My son has this car, but the engine won’t run for very long. It will start but will not go into gear (auto tranny) and when the accelerator is pushed will die. Most of the times, it dies on its own. Obviously it gets spark and fuel. What I don’t know is if there is something causing the spark or fuel to go away. Also, I am suspecting a vacuum leak. Of the 6 intake manifold bolts, the two in the middle are missing.
Need some help.
mspart
If there are intake manifold bolts missing, those must be replaced and torqued to spec before it can be determined if that’s causing the problem.
Is the Check Engine light on?
Tester
I had a Mercury Mystique 2.5L V6 (its sister car) and it will also die on its own. Dealer replaced the ignition module and everything went well after that.
You can’t make that assumption. The spark could be very weak or the fuel pressure very low.
Yes, a vacuum leak is also a possibility.
Or the compression could be almost nonexistent. Causes for this include well worn cylinders combined with tired old piston rings and/or valve problems. The valves need to open fully, close effectively, and be properly timed to get good compression.
I hate to say it, but this 19 year old engine needs a thorough going over by someone who knows cars.
Thank you for the responses:
Tester - No check engine light. There are no OBD-II codes.
Rascal - I appreciate the experience. My kid got this car for free from a friend who said it ran with no problems. Just needed to get rid of it. I’m thinking there was more to it than just needing to get rid of it. Ha!!
the_same_mountainbik - Yep, all those things could be it for sure. I have a compression tester and will use that to check compression. My son says he checked fuel pressure and it checked out. I’m not sure how reliable that is. It might need a thorough going over as you say. I also have a timing light that I was going to use to check the spark.
I have read about multiple items, fuel module, crankshaft sensor, and other stuff that feeds the computer. With no codes and no access to much, it is hard to say. The vacuum lines coming out from the manifold look in good shape, but they go behind the engine and disappear. So it is hard to say if they are good or not. I was going to take the line off the manifold and put a suction on it to see if it would hold but I can’t get that line off. I feel like I can work on it but I really don’t have the knowledge to troubleshoot so many things. I can hit a few but the others I don’t know much about.
So I have more to share about this, hopefully this will help. The car will not start anymore. It turns over no problem. I put an old timing light on each spark plug wire and they are firing. I got some bolts and bolted down the upper intake manifold so now it is secure. The intake manifold gasket looked good too.
We got the car to fire with starting fluid. So I’m thinking fuel is not getting there. Here is my question. When we turn the ignition switch to ON, we don’t hear the fuel pump charging the line. All quite. My caravan is noisy at the beginning, you can definitely hear the pump. What I don’t know is if this is normal for the Contour or not. I am assuming it is not normal. Due to the erratic nature of the engine failing, I don’t think it is a fuse or switch. I will check those as well as the injectors to see if they are operating properly. But coming back to the fuel pump, should I hear it charge up the line before the engine cranks to start? That is my question for now.
Thanks in advance - mspart
I don’t recall hearing a whining noise when the ignition switch was in the “on” postion in my Mercury Mystique. I remember having the alternator replaced under warranty because of a no start situation. Dealers apparently replaced a lot of them on the Contour and Mystique for the same reason.
Sure sounds like you need a new fuel pump. Don’t forget to also change the fuel filter:
I think so. I am going to run the wiring, fuse, relay, and final grounding to ground before I do the pump. I don’t want some relay or switch or fuse or corroded ground to be the problem but replace the pump anyway. So that is my next move. After that, if the electrical all checks out and the pump still doesn’t work, I will look into changing the pump.
I appreciate all the help. Keep it coming if you have ideas.
mspart
Good for you, it sounds like you are on the case and doing the diagnosis well. You might try measuring the voltage at the pump during cranking. If its not getting proper voltage it won’t be doing any pumping, even though the pump itself may be fine. That way you’d know it was an electrical problem like a faulty fuel pump relay, or corroded or burned connector. I had a VW Rabbit one time that had a fuel pump electrical problem that turned out to be the entire relay plate was damaged.
Well, we did all the electrical checks. We got power at the fuel pump connector. Fuel pump did not seem to drive. I put an ohm meter on the the connector for the pump terminals and there was infinite resistance - open circuit. So the pump is bad. So we are getting a new pump or hanger assy (my son’s choice).
One thing weird that we found was 6.5 volts on the connector and at the fuse (fuse is downstream of the relay) with the key on. I’m not sure where that voltage is coming from.
Anyway, I think we have solved this one. I appreciate everyone’s help and will provide news when the car is running.
mspart
On some cars the pump is run at different voltages I think. On those it is not just on or off but can be in between, on, but lower flow than full on. Maybe that’s why you measured 6.5 volts at the pump connector with the key in on.
Thanks for that. Hopefully that is correct. However, there isn’t anything like that on the wiring diagram. My son has time on Tue to do this job. I think he is getting the whole unit so we just yank the old one out and put the new one in. And hopefully that works. It should. We’ll find out when we try to relieve fuel pressure.
mspart
The wiring diagram may not show it, but that doesn’t mean it doesn’t exist.
There’s another document, a schematic, that shows the circuit electrically. This is different than a wiring diagram, which is just a physical routing description of the wiring.
I’d guess that the overwhelming majority of people think the two are the same.
A schematic would also show if there is a circuit in series to the pump circuit that’s “dropping” some voltage, like a resistor in a relay or something of that sort. That detail will lower the voltage at the pump but won’t show on the typical wiring diagram.
First change the pump. Then see if it’s fixed. And please post back, as we always enjoy following good diagnostic workmanship.
Thank you. I will be posting our results on Wed. It’s always nice to close the loop on these things.
mspart
Well, my son bought the wrong unit. So we ordered the correct one and will be able to replace it next week. However, when we relieved the fuel pressure, there was very little to relieve. Of course the car had been sitting for awhile.
mspart
I usually relieve the fuel pressure on my Corolla by removing the fuel pump relay then cranking the engine. Usually it starts up and runs for 10 -15 seconds and stalls. At that point the fuel pressure is relieved. Avoids the mess and safety concerns created by the other method, loosing a fuel connection slowly and let it spray fuel, with a rag around it to catch as much of the gasoline as you can.
OK. Finally we got around to it. My son installed the new fuel pump unit (sending unit and all that) and tried to start the car. It started! It idled! It rev’d up! He didn’t take it home but I think will later this week. I have to say I am happy with the result. I am grateful to all of your input on this. It sparked ideas and got me thinking properly to troubleshoot it right. So it looks like it was a fuel pump that was going intermittent and finally failed completely.
This has been a great learning experience and one of the only ones that I actually used electrical schematics to work through. I do that in my job all the time so it is not a new thing for me. Just with cars.
mspart
Sincere congrats on your success!
And sincere thanks for posting back. A happy ending is always welcomed.
I hope you replaced the fuel filter (as I mentioned 3 weeks ago), otherwise, the new fuel pump will fail in a few months.