Engine missing
03-24-2009, 09:50 PM
#1
Engine missing
Ok I have a 94 F150 recently put another motor in it , new water pump , oil pump , timing chain , chain cover , new distributor cap , new ignition rotor , new plug wires , new spark plugs , new thermostat, all new vaccum hoses , all new seals throughout. Only thing I didnt do was the lower intake gasket and head gaskets. The problem is when you are driving it bogs down untill higher rpms, then it gets power , and when you are just giving it gas at cruising speed holding the throttle steady you can feel it missing or hesitating. I have a OBD1 tester and all codes are clear , only thing is when you are doing the key on engine running test it comes back cylinder 6. Then you can turn the engine off and turn it back on it and will say cylinder 8. Turn it off and start it again and it just goes back and forth. Ive checked all the injectors , checked to make sure it was getting spark on both. Only thing I havent done is a compression check on those two cylinders. Also I read in the ODB1 book that the timing being off could throw off the code reader. Could that maybe be the problem the timing just needing to be reset? Im going to run a compression check and timing check on it tomorrow if nothing else.
03-24-2009, 11:26 PM
#2
Senior Member
There's another thread that I just brought back to the top about a similar (maybe the same) issue. Is yours an automatic?
We've been through several things to check like u-joints, drive shaft balance, tranny service, VSS, RABS, etc. Maybe a few things to check out/think about...
I even ordered an additive called 'shudder fix' but I'm waiting to find out how much to add before trying it.
We've been through several things to check like u-joints, drive shaft balance, tranny service, VSS, RABS, etc. Maybe a few things to check out/think about...
I even ordered an additive called 'shudder fix' but I'm waiting to find out how much to add before trying it.
03-25-2009, 02:02 AM
#4
With the key on and the engine running and when you hit the test button on the code tester I have , it says Cyl 6 on it , then you can shut the truck off start it back up and it will say cyl 8. But with the Key on engine off test the codes come back clear. But in the book I have that came with the tester it says if the timing isnt correct then you wont get a correct reading with the key on engine running test. So I dont know , Im going to check the compression on both cylinders tomorrow and check the timing. I will keep you all posted.
03-25-2009, 04:55 PM
#6
http://www.amazon.com/Equus-3145-For.../dp/B000EW0KHW
Thats what Im using , you can do the key on engine off tests and it will give you number codes but they are all clear , but when the truck is running and you do the key on engine running test it comes back cylinder 8 , then u shut it off start it back up says 6 , then 8 lol ect... I checked the compression on both cylinders today both are good , brand new plug wires , plugs , disty cap , igition rotor , all that. ALso I reset the timing on it today it was off now it doesnt bog down like before. But Im still getting hesitation at just cruizing speed barily giving it gas it acts like its missing . I read somewhere the plug wires have to be ran a certain way or it can cause induction misfire, checked all those. Still cant figure it out , theres no check engine light or anything.
Thats what Im using , you can do the key on engine off tests and it will give you number codes but they are all clear , but when the truck is running and you do the key on engine running test it comes back cylinder 8 , then u shut it off start it back up says 6 , then 8 lol ect... I checked the compression on both cylinders today both are good , brand new plug wires , plugs , disty cap , igition rotor , all that. ALso I reset the timing on it today it was off now it doesnt bog down like before. But Im still getting hesitation at just cruizing speed barily giving it gas it acts like its missing . I read somewhere the plug wires have to be ran a certain way or it can cause induction misfire, checked all those. Still cant figure it out , theres no check engine light or anything.
03-27-2009, 02:27 PM
#7
Ok I think I might have it narrowed down now. Its throwing code 334 EGR closed-valve voltage higher than expected , before it through another code for the EGR I cant remember what, but it was EGR valve flow minimal , so I swapped it out with another EGR valve I had and I guess its bad. With that valve being closed do you think that could cause the engine to hesistate and jerk , it only hesitates and stuff when you are barily giving it gas just cruising, like I was saying above. What do you think guys?
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03-27-2009, 04:25 PM
#8
Senior Member
I'd think so - yours sounds a lot like mine - only at light throttle, only when it's warmed up, etc. During my EGR issues last fall, that's the symptoms I had, but much worse. I've thought that the EGR might be the case again, but didn't want to think about it. I checked for codes again last night, and got the EGR code 33 (movement not detected). I think mine is sticking a little bit at low throttle, but with more throttle/vacuum it opens up.
...might have been chasing the wrong tail all along.
...might have been chasing the wrong tail all along.
