Stalling issues - Will my LC ever be reliable? (1 Viewer)

[DrEgon]

Hello masterminds of Mud,

So I’ve had my 94 LC for about a year. The whole time, its been in an out of the shop. It’s always had a rough idle / stalling issue and after multiple trips to my mechanic, nothing seems to fix the darn issue. Sometimes, I’ll get a rough low idle and the engine fights to stay running. I’ll give it gas and it’ll run very jerky until i shut it off. Other times, I’ll come to a stop to make a turn and when I do, it just shuts off immediately. I have to then put it in P and start it back up. Which it then runs rough until I shut it off for 5 minutes then it kicks on and turns fine. Lately, after doing all new fuel system work, its been taking a bit of time to turn over. Ill turn the key and the car will crank for a bit longer than normal before firing up.

So far, I’ve done:
• New MAF sensor.
• New Intake hose (previous was very old and brittle)
• Engine harness re-wrap
• Tightened all connections
• New radiator
• New fuel regulator
• New fuel pump
• New fuel injectors

I just want to enjoy this damn truck. Ive been wanting one for so long. I’m willing to put in the work but my goodness, I’m stumped. I search Mud constantly. Even tried a few things I found but nothing to solve the issue yet. The only other major issue i have is some serious clunking in the drive shaft. Or I think its that at least.

Anyone got any other suggestions? As always, appreciate you guys and this forum.

 

[scottryana]

Nope, I am kind of stumped but that is frustrating, good luck! There are some smart guys that will have some ideas I am sure.

 

[DrEgon]

Nope

A new way of life?

 

[Rifleman]

How many miles do your O2 sensors have on them since they were last changed? I too own a 1994 and below are 2 threads that deal with the ruff idle problems i had.

How i fixed my 94 L.C. check engine light Code 26

I Went to the store the other day, and as i was pulling out of the parking lot i noticed my engine RPM's floating up and down. Next, i noticed as i pulled up to the stop light the motor wanted to die, and got worse with the AC turned on. When i turned the AC off, it seemed to make the motor...

forum.ih8mud.com

To save you some time reading the whole thread below, I've coped the finial source of my problem, but if you want an overall picture of all the things i checked you can read the whole thread.

No check engine light, ruff idle problem

I've run into a intermittent ruff idle problem the past few days, but do to limited time i haven't had a chance to trouble shoot it yet. I'm working with a 1994 Land Cruiser. So far the problem seems to only cause the idle to drift up, and down between 650, and 475 RPM while in drive, with AC...

forum.ih8mud.com

Quote from the above thread. " I found what I'm sure is the source of my code 26 and ruff idle problem. While checking the Ohm's on each O2 sensor i found the right (passengers side) O2 sensor connector was full of water.

I'm sure all that water would cause all kinds of conflicting signals to be sent to the computer. After blowing all the water out of both connectors, i reconnected them, started the truck up, both O2 sensors were now working right, and the idle was rock steady at 650.

What i found, my truck is a 94 so I'm sure this will effect the 93 too, is the right side O2 sensor connector where it connects to the wiring harness connector is held in a vertical position. The problem with this position, even though the connector is supposed to be a weather tight connector, the bottom part of the connector is shaped just like a cup.

So any water that gets inside the connector will be held there, causing corrosion and never being able to drain out. What I've done to hopefully prevent this from happening again, I've turned the connector horizontally and tied it in place. This should allow any water that may get inside the ability to drain and dry out."

 

[SNLC]

Find a new mechanic.

Replace all vacuum lines.

Clean EGR system and throttle body plus at the minimum top intake manifold.

Replace o2’s and check wiring plus plugs to them.

Check charcoal canister and it’s hoses, replace as needed.

Check for exhaust leaks, in particular at the manifold.

Check and replace as needed; fuel pickup in tank, fuel pump and fuel filter.

Check ignition system, plugs, wires, dizzy cap and rotor. Check and set timing.

Plenty more to check but that is a solid start.

Cheers

 

[inkpot]

do a compression check. We just had one in the shop with very similar problems. Intermittant. Turns out head was cracked in the chanbers. Several cylinders were very weak comapression.

 

[NorCalFJ100]

Have you inspected your catalytic converter?

 

[Squash]

Maybe.
89422-35010 ECT sensor for EFI . Check the wiring first.
Drivers side, first sensor from rad is gauge, second is oil and third is Engine Coolant Sensor. Bit of a pain to remove connector but take your time and use a deep socket.

 

[ppc]

Did you open up carefully inspect the engine harness at the point it passes the EGR or did you just rewrap it?

