The car was running great my battery went dead the other day and now the car is stumbling bad. It doesn't even sound the same at idle. It gets up and goes but really doesn't come alive till 5,000 rpm. I replaced the distributor cap and button with a MSD one yesterday and it seemed to help. The car is back firing in the headers from what I can tell. Its not bad just making a popping sound. A buddy on mine is goin to check my timing tomorrow. When I let off the gas pulling up to a redlight the rpm will go up to about 1,300 rpm or so before it drops to about 900 rpm. The car was idleing at about 700rpm when I bought it. Motor seems to be making like a ticking sound or something like that when driving normal at 2,000 to 2,500 rpm's. If I floor it at this rpm it stumbles bad and pops some till it hits 5,000 rpm then it hauls ass. I'm a extreme newbie to mustangs. What do you guys think? The car does have a pretty radical cam in it.
1993 LX 5.0 Stumbles till it hits 5,000 rpm then takes off?
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Your symptoms indicate that your charging system has gone south. The dead battery may have been only a indication that your alternator or some other portion of your charging system is hosed.
Check all your power and ground going to/from the battery and alternator. Have the alternator itself checked out.
Backfiring indicates an extremely rich condition caused by a partial combustion burn. A condition that can be created by a weak electrical system.
Check all your power and ground going to/from the battery and alternator. Have the alternator itself checked out.
Backfiring indicates an extremely rich condition caused by a partial combustion burn. A condition that can be created by a weak electrical system.
Ok well the charging system is working good now. I have had everything checked in the charging system or replaced. The alternator was checked and is fine. The battery was tested and is good. I fixed my problem with my gauge. Replace both alternator plugs and fuseable link. The car is running two electric fans on a looks to be stock electrical system. One in front of the radiator and one behind the radiator. The distributor cap and button I changed on it yesterday made a difference. The old buttom was rusted lookin and the cap had corriosion on the lil probes. You dont think it would have anything to with the distributor maybe having corrioded parts down in it? I told my buddy about in and he said the distributor must have got moisture in it. Sorry if the info I have given you is lame but I'm not a engine person I do lift kits on trucks mostly. And basic maintance.
You're running two electric fans from the stock 80 amp alternator and stock wiring?
I would characterise that as an "electrical problem". Neither the wiring or componenets were designed to handle that kind of a current draw. Aside from electrical gremlins, you also run the risk of having an under-hood fire from overloading the wiring and alt.
Try disconnecting those fans for at least long enough to drive the car around the block.
Also look at your plug wires and terminal ends. I don't see where you said you checked your power and grounds. Remove them, clean them and reinstall them. Checking a weak ground with a multi-meter is not an option.
I would characterise that as an "electrical problem". Neither the wiring or componenets were designed to handle that kind of a current draw. Aside from electrical gremlins, you also run the risk of having an under-hood fire from overloading the wiring and alt.
Try disconnecting those fans for at least long enough to drive the car around the block.
Also look at your plug wires and terminal ends. I don't see where you said you checked your power and grounds. Remove them, clean them and reinstall them. Checking a weak ground with a multi-meter is not an option.
FSTNG
New Member
it sounds like he is describing a lean backfire through the intake (sound coming from up front instead of out the tailpipe). The cause could be several different things, the only way to tell is just run through the basic diagnostics to check your electrical system like mentioned above, check your timing with the spout off, check your fuel pressure, check your ignition system (plugs/gaps, bad plug wires, coil). One thing that I would be sure to check is that your MAF is functioning properly, the connector is fully seated, etc. Just eliminate things one at a time until you find the culprit.
The other thing is that since your battery went dead, your adaptive tables in the EEC got reset so depending on your level of modifications it could take the computer some drive time to re-adjust itself again. I wouldn't think that it would cause a severe misfire like you describe though, unless you are running mismatched injectors/MAF.
I wouldn't drive the car until you fix the problem since running too lean/too rich (whichever the case may be) and misfiring is hard on a motor. I don't know if you are boosted or not but if so, it is especially important not to drive the car in boost at all.
The other thing is that since your battery went dead, your adaptive tables in the EEC got reset so depending on your level of modifications it could take the computer some drive time to re-adjust itself again. I wouldn't think that it would cause a severe misfire like you describe though, unless you are running mismatched injectors/MAF.
I wouldn't drive the car until you fix the problem since running too lean/too rich (whichever the case may be) and misfiring is hard on a motor. I don't know if you are boosted or not but if so, it is especially important not to drive the car in boost at all.
