I recently swapped out a blown motor in my 94 M8 and the newer engine has a miss every once in a while upon hard exceleration and alot of missing after 3500 rpm's. I can also feel a stummble just from a stop. I thought i put all the vacume ,ined on and it has a new battery, alternator and pigtail, new auto lite plugs, k&N cone filter stock maf, shaved intake tube, duel from front cats back with H pipe, new cam position sensor, new crenk position sensor,I swapped the coils wires and starter wire harness from the blown engine, the fuel injectors were also swopped with the rails, I also had to swap the throttle body over. I cleaned the intake with intake cleaned then lubed it with wd-40. When I put new plugs in it the #8 was whitish and theold ones were way over gapped. The car purs like a kitten and when in P it revs fine. I have had a spuratic problem whith cold starts not often. the car will run fine until i go to d then dies. I rev it and no more stall? I have run a self diagnostic test and it came back 133 I dont know if i am reading it wright because I cant find a 133 code. I have to get a code reader tomarow. I have not checked the fuel pressure though either the fuel filter was changed 6 months ago. I did accidentaly drop the fuel tank when I was removing the drive shaft. I had to man handle it back up and I really did not check it afterwards. what is the most effective way to check for vacume leaks? How do you test the fuel pressure and what is the fuel pressure supposed to be?
Hiccup/misfire at wot after 35000
- Thread starter junk mark
- Start date
RE: Hiccup/misfire at wot after 35000
Usually, a high speed miss is ignition related. I would suspect plug wires. What type of wires/plugs? Age? Mileage?
Look here... http://fordfuelinjection.com/?p=13 for how to run a self test to check for codes on an OBD-I without a code scanner.
Fuel pressure should be 39 psi at idle with vacuum disconnected from fuel pressure regulator. You can get a fuel pressure test guage from any auto parts store that will thread onto the schrader valve on the fuel rail.
Testing for vacuum leaks can be a tedious process. Old timers use methods utilizing propane or engine starting fluid, spraying at connections or other suspect areas while observing for a change in engine idle(obviously a potentially risk of fire). Modern shops use equipment such as a smoke machine. Either way, follow the vacuum schematic and systematically trace and check each circuit.
Usually, a high speed miss is ignition related. I would suspect plug wires. What type of wires/plugs? Age? Mileage?
Look here... http://fordfuelinjection.com/?p=13 for how to run a self test to check for codes on an OBD-I without a code scanner.
Fuel pressure should be 39 psi at idle with vacuum disconnected from fuel pressure regulator. You can get a fuel pressure test guage from any auto parts store that will thread onto the schrader valve on the fuel rail.
Testing for vacuum leaks can be a tedious process. Old timers use methods utilizing propane or engine starting fluid, spraying at connections or other suspect areas while observing for a change in engine idle(obviously a potentially risk of fire). Modern shops use equipment such as a smoke machine. Either way, follow the vacuum schematic and systematically trace and check each circuit.
RE: Hiccup/misfire at wot after 35000
picked up a code reader/tester/reseter. I cant use it tonight and I need to drive it cause I reset my codes yesterday when i was working on the alternator (disconnected my battery). have to wait till the daytime because there is a WOT test, that wont bode well with the neighbors. I will post more tomarow once I run all the tests. Yesterday something funny happened as I backed out of my driveway. The check engine light flashed 4 times and the car reved and idled down real low. ???????
I know it will end up being something really simple but expensive in the end. Again thanks for all your help. You guys are great.
picked up a code reader/tester/reseter. I cant use it tonight and I need to drive it cause I reset my codes yesterday when i was working on the alternator (disconnected my battery). have to wait till the daytime because there is a WOT test, that wont bode well with the neighbors. I will post more tomarow once I run all the tests. Yesterday something funny happened as I backed out of my driveway. The check engine light flashed 4 times and the car reved and idled down real low. ???????
I know it will end up being something really simple but expensive in the end. Again thanks for all your help. You guys are great.
RE: Hiccup/misfire at wot after 35000
replaced them both with a set off a 96 exployer 5.0
By the way I use outinbfe21 at home and junk mark at work.
