Bouncing RPM's and jerking throttle feathering
08-31-2013, 11:20 AM
#11
2nd Gear Member
Thread Starter
Join Date: Dec 2009
Location: Oklahoma
Posts: 152
Got everything done, and problem still persist. So I went a head and logged about 15 mins of driving with the sct and livelink. I'm trying to make sense of all this info. I'll upload the livelink file if anyone with a little more experience could decipher all this info, it would be much appreciated.
https://docs.google.com/file/d/0B-sA...it?usp=sharing
https://docs.google.com/file/d/0B-sA...it?usp=sharing
09-24-2013, 05:03 AM
#12
2nd Gear Member
Thread Starter
Join Date: Dec 2009
Location: Oklahoma
Posts: 152
Still trying to figure this one out.
So far I've
Replaced fuel filter
2 tanks of seafoam
new plugs
new TPS
cleaned TB
cleaned EGR valve
tested/bypassed the egr/dpfe
new tune
tried propane enrichment to find vacuum leak with no luck, also fuel trims were within around +1,-1 percent.
I've done quite a bit of searching and it seems that these problems are common across many different vehicles but the source of the problem is just as random. I may end up taking it somewhere for diagnosis and repair myself if it is feasible. Would probably be more cost effective to pay a shop for an hour to find it, rather than burn money chasing it around.
A little more detail on the problem.
The hunting idle only happens when the vehicle is in motion. When I clutch in to come to a stop, the rpms will fall well below idle, recover, repeat until I come to a stop. Sometimes it will just stall out. It seems both problems are more prevalent now that the temperature has dropped. I can reproduce the problem while coasting at a steady speed with the clutch in or the car in neutral. RPM's will fluctuate around idle until it stalls, I blip the throttle, or I put it back in gear.
The jerking, bucking usually is over 40mph with just a breath of throttle. Like just resting your foot on the accelerator pushing your big toe through your shoe. Any more and the problem clears up. The car stumbles as if power is cut off and on very quickly every couple of seconds.
I almost wish it would throw a code so I'd have some idea what i need to look at. Anyway up for any ideas of anyone has them. I'm going to try a couple of more diagnoses on my own and then it's headed in to the shop. I do have data logging capability if there is anything specific I should be looking at.
So far I've
Replaced fuel filter
2 tanks of seafoam
new plugs
new TPS
cleaned TB
cleaned EGR valve
tested/bypassed the egr/dpfe
new tune
tried propane enrichment to find vacuum leak with no luck, also fuel trims were within around +1,-1 percent.
I've done quite a bit of searching and it seems that these problems are common across many different vehicles but the source of the problem is just as random. I may end up taking it somewhere for diagnosis and repair myself if it is feasible. Would probably be more cost effective to pay a shop for an hour to find it, rather than burn money chasing it around.
A little more detail on the problem.
The hunting idle only happens when the vehicle is in motion. When I clutch in to come to a stop, the rpms will fall well below idle, recover, repeat until I come to a stop. Sometimes it will just stall out. It seems both problems are more prevalent now that the temperature has dropped. I can reproduce the problem while coasting at a steady speed with the clutch in or the car in neutral. RPM's will fluctuate around idle until it stalls, I blip the throttle, or I put it back in gear.
The jerking, bucking usually is over 40mph with just a breath of throttle. Like just resting your foot on the accelerator pushing your big toe through your shoe. Any more and the problem clears up. The car stumbles as if power is cut off and on very quickly every couple of seconds.
I almost wish it would throw a code so I'd have some idea what i need to look at. Anyway up for any ideas of anyone has them. I'm going to try a couple of more diagnoses on my own and then it's headed in to the shop. I do have data logging capability if there is anything specific I should be looking at.
Last edited by Stangbass; 09-24-2013 at 05:05 AM.
09-24-2013, 08:23 AM
#13
5th Gear Member
Join Date: Apr 2008
Location: Acworth, GA
Posts: 3,666
I had an issue with my manual Ford Explorer Sport (4.0 engine), when I returned from a long trip. The next morning the Explorer kept idling real low and wanted to stall out when coming to a stop. I had to keep my foot on the accelator to keep from stalling out. I drove to the nearest auto shop and they ran a diagnostics. It turned out, my fuel filter and fuel lines were all gunked up, which caused the fuel pump to fail. They replaced everything and cleaned out the fuel lines and all was good.
I am not sure if this is your issue, however I wanted to relay.
I am not sure if this is your issue, however I wanted to relay.
Last edited by kevinmalec; 09-24-2013 at 08:25 AM.
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