I bought a totalled 03 Mach 1 which I did hear run perfectly before I purchased it. Got it home on the 8th and completely converted it by the 16th and took it to Ford for their brake bleeding machine. All computers, wiring, whole dash, total drivetrain, etc. The only thing remaining was the body of the 99, lights, speakers, only the passenger door wiring for the lock/window, and the ventililation system. I did reuse the A/C compressor from the GT and did not depressureize the A/C system. All goes back together perfectly. Car runs like a scalded dog, for a few days, about 150 miles. Then the problem. It at first didnt want to start in the morning. It was parked in my driveway which is somewhat steep, car facing uphill with about 1/8th of a tank, which was transplanted from the Mach also. I at first thought ok low fuel and its all in the back of the tank. I add about three gallons right there in the driveway. Car starts and I think all is OK. Go fill up, 93 oct and off I go. Next day I try to start in the morning and does start (parked in Driveway on same hill) but it cannot stay running if Im not pushing the throttle. If I push pedal fast it bogs and want to shut off, push gradually and it almost seems fine. Manual trans by the way. While I am trying to keep it running, the odometer is randomly dimming and disapearing back and forth. CEL comes on. I reset comp (disconnect pos and neg for 30+mins. Starts and goes perfectly. Next morning same thing. I reset comp but this time it is not going for the reset comp thing. When I turn the headlights on the odo brightens right up and quits dimming every time but the idleing problem is unaffected by turning the lights on. I am no wizard but it kinda looked like I was having a ground problem and being aware of how important grounding is I tool the time to use a dremel with a wire wheel and cleaned all the underhood ground wires and where they made contact with the body. On the driver side there is one under the rear seat, one attatched to the engine and going to the frame by the driver side wheel. Under the hood there are four, two in front of the battery, one on the opposite side of the radiator on the passenger side and one going from the hood to the hood hinge, I did not use the hood hinge ground and dont think it is part of the prob cause it is just for the underhood light which is not there. The only other one is the one going through the passenger firewall behind the fender with 4 other plugs, one of which goes to the main computer at the passenger footwell. THIS GROUND WIRE from the 03 Mach 1 wiring loom was odd to me. It was not grounded in the Mach. I didnt know this beforehand but when taking all the wiring out I did notice the single black wire was there but not grounded, nor was the end of the wire there for the green bolt to go through. I took same black wire off the GT wiring, tied together and heat shrunk it into perfection. I noticed that the wire seemed corroded (dull brown copper strands of wire instead of shiny) no matter how far up the wire I cut on the Mach wiring to add my GT end. After this problem I took a new wire and grounded the chassis of the comp directly from one of the corner 5.5mm nuts to the same green grounding bolt behind the passenger kick panel. About a 8 inch long pc. Reconnect battery, non change. Clean MAF sensor with a carb type of cleaner and the little silver "wires" were visibly cleaner. Reconnect battery, start, no change. Clean EGR, reconnect bat, start, no change. Remove PCV and shake it, ball moves freely. So the car still starts, I have to pedal it to keep it going, while it is running the odometer still dims, disappears, and turning even just the parking lights on stops the odo problem but the idle still is unaffected. I admit, although my wife (she did help ALOT) and I took on a huge project, it is quite simple to just gut a car and start moving pcs from the other car one pc at a time. I do not know where the IAC is to try to clean it as unbelieveably I have no manual for working on the car. I am going to replace the fuel filter tomorrow but I doubt that is the real problem. I would upload a pic but it keep saying "upload failed" and gives no reason. Any help is appreciated
99 GT, rough idle after 03 Mach 1 transplant
- Thread starter l8rg8rz
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wmburns
SN Certified Technician
Likely you have damaged the MAF by cleaning with carb style cleaner. The sensor is easily damaged by harsh cleaners and should NEVER be cleaned with anything except cleaner made for the purpose. Try disconnecting the MAF electrical connector. Does this improve starting?
The bogging down may be because the MAF has been damaged and the PCM is using default data to replace the missing/bad sensor data.
Today's cars WILL NOT run correctly without a stong battery and charging system. Connect a volt meter to the battery. Post the voltage at idle and 2k RPM's.
Confirm that you re-installed the ground strap from the Left motor mount to the car frame rail (from your post it appears so).
Read the following from Post #3. The IAC is on the throttle body near the butterfly valve.
http://www.stangnet.com/mustang-forums/810729-starts-but-dies-idle-help.html
Turn the key on/off several times without starting. Does this improve starting?
Crack the throttle half way open. Does this improve starting?
Being parked on a hill should not cause this problem. Remember, the fuel system should remain pressurized after the car has shut down.
Also, try uploading the pictures one at at time. If they still will not upload, they are too big. Make them smaller.
The bogging down may be because the MAF has been damaged and the PCM is using default data to replace the missing/bad sensor data.
Today's cars WILL NOT run correctly without a stong battery and charging system. Connect a volt meter to the battery. Post the voltage at idle and 2k RPM's.