I drove it about 40 miles today and ran a engine off test no codes. havent had a chance to do the other tests yet. will complete tomarow. I changed out the old plug wires and the car ran worse. I changed out the fuel rail and un tightened 4 upper intake bolts in the process any ideas on torque secs to see if I caused a leak. also the throttle boddy. My oil tem sensor is not working properly would this matter? The symptoms ar4e consistant from 700rpm to 1200 there is kindof a bog i can barely feel it, then when ever it goes above 4500 rpm it spits and spuuters but never before. I ran a few test runs today to see if I could generate a test light no luck but I dit get specifics on the symptoms. I put a gauge on the fuel rail this morning it read 40psi unplugged and 36 psi plugged in I will take get a scew on permanent type when I fing one. cool; stuff like that is hard to come by here in Minot ND. Could. Buy for now.
replaced them both with a set off a 96 exployer 5.0
By the way I use outinbfe21 at home and junk mark at work.
I drove it about 40 miles today and ran a engine off test no codes. havent had a chance to do the other tests yet. will complete tomarow. I changed out the old plug wires and the car ran worse. I changed out the fuel rail and un tightened 4 upper intake bolts in the process any ideas on torque secs to see if I caused a leak. also the throttle boddy. My oil tem sensor is not working properly would this matter? The symptoms ar4e consistant from 700rpm to 1200 there is kindof a bog i can barely feel it, then when ever it goes above 4500 rpm it spits and spuuters but never before. I ran a few test runs today to see if I could generate a test light no luck but I dit get specifics on the symptoms. I put a gauge on the fuel rail this morning it read 40psi unplugged and 36 psi plugged in I will take get a scew on permanent type when I fing one. cool; stuff like that is hard to come by here in Minot ND. Could. Buy for now.
RE: Hiccup/misfire at wot after 35000
sorry to ask so many questions and thank you for being so helpful. I put the new 8mmm premium plug wires on it swapped the intake tube gasket and air temp sensor, coils, plugs, oil sensor, fixed a huge vacume leak and replaced all the rubber connections I could. It runs alot better but it still has a slight stumble off the start and the popcorn maker sound waaaaapopopwaaaaaaapop. I checked the IMRC's and they function good and fast responce to the throttle. I also put a buddies cheep fuel gauge on it for a few minutes. It read 36 reg and around 40 with the hose off. I recleaned the throttle body and intake with spray cleaner. The only codes I got in the this week were lean reading from the O2 sensor and a manual lever input higher aor lower than expected? both only showed up once then went away. I think the lean was due to the vacume leak on the vacume line and a bad seal on the intake tube. My wife says sell but I want to fix it. Like I said before it runs alot better but it still has issues. The Air Intake Motore works fine too
PS is there any test for WOT and other fuel pressures? to see if it drops or raises however it works?
Thanks again for all your patients and help.
sorry to ask so many questions and thank you for being so helpful. I put the new 8mmm premium plug wires on it swapped the intake tube gasket and air temp sensor, coils, plugs, oil sensor, fixed a huge vacume leak and replaced all the rubber connections I could. It runs alot better but it still has a slight stumble off the start and the popcorn maker sound waaaaapopopwaaaaaaapop. I checked the IMRC's and they function good and fast responce to the throttle. I also put a buddies cheep fuel gauge on it for a few minutes. It read 36 reg and around 40 with the hose off. I recleaned the throttle body and intake with spray cleaner. The only codes I got in the this week were lean reading from the O2 sensor and a manual lever input higher aor lower than expected? both only showed up once then went away. I think the lean was due to the vacume leak on the vacume line and a bad seal on the intake tube. My wife says sell but I want to fix it. Like I said before it runs alot better but it still has issues. The Air Intake Motore works fine too
PS is there any test for WOT and other fuel pressures? to see if it drops or raises however it works?
Thanks again for all your patients and help.
RE: Hiccup/misfire at wot after 35000
The only way I know to check fuel delivery under load is to drive the car with a fuel pressure guage with a extension hose temporarily hooked up to the schrader valve and the guage remotely mounted taped to the windshield. For safety's sake, have a passenger monitor the fuel pressure while you drive WOT under load. If you had 40 psi with the vacuum disconnected from the fuel regulator, you should have 40 psi fuel pressure under load at WOT.
I wonder... what computer do you have in the car? The original or the one from the swapped motor?
