I have struggled with this intermittent problem for a year now and this is my daily driver. Luckily I am currently working from home and have been able to get by.
The Problem:
Intermittently, as in driving for three days 100 miles with maybe 20 starts and stops with no problems. Then while driving or at a stop, it will start to have a feeling of cutting out at any and all speeds. It slowly progresses for a few minutes to cut out and buck and backfire if you stay in or just touch the throttle. It gets worse over about a minute till you are at idle, trying to limp along. You can turn it off and let it sit for hours or a day and it will still do it immediately upon start-up. Other times you start it up and it will drive fine for a few days. Most of the vehicle is replaced or rebuilt at this point. (List below) With adjustments and part replacements, I seem to get a few days of hope that I have found the issue and it runs perfectly. >>>>> Then it just repeats. Cruising along and starts to stutter and progresses as described.
I have dropped it at shops for weeks at a time without it doing the failure mode for them. One shop said it had low compression and vacuum leaks around the Intake manifold. The next shop found good compression and ok via leak down test and no vacuum leaks and did multiple test drives without the issue occurring.
Vehicle run down. Started as a brilliant plan in the pandemic to get a rust-free Bronco from AZ where my son lives and build it up versus the impossibility of buying a Gen6. Well, we bought a disaster. A year and a half later flew out and drove it back with my son with only a little difficulty. (Loud, C6, One breakdown, Super high Idle, broke in engine rebuild) Drove about another 4,000 miles without this issue trying to figure out idle and other issues. Then it started this horrible issue.
Mechanical work done that I think could be pertinent to the problem. Leaving endless mostly cosmetic stuff off:
-Engine rebuilt in AZ by local shop; standard cam, nothing fancy; Was timed wrong when installed and got hot enough to melt the paint off new headers and melt the airpump emission parts. (AC box melted) (Yes I should have never accepted the vehicle but had just flown out from NY to AZ when was filled in properly)
-Injectors refurbished
-numerous parts were replaced in the rebuild; from the water pump to the radiator; the fuel system was cleaned out and replaced pump(s) and filter were also.
-Airpump system was removed and plugged out. TAD and TAB block outs installed. Fivologyracing.com
-New exhaust headers installed, New exhaust and new CAT.
-C6 rebuild
-Rear axle rebuild
-Ignition tumbler
-backup lights switch was bypassed due to not being able to get the OEM switch anymore.
-The TFI on the distributor changed
-Engine Coolant Sensor
-Throttle Air Bypass Solenoid
-TPS (Still working to adjust properly but running at .8V with higher idle than desired. Going to drill out TPS next to make it adjustable enough to have right volts and good idle. )
-Got refurbished computer. (I thought that was the issue and it ran great for a week. Better than before so may have been some issue there)\
-MAP Sensor replaced. (Helped for a couple of days)
Tests done that I think are of interest:
-Fuel pressure good per shops
-removed O2 sensor and drove to test if cat restricted
-timing checked and set a couple of times. (Distributor had been installed a tooth of and had to be moved)
-Removed battery cable/ power for a few minutes. Re-attach, and it will sit and warm up for ten minute and then you get about 60 seconds of pure perfect acceleration or regular driving and then you are violently back to limp mode. (This one leads me back to sensors and being outside of the computers acceptable program/chart)
-Removed different sensors and drove without them with Check engine light on: TPS; Temp sensor. etc. Seems to help at times but not others! Now not helping.
I am thinking I have some sensor intermittently sending bad news to the computer and it shuts off the ability to run. What sensor could it be???
HELP
Still To be done:
-The steering column could use some attention/rebuild etc. (Mention due to ignition is a little touchy in that you have to manually move it to the right spot by feel.)
-Springs and shocks could use a refresh
-ETC. ETC. ETC.........
The Problem:
Intermittently, as in driving for three days 100 miles with maybe 20 starts and stops with no problems. Then while driving or at a stop, it will start to have a feeling of cutting out at any and all speeds. It slowly progresses for a few minutes to cut out and buck and backfire if you stay in or just touch the throttle. It gets worse over about a minute till you are at idle, trying to limp along. You can turn it off and let it sit for hours or a day and it will still do it immediately upon start-up. Other times you start it up and it will drive fine for a few days. Most of the vehicle is replaced or rebuilt at this point. (List below) With adjustments and part replacements, I seem to get a few days of hope that I have found the issue and it runs perfectly. >>>>> Then it just repeats. Cruising along and starts to stutter and progresses as described.
I have dropped it at shops for weeks at a time without it doing the failure mode for them. One shop said it had low compression and vacuum leaks around the Intake manifold. The next shop found good compression and ok via leak down test and no vacuum leaks and did multiple test drives without the issue occurring.
Vehicle run down. Started as a brilliant plan in the pandemic to get a rust-free Bronco from AZ where my son lives and build it up versus the impossibility of buying a Gen6. Well, we bought a disaster. A year and a half later flew out and drove it back with my son with only a little difficulty. (Loud, C6, One breakdown, Super high Idle, broke in engine rebuild) Drove about another 4,000 miles without this issue trying to figure out idle and other issues. Then it started this horrible issue.
Mechanical work done that I think could be pertinent to the problem. Leaving endless mostly cosmetic stuff off:
-Engine rebuilt in AZ by local shop; standard cam, nothing fancy; Was timed wrong when installed and got hot enough to melt the paint off new headers and melt the airpump emission parts. (AC box melted) (Yes I should have never accepted the vehicle but had just flown out from NY to AZ when was filled in properly)
-Injectors refurbished
-numerous parts were replaced in the rebuild; from the water pump to the radiator; the fuel system was cleaned out and replaced pump(s) and filter were also.
-Airpump system was removed and plugged out. TAD and TAB block outs installed. Fivologyracing.com
-New exhaust headers installed, New exhaust and new CAT.
-C6 rebuild
-Rear axle rebuild
-Ignition tumbler
-backup lights switch was bypassed due to not being able to get the OEM switch anymore.
-The TFI on the distributor changed
-Engine Coolant Sensor
-Throttle Air Bypass Solenoid
-TPS (Still working to adjust properly but running at .8V with higher idle than desired. Going to drill out TPS next to make it adjustable enough to have right volts and good idle. )
-Got refurbished computer. (I thought that was the issue and it ran great for a week. Better than before so may have been some issue there)\
-MAP Sensor replaced. (Helped for a couple of days)
Tests done that I think are of interest:
-Fuel pressure good per shops
-removed O2 sensor and drove to test if cat restricted
-timing checked and set a couple of times. (Distributor had been installed a tooth of and had to be moved)
-Removed battery cable/ power for a few minutes. Re-attach, and it will sit and warm up for ten minute and then you get about 60 seconds of pure perfect acceleration or regular driving and then you are violently back to limp mode. (This one leads me back to sensors and being outside of the computers acceptable program/chart)
-Removed different sensors and drove without them with Check engine light on: TPS; Temp sensor. etc. Seems to help at times but not others! Now not helping.
I am thinking I have some sensor intermittently sending bad news to the computer and it shuts off the ability to run. What sensor could it be???
HELP
Still To be done:
-The steering column could use some attention/rebuild etc. (Mention due to ignition is a little touchy in that you have to manually move it to the right spot by feel.)
-Springs and shocks could use a refresh
-ETC. ETC. ETC.........
