EscapeWagon62
SILVER Star
All,
Need a hand chasing down an issue where my vehicle is bogging down/stuttering. I had experienced this same symptom recently and I threw a CEL code 22 (water temp sensor). Replaced the water temperature sensor and all was well but the condition reappeared and I'm not throwing any CEL codes now (which is a good sign).
What is the symptom?
- After the vehicle has been sitting either overnight for for an hour or so, It will bog down/almost stall within a short distance. It is intermittent, I'd say one out of every 6-10 start ups. When I say bogging (almost a violent stall) , it's like I lose all power unless I reduce throttle to minimal, put it in neutral and try again.
- Happens in warm of cold weather
- Has happened on a cold engine and a warm engine
- When starting the vehicle starts and idles fine, the bogging occurs only when I apply more than (my guess) 40% throttle input.
- It is jarring in that the engine seems like it seizes (feels like fuel cutoff, electrical cutoff in that it is very sudden vs progressively bogging down) . I can put the clutch in (I have an H55 swap) and it returns to normal and I limp to a parking lot under very moderate throttle.
- If I pull off the road and sit for a minute or turn off the car and restart it....everything is normal and I can drive with no further issues whatsoever.
Have you checked the usual suspects?
- Fuel filter is new within a few thousand miles
- Fuel pressure regulator is new as is the pulsation damper (both replaced when I had it disassembled for my intake/exhaust manifold gasket a couple thousand miles ago)
- Water temperature sensor was replaced with an OEM (condition existed prior to the replacement but I did throw a CEL 22 before the replacement and I'm not throwing one now). I did have to drain a gallon of coolant during the replacement which has been refilled and burped to the best of my ability.
- Electrical - not an expert in this line of work so I don't know if something would cause this and be able to reset it simply by pulling over and waiting nor would it explain why it only seems to happen after sitting for a bit. No other electrical issues occur when the bogging happens that I am aware of.
- Valve adjustment - I know if they are over-tight, aside from not being recommended, it will generally cause a "dead spot in power" vs a more immediate engine bogging
- While I don't think this would be of interest, I have a fully functioning charcoal cannister (tested per FSM)n and the vehicle is not de-smogged in any way.
- I did recently have the A/C serviced as the seals on the compressor failed.
Any other thoughts? The only other two items I can think of are:
- Fuel pump - I have an OEM replacement as they tend to go bad. I just can't seem to logically convince myself that a fuel pump would only show failure in specific instances like this
- Throttle position sensor - Same as above - possible but only at start up seems like a weird failure and I'm not throwing a code.
- Some weird electrical gremlin that only appears in the first few hundred yards of travel.
- Vacuum leak - Possible but idle is perfect and this only happens under throttle greater than roughly 40% and only for a short distance after startup. If I shut the vehicle off and restart the condition disappears which lead me to believe it isn't anything vacuum related. Could be convinced otherwise.
Any advice appreciated.
Need a hand chasing down an issue where my vehicle is bogging down/stuttering. I had experienced this same symptom recently and I threw a CEL code 22 (water temp sensor). Replaced the water temperature sensor and all was well but the condition reappeared and I'm not throwing any CEL codes now (which is a good sign).
What is the symptom?
- After the vehicle has been sitting either overnight for for an hour or so, It will bog down/almost stall within a short distance. It is intermittent, I'd say one out of every 6-10 start ups. When I say bogging (almost a violent stall) , it's like I lose all power unless I reduce throttle to minimal, put it in neutral and try again.
- Happens in warm of cold weather
- Has happened on a cold engine and a warm engine
- When starting the vehicle starts and idles fine, the bogging occurs only when I apply more than (my guess) 40% throttle input.
- It is jarring in that the engine seems like it seizes (feels like fuel cutoff, electrical cutoff in that it is very sudden vs progressively bogging down) . I can put the clutch in (I have an H55 swap) and it returns to normal and I limp to a parking lot under very moderate throttle.
- If I pull off the road and sit for a minute or turn off the car and restart it....everything is normal and I can drive with no further issues whatsoever.
Have you checked the usual suspects?
- Fuel filter is new within a few thousand miles
- Fuel pressure regulator is new as is the pulsation damper (both replaced when I had it disassembled for my intake/exhaust manifold gasket a couple thousand miles ago)
- Water temperature sensor was replaced with an OEM (condition existed prior to the replacement but I did throw a CEL 22 before the replacement and I'm not throwing one now). I did have to drain a gallon of coolant during the replacement which has been refilled and burped to the best of my ability.
- Electrical - not an expert in this line of work so I don't know if something would cause this and be able to reset it simply by pulling over and waiting nor would it explain why it only seems to happen after sitting for a bit. No other electrical issues occur when the bogging happens that I am aware of.
- Valve adjustment - I know if they are over-tight, aside from not being recommended, it will generally cause a "dead spot in power" vs a more immediate engine bogging
- While I don't think this would be of interest, I have a fully functioning charcoal cannister (tested per FSM)n and the vehicle is not de-smogged in any way.
- I did recently have the A/C serviced as the seals on the compressor failed.
Any other thoughts? The only other two items I can think of are:
- Fuel pump - I have an OEM replacement as they tend to go bad. I just can't seem to logically convince myself that a fuel pump would only show failure in specific instances like this
- Throttle position sensor - Same as above - possible but only at start up seems like a weird failure and I'm not throwing a code.
- Some weird electrical gremlin that only appears in the first few hundred yards of travel.
- Vacuum leak - Possible but idle is perfect and this only happens under throttle greater than roughly 40% and only for a short distance after startup. If I shut the vehicle off and restart the condition disappears which lead me to believe it isn't anything vacuum related. Could be convinced otherwise.
Any advice appreciated.
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