02 sensons were just replaced according to the guy I bought the car from and looking under the car they look new. I pulled a spark plug today and looking at it and it looked good. Like I said I will be getting a friend who drag races and builds motors to check the timing and maybe he can give me some clues on the problem. It just kinda funny that the car was running perfect then all the sudden runs like crap. The is car has no power adder. The motor has a pretty hard hitting cam and runs great. But is stumbling now at lower rpms. The fuseable link by the battery I replaced it. The stock one is 26 amp. I couldn't find a 26 amp so I replaced it with a 30 amp. But that wasn't the problem so I will be putting the 26 back on tomorrow for safety. I know about the problems from to small of wires and to high of current draw. I'm a Hvac Tech. This might be a stupid question but how would it be the electric system if the car runs perfect at once it hits about 5,000 rpm's? You can just feel the car kinda jerking a lil if you get down on it at lower rpm's. I'm going to rewire the fans in a differnt way so I can toggle them off. Right now they way in which they are wired they run all the time. Once you run the key on the fans come on. Thanks again for all the info. I will be upgrading the wiring soon after reading about the charging system and wiring.
Aight guys I had the timing checked by a buddy of mine today and he says its on where it needed to be. And told me he thinks my problem is fueling. If I run the car like I was at a drag strip then drive normal it smokes really bad like its fluiding with gas. I reved it up today in neutral after running it hard and it back fired pretty loud out the tail pipe. I talked to a performance center in mobile and the guy told me he could check the fuel pressure and on monday or tuesday. On a stock mustang can you hear the fuel pump come on with the key on before start up? Because you can hear mine. Once again I don't know what all the car has done to it. Thanks everyone for the help.
Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
See http://www.troublecodes.net/Ford/
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.
Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great. You watch the flashing test lamp or Check Engine Light and count the flashes.
See http://www.troublecodes.net/Ford/
If your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.
89 through 95 cars have a working Check Engine light. Watch it instead of using a test lamp.
Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.
Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.
For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.
Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.
I just came in the house from crawling under the car. I have noticed that the 02 sensors on the car have not been replaced like the guy told me they had and one of them as had the wires cut from it and rewired. They both look pretty beat up to so changing them will be my next thing to try. I try to check the codes and see what I get. Thanks for the help.
bloopbloob
Member
yes you can hear the fuel pump prime before you start the car.
if your car "comes alive at 5000rpms, then takes off", how far are you going!!!!!! what are you revving to??????
if your car "comes alive at 5000rpms, then takes off", how far are you going!!!!!! what are you revving to??????
O2's won't make your car run like that/
Dump the codes first instead of throwing money at the car.
Check your firing order first. Make sure each plug wire is running to where it should be.
Codes codes codes. They will give you a hint as to where to start.
BTW, how far are you revving if it comes alive at 5000RPM??
Dump the codes first instead of throwing money at the car.
Check your firing order first. Make sure each plug wire is running to where it should be.
Codes codes codes. They will give you a hint as to where to start.
BTW, how far are you revving if it comes alive at 5000RPM??
I was scrolling down to the bottom of the page to type that very same thing.
You need to exhaust the suggestion that you've got so far before looking for new.
The car doesn't have a rev limiter. I would say I'm reving it to about 6,500 rpm's. I bought a fuel pressure regulator today to and was hoping to change that but I don't have a tool that can get the screws it has out. I have a bit to fit the screws but nothing small enough to get in to turn it. I will try to check the codes tomorrow. I wasn't really throughing money at the car. While I'm looking for problems I might as well fix future problems I see. Just tring to do some over due maintance. The car has a racing tac in it with a shift light but it wasn't working so my buddy hooked it up and I set the shift light to 6,000 rpm.
Why don't you have a rev limiter?
WHat mods do you have done to the car? i think we need a list of mods to help you solve this problem any further.
If your car has stock heads and cam, revving to 6000 is a waste. 5200 is when the stock heads and cam stop breathing well, you should be shifting around 5400. In fact, saying the car pulls hard at 5000RPM makes me laugh because the 5.0 tends to start to wheeze about 5000RPM and up.
Factory rev limiter is 6250.
Safe to say we need some idea of what you have done to this car.
WHat mods do you have done to the car? i think we need a list of mods to help you solve this problem any further.
If your car has stock heads and cam, revving to 6000 is a waste. 5200 is when the stock heads and cam stop breathing well, you should be shifting around 5400. In fact, saying the car pulls hard at 5000RPM makes me laugh because the 5.0 tends to start to wheeze about 5000RPM and up.
Factory rev limiter is 6250.
Safe to say we need some idea of what you have done to this car.
You can make your check engine light flash the codes with a paper clip
http://www.corral.net/tech/maintenance/eecivtest.html
http://www.corral.net/tech/maintenance/eecivtest.html
Thats one of the problems I have is I dont know what all has been done in the motor of the car other than it has a hard loping cam. The car has a cobra intake, 70mm bbk throttle body with a cone filter. Thats only the things I can see. The motor doesnt start making power you can feel till like 3,000 and pulls really hard the higher the rpm's get up to about 6,500. I guess that could be b/c of the cam that the car has in it. I'm not an engine person I can just tell you how it drives. I have owned the car for about 2 to 3 weeks now. The car was bought from a car auction and I bought it two weeks later from the guy who bought it from the auction. So I dont know the who did the work to the car. The firing order is right and has been checked with a manual. Thanks for all the help.
