97 F150 4.2 Rough idle, Shakes/stalls at start sometimes
#16
12-14-2014, 07:58 PM
I had a mechanic fix this for me
My 97 4.2 , was doing the same thing, after reading numerous posts about the same issue, I found out that the vacuum hoses underneath the intake manifold on the passenger side came off their connections..... Not visible to the human eye...... I watched my guy fumble around with his fingers, ever since he reattached these hoses I have not had an issue at all...... Starts better, runs smooth, and gets great gas mileage.... @ 325500 km's.....
#17
01-22-2015, 02:51 AM
I think your on to it if there was no change when you pulled the plug ide go for it
Hello,
1997 F-150 4.2L
I have been trying to troubleshoot this problem for the past year without much luck, in fact it seems to be getting worse.
Recent mechanical history:
Hydrolocked, coolant in #1 and lower intake gasket replaced last year. Coolant temp sensor, idle air control IAC and intake temp sensor changed. Fuel filter changed. I also tested the throttle position sensor, coolant temp sensor and intake temp sensor with a multimeter and they were all in the normal range. I also replace one of the vac hoses on the intake manifold and inspected the others and they seem fine.
I swapped the coil pack for a new one and it made zero difference. I though I might have a problem with the EGR system so I spent a while troubleshooting that and everything seems to be working perfectly. I checked vacuum pressure at the intake manifold and I am getting a pretty steady 18.5-19.5 in. of pressure which is what a healthy engine should get and this hopefully also means that there aren't any vacuum leaks. I also cleaned the MAF with special CRC electronics cleaner and no difference. New spark plugs and wires. Finally I pulled the vacuum hose off the fuel pressure regulator and no change in how the engine was idling, does this mean the regulator could be bad? Its vacuum line is getting pretty good suction.
SYMPTOMS:
-The old autolight platinum plugs were pretty carboned up but the engine doesn't consume any oil so it must be running rich?
-No check engine light
-Rough idle (seems to be when warm, engine vibration almost seems like an occasional miss)
-about 1 out of every ten times I start it, it shakes violently and stalls after about 5 seconds. If you press the gas it usually will not stall.
-Poor gas mileage?
Any ideas? This is driving me crazy, I can't figure it out! Thanks
1997 F-150 4.2L
I have been trying to troubleshoot this problem for the past year without much luck, in fact it seems to be getting worse.
Recent mechanical history:
Hydrolocked, coolant in #1 and lower intake gasket replaced last year. Coolant temp sensor, idle air control IAC and intake temp sensor changed. Fuel filter changed. I also tested the throttle position sensor, coolant temp sensor and intake temp sensor with a multimeter and they were all in the normal range. I also replace one of the vac hoses on the intake manifold and inspected the others and they seem fine.
I swapped the coil pack for a new one and it made zero difference. I though I might have a problem with the EGR system so I spent a while troubleshooting that and everything seems to be working perfectly. I checked vacuum pressure at the intake manifold and I am getting a pretty steady 18.5-19.5 in. of pressure which is what a healthy engine should get and this hopefully also means that there aren't any vacuum leaks. I also cleaned the MAF with special CRC electronics cleaner and no difference. New spark plugs and wires. Finally I pulled the vacuum hose off the fuel pressure regulator and no change in how the engine was idling, does this mean the regulator could be bad? Its vacuum line is getting pretty good suction.
SYMPTOMS:
-The old autolight platinum plugs were pretty carboned up but the engine doesn't consume any oil so it must be running rich?
-No check engine light
-Rough idle (seems to be when warm, engine vibration almost seems like an occasional miss)
-about 1 out of every ten times I start it, it shakes violently and stalls after about 5 seconds. If you press the gas it usually will not stall.
-Poor gas mileage?
Any ideas? This is driving me crazy, I can't figure it out! Thanks
#21
02-18-2015, 01:30 AM
With that taken care of, assuming you have a 97-03 F-150, download the factory service manual here:
https://drive.google.com/file/d/0B52...ew?usp=sharing
If that doesn't answer your question, please start a new thread in the appropriate forum and someone will help you. Thank you. If you start a new thread, please provide your truck details (model, year, engine, etc.).
#22
08-05-2015, 01:55 AM
technical service bulletin for this problem
For anyone currently having trouble with these year model trucks ford issued a tsb a few years back concerning this..Your throttle body has a gasket behind it when this gasket breaks down or moves it causes a vacuum leak since this is where certain vacuums originate from..You need to check that gasket..Do a google search for the problem some guy has a video out about it.
#23
11-01-2015, 06:57 PM
[QUOTE=Okieboy;2834094]
Originally Posted by jeffceo
Hello,
1997 F-150 4.2L
I have been trying to troubleshoot this problem for the past year without much luck, in fact it seems to be getting worse.
Jeff, Whats the fuel pressure reading @ idle and then dead head pressure. If you install a fuel pressure gage @ the fuel rail, (You may have to remove the shrader valve) turn the vehicle to run but not start. Take that reading down. Then start the vehicle, check that reading, it should be primairly the same, then find the fuel return line to the fuel tank (rubber) and crimp it. Your readings usually double but you'll need to ask ford or a tech here @ this site. Ive seen 80psi on some vehicles it may be the same or close. 1.) What may be happening is your fuel pump is not meeting the demand for the engine @ idle. 2.) Or your IAC is playing and not allowing enought air to pass to keep engine @ idle? 3.) Possiable broke plug wire. #'s of thing right now, hard to say without seeing, but keep plugging @ it.
1997 F-150 4.2L
I have been trying to troubleshoot this problem for the past year without much luck, in fact it seems to be getting worse.
Jeff, Whats the fuel pressure reading @ idle and then dead head pressure. If you install a fuel pressure gage @ the fuel rail, (You may have to remove the shrader valve) turn the vehicle to run but not start. Take that reading down. Then start the vehicle, check that reading, it should be primairly the same, then find the fuel return line to the fuel tank (rubber) and crimp it. Your readings usually double but you'll need to ask ford or a tech here @ this site. Ive seen 80psi on some vehicles it may be the same or close. 1.) What may be happening is your fuel pump is not meeting the demand for the engine @ idle. 2.) Or your IAC is playing and not allowing enought air to pass to keep engine @ idle? 3.) Possiable broke plug wire. #'s of thing right now, hard to say without seeing, but keep plugging @ it.
#24
11-01-2015, 07:05 PM
Got an e250 5.4 was running rich so I replaced coil packs, fuel filter ,vacuums,plugs, 02 censors. Changed nothing running so rich it burns your eyes while driving it loses power and the engine shakes so I said the heck with the nickel and dime because the engine blew plugs and ticked. So I bought brand new engine put it in and new fuel injectors and to my unbelievable luck it didn't change a thing. It's driving me crazy the codes came up p1132 and p1152 it's has to be something simple at this point what is left to replace.
#25
11-01-2015, 07:14 PM