We've been fighting this problem for a while now. It's been a progressive problem. It started out where it'd just lose power once in a while like it just ran out of gas, but it'd get going again in a couple seconds. Then it got harder to start, and as it would crank, it'd billow out smoke. We thought it must be a gas issue, and really thought it was the injectors. We just changed out the injectors and it starts easier after it stops, but it still is a situation where we're cranking on it awhile. We also changed the fuel filter in the engine. The fuel pressure regulator was checked and it's fine. So what next?
It's black. So far we've changed the fuel filter, the fuel injectors, plugs, wires, cap, rotor and now the damn thing won't start. It "started" but idled at like 100ish RPM for like 20 seconds then died. It acts like it's not getting any gas. How hard is the fuel pump to change and clean the lines?
With that smoke being black I would say that you have some kind of spark issue. That sounds like unburned fuel. Should smell like it also. I would not suspect a pump problem, because you said that the pressure regulator is fine so I would think that the pump would be ok.
With that smoke being black I would say that you have some kind of spark issue. That sounds like unburned fuel. Should smell like it also. I would not suspect a pump problem, because you said that the pressure regulator is fine so I would think that the pump would be ok.
What else should I look at with the spark system? It's got new plugs, cap, rotor, wires, Should I check the coil?
I don't think there are any specs on the igniter/coil. If you could pick one up for cheap at a local junkyard you might be able to get it started. Otherwise run some tests on the distributor to see if there is a breakdown on that. At this point it could also be the ECU. They are pretty hardy though, they don't go bad often.
The only problem with the sensor is that is should start eihter cold and die after it gets hot or it is just difficult to start cold but at some point it should start. I bought a corolla one time and it was missing the cold start everything. But it would start just not right away. But once warm it would start without issues. I new this before hand and found all the parts needed to fix it.
I would look into the igniter/coil first. Like I said it is rare for the ECU to go bad, and as I said I would suspect something else first.
The fuel injectors will only allow so much fuel when triggered. If your regulator is working fine and the pressure is normal then I would think that there is no spark happening. I could be wrong and maybe I am but remember this is internet trouble shooting.
I am assuming that you have not pulled a spark plug out to see if it has a healthy spark? Because if it did that would blow my theory out the window.
The only problem with the sensor is that is should start eihter cold and die after it gets hot or it is just difficult to start cold but at some point it should start. I bought a corolla one time and it was missing the cold start everything. But it would start just not right away. But once warm it would start without issues. I new this before hand and found all the parts needed to fix it.
I would look into the igniter/coil first. Like I said it is rare for the ECU to go bad, and as I said I would suspect something else first.
The fuel injectors will only allow so much fuel when triggered. If your regulator is working fine and the pressure is normal then I would think that there is no spark happening. I could be wrong and maybe I am but remember this is internet trouble shooting.
I am assuming that you have not pulled a spark plug out to see if it has a healthy spark? Because if it did that would blow my theory out the window.
I replaced the plugs and my kids were far too efficient and threw them away before I could get pictures. These plugs were replaced about 5 months 3k miles ago. They were grey and had some carbon build up that was a medium gray, somewhat crusty on the electrode, but not too bad. I have new NGK's in there now. Could it be when the coil gets too hot that it sends a weak spark and that's what is causing the crusty buildup on the electrodes?
it starts almost immediately when it's cold. Drive it a while, full operating temp, stop, try to start it 10 minutes to 30 minutes later, and you'd swear its out of gas.
Ok now we are getting somewhere.
It sounds like the cold start circuit is not shutting off after it is hot. There are two things in the system that will effect that.
1) Engine coolant temp sensor
2) Cold start timer
3) Bad/leaking cold start injector
I would start there and check that those two items are functioning properly. It sounds like it has been intermittant for awhile. Which could explain why it bogs down on you. When the sensor or the timer fail it will kick in extra gas and cause a bog down. This will cause hard starting when hot.
I would suspect the sensor first. And it might be a good idea just to replace it. They are not that expensive.
Ok now we are getting somewhere.
It sounds like the cold start circuit is not shutting off after it is hot. There are two things in the system that will effect that.
1) Engine coolant temp sensor
2) Cold start timer
3) Bad/leaking cold start injector
I would start there and check that those two items are functioning properly. It sounds like it has been intermittant for awhile. Which could explain why it bogs down on you. When the sensor or the timer fail it will kick in extra gas and cause a bog down. This will cause hard starting when hot.
I would suspect the sensor first. And it might be a good idea just to replace it. They are not that expensive.
I disconnected the cold start injector and it ran and started fine for a number of hours. Then the same symptoms returned where would I find the engine coolant temp sensor, and the cold start timer?
The temp sensor is located behind the intake manifold on top of motor next to the fire wall. There are I believe 4 sensors back there but the temp sensor has a green connector on it. Which directly influences the Throttle Position Sensor and the fuel system. Also the timer switch is located in the same area, it has a dark gray connector on it. I would not suspect the timer switch if you disconnected the injector.
Here is some info for the temp sensor:
1) 4-7 ohms @ (0c or 32f deg.)
2) 3K ohms @ (20c or 68F)
3) 0.9-1.3 ohms @ (40c or 104F)
4) 0.4-0.7 ohms @ (60c or 140F)
5) 0.2-0.4 ohms @ (80c or 176F)
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