The only way I know to check fuel delivery under load is to drive the car with a fuel pressure guage with a extension hose temporarily hooked up to the schrader valve and the guage remotely mounted taped to the windshield. For safety's sake, have a passenger monitor the fuel pressure while you drive WOT under load. If you had 40 psi with the vacuum disconnected from the fuel regulator, you should have 40 psi fuel pressure under load at WOT.
I wonder... what computer do you have in the car? The original or the one from the swapped motor?
RE: Hiccup/misfire at wot after 35000
It is the cars original CPU not the swapped one. I had to rewire an O2 sensor to put a new plug on it cause the old one got crushed. I was sure I matched the wires up but they were kindof dirty. I will recheck. I am going to run more tests on the car tonight at work. I ran a cylider bank test and it came back 90 wich is normal all cylinders contributing equally. I started it cold tonight and it still flashes the check engine light four times then idle up then down???? I will do the fuel test tomarow.
It is the cars original CPU not the swapped one. I had to rewire an O2 sensor to put a new plug on it cause the old one got crushed. I was sure I matched the wires up but they were kindof dirty. I will recheck. I am going to run more tests on the car tonight at work. I ran a cylider bank test and it came back 90 wich is normal all cylinders contributing equally. I started it cold tonight and it still flashes the check engine light four times then idle up then down???? I will do the fuel test tomarow.
RE: Hiccup/misfire at wot after 35000
Do you have the swapped computer? If you do, I would try it but have no idea if it makes a difference.
I've never heard of the CEL flashing repetively like that... I almost think it's a "CPU" problem. Kind of like how a PC motherboard beeps on hard errors.
Do you have the swapped computer? If you do, I would try it but have no idea if it makes a difference.
I've never heard of the CEL flashing repetively like that... I almost think it's a "CPU" problem. Kind of like how a PC motherboard beeps on hard errors.
RE: Hiccup/misfire at wot after 35000
I do not and the original car is long gone. What would happenned if I hooked up the o2 sensor wire wrong? Also when I was uner the car I noticed my fuel pump wirer used to hang dow but the wires and connector got put up between the tank and tha body. I will lower it check the connector for damage and rehang it. This morning I drove it hard when it was cold. If it did miss it was not noticable. As it got warmer it got worse. I have read the CE light flashes when there is something wrong and it could hurt your cats. all i have found.
Recap the details.
1. High RPM missfire 3500 and up under load
2. just after starting (mostly cold under the Normal line)car between 10 and 30 secoonds CE light will flash 4X's and turn off
car will idle way up and die or die when i put it in drive
3. no permanent codes stored
4. very slight (barely noticable) stumble off start from stop or slow speed
5. Gas MPG suck
Other than that it idles and runs great up to 3500 rpm still chirps second and pulls hard up to that point. warmer=worse
what I have done
1. New plugs
2. new wires 8MM
3. swapped coils
4. swapped throttle body and TPS
5. swapped air temp sensor
6. new PCV
7. replaced most of the larger vacume line and fixed broken small lines
8. replaced broken O-2 sensor femele plug end on passenger side
9. bought code reader onle codes I received were
A. MPL out of range. Adjusted and good
B. O-2 Sensor lean signal
10. ran KOEO passed no codes
11. ran KOER passed no codes
12. fuel injector bank test all passed
13. all fuel injectors and coil have power
14. static fuel pressure test good
15. idle fuel pressure test 36 PSI with vacume and 39 to 40 without vacume line.
16. change oil temp sensor
17. clean the intake several times it is still a little dirty
18 added acetone to the tank to clean out the fuel system
19 retorqued throttle body bolts
20. retorque intake bolts
21. swapped fuel injectors from old engine doner engine injectors fell apart.
22. while running imrc open an close quickly with no sticking
23. new crank sensor
24. cam sensor only 3 months old off the old engine, same side as broken chain on old motor (Need to check it)
Things to do yet
1. test resisatance of fuel injectors
2. vaume test
3. full load (driving) fuel pressure test
4. check egr for sticking
5. change fuel filter
6. test restitance hot/cold other sensors
Any ideas would be greatly apreciated if I have missed something
I do not and the original car is long gone. What would happenned if I hooked up the o2 sensor wire wrong? Also when I was uner the car I noticed my fuel pump wirer used to hang dow but the wires and connector got put up between the tank and tha body. I will lower it check the connector for damage and rehang it. This morning I drove it hard when it was cold. If it did miss it was not noticable. As it got warmer it got worse. I have read the CE light flashes when there is something wrong and it could hurt your cats. all i have found.
