1993 Mustang Cobra "my tow vehicle" not really but need help!
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So I have had this car since 1994, it now has 125,000 miles on it. It has the original water pump, fuel pump, etc. It has been a really reliable car. But for some reason it no longer wants to get up and go. Over the past 5,000 miles I have noticed that sometimes when you pin the throttle the car just takes off, and other times is bogs down then wakes up and goes. But now when you give the car more than 20% throttle it just bogs down. It seems like a fuel delivery issue? Almost like to much gas goes in and the ignition system wont ignite the fuel? I recently put in new spark plugs. Any thoughts would be greatly appreciated! I also replace the fuel filter roughly 15,000 miles ago.
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Very cool Cobra, not the fastest but definately gaining more popularity with collectors.
As far as your issues, I would check a few things. First, pull the plugs and look at them. Are they fouled up? Do they look burnt? Next I would check the oil and coolant, and see if one has mixed with the other. After that, look around for a Mustang specialist that can help. There are plenty of shops and clubs on the web that I am sure know more about what makes those things tick. Just my thoughts... |
Not a huge motor guy but I had a similar problem in my sand rail...ended up being the foam block disintegrating and clogging the lines and fuel filter. Pulled the cell, replaced the foam block, cleaned the lines, replaced the pump and pre and post filters, and put a new foam block in. Runs perfectly now for 2 seasons of duning.
Is this a fuel injected 5.0? It sounds like a pump problem to me. I would check your connections to your fuel pump, as well as possibly running a fuel injector cleaner through a tank of gas for starters. |
we all have 27 in our nicknames. how bizarre, how bizarre.
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Fuel filter maybe? Check the pump to see if it's clogged too.
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I can pull the plugs and replace the fuel filter. But only the fuel filter in-line, not the one in the tank. That would take hours. But a good start.
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if no code being thrown, then here's your list of things to run down. As above, fuel filter, check plugs, plug wires, dist cap and rotor, then have your cat. checked, map sensor, o2 sensors. could also be coil or coil pack.
maybe do a tripple threat sea foam treatment (directions on the can) check all vacuum lines too and the evap canister if it has one. good luck... |
Not sure if this is relevant but I had a '94 Ranger w/4.0L v6 that I had inherited from my grandfather when he died. He never told me about it but I saw in the service records going back to when it was only 4-5 years old that it was randomly throwing check engine lights for the MAF (Or MAP, can't remember which it had). The dealer couldn't figure out why so it just stayed that way. After I had it for about 6 months (Driving it much more than it had been driven in years) it was loosing more and more power. Finally it started stalling randomly and wouldn't start sometimes. It would sputter and spit black smoke and was fouling the plugs. Replaced the MAF and the problem didn't go away.
I went through the whole truck fixing minor vacuum leaks (Testing with Mighty Vac, replacing fittings and hoses) and what not but the problem didn't go away. Replaced plugs, wires and fuel filter because I was out of ideas. It hurt me to do it but I brought it to a local mechanic and he couldn't figure out what was wrong with it. Brought it to the Ford dealer and they couldn't figure it out either but thought it was computer related. They wanted me to buy a $500 ECU with no guarantee that it would fix the problem so I picked it up. I found a dude on eBay offering ECU repair services. He said he'd diagnose it for $65 and give me a quote to do the repair not to exceed a total of $125. So, I sent it to him and he determined that it had bad capacitors. He repaired it for $100 and it was like a new truck. 40-50% faster, no stalling, no CELs, no fouled plugs for the rest of the time that I owned it. Here's why I mention this: The guy that repaired the ECU claimed that this problem was very common in the Ford ECUs that vintage due to a lot of bad capacitors on the market. They'd rupture, leak onto the board and cause loss of performance and erratic behavior. If you could get your hands on a known good ECU to test with it's likely about a 5-8 minute job to swap it in (That's how long it took on the Ranger). Before you spend money though I'd start with a compression test and look/listen for vacuum leaks around the engine bay. You might as well do the simple stuff too for good measure like the fuel filter and clean/replace the sparkplugs again. If that checks out then I'd explore the ECU/capacitor issue. |
Oh yeah, I checked fuel pressure on my Ranger too, even while driving, and everything checked out. I'd check yours though. You can get a gauge for about $30
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Also, if you're comfortable doing it you can pull your ECU and remove the metal housing. It should be pretty obvious if the capacitors are failing (I've seen it hundreds of times on desktop computers and even central AC systems). They're the little cylinders on the board. The tops should be perfectly flat, not domed up. If you see any stains on/around them or the tops are puffed up they are bad.
http://www.wheresmydrink.com/wp-cont...2009/capci.jpg http://www.instructables.com/image/F...-Capacitor.jpg |
That motor has a tendency to fill the catalytic converters when it isn't run hard. I suggest checking the Cats and be sure they aren't clogged. you can change them out fairly easily to a high flow cat that will allow the car to breathe better. You may also want to check your fuel flow rates. Change out the fuel filter and check the ECM with an ODB1 scan.
