Died and Won't Start...HELP

[sheppard22]

I have a 97 Protege, I was driving down the highway and it died and wont start gain. It turns over, there was barely any oil in the car when it died, didn't over heat, timing chain is still tight, no visible damage under valve cover, I tried spraying some gas into manifold and that made no difference, when you pump the gas while turning it over it kinda half starts. If anyone has any suggestions please help...thanks

[grey1]

you need air, fuel, and spark to start and run...


check compression and timing marks- belt could slip

[mannydingo]

If it didn't make any horrible noises before shutting off then I doubt you ruined the engine due to oil starvation. If there was absolutely no noise, a good chance is that the teeth on the timing belt stripped yet the belt is still fully on. This happened to me once on a 91 Escort. Upon removal of the upper timing belt cover, the teeth looked fine. When I manually turned the crankshaft pulley, the belt wouldn't turn because the teeth down at the bottom were now shaved off thus just skating on the sprocket teeth of the crankshaft end. Ofcourse, a bad computer can do the same and other things. Get a hand-held computer scanner and see if anything is there.

[RicardoS]

make sure the pcm has been reset by taking the ground wire off and depressing the brake for 5 seconds or so (read in some manual somewhere) make sure your maf and iac are clean and not obstructed by any depree, (both are along the intake) when my fiance owned the vechicle turned out to just be a bad rotar! (same explaination when she broke down on the freeway) injector failure can definitely be another culpret! Be nice if you could swap for some other injectors, 160cc is the stock spec on our injectors. Only other thing I could think of off the top off my head is whether or not you seized it, or if it was raining and you have cai or something regarding water in the intake? I've ran a toyota dead dry (oil) before but I was only traveling at 35mph and fed it some oil and booyah! check valve? (pcv) not sure, just know that if clogged, car won't idle, take it off and make sure it raddles like a spray can inside.

[dtatham]

Pumping the gas isn't what it used to be. It actually just opens the throttle body to allow more air. The MAF see the increase air and tells the computer to open the injectors for longer.
You may have a bad fuel pump, if so, you would have noticed that it acted like the accelerator wasn't pushed down and you had to floor it just to keep running. If that wasn't the case, it's probably something else. Try spraying some starter spray into the manifold.
Other than that, check Grey1's advise.

[mannydingo]

Pumping the gas isn't what it used to be. It actually just opens the throttle body to allow more air. The MAF see the increase air and tells the computer to open the injectors for longer.

I'm not familiar with that so I'm not saying you're wrong. However, the MAF sensor comes before the Throttle Body so why would it see more air coming in just because the TB opened up more? At the front of the intake, the amount of air coming in stays the same regardless of whether the TB opens up more or not. I can see if the TB had an air flow sensor or somewhere down the line after the TB there was an air flow sensor. However, the MAF is before on the air intake path.

[dtatham]

The air flows across the MAF on it's way to the throttle body. When the engine rotates it sucks air into it creating a vacuum which draws air through the filter, across the MAF, through the throttle body, into the intake manifold, and into the cylinders. There is a bypass to the throttle body, the idle stabilizer, that allows enough air to flow to keep a constant RPM when the throttle isn't being pressed. One of the major reasons why vacuum leaks are such a problem is that it allows air to be sucked into the engine without going past the MAF. This causes the computer to think that the accellerater isn't being pressed as far so it reduces the open time for the injectors and your fuel/air mixture is thrown off.

[mannydingo]

I never thought about the vaccum effect. I've dealt with vacuum leaks with cars and yet didn't make the connection as far as the above topic is concerned. I figured the vacuum happened somewhere else down the line. You are sure the sucking in of air is felt at the throttle body, right?

[dtatham]

The vacuum source is the piston moving down with the intake valve open so that it can draw in air. It's basically the same thing as pulling the plunger out on the syringe. The cylinder pulls air out of the intake manifold (vacuum) the air flows into the intake manifold through the throttle body and so on.

[mannydingo]

The vacuum source is the piston moving down with the intake valve open so that it can draw in air. It's basically the same thing as pulling the plunger out on the syringe. The cylinder pulls air out of the intake manifold (vacuum) the air flows into the intake manifold through the throttle body and so on.

I kind of figured it would start at the piston's downward motion but did not know if this went all the way to the TB or somewhere else and that the TB just introduced air into the system to mix with the gas with no actual suction of air. I thought just the push of the air from the car moving was its way of getting into the engine. Then again, then that wouldn't work when the car was not moving. I get the picture now. Thanks for the info.