I have a 98 Tacoma PreRunner with about 74k miles on it. About three weeks ago I had a problem when it started to sputter and the check engine light came on. Took it to the Firestone center near my office. The said the code indicated a misfire in the #1 cyl. So replaced the plugs and wires. Then they indicted it was a bad injector…so changed the injector. Got the truck back and next day noticed gasoline smell and that it was hard to start after the car had been sitting for over an hour. Took it back in, they found a broken o-ring on the fuel rack and replaced it. A couple of days went by and still had the problems starting after had been sitting for an hour or more. Took it back and they indicated they cleaned the idle air control motor and another sensor just behind the air filter. It worked a little better for about a day. Then about three days later I notice the gasoline smell again. Took it back and they told me another injector had started leaking out the back side of the injector. They recommended replacing all the injectors so I did. Got the truck back and I’m still having the problems starting after has been sitting and cools down for say over an hour. But after it has been running for a few mins, it starts with no problems…on the first crank as opposed to 2nd or 3rd crank. I’ve had this truck for 11 years and never had any problems. It has always started on the first crank, even in freezing temps. But now that I have let someone start tinkering with the thing it is giving me problems and they can’t seem to figure it out. I am at my wits end and I’m already into this for over $1200. Does anyone have some suggestions?
Firestone is a place to buy tires. Why would you go there for anything but tires?
Oh yeah, I remember, it’s “near my office.”
Convenience is everything, right?
How’s that working out?
Suggestion: stop wasting your money. Take your Tacoma to a mechanic; a REAL mechanic, not a tire store.
mcparadise…I appreciate your input…but unfortunately your sarcasm doesn’t really help me diagnose my problem or get me closer to a remedy.
Can anyone else offer some ideas to help troubleshoot things further.
Is the difficulty in starting the engine, when it’s cold, the only symptom, now? Is the check engine light on? If so, what is the code?
It seems like the shop has been doing symptom repair. This technique is flawed. Ask your medical doctor, if it isn’t.
The problem seems to be centered on the fuel system. Is the engine too rich, or too lean, to start? Fuel pressure checks (static, and residual tests) will reveal if: the fuel pressure is holding after the engine is shut off, or bleeding down quickly, and if there is adequate fuel pressure for starting.
If the engine coolant temperature sensor, and or, the the intake air temperature sensor send the wrong temperature signals to the engine computer, the computer may order the wrong amount of fuel for starting.
There is a tool which can display the values from the sensors to the engine computer. The mechanic uses that data to determine if those values are (or, not) acceptable, and decides what remedy may be needed. The tool is called a scan tool.
Now, they owe you a fix at no additional charge; or, you may decide to go to another shop with more skilled mechanics.
I wonder if the fuel is back flowing to the tank. There should be a check valve in the pump to stop that from happening but they go bad sometimes. To see if that may be the trouble you should be able to turn the ignition on before you start the engine and turn the fuel pump on. Leave it on for about 5 seconds before you go to start and then see if the starting goes any easier.
From your posts about the shop work it doesn’t sound too good. It seems each time they touch the truck something happens to it and it costs you more money.
Thanks for the info Hellokit. The difficulty starting is after the engine has been stopped for a bit. I would not necessarily say when it is cold…I live in FL…so this is happening even after the truck has been sitting in 80 degree sun. I think the theory about fuel pressure may be good…and I have had my doubts about some of the air sensors too. They had checked the idle air control valve/motor…they said it was dirty and cleaned it. They indicated the only way they had to check if it was working was an ohm meter. I’ve had my doubts about if this was over their heads or not.
Other than a dealer…what kind of shop would have a scan tool or the tools to do some more diagonistics? Would a PepBoys be albe to help me?
I think it’s time to bring it to a reputable independant shop, tell them the whole story, and let them fix it.
Recognize that once they get the injectors squared away they may still have to diagnose and repair the real cause. It sounds like the guys at the Firestone shop have just been throwing parts at it.
Unfortuantely an engine can misfire for a long list of possible rasons. A good shop can find the true cause.
Cougar…thanks for the advice. I tried leaving the key on for about 10 secs before I cranked the engine…but did not have any better results. I was hoping that might provide some insight and some results.
Following up on the theory about a check valve…I found online a Toyota service manual for the truck and there is a “Fuel Pressure Regulator” which is attached at the end of the fuel rail. I suspect this serves as the check valve? It also looks like it would have been disturbed when they replaced that first injector. But it would seem that if that valve is acting up then I would have problems at other times than just cranking when cold?
If you haven’t tried spraying some starter fluid into the intake when it is cold then see if that makes a difference. It has to be a fuel or ignition problem. If the starter fluid works then maybe the fuel pump relay is the trouble.
