1FZFE rough idle, stumbles, stalls...

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woody

woody

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As luck would have it...first 'long' trip in the 80 in a couple years...ran excellent for the 300 mile drive down, wheeled/ran great on Friday, and started out great this morning....

Following another 80 thru the snow/slush/water, and after crossing a 'top of the rims' long puddle, it started stumbling...and got progressively worse...

Traded the MAF with a known good off another 1996, no change.

Fuel filter has 70kish on it, fuel was from a local stop that a few of us filled up at on Fri morning...down 1/4 tank since then.

Checked codes, have the 'full assortment'
P0300
P0301-6
P0100

Cleared, them none have returned...but the issue is still present...won't run, stalls out, idles terrible...

This video is typical of what it's doing...



Working on arrangements to get home tomorrow, then return on Monday early to trailer it back...unless some magic elixir appears tonite...
 
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The 300 series codes are misfires (on every cylinder apparently) so I would suspect anything that all 6 cylinders have in common. Check the distributor cap for water, make sure the plug wires and coil wire are all properly hooked up at both ends. Other possible common links would be the ignition coil, fuel pressure regulator, intake tube (check for cracks), injector wires near the EGR (although all 6 at once is rather unlikely), EGR valve stuck open, or a major vacuum leak somewhere. I would think that there is water somewhere the engine doesn't like water. Can you keep it running long enough to heat up and evaporate the water, or park it in a heated garage?
 

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i have just gone through the same problem i just fueled up and wen i switched it off she never started up the same so changed the fuel regulator,filter,some of the lines cleaned the intake system and a bunch of other crap but still had no change my next step was to check the pipe from the fuel pump in to the tank to see if it was cloged but i stoped the other day on a lean and switched the car off for bout 10 min and wen i started her up to go she was running normal again and its been a week and she is still fine so i never found the problem but but im still going to check the fuel pump pipe but its great to hear her runnig fine again i dont think this helps but good luck!!
 
96r50 said:
The 300 series codes are misfires (on every cylinder apparently) so I would suspect anything that all 6 cylinders have in common. Check the distributor cap for water, make sure the plug wires and coil wire are all properly hooked up at both ends. Other possible common links would be the ignition coil, fuel pressure regulator, intake tube (check for cracks), injector wires near the EGR (although all 6 at once is rather unlikely), EGR valve stuck open, or a major vacuum leak somewhere. I would think that there is water somewhere the engine doesn't like water. Can you keep it running long enough to heat up and evaporate the water, or park it in a heated garage?
Click to expand...

cap and rotor are new and dry, plugs and wires are new and dry, pulled one and it's perfect, fuel pressure regulator appears to be working, intake tube is replaced and fine, engine wiring harness is OEM new, injectors were just redone.

tapped the EGR, no change.

300 miles from home, but might have a heated option avail...however, unable to 'hang' here for long, so dry time may be limited.

Had it running for at least an hour after the issues, and they have varied in intensity, but have persisted.
 
Woody, I know you said water was to the top of the rims only but could fan have kick some up and gotten water in some places up where it shouldn't.

What about the TPS or any of the other sensors? Would a ground cause any of these issues?

Also you said you pulled one of the plugs, what about the possibility of water in one of the other boots?
 
CJF said:
Just to be clear:

You've popped the cap and cleaned/dried the inside since the issue started?
Click to expand...

correct....popped, wiped, and it was completely dry.

CJF said:
Connecter for that is definitely the next place to check.

And of course, rule out any cracks/tears in the intake tube.

Curtis
Click to expand...

intake tube inspected, and it's fine...will double check the TPS connector

landtank said:
I can't see the video, is your membership up to date?
Click to expand...
wrong permission setting on Youtube...oops...lol
 
I'd check the ground wires where the connect to the block and frame (lower end of things).

Also, this is a total WAG but I've seen and experienced that same kind of behavior from the small rubber hose going from the bottom of the EGR vacuum modulator to the actual EGR valve having a split in it or it no longer being connected/missing.
EGR..1.webp
 
more info:

started this morning, running excellent at high idle...as it warmed up, and idle dropped, it began to stumble again and finally stalled...

out to check hoses now...

