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Hi guys,
I have been having problems with my 1997 Mercury Cougar 3.8L V6. The car has 91,000 miles on it.
Earlier this week, I could not get it started at all. Then yesterday, just by chance, I went to check it to run through fuses and relays (no problems) and it started right up, for 3 consecutive starts. I had suspected the fuel system, but while it was running the engine seemed to run like a champ, I sensed no hesitation to indicate a spark or fuel system problem.
Tonight went out to drive…nothing. This is frustrating because it appears that the fuel system, ignition system and mechanical parts are all in order. I checked the fuel cut off switch, was set properly. I’m now beginning to suspect a faulty relay on the “anti-theft” module that I didn’t even know I had. It’s clear that I have a lot of diagnosis ahead of me. I’ll have to go ahead and get the codes checked, I suspect this may not even show up, especially as a older model OBD II. Is this the right line of though?
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have you tried starting the vehicle with a direct line from the positive to the starter? ive had similar problem with a 99 that had multiple security issues. if it starts and stays running its not the security issues. if it doesnt then its a security issue
Joe, thanks for your reply. The starter motor runs, engine turns fine. I don’t hear the fuel pump at all during startup, I was wondering if the Anti-theft device would disable the fuel pump, but schematics in the Hayne’s manual suggest not, as you have suggested. Though, I know ford has changed this car significantly in it’s history and I’ve found this manual not completely accurate. When it did run yesterday, the engine ran smoothly and had no apparent fuel delivery issues. I think this is an electrical issue.
I don’t hear the fuel pump turning on when the key is in the “on” position though I do hear a series of clicks. Unfortunately, Ford designed the car so that the fuel pump relay is not a serviceable part, it must be replaced as a whole “control” module. It appears that there is not juice flowing to the fuel pump, I disconnected the Inertia switch and ran my multimeter across the harness, it only had a potential of 0.38 V…I’m going to try to apply +12 V to this circuit to see if I can get the fuel pump to run and go from there.
Does it have a after market alarm or factory? if after market, its probably faulty, but a Anti-theft system WILL cause a vehicle not to start. If you have a chip key, the chip could be bad, making the computer think someone is drying to steal it. Check the key, also check the remote, also maybe check the Anit-Theft module if it has one, also, check to see if it has a fuel pump shut off relay for accidents, make sure it has good connections and grounds, and yes, most fords have fuel module relays, but you have to replace the whole module.(yes it sux ford really didnt think that through). well first, make sure all your grounds have good connections and are not corroded or loose. and the battery terminals are tight and clean.
When the car won’t start, you need to find what’s missing, as in spark/fuel/compression. Since the car runs fine sometimes, you can knock out compression. So you need to test for spark or fuel. Here’s a good starter video on finding what’s missing.
http://www.youtube.com/watch?v=FBUYs539cy4
Good luck.
It’s possible that it could be related to the security system however you need to find out what is missing during the no start condition first, the video that Beefy posted should give you a start on that. Keep us posted.
Thanks for your comments guys. I really appreciate your help.
The plot has thickened: I ran a +12 V from the battery to the fuel pump via the inertia switch harness and nothing happened. I don’t have a spark tester or a fuel pressure gauge, but I will acquire them for the future. I recently purchased a OBD II scan tool and wanted to see what the computer knows, unfortunately the car battery had completely died by this point, with no apparent load. It appears that a.) the battery is faulty and/or b.) there is a electrical short/sink that is draining the battery. The latter may be related to the circuit that is causing the lack of start. This may indicate that even though I did apply voltage from the battery to the fuel pump, it may not have been at a proper current to run the pump. While sitting in the car, I also heard some erratic clicking noises, perhaps a failing relay?
Unfortunately, this is my only car and I need it so I am going to get some professional help. I hate to admit defeat but I don’t really have the means to fix this car. I’ll keep you posted on what they say.
If the battery is that low. then you don’t have a good 12v to run or even start the car. keep us posted on
your progressC8-)I would focus on the battery for now, if you don’t have the proper voltage to run the vehicle all kinds of crazy things can happen. If you do have a problem with a battery drain perhaps this video can help you solve it.
http://www.youtube.com/watch?v=KF1gijj03_0Sorry for not positing sooner.
The mechanics found that the fuel pump had indeed failed. It’s one of those in-tank suckers so it was a $700 repair including the tow. It was definitely worth it, considering I don’t have the tools or location to do the job right.
I was really thrown off by the dead battery, I’m not sure what caused it. There were relays clicking like crazy in the suspected anti-theft module just before it was towed away. Yet the battery could only barely illuminate the instrument clusters? I guess this is normal? I’ll look into battery drains as Eric suggests, and I’m really thinking about just going ahead and replacing the battery before it flat out dies and leaves me stranded. It’s closing in on the 6 year mark anyways.
Thanks for your help guys, I truly appreciate it.
Battery voltage is everything when it comes to the vehicle electrical system, if it falls below a certain point it can cause all kinds of strange behaviors. Glad you found the problem, thanks for keeping us up to date and for using the ETCG forum.
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