Recap the details.
1. High RPM missfire 3500 and up under load
2. just after starting (mostly cold under the Normal line)car between 10 and 30 secoonds CE light will flash 4X's and turn off
car will idle way up and die or die when i put it in drive
3. no permanent codes stored
4. very slight (barely noticable) stumble off start from stop or slow speed
5. Gas MPG suck
Other than that it idles and runs great up to 3500 rpm still chirps second and pulls hard up to that point. warmer=worse
what I have done
1. New plugs
2. new wires 8MM
3. swapped coils
4. swapped throttle body and TPS
5. swapped air temp sensor
6. new PCV
7. replaced most of the larger vacume line and fixed broken small lines
8. replaced broken O-2 sensor femele plug end on passenger side
9. bought code reader onle codes I received were
A. MPL out of range. Adjusted and good
B. O-2 Sensor lean signal
10. ran KOEO passed no codes
11. ran KOER passed no codes
12. fuel injector bank test all passed
13. all fuel injectors and coil have power
14. static fuel pressure test good
15. idle fuel pressure test 36 PSI with vacume and 39 to 40 without vacume line.
16. change oil temp sensor
17. clean the intake several times it is still a little dirty
18 added acetone to the tank to clean out the fuel system
19 retorqued throttle body bolts
20. retorque intake bolts
21. swapped fuel injectors from old engine doner engine injectors fell apart.
22. while running imrc open an close quickly with no sticking
23. new crank sensor
24. cam sensor only 3 months old off the old engine, same side as broken chain on old motor (Need to check it)
Things to do yet
1. test resisatance of fuel injectors
2. vaume test
3. full load (driving) fuel pressure test
4. check egr for sticking
5. change fuel filter
6. test restitance hot/cold other sensors
Any ideas would be greatly apreciated if I have missed something
RE: Hiccup/misfire at wot after 35000
unpluged the o2 sensor I rewired and the CE light did not flash so I will rewire it any body help me with the colors because the wires are slightly different colors. dont know why though. maybe they faded in the junk yard.
update tomarow.
unpluged the o2 sensor I rewired and the CE light did not flash so I will rewire it any body help me with the colors because the wires are slightly different colors. dont know why though. maybe they faded in the junk yard.
update tomarow.
RE: Hiccup/misfire at wot after 35000
second start with o2 sensor unplugged no flasshing light although when motoe went to open loop the CE came on steady. it ran better than before but it still had the studder. will be picking up o2 sensors and plug today and replacing Coolant temp sensor.
second start with o2 sensor unplugged no flasshing light although when motoe went to open loop the CE came on steady. it ran better than before but it still had the studder. will be picking up o2 sensors and plug today and replacing Coolant temp sensor.
RE: Hiccup/misfire at wot after 35000
[div class="dcquote"][strong]Quote[/strong]
unpluged the o2 sensor I rewired and the CE light did not flash so I will rewire it any body help me with the colors because the wires are slightly different colors. dont know why though. maybe they faded in the junk yard.update tomarow.
[/div]
http://www.lincolnsclub.org/forum/user_files/1904.jpg
[div class="dcquote"][strong]Quote[/strong]
unpluged the o2 sensor I rewired and the CE light did not flash so I will rewire it any body help me with the colors because the wires are slightly different colors. dont know why though. maybe they faded in the junk yard.update tomarow.
