4.7L Jumping Time
#11
10-02-2011, 06:16 PM
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Ok pulled the IAC and cleaned still ran the same. Had to hold it at 2k rpm to stay running. I pulled the connector off the IAC and still the same. Pulled the TPS sensor connector and it cranked up and ran fine idled at 500 rpm. Speedo is still sitting at 120 mph. Will replace TPS and see how it goes.
#14
10-23-2011, 08:09 AM
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Cleaned the TB, replaced the IAC, TPS. Checked all vacuum connections and load tested battery. Cranks and idles at 600 rpm cold, 700 hot. Test drove all ok until I hit the brakes, then it stalled. Had to hold gas to floor to crank. Then it idles at 300 a few minutes and comes back up to 700. Then all ok until I brake again. No check engine light. Any ideas?
#15
10-23-2011, 01:28 PM
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#16
10-24-2011, 05:47 AM
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Nope! Checked for vacuum leaks with starter fluid. Replaced check valve. At idle in park and neutral all ok. Even with brake pedal in. Drive it down road, press brake to slow or stop it cuts off, no matter the speed. Calling a junkyard today to see what scrap metal price is. Gonna find something else. Been under the hood of this thing since March. Sick of fooling with it.
#17
02-12-2019, 08:31 AM
if i were you (convinced that its a timing issue) id open it up and check the timing if you are so certain thats what it is, but i have never seen these engines jump time without breaking a tooth off the gear or damaged chain, when you put it on i believe you are supposed to rotate the engine twice to make sure the timing marks still line up correctly.
however other things that contribute to not running w/o your foot on the gas are weak battery (idc if its new, at the very least get it load tested, its FREE!!!!!!!!) a bad IAC motor will choke the engine out, a bad TPS will screw with the readings to the computer.
also check that all the sensors going into the top of the engine are in good and the connections are tight.
however other things that contribute to not running w/o your foot on the gas are weak battery (idc if its new, at the very least get it load tested, its FREE!!!!!!!!) a bad IAC motor will choke the engine out, a bad TPS will screw with the readings to the computer.
also check that all the sensors going into the top of the engine are in good and the connections are tight.
Last edited by davidpowell; 02-12-2019 at 08:33 AM. Reason: add on
#18
02-12-2019, 08:41 AM
I know that I'm way to late, but this may be of use to others searching for a fix to this problem!
When in doubt, run a compression test, if one whole bank is different than the other, then that is the side that either jumped time or damage to all valves!
Don't make the mistake that it can't jump time, it can jump one tooth and still run very rough and not do any damage to the valves or pistons.
I know I've got a lemon, but she rides nice!!!
When in doubt, run a compression test, if one whole bank is different than the other, then that is the side that either jumped time or damage to all valves!
Don't make the mistake that it can't jump time, it can jump one tooth and still run very rough and not do any damage to the valves or pistons.
I know I've got a lemon, but she rides nice!!!