98 contour, will crank but won't fire

outlaw7532 · 03-29-2008, 08:40 AM

I just purchased a 98 contour 2.5 (non svt) with auto trans last week. It ran perfect when I drove it. I noticed the fuel pump was getting real noisy when the car key would turn. It still ran fine. No problems driving. Coming home, the car shuts off while I'm driving. I had it towed home and found the eec 20a fuse was blown. So I replaced it turn the key and it blew. I jiggled some wires around and finally got the fuse to not blow but it still will not start. It turns over but doesn't start. I replaced the fuel pump and the camshaft position sensor and still won't start. Also, the overdrive button didn't work either. Now when I turn the key, the fuel pump does not come on and the plugs are not firing but the car will still turns over. I checked all the fuses again, the fuel shutoff button, and any visual broken/touching wires, everything is ok. I'm thinking it might be the pcm or the pcm for the fuel pump if applicable. Any ideas?

Selectron · 03-29-2008, 02:38 PM

That sounds like one of the early '98s with the bad wiring harness eh. It's unlikely that you'll locate the problem(s) without the aid of a multimeter, and even then it could still be a difficult job. I'd say it's too early to condemn the PCM, because you don't even know if it's receiving its supply voltage, or if it still has a good ground connection, etc., so you could fit a replacement and still be in exactly the same position.

Since you know that the fuel pump should come on when the ignition is switched on, but it's failing to do that, I'd make that my starting point. I'd check first for 12V at the inertia fuel shut-off switch, and if that was missing then I'd move up front and check the voltages at the fuel pump relay. If that was all in order then I'd check the ground end of the fuel pump relay coil, which is switched to ground by the PCM when it wants the relay to be energised. If the coil wasn't being grounded by the PCM at ignition switch-on then I'd start looking at the supply voltages to the PCM itself, and the ground connections for the PCM.

Depending on the condition of the harness though, you might get the fuel pump working once more, only to find that you have another fault (or faults) which still leaves you with no spark.

The fuel pump circuit would be the obvious starting point though. If you need the wiring diagrams, follow the instructions in the first post on this thread and you'll find them there - when you reach the Wiring Diagrams section, look for Engine Controls and Power Distribution.

http://www.automotiveforums.com/vbul...d.php?t=890909

outlaw7532 · 03-29-2008, 08:53 PM

Well I took it to Firestone and the tech hooked it up to a computer and it said the pcm was bad, in a nutshell. My new pcm should be here Tuesday. I still think there is a wiring problem though because the fuse kept blowing and as soon as I jiggled some of the wires, the fuse for the fuel pump stopped blowing. I'll know something Tuesday I hope.

beyondloadedSE · 03-30-2008, 09:32 AM

Quote:

Originally Posted by outlaw7532

Well I took it to Firestone and the tech hooked it up to a computer and it said the pcm was bad, in a nutshell. My new pcm should be here Tuesday. I still think there is a wiring problem though because the fuse kept blowing and as soon as I jiggled some of the wires, the fuse for the fuel pump stopped blowing. I'll know something Tuesday I hope.

I doubt its your PCM. Hopefully you didn't pay much for a new one. You can get plenty of used PCMs for sale on the CEG classifieds.

Btw, you could check the schraeder valve on the fuel rail to see if your getting fuel pressure.

outlaw7532 · 03-30-2008, 09:45 AM

I'm not getting any fuel pressure or spark. The pump does not even prime itself. The computer was new for $130 just waiting for it to get flashed, should be here Tuesday. Where do the wires by the radiator and under the intake usually short out? I don't see how the eec fuse kept blowing and as soon as I jiggled some wires around it stopped. Any help....

beyondloadedSE · 03-30-2008, 12:30 PM

Quote:

Originally Posted by outlaw7532

I'm not getting any fuel pressure or spark. The pump does not even prime itself. The computer was new for $130 just waiting for it to get flashed, should be here Tuesday. Where do the wires by the radiator and under the intake usually short out? I don't see how the eec fuse kept blowing and as soon as I jiggled some wires around it stopped. Any help....

What wires are you talking about? The harness under the upper intake manifold attached to the fuel rail? Not sure what wires your talking about by the radiator.

Your PCM could be bad, but if it is, its probably wiring caused. Im fearful, your going to get a new PCM and your going to left with the same problems since the wiring is the culprit.

Check the main harnesses back by the passenger strut tower. Thats where it connects to the PCM. You may want to pull your UIM and check the fuel harness. Those crack due to engine heat and can arch off the LIM.

rhandwor · 03-30-2008, 06:25 PM

Disconnect the battery ground and pull up the relay center. Look for corroded or wires rubbing against something. Also check anywhere the plastic cover for the wiring harness rubs against something or goes through the firewall.

outlaw7532 · 03-31-2008, 08:27 PM

I'm afraid that if I put the computer in and there is a short, it might damage the computer again. I don't see any corroded wires...

rhandwor · 03-31-2008, 08:37 PM

You are going to have to look harder wher you wiggled the wires and it changed. Remove the plastic loom and inspect each wire. It will take some time but save you big money if you find it.

outlaw7532 · 04-01-2008, 06:24 AM

Well is it safe to put the new pcm in and see if the car starts or should I take the whole harness out and look for touching wires?

rhandwor · 04-01-2008, 07:12 AM

I don't think your computer is bad I would check the wires. Use the old computer and check voltages. Check the relay for the fuel pump is good. The relays go bad sometimes.
http://www.alldata.com/ sells a yearly subscription for $25.00 they have detailed wiring diagrams print one off and check all grounds.
Ford has bad wiring and I had to pull the harness and physically inspect it. I used terminal tools and another harness from a scrap yard. The car worked fine after this. It took the better part of a day. I also ohmed each wire.

outlaw7532 · 04-01-2008, 04:34 PM

My relay is good i switched it with the horn relay and checked. I'll pull the harness and check the wires.

outlaw7532 · 04-02-2008, 06:20 PM

Well I replaced the PCM and it still does not start. I look at most the wires and relays but none of them are corroded. What next?

outlaw7532 · 04-02-2008, 06:22 PM

Should I just pull the whole harness out the car and start over? My car does not have ABS but will a wiring harness with ABS work?

rhandwor · 04-02-2008, 06:54 PM

You have to use a wiring diagram and with the wires unplugged. Ohm each wire on the fuse. Get some copper wire so you can reach from one end to the other end. Touch the two wires of the ohm meter together and this is the reading you should get. If a wire is going to ground it will be different. Then on one end only put one end on the wire and the other end on the body ground. You should get the same as when the wires aren't touching. They are hard to find.
Normally the manufacturers use the same harness but not everything is plugged in but I haven't been doing it for a few years and they might have changed.
You can look at a yard to find one but they have a habit of cutting rather than unplugging.
Ohm the wire to the fuel pump it could have shorted out.

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