1993 mark viii problems......HELP!!

B

bryan9885

Registered
Hi everyone,
I have just purchased a 1993 mark, it has a couple of goodies on it but not a whole lot to my knowledge and the person i bought it from knew even less about the car then i did as he wasnt the one who did anything to the car, it has 135k miles it has a lms chip it it which i hear gives it about 20hp and firms the shifts right up, all 3 cats on it are new with 3inch exhaust back to 4 inch tips it also has k&n cone filter on it,i gotta say i love this car....when it runs right , every so often it will just crank and crank and just sputter like it wants to start but wont then when it finally does it runs like crap missfiring and popping through the exhaust but a few revs and it clears out and drives fine.....at least once a day it will be driving and lose all power for a second sometimes stall out but then start right back up like nothing is wrong and sometimes it wont stall at all but bog down then pick right back up as normal and for the life of me i cant figure out why because it has happened at all different times while driving it is like the ignition was just switched off for a second and then its back online, the other thing is my doors will randomly lock for no apparent reason and there is a fan or humming sound that randomly comes from my drivers door randomly starting to wonder if i bought the Lincoln version of Christine hahaha any help you could offer will be much appreciated :confused:
 
I'd remove the chip first and see how it runs then, it might have a bad connection.

If it still runs bad, I'd replace the wires and plugs if they look old.

Also, I'd check all the wire connections especially near the cone air filter.
 
Change the fuel filter and check the fuel pump delivery.

Oh, and... Welcome! :)
 
the wires are a fairly new set of ford racing wires, but i will have a look at replacing the fuel filter and see if that helps thanks for the input guys
 
You can also clean the LMS chip terminal where it connects, could have been in there for a while and the pins get corroded.

Welcome to the club, post some pictures in the new member section. :D
 
J said:
You can also clean the LMS chip terminal where it connects, could have been in there for a while and the pins get corroded.

Welcome to the club, post some pictures in the new member section. :D
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any idea where it would connect im really not sure? still new to these cars, but im mad at myself for taking so long to buy one
 
ok today replaced fuel filter ran fine for a few hours then pulled same problem but much worse took almost 25 mins for it to fire up im thinking cps sensor but no clue where it is on this car:confused:
 
bryan9885 said:
ok today replaced fuel filter ran fine for a few hours then pulled same problem but much worse took almost 25 mins for it to fire up im thinking cps sensor but no clue where it is on this car:confused:
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First we need to check for fuel pressure.

Locate the schrader valve on the forward end of the drivers side fuel rail and remove the cap. Cycle the key on/off (do not start) a few times to build fuel pressure. Use a rag to prevent fuel spray and depress the schrader valve plunger to check for presence of fuel pressure.

If no fuel pressure is present - the fuel pump is not working. If there is apparent fuel pressure, the Cam Position Sensor (CPS) is located behind the power steering reservoir on the front of the drivers side head. Oftentimes the harness connection can be faulty rather than the sensor itself.

The other intermittent cause is no spark - caused by a faulty Crank Position Sensor (CKS). It is located on the lower front corner of the block on the passenger side besides the AC compressor. Unplug the harness connector and check for corrosion. Clean and reconnect the harness connection and retest.

Both the CPS and CKS sensors are relatively inexpensive to replace.
 
driller said:
First we need to check for fuel pressure.

Locate the schrader valve on the forward end of the drivers side fuel rail and remove the cap. Cycle the key on/off (do not start) a few times to build fuel pressure. Use a rag to prevent fuel spray and depress the schrader valve plunger to check for presence of fuel pressure.

If no fuel pressure is present - the fuel pump is not working. If there is apparent fuel pressure, the Cam Position Sensor (CPS) is located behind the power steering reservoir on the front of the drivers side head. Oftentimes the harness connection can be faulty rather than the sensor itself.

The other intermittent cause is no spark - caused by a faulty Crank Position Sensor (CKS). It is located on the lower front corner of the block on the passenger side besides the AC compressor. Unplug the harness connector and check for corrosion. Clean and reconnect the harness connection and retest.

Both the CPS and CKS sensors are relatively inexpensive to replace.
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thank you i will be under the hood tomorrow, just want it to run right because i love driving this car it alot of fun :)
 
ok so......

ok so......

im really lost at this one right now, im not sure what im looking at is really my cks sensor as it looks to be connected directly to my a/c compressor is that the plug im looking for? either way i disconnected and reconnected the cam sensor and that has done nothing for my problem which is happening more frequent and is a real pain in the a** , i have also noticed my car seems to be running very rich my last tank of gas averaged 12.2mpg with a mixture of driving , and when it pulls it not wanting to start my car reeks of gas so i don't think fuel is a problem and i checked the schrader valve and it has pressure, it will fire for a second then immediately choke it self right out, then when it does start it runs horrible until i rev it a few times and clear it out then runs perfectly normal i really need to get this issue fixed because as of right now its a risk to take it anywhere and sometimes will almost completely kill the battery before it starts:mad:
 
You need to check your fuel pressure your pressure regulator could be letting too much pressure by and be causing you to push fuel past your injectors also unplug the vaccine line off of the fuel pressure regulator and see. If gas comes out of the hole its bad also did you pull the engine codes yet
 
kjm42 said:
You need to check your fuel pressure your pressure regulator could be letting too much pressure by and be causing you to push fuel past your injectors also unplug the vaccine line off of the fuel pressure regulator and see. If gas comes out of the hole its bad also did you pull the engine codes yet
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where is the fuel pressure regulator located? i am still very new to these cars
 
also i did pull the codes but i didnt do the goose test just started it up and pulled the codes but they came up as follows 116,411,538,536,543,632
 
kjm42 said:
You need to check your fuel pressure your pressure regulator could be letting too much pressure by and be causing you to push fuel past your injectors also unplug the vaccine line off of the fuel pressure regulator and see. If gas comes out of the hole its bad also did you pull the engine codes yet
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ok pull the hose with the car off, with it cold and running and with it at operating temp and running only thing it did was make my car idle up a little bit but there was no gas leaking from it, soo.....:confused:
 
Put a fuel pressure gauge on it and check the fuel pressure with the vacuum line disconnected from the pressure regulator.
 
Is your car a 93 those codes u posted are a obd2 codes the 95 and prior are going to have two digit codes not three digit. If these are. Your codes one of them says your fuel pump is not responding during testing from the pcm
 
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