...nothing appears bad, but hard to check with a 15mph wind blowing thru and wind chills in the low teens...

at this point, will get it trailered home by tomorrow and into a warm shop to deal with
 
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Woody,

I had a similiar issue and discovered the plug into the top of distributor had several wires with insulation that was cracked/heat damaged causing the resistance values to be effected by moisture. I also noticed that if I moved the wires up and down in any direction that I could re-create the same problem. Short term fix was electrical tape, long term heat shrink this was over 2 years ago and no issues....
 
got 'er back to the shop last Monday, but have been too busy to look into it....so, tackled it a bit today...

NO engine codes...none...so, start with the FSM Matrix Chart...and decided the 'engine stall - soon after starting' was the most logical.

New fuel filter installed...those are not fun...and didn't make any difference...

so, start at page EG-290...since it runs, we know there is fuel...inspected the Circuit Opening Relay behind the drivers side kick panel, ran the tests, and it passed. Checked voltage at the ECM, pass. Checked fuel pump relay, pass.

On a whim, and reading ahead, I opted to replace the Pressure Regulator on the fuel rail with another I had laying around...

magically, it now idles much better, and hitting the throttle actually revs the engine...there still appears to be a 'bit' of a roughness to the idle tho...but this time, it remained idling in the garage until I either needed to leave a note or shut the engine off. Next up is a road test, plan to do that a bit later this aft. If it passes, I'll order up a new regulator....replacing that leads me to a sneaking suspicion that the VSV on the intake is bad...going to inspect that as well.

now, to get the 100# propane tank in the shop refilled...it's chilly...
 
FYI, not fixed...

so yesterday evening, I start the truck to move it forward enough to clear the propane tank...considering how 'decent' it ran earlier in the day, I was hoping for the best...it barely idled, sputtered, and I ended up pushing it forward...

[strike]Now, today...just a few minutes ago, after getting heat in the shop, I fire 'er up to back it up and work on it....HIGH rev...

like, instantly to 4000rpm, and it kept climbing...shut 'er off when it hit 4800 rpm...[/strike]
[chalk that up to stupidity...stupid floor mat...]

however, still a poor idle, stumble as soon as it warms...at least tomorrow I have a warm shop to work in...if I can find time to get out there...
 
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The fuel pressure regulator seemed to make a slight difference when we unplugged it in Attica, but nothing big. Unplugging it provides more fuel pressure and makes it run rich.

Fuel filter sucks. I feel for ya.

The part that bugs me is that it ran pretty good in limp in mode with the MAF unplugged. That suggests it's not fuel or spark related, but some sensor that was being ignored in limp in.

That being said - have you pulled the plugs? A fouled plug might produce some of what you have. I would be more happy with that diagnoses if you had the o2s hooked up. A fouled plug would dump O2 into the exhaust and the ECM would enrichen the mixture trying to fix it making it progressively worse.

I wonder if the dunking in the water could have effected the dangling O2 wires.

I have a spare ECM if you want to throw one at it. For that matter I have spare everything except MAF which you already tried.

Hows the wires behind the EGR?
 
Sounds to me like you have a small crack in the intake somewhere. As soon as the high idle drops down ant he engine warms up, the crack opens up and you are running lean.

Why aren't the O2 sensors hooked up?
 
the engine is not 'warm' when the high idle drops...with outside temps in the single digits and in-shop temps in the 50's, it's only warm enuf to come off high idle. And it stumbles well before dropping to a true warm idle rpm.

Hope to get out there tomorrow and hook up the laptop to monitor data...too busy with other stuff right now to invest much more than 30 minutes at a time, and hardly see the point...another reason to push it off to a shop...REALLY sux that there are no Cruiser shops in this area...or within a couple hundred miles even....ah well...

O2's are not hooked because the ones installed are junk from the previous motor and the exhaust is so Wisconsin-rusted that taking them out and installing the two new ones I have will likely require a new exhaust...outta plug the old ones in tho and see what that changes....

You don't get instant rust in Vegas...stuff here corrodes solid within 24 hours, especially this time of year...
 
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