We still don’t know if the engine gets too much fuel, or too little fuel, during cool starts. Try to lessen the possibilities by trying different things:
Turn the ignition key ON for two seconds, off a few seconds, ON for two, OFF for two, ON and START. This should “prime the pump”, if it has lost its prime. Result?
Push the gas pedal to the floor, and hold it there. Turn the ignition key to START and crank the engine – while STILL holding the gas pedal to the floor. Crank for about 15 seconds. If the engine starts, ease up on the gas pedal. Result?
If the above didn’t work, add fuel. Pull a small vacuum hose off and spray a two second burst of the Starting Fluid (from your auto parts store) into the engine intake direction. Reconnect the vacuum hose. Try to start the engine. Result?
If the engine still doesn’t start, disconnect a vacuum; but, DON’T use the Starting Fluid. Crank the engine. Result?
Tell me/we/us the Results.
Results?
Ok…tried the following:
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Turn key to ON for 2-3 sec then to OFF, repeated about 5 times…no difference.
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Turned key ON waited and pumped gas pedal for 10 sec before starting…no difference.
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Sprayed starter fluid directly into the air intake assembly/throttle body, reconnected hose, and started…no difference…if anything it was maybe a little harder to start
I’m not sure if I disconnected the correct hose? The one I disconnected is the one which comes from the air filter and goes to the throttle body.
After not cranking with the start fluid…I’m beginning to wonder if the problem might be that the first injector they replaced might be leaking? How would I tell if the injector is leaking?
Ok…figured out which was was the vacuum hose…small hose attached to the throttle body. I disconnected it…and with NO starting fluid applied…the engine cranked almost immediately!
So what does that mean and what needs to be done? Or does this just help point down the correct road for further troubleshooting?
Thanks a bunch for the suggestions. Look forward to more feedback on where to go next.
Since pulling the vacuum hose off helped then it seems to me the fuel mixture is too rich. By pulling the hose off you allowed more air into the intake.
Were you able to start it more than once, with the vacuum hose disconnected? If so, that indicates that the engine is running rich. The reasons for a rich running engine are numerous.
The mechanics need to work on this rich condition. They need to check/clean the MAF (Mass Air Flow) sensor; clean/check the iac valve (idle air control); check the engine coolant temperature sensor(ect), and the intake air temperature (iat) sensor; fuel pump pressure control/regulator.
Hellokit and Cougar…thanks for the suggestions. At least know which direction to head.
On one of the previous visits they did check and clean the MAF and IAC valve. The tech/mechanic said he thought it was possible the IAC might need replacing soon. But before I throw more money at this…what is the likelihood that the rich condition could be created by one of the injectors leaking back into one of the cylinders? Would that create similar symptoms? I keep going back to the fact I did not have this problem until after my first visit when they replaced that initial injector.
The injectors were replaced so that should rule them out normally. As Hellokit mentioned previously the coolant sensor for the ECU may be causing the trouble. Checking for the proper resistance would be a good thing to do.
Make sure the MAF is working ok and the fuel pressure regulator isn’t overpressuring. Since things have been leaking the trouble may be with the regulator.
Ok…took the truck back in on Monday and explained all the troubleshooting done so far and re-emphasized that the problem showed up after they changed the first injector. Explained about the vacuum line disconnection and how it started immediately.
They kept it for the day and did more testing of sensors etc. Came back that the MAF was getting a reading lower than the limit suggested? So they changed it (at no cost) and claimed that should take care of things. They indicated the fuel pressure regulator was checked and working normally. I asked about the possibility of leaking injectors and if they were able to test them…they indicated the injectors were good…I suspect they probably didn’t check them. They also indicated that if the replacement of the MAF didn’t work I should probably consider taking it to a dealer next where they might be able to do more sophisticated diagonistics.
Well…went to start the truck this AM and met the same result…took 3 cranks before it would start. Tomorrow AM I will again disconnect the vacuum line to make sure it still starts when that is removed.
Also I’m still suspect of that first injector. Is it possible that one injector leaking would could leak enough to cause this problem? And is there a way to test the injectors without pulling them…is there some tool that can be hooked up to them?
I suppose there could be a leaking injector but I thought they were all replaced with new ones in an effort to solve this problem. I also doubt that just one leaky one would cause this trouble.
Going back to the original post, the problem was a misfiring #1 cylinder. At this point the injectors have been changed and everything fuel related seems to have been checked.
Perhaps the problem was never an injector or fuel delivery problem to begin with. I haven’t seen anywhere here where sensors and components relative to the ignition have been looked at. Perhaps that’s a path to begin down.
Have you had the codes read again? That may be a good idea. Post them here.