Confirm that you re-installed the ground strap from the Left motor mount to the car frame rail (from your post it appears so).
Read the following from Post #3. The IAC is on the throttle body near the butterfly valve.
http://www.stangnet.com/mustang-forums/810729-starts-but-dies-idle-help.html
Turn the key on/off several times without starting. Does this improve starting?
Crack the throttle half way open. Does this improve starting?
Being parked on a hill should not cause this problem. Remember, the fuel system should remain pressurized after the car has shut down.
Also, try uploading the pictures one at at time. If they still will not upload, they are too big. Make them smaller.
twogts4us
15 Year Member
I havent had time yet today to do much but I did take some pics I hope will show up. In the first one you see on a concrete floor, the removed and now unused 99 GT main computer harness wiring that was behind the passenger footwell. You will see three shiny 11 year old bare ends of copper wires. These are the ground, the two connected to the exposed/bare wire wrapped in silver "metallic type tape" are: one to the computer harness which is the third wire you see closest to the big plug which was accidentally cut, the other is the one which goes to the green bolt to ground the wire to the body behind the footwell. Which is what you now see in the second pic. The footwell with the 03 Mach 1 wiring. You can see at the bottom of the second pic the green bolt I refer to which is between the red wires and black covered wire loom. The Mach ran perfectly without this green bolt grounding the end of the wire. It was bare and unconnected in the Mach 1. I used the end of my GT wiring as it had the proper sized eyehole for the green bolt and shrunk wrapped them together. AFTER this problem started I then ran the GREEN wire you see going from the corner of computer chassis to the same green bolt. No change in how it ran. This is maybe because as you can see on the newer 03 wiring, the end of the ground wire seems to be corroded or something. I cut as close as I felt comfortable without getting into the elec tape of the wire loom trying to find shiny copper strands but there were none. Could this be my problem as it is the only ground wire between that point and the ground by the radiator on the passenger side? I disconnected the ground in the pic to show the difference in color of wire
View attachment 62406
View attachment 62406
wmburns
SN Certified Technician
The foil is the ground shield for selected sensors. It is there to reduce stay electrical signals from being introduced. Unlikely this is your problem. In any case, your repair should be effective.
Note, the PCM has multiple ground wires connecting to chassis ground.
IMO, you should diagnose this problem as a no-start problem. Think FAST. Fuel, Air, Spark, Timing.
Note, the PCM has multiple ground wires connecting to chassis ground.
IMO, you should diagnose this problem as a no-start problem. Think FAST. Fuel, Air, Spark, Timing.
Ok I added a much closer pic in my garage of the bad wire. Couldnt add here, said I used too much memory. I will fix it tomorrow as I feel I will probably have to remove the loom from the fender well to trace it all the way back to where I can get a perfect connection. This is also the body ground for the big square bolted plug that comes from the engine into the tight corner near the hood hinge on the passenger side, also, that is the only ground for the entire wire loom behind the pass fender plastic which passes thru hole into front eng area and includes the MAF, AC plug and cooling fan plug. What do you think would cause this problem as I dont want it to come back. I will also just go buy a MAF and stick it on since you feel I have most likely damaged it. I did spray quite a bit into it. :o) Oh well, the price of an education..I will post back tomorrow with results. Thank you Burns I will try your suggestions as well, they will be helpful if this ground is not the problem
twogts4us
15 Year Member
I'm placing my bet on a toasted MAF too. I dropped one a couple years ago and one of the wires broke. I didn't notice the break at first and went ahead and reinstalled it. I experienced the same issues that you've described. It'll start, but you'll have a hard time keeping it running. You can disconn the MAF and see if the problem is any different...I'd bet it is exactly the same, telling you the MAF is bad.
I did everything to create a good ground. All five grounds, frame to eng mt(driver side), two by battery, one by radiator and the one at passenger footwell were methidically cleaned , body surface to shiny metal and BOTH sides of the "eyelet" at end of wire and the base of the green bolt. Still same probs though with a short somwhere im sure. I cannot open the windows, the power seat only goes backwards. When I try to open window,move seat everything goes dim and the courtesy light will go off. Understand I can EASILY crank and crank, sometimes it wont start, with the headlights on, and then crank again to start. No battery charger has been put on the car to get it to start except at the dealer when they drained battery doing the brake flush 4 times. The battery has plenty of juice and the charging system seems ok (I will test tomorrow) because I have started the car at least 20 times since Thursday.
This is the ground wire to the computer. It was uncut in the pic showing it in the footwell. When I took the whole loom out thru the fender to fix the ground wire I could see was bad, I decided to cut this one and see how bad it was. Then I just took it out of the large plug that goes into computer and cut all the wire out of the insulation and as you can see it is black all the way to the pin. I replaced it with the 99 GT pin and put all together again and same problem. I didnt get MAF but it wouldnt be causing the dimming of everything when I try to open window or power seat. Power locks work fine though. It did run fine for about 30 seconds. The odo brightened up and everything (window,seat, snap accellerator and no bogging) worked fine. I got a lil woody thinking it was all good, then right back to the BS. Could this corrosion have worked its way into the computer and caused an intermittent ground issue within the computer?