[/div]
http://www.lincolnsclub.org/forum/user_files/1904.jpg
RE: Hiccup/misfire at wot after 35000
pulled the o2 wire and the grey yellow wire hwas coroded terninal and green blue goup on it the rest were clean. did not start it cause its in the garage uner the bedroom also all the wires were hooked up properly. I changed the coolant tmp sensor. I talked to an ex ford repairman that spesializes in fords and he said he would swich all the sensors off the old engine because some of them are different and the sensors are different ???? Most of the sensors on the 4.6 are interchageable I thought. I also dropped the tank down a little and cleared the wires. I have to get under there in the daytime to see if I messed something up when the tank dropped on me during the engine swap Dropped it to pull the drive shaft. It fell 3 feet and the hoses caught it. can anyone point me to a freindly dealer or mechanic that can advise me on the flashing light? it flashes 4 times just after a cold start. I still need to do the o2 sensors. thay were bad prior to the engine swap. the car does not throw a code but when it was on the machine at the shop for a transmision problem it gave me a cam position sensor bad I fixed that and was about to get the O2 sensors and the engine blew. The mechanic also said the car probably stored a code when the engine blew and its causing havoc on the new engine. aaaaaahhhhhhhrrrrrrg as charly brown would say.
pulled the o2 wire and the grey yellow wire hwas coroded terninal and green blue goup on it the rest were clean. did not start it cause its in the garage uner the bedroom also all the wires were hooked up properly. I changed the coolant tmp sensor. I talked to an ex ford repairman that spesializes in fords and he said he would swich all the sensors off the old engine because some of them are different and the sensors are different ???? Most of the sensors on the 4.6 are interchageable I thought. I also dropped the tank down a little and cleared the wires. I have to get under there in the daytime to see if I messed something up when the tank dropped on me during the engine swap Dropped it to pull the drive shaft. It fell 3 feet and the hoses caught it. can anyone point me to a freindly dealer or mechanic that can advise me on the flashing light? it flashes 4 times just after a cold start. I still need to do the o2 sensors. thay were bad prior to the engine swap. the car does not throw a code but when it was on the machine at the shop for a transmision problem it gave me a cam position sensor bad I fixed that and was about to get the O2 sensors and the engine blew. The mechanic also said the car probably stored a code when the engine blew and its causing havoc on the new engine. aaaaaahhhhhhhrrrrrrg as charly brown would say.
RE: Hiccup/misfire at wot after 35000
I use this site as a cross reference for sensors...
http://www.smpcorp.com/web_app/catalog/publiccatalog.asp
I use this site as a cross reference for sensors...
http://www.smpcorp.com/web_app/catalog/publiccatalog.asp
RE: Hiccup/misfire at wot after 35000
cool site, reconected the O2 sensor the wireing was correct. car still starts CE lite flashes then idles up. bog off start has gotten worse. I will be redoing the fuel injectors and getting new seals. pulling them cleaning and checking the injectors. all the injectors are getting power and are pulsing. the same for the coils. I untangled the fuel pump wire and I still need to free the rest of the wires back there and check all the hoses for cracks and for disconects or pinched hoses. I have had no time to do anything the last couple weeks.
I will also put the old cam and crank position sensor and puttin a new gasket on the throttle body, because I used an old one in my haste toi finish (I know stupid move not the first and definately not my last)
What is the best way mechanic wise to find out what is wrong with my car a full ford diagnotic $75+tax, mechanic with a dynotuner est $80 an hour + tax, or a regular laptop style or small standalone tester $35+tax, because there is nothing I hate worse than waisting my time and the little money I have to fix it. The Ford dealership does not know about the car and does not work on cobra's or sell too many. most of the parts I have tried to get are disconnected.
cool site, reconected the O2 sensor the wireing was correct. car still starts CE lite flashes then idles up. bog off start has gotten worse. I will be redoing the fuel injectors and getting new seals. pulling them cleaning and checking the injectors. all the injectors are getting power and are pulsing. the same for the coils. I untangled the fuel pump wire and I still need to free the rest of the wires back there and check all the hoses for cracks and for disconects or pinched hoses. I have had no time to do anything the last couple weeks.
I will also put the old cam and crank position sensor and puttin a new gasket on the throttle body, because I used an old one in my haste toi finish (I know stupid move not the first and definately not my last)
What is the best way mechanic wise to find out what is wrong with my car a full ford diagnotic $75+tax, mechanic with a dynotuner est $80 an hour + tax, or a regular laptop style or small standalone tester $35+tax, because there is nothing I hate worse than waisting my time and the little money I have to fix it. The Ford dealership does not know about the car and does not work on cobra's or sell too many. most of the parts I have tried to get are disconnected.