnecting the plug on the idle speed control but it still does the same thing. Runs at a high idle, then just dies. Thanks for the ideas, but no joy yet.

masagsxr, I know what you mean with the motorcycles. I've been using mine a lot lately, and boy do I hate riding in cold rain! But I think with the MR2 the equivalent rectifiers are in the alternator and if those went bad I should get an error message and a light on the dash, but I don't get either. Good thought, though!

So it just about has to be something to do with the fuel, but what? Could an injector fail in some way that just lets fuel "dump?" And if it did wouldn't the engine just run badly, not just stop altogether? Or, does the computer somehow sense a low fuel pressure condition and shut things down? But wouldn't that shut down the spark as well and give me an error code?

HELP!!!! It's too cold for motorcycles!

BillyDoc

12-13-2008, 02:41 PM	#6 (permalink)
BillyDoc No Skills Join Date: Dec 2008 Posts: 32 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Still the same symptoms, but with a good spark MR2-MRnot. Well, it rained for two days and then I had some other work to do and couldn't get to it - - - but I just did. I rigged up a timing light with an inductive pickup tied to the back engine cover so I could see it in my rearview mirror and went for a drive. Unfortunately, when the motor died I still had a good spark. When trying to restart it before the mandatory waiting period, it also showed a good spark. After about 5 minutes it started up and I hustled home. I did get something of a clue, though, that I had noticed before and forgotten. When trying to start it when it won't, when I let off on the key I can hear the fuel pump (I think) keep going with about a one to two second brrrruuuup then stop. It sounds like the fuel pressure is low and the pump is catching up. This is why I changed the fuel pressure regulator originally, I thought it must be sticking open or something so the fuel was just dumping thus causing the fuel pressure to be low. That didn't change anything, so I replaced the fuel pump next (and the filter hidden underneath and the one in the tank) --- and again no joy. When I tested the fuel pump relay it did test bad (bad contact) and I replaced that but the dying didn't change at all. Ben, It idles just fine when it runs and I cleaned the throttle body too. I tried just disconnecting the plug on the idle speed control but it still does the same thing. Runs at a high idle, then just dies. Thanks for the ideas, but no joy yet. masagsxr, I know what you mean with the motorcycles. I've been using mine a lot lately, and boy do I hate riding in cold rain! But I think with the MR2 the equivalent rectifiers are in the alternator and if those went bad I should get an error message and a light on the dash, but I don't get either. Good thought, though! So it just about has to be something to do with the fuel, but what? Could an injector fail in some way that just lets fuel "dump?" And if it did wouldn't the engine just run badly, not just stop altogether? Or, does the computer somehow sense a low fuel pressure condition and shut things down? But wouldn't that shut down the spark as well and give me an error code? HELP!!!! It's too cold for motorcycles! BillyDoc