QuestionHistory;
This has happened intermittantly 1-2 times a year for 4 years. Most times wait 5 minutes and restart and it was fine.
In the last 5-6 weeks any time I get stuck at a light or in rush hour traffic I stay in the right lane so I can get to the shoulder!
Replaced;
Thermestat,O2 Sensor, Ignition Control Module, Coil Pack, Plugs and Wires.
Troubleshooting;
Blocked off EGR Valve, Hot wired the cooling fan, removed gas cap, (All have been undone)
Loosened the radiator cap. When sitting on the shoulderof the road. Didn't help.
Symptoms;
Previously if the car sat for 3-4 days sometimes it wouldn't start until you loosened the gas cap.
This has resolved itself in the last year.
Has mostly been running fine until you get stuck in traffic.
Now a 12 mile trip caused issue.
Car appears to flutter and miss and has no power.
If you try to put it in gear and press the gas it will pop through the intake and die. It will idle although it misses and shakes, it will run.
Car is fine as long as 3 lines before midline on temp gauge.This is the normal position. It wont move from there until the onset of this issue.
If temp goes above that it acts up.
If temp goes past midline the car will no longer idle.
I can "feel' when the problem is starting( acceleration is poor and power drops)Although the car will get you home if you dont have to idle.
If you let it set for about an hour it will run fine again.
Problem was extremely intermittent but has worsened in the last weeks.
Problem appears to be brought on by temperature or idle.
Unless the temp sensor is bad the temp NEVER goes above midline on temp gauge.It appears not to be over temp as you can remove the Radiator cap with little fuss or spray.
If you are able to get out of traffic and get up to highway speed(exit onto hiway) the temp will move back down, but not for 10-20 miles,and it runs normally after that.
If the above happens and you hit a long traffic light it will resurface quickly.
Check engine light only came on when EGR valve was blocked off.
Check engine light has never come on before. Even when car won't run the "check engine" light won't come on.
Lastly when this occurs the gas gauge will drop to almost empty and low fuel light comes on,when you get it to run normally again the gauge is back to normal. Wierd!
Help!! I love this car and with 150,000 miles it still gets 30-33 MPG!
AnswerHello Buddy,
WOW!! Great description of symptoms, and for sure, a wierd problem.
Your mention of the fuel gauge associated with the engine problem makes me think you might possibly have a wire connection problem. My thoughts were first the ground connection near the fuel tank, and that might still be it.
The ground wire supplies the ground for the fuel sender, but it also supplies ground for the fuel pump.
If the ground integrity is lost, the pressure could drop, which should cause a lean condition, which in turn could cause the overheating, (assuming it really is overheating). But it would cause it to run poorly.
Grasping at straws here, but sometimes wierd problems require that.
I am not sure where that ground wire connects on that car, but on pickups, it bolts to the frame near the tank.
Lets say the ground is not totally lost, but just not as good as is needed...the fuel pump will attempt to run by grounding through the other circuit that shares the same ground, which is the fuel level sender, and back through the gauge. That could cause feedback through the fuel gauge, and possibly some other gauges, like the temp gauge, and heavens knows what else in the instrument cluster. (Grasping those straws again.) But the gauges and instruments could actually be supplying part of the ground circuit for the pump.
You cool the engine down by running down the highway, and no telling what effect you have on the pump through the temp gauge, etc. etc. And like you say, the engine may not even really be hot, but just a faulty reading on the gauge.
Back inside the tank, where the wires from the pump and sender connect to the underside of the tank unit, and out through it to the wire harness connector, I have seen the connections become loose at the rivets. The rivets go through plastic where I saw that problem, and squeeze the wire ends that way. Heat generated by loose connections melts the plastic, which makes them looser yet....vicious circle. (Your tank unit may not be plastic.)
So the bad ground could actually be there, rather than where the wire connects to the frame, but I would check the frame ground first.
One possible test would be to connect a fuel pressure gauge to the system, and see what it says during the sluggish running. That should have throttle body injection, so the pressure should be 12 to 15 PSI. I like 13, and it should maintain that 13 PSI till AFTER the engine dies, reguardless of how the engine is running.
Granted, low pressure could indicate a bad pump, dirty filter, or bad fuel pressure regulator, but by pinching off the return line, the pressure should max out at 15, even if the filter is dirty. But if you don't have the full voltage through the pump, it also won't reach its full potential.
Now your problem could be somewhere else, and the fuel pump and wire system be just fine, but it is a possibility.
There is no fault code for low fuel pressure, so it wouldn't light the engine light, unless an oxygen sensor got tired of the lean condition, but before that happened, the ecm would be trying to compensate for it.
Setting for an hour....that could possibly be explained in my theory by hot connections producing more resistance.
Removing the gas cap...hmmm. Could it be possible that doing that just wiggles the tank enough to restore a connection? Is there pressure or vacuum trapped inside the tank when the cap is released? Can you hear the pump run during those start attempts? Should run for two to three seconds when the key is turned to run.
These are just some meandering thoughts there, that may not help you at all, but then again, they sure may.
Good luck,
Van
