1HZ Losing Power Under Load - Help Diagnose!

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Joined
Dec 25, 2019
Threads
4
Messages
40
Location
Sacramento, CA
I recently sold my 1993 1HZ Troopy. This was a rig I had put several thousand trouble-free (more or less) miles on and never had any problems with driveability. Generally speaking it is a good running, low mileage rig. Within the past 1,000 miles it has had a new water pump, timing belt and accessories, oil change and filter, fuel filter, belts, etc. I shipped it down to its new owner in San Diego this week and he is having some strange problems with it right out the gate. I will try to detail the symptoms out as best as possible, but will also forward him a link to this thread so he can chime in. From what I was told:
  • When it arrived, took a short trip "up into the hills" with no issue.
  • Was driving to the beach, and after about 30 minutes of driving, again with no issues, the power loss occurred.
  • Described as if it is maybe not getting enough fuel, will not accelerate through the gears as it should (I took this as if he up shifts he cannot pick up speed).
  • I believe he also mentioned it surging or bucking.
  • Initially could still drive with minimal issues at slower speeds (lower gears presumably), but eventually it lost power at these speeds as well and I think he had to have it towed.
  • Engine never stalled or died.
  • Idle was normal. He did NOT test to see if it would rev up at a stop without issues (load vs. no load)
  • Fuel filter primer was not soft.
  • Fuel gauge read half a tank, but he thought maybe the gauge was off. Filled up and it only took 10 gallons, so that was not it.
My initial thoughts are air in the fuel system, possibly a crack in a line after the engine warms up. I have not heard from him yet on if the issue persisted after the engine cooled down though, which could help confirm this. I also suggested switching to the rear tank to see if the fuel tank pickup may have gotten clogged - although honestly I've never been able to get a straight answer on if the rear tank feeds the engine directly or just replenishes the main tank. The fuel filter is also very new, so maybe a bad seal? I have not driven it more than 20 minutes or so at a time for the past couple of months (but I have definitely taken longer trips with it before), so its possible the underlying cause may have been present longer than we have seen the symptoms. Would really like to help him get this resolved as I can't think of too much worse than getting your new dream rig and immediately encountering issues. Would appreciate any other thoughts, etc.
 
Any smoke? easy to connect a test 1/2 gal or so fuel tank under the hood with a inline fuel filter directly to the injection pump and see if that makes a difference. this can rule out:
fuel filter, housing, all the pipes, hoses and pickups as well as bad fuel.
 
Any smoke? easy to connect a test 1/2 gal or so fuel tank under the hood with a inline fuel filter directly to the injection pump and see if that makes a difference. this can rule out:
fuel filter, housing, all the pipes, hoses and pickups as well as bad fuel.
Will ask the owner on the smoke.

The 1/2 gallon under the hood is a good idea, presuming the issue persists and is not distance/temp dependent.
 
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