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Jeff, I have seen that problem on computers (dell) before. I know what to look for.
For now I am liking the filled Catalytic idea. About 4 months ago I had the heater core hose break, the one between the firewall and th back of the motor. Well after I replaced that hose the car would not ideal. It was really bad. I looked under the car and the passenger side cat was smoking hot (white). Anyway come to find out while fixing the heater hose I must have leaned on a vacuum line and broke it. That vacuum line went to some smog exhaust solenoid thingy. Once I put the new vacuum line on the car ran perfect. I also replace the plugs right after that just for good measure. At ideal now the car runs great. Just under a load its a dog. Can I buy a cheap OBD reader and get accurate codes? I do not have any check engine lights as of now. Thanks |
It SOUNDS like a fuel delivery prob. Sounds like the demand is to high for the dirty fuel filter. Change the fuel filter!! Jet
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Try these forums... You will get a lot more educated info quicker.
www.corral.net www.stangnet.com/mustang-forums www.mustangforums.com www.moddedmustangs.com/forums Do you see black smoke in your rearview mirrors where trying to accelerate? That will be a dead give away it's running too rich. Most everything I can think of that it might be should throw a code... i.e. MAF sensor, O2 sensors, MAP. It could possibly be cloged CATS, but being in CA you can't just yank them off like us Southerns can. You mentioned you replaced the plugs recently... I assume this was after the problems started getting bad. You may want to make positive you got the firing order correct as even one dead cylinder can cause lots of power loss. If you have the means, check the fuel pressure, you're regulator may have gone bad sending too much fuel pressure as well. Good luck with it! |
I have no advice for fixing your car but dang I love those fox body cobras. They are soooooo much better then any Mustang made since then. The 5.0 is awesome and there are so many things you can do to add HP. Love the car.
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I had a 1990 model 5.0 that had 185,000 miles on it. Before i sold it I replaced the ECU and it took care of the slugishness. You can pick up an ECU at most auto parts stores for around 100.00. Replacing is simple and probably worth your 100.00.
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This is the cyber version of raising the hood in your driveway and all the guy neighbors come by ...we cant help it.
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The fuel pump is a solid thought as are the cats. I will add one more thing, and ask if the timing has beed checked lately. If so, make sure the SPOUT (spark output jumper, little gray square attached near the distributor on its own 2 leads) is in, and possibly pull the distributor and check for excessive wear on the dizzy sproket. I have seen it be enough to throw off the timing and make a car run like crap. Easy start to that is take off the cap and wiggle the rotor, if there is excessive play, check the sproket.
Unless you live in emission controlled area, a catless H or X pipe is a completely horrible idea and should never be used because you will destroy the o-zone;):D Oh yeah and they are worth like 15 hp. |
I know this doesnt help much.. but that car with those wheels is one of my top three mustangs ever built... very nice ride.
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Me too. Totally love the fox bodies. would love to have an 86 svo or an 89 saleen for old times sake.
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I did notice the harmonic balancer was a little wabally when at idle. Can that effect the timing?
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I have a 95 cobra and have had similar problems and it was the MAF sensor. You can clean it but i've never had luck with that and had to replace 2, but others have. Crawl under and check the harmonic balancer to see if the rubber piece on the side closest to the engine is pulling out, that is a sign that the balancer is bad or going bad, this is pretty common of the 5.0 mustangs. I would also suggest a new cap and rotor and a set of wires. Don't get ford racing wires they are entirely too long for these cars and make your engine bay look bad.
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Vacuum advance problem?
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I would expect you should replace the balancer. Like brandon said, the rubber will start pushing out the back. It happens all the time on the 5.0s. The MAF sensor is another solid lead. You can take it out (in the intake tract, has a 4 wire connector flat going to it) and spray it down with either electrical contact cleaner or brake cleaner. I have always used brake cleaner myself.
Show, this car has electrical advance, load based. I also have a 95 (gt), had it for 7 years now. Great cars, great motor, mine is supercharged among other things. Good luck, keep up posted. |
Ok guys, I took the car to the local mechanic that I trust. I didn 't want to spend 5 hours trouble shooting my car when I could be watching the Sharks beat the Wings in an epic series.
Anyway turns out the mass air flow sensor needed to be cleaned. But then the car would not idle. So he hooked up and old 1993 code reader type device and reset the ECU to factory specs. OMG, my car is alive. It's sofa king fast again. I didn't realize how much the car slowed over the years. So thanks for all the help. The people who suggested the ecu and mass air flow sensor win the prize for being right. Thanks guys. |
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