This is the ground wire to the computer. It was uncut in the pic showing it in the footwell. When I took the whole loom out thru the fender to fix the ground wire I could see was bad, I decided to cut this one and see how bad it was. Then I just took it out of the large plug that goes into computer and cut all the wire out of the insulation and as you can see it is black all the way to the pin. I replaced it with the 99 GT pin and put all together again and same problem. I didnt get MAF but it wouldnt be causing the dimming of everything when I try to open window or power seat. Power locks work fine though. It did run fine for about 30 seconds. The odo brightened up and everything (window,seat, snap accellerator and no bogging) worked fine. I got a lil woody thinking it was all good, then right back to the BS. Could this corrosion have worked its way into the computer and caused an intermittent ground issue within the computer?
try unplugging the maf and running the car WITHOUT the maf plugged in..
You will be surprised how much time I have saved myself over the years doing that in the shop with symptoms like yours.
Just try it might not change anything but it's simple and takes 2 seconds
I have done what your doing right now on some bad problems, your thinking too much and taking wild stabs.. Just walk away for a second and get back to basics..
You will be surprised how much time I have saved myself over the years doing that in the shop with symptoms like yours.
Just try it might not change anything but it's simple and takes 2 seconds
I have done what your doing right now on some bad problems, your thinking too much and taking wild stabs.. Just walk away for a second and get back to basics..
nyuk98gt
15 Year Member
l8rg8rz:
How old is that battery? If it is more than about 3 or 4 years then it may be failing. If it is the battery out of the wrecked car, it may be damaged internally. The whole dim odo thing has me thinking that the battery is on its last legs. (I could be wrong but the battery is a big factor in the performance of our cars.)
In any case, I'm glad that your car is running well. That was some major surgery you performed (and successfully, at that).
HTH,
Chris
How old is that battery? If it is more than about 3 or 4 years then it may be failing. If it is the battery out of the wrecked car, it may be damaged internally. The whole dim odo thing has me thinking that the battery is on its last legs. (I could be wrong but the battery is a big factor in the performance of our cars.)
In any case, I'm glad that your car is running well. That was some major surgery you performed (and successfully, at that).
HTH,
Chris
twogts4us
15 Year Member
Bro - you stole my post (see above). Glad to see I was on the mark with you however...!
wmburns
SN Certified Technician
For a crank with no-start condition, there are relativaly few sensors needed to start the motor (many more are needed to run). Again, think FAST (Fuel, Air, Timing, Spark). Keep this post in mind should the problem return.
Do you have an ODB2 scanner? Can you monitor operational PID's? Monitor RPM's during cranking. Does it change? A faulty crank shaft position sensor can cause a no-start.
Check all of your fuses. Sometimes they can be hard to see from above. Recommend pulling each fuse one at a time and Ohm it out.
Inspect the crank shaft position sensor. Look for loose wires, bad connections, cracks, or anything else out of the ordinary.
What is the theft light doing? When the key is turned to "on", the theft light should go out after three seconds. Post.
Confirm fuel pressure. Best way is with an ODB2 scanner. Post the fuel pressure.
Confirm the MAF is sending a basic signal. Monitor air flow during cranking. Post the PID range during cranking.
Use a noid style test light to confirm if the COP are firing.
Use a noid style test light to confirm if the fuel injectors are firing.
+1 on the Battery. Vital the battery is good and strong.
I really feel that you have a couple of different problems that may or may not be related. The foil covering the DB and GY wires is the shield for the crank shaft position sensor. If you look at the wiring diagrams you will note that the foil is only grounded on one side. It does not carry a signal. Even if it is not connected, the sensor will still work (for the most part).
Do you have an ODB2 scanner? Can you monitor operational PID's? Monitor RPM's during cranking. Does it change? A faulty crank shaft position sensor can cause a no-start.
Check all of your fuses. Sometimes they can be hard to see from above. Recommend pulling each fuse one at a time and Ohm it out.
Inspect the crank shaft position sensor. Look for loose wires, bad connections, cracks, or anything else out of the ordinary.
What is the theft light doing? When the key is turned to "on", the theft light should go out after three seconds. Post.
Confirm fuel pressure. Best way is with an ODB2 scanner. Post the fuel pressure.
Confirm the MAF is sending a basic signal. Monitor air flow during cranking. Post the PID range during cranking.
Use a noid style test light to confirm if the COP are firing.
Use a noid style test light to confirm if the fuel injectors are firing.
+1 on the Battery. Vital the battery is good and strong.
I really feel that you have a couple of different problems that may or may not be related. The foil covering the DB and GY wires is the shield for the crank shaft position sensor. If you look at the wiring diagrams you will note that the foil is only grounded on one side. It does not carry a signal. Even if it is not connected, the sensor will still work (for the most part).
Bro - you stole my post (see above). Glad to see I was on the mark with you however...!
Yeah thats one of the first things I check with symptoms like his.
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