Rough idle - my fault, but I don't know what I did (1 Viewer)
- Thread starter CharlieS
- Start date
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Go the other way.
Pos in coolant, neg at neg batt post/chassis.
Pos in coolant, neg at neg batt post/chassis.
Ok, you're good. (just under .1VDC for those not familiar)
Just my opinion, I don't feel that a ground issue is present.
Just my opinion, I don't feel that a ground issue is present.
I’ve never deleted all that stuff, but it seems weird to apply constant engine vacuum to the fuel pressure regulator. If that’s typical for this mod, ignore me. But normally fuel pressure is controlled (more of like 2 steps) by a vsv that you removed.
CharlieS
GOLD Star
- Thread starter
- #69
I removed that straight vacuum hose and plugged both the FPR and gas filter with a short section of new vacuum line with a bb in it. No change in behavior as far as I can tell, in a quick test in the garage (no driving).
To expand on that - There is a bb in both of those hose stubs so there is no vacuum leak at the intake, and there is no vacuum to the fuel pressure regulator. This is for testing purposes to eliminate a variable.
To catch things up to where I am - the behavior I am seeing is something like this:
Cold Start -
Warm start
To expand on that - There is a bb in both of those hose stubs so there is no vacuum leak at the intake, and there is no vacuum to the fuel pressure regulator. This is for testing purposes to eliminate a variable.
To catch things up to where I am - the behavior I am seeing is something like this:
Cold Start -
- initial ~2200 rpm steady
- 30 seconds ~1500 rpm steady
- 60 seconds ~1200 rpm steady
- 90 seconds ~900 rpm steady
- 120 seconds ~650 rpm hunting/rough
- few seconds later it drops down to 2-300 and fluctuates lower, and may stall, but may catch and rev up too 1000 rpm before dropping back to that low lumpy idle, and fluctuating between low idle, wanting to stall, and catching itself and revving
Warm start
- initial ~2200 rpm
- 30 seconds ~1100 rpm
- few seconds later it drops down to 2-300 and fluctuates lower, and may stall, but may catch and rev up too 1000 rpm before dropping back to that low lumpy idle, and fluctuating between low idle, wanting to stall, and catching itself and revving.
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CharlieS
GOLD Star
- Thread starter
- #70
Upon further reflection, I think that torx fitting in the plunger may be so a tool can be used to set the resting depth of the plunger. That plunger is on a coarse threaded screw inside the magnet that turns to adjust the plunger depth when actuated. Turning either the magnet or the plunger end will change the resting depth of the plunger part. So I think this torx fitting can be used to rotate the plunger to get the proper plunger depth without disassembling the unit.
The moral of the story here is to measure the plunger depth before disassembly, so you can set it to the same depth upon reassembly.
CharlieS
GOLD Star
- Thread starter
- #73
Correction - I pulled the wrong sensor.
I pulled the ECT cut switch and it tested open as it should (until it is heated up). I believe this is to kill the AC if the engine gets too hot.
I subsequently pulled the ECT sensor and tested it. It reads lower than spec: 1.2 K ohms at ~72 deg F when the spec is 2-3 K ohms at 68 deg F.
I may do some further testing on it after work.
This diagram found on mud was super helpful - 1FZ-FE head sensor ID - https://forum.ih8mud.com/threads/1fz-fe-head-sensor-id.1276446/post-14296426
I pulled the ECT cut switch and it tested open as it should (until it is heated up). I believe this is to kill the AC if the engine gets too hot.
I subsequently pulled the ECT sensor and tested it. It reads lower than spec: 1.2 K ohms at ~72 deg F when the spec is 2-3 K ohms at 68 deg F.
I may do some further testing on it after work.
This diagram found on mud was super helpful - 1FZ-FE head sensor ID - https://forum.ih8mud.com/threads/1fz-fe-head-sensor-id.1276446/post-14296426
Thank you for actually doing the checks.
Alot of info is shared with OPs by very knowledgeable members but the trail goes cold with no action/response.
I'm sure you're familiar.
CharlieS
GOLD Star
- Thread starter
- #77
I just want to acknowledge that @BILT4ME called out both the temp sensor and the IAC valve very early in this thread. Thanks, man!
Also, thanks to everyone that replied to this and gave me guidance.
I'm running back through re-reading everything and making sure I didn't miss any recommendations in my haste.
I think this thread has ruin its course and I'm going to let it die off. If I find a vacuum leak, I'll provide an update. Otherwise, I think I'll put this one to bed and move on to my alternator, idler and radiator project. New threads as needed.
I've learned a lot and appreciate all of the insight and guidance that you all provided. Thank you all!
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You have done an incredible job walking through each and every diagnostic bit and documenting it.
You have gone much further than I have the patience for.
Nice work!
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Malleus
Far west of Siegen
...and there goes another satisfied customer.