 

[ProjectsNMotion]

Find a new mechanic

This right here

Your mechanic seems intent on firing the parts cannon at your LC until the issues go away. You need to find a competent mechanic that can properly diagnose the issue before replacing anything.

Cheers

 

[flintknapper]

That your issue(s) are 'intermittent' is an important clue. Your mechanic should pay special attention to this.

First thing I'd do is get a new mechanic. Someone who can/will do more diagnostics than 'guessing' and parts replacement.

Second I'd have some baseline testing done just so you know the relative health of your engine. I'd have a compression check performed, complete exhaust system inspection, have ALL ground points carefully checked and revisit that engine harness 're-wrap'.

Don't wrap a wiring harness bundle until you've carefully inspected each and every wire in that area. It is VERY common to have wiring issues (some hidden) in the harness right next to the EGR pipe. Have a new fuel filter (under the intake) installed if your is original or very old and have the fuel pressure checked.

Once you have the basics above covered you can move on to determining what is causing your issue (if not already remedied).

1. Is it spark related?
2. Fuel related?
3. Sensor related?

A 'good' mechanic will spend his time testing and narrowing down the possibilities as long as testing time is not exceeding the cost of replacing a suspected part/component.

 

[bajaphile]

When it is running rough, does it only run rough at idle, or through entire RPM band?

 

[rolliges]

What @flintknapper said AND there is also a fuel filter that's fun to change.

 

[DrEgon]

How many miles do your O2 sensors have on them since they were last changed? I too own a 1994 and below are 2 threads that deal with the ruff idle problems i had.

How i fixed my 94 L.C. check engine light Code 26

I Went to the store the other day, and as i was pulling out of the parking lot i noticed my engine RPM's floating up and down. Next, i noticed as i pulled up to the stop light the motor wanted to die, and got worse with the AC turned on. When i turned the AC off, it seemed to make the motor...

forum.ih8mud.com

To save you some time reading the whole thread below, I've coped the finial source of my problem, but if you want an overall picture of all the things i checked you can read the whole thread.

No check engine light, ruff idle problem

I've run into a intermittent ruff idle problem the past few days, but do to limited time i haven't had a chance to trouble shoot it yet. I'm working with a 1994 Land Cruiser. So far the problem seems to only cause the idle to drift up, and down between 650, and 475 RPM while in drive, with AC...

forum.ih8mud.com

Quote from the above thread. " I found what I'm sure is the source of my code 26 and ruff idle problem. While checking the Ohm's on each O2 sensor i found the right (passengers side) O2 sensor connector was full of water.

I'm sure all that water would cause all kinds of conflicting signals to be sent to the computer. After blowing all the water out of both connectors, i reconnected them, started the truck up, both O2 sensors were now working right, and the idle was rock steady at 650.

What i found, my truck is a 94 so I'm sure this will effect the 93 too, is the right side O2 sensor connector where it connects to the wiring harness connector is held in a vertical position. The problem with this position, even though the connector is supposed to be a weather tight connector, the bottom part of the connector is shaped just like a cup.

So any water that gets inside the connector will be held there, causing corrosion and never being able to drain out. What I've done to hopefully prevent this from happening again, I've turned the connector horizontally and tied it in place. This should allow any water that may get inside the ability to drain and dry out."

Thanks for linking this ( and giving me the short version ) . I'm pretty sure it still has the original o2. Mechanics said they checked them and seemed to be fine. Either way, this is good info to have for down the line.

 

[DrEgon]

Find a new mechanic.

Replace all vacuum lines.

Clean EGR system and throttle body plus at the minimum top intake manifold.

Replace o2’s and check wiring plus plugs to them.

Check charcoal canister and it’s hoses, replace as needed.

Check for exhaust leaks, in particular at the manifold.

Check and replace as needed; fuel pickup in tank, fuel pump and fuel filter.

Check ignition system, plugs, wires, dizzy cap and rotor. Check and set timing.

Plenty more to check but that is a solid start.

Cheers

Im considering it. I'm sad. I like these guys a lot.

I know they said they checked a ton of this stuff. o2, EGR, plugs. Haven't specifically asked about dizzy but Im sure (or hoping) that they did.

Yes, I agree, this is a good start. I'll continue on. Fingers crossed.

 

[DrEgon]

This right here

Your mechanic seems intent on firing the parts cannon at your LC until the issues go away. You need to find a competent mechanic that can properly diagnose the issue before replacing anything.

Cheers

Sigh. Maybe. I like my guys a lot. Solid people. But maybe my rig is too much for them to take on at this time. Its certainly not the fun stuff like putting lift kits on.

 

[DrEgon]

That your issue(s) are 'intermittent' is an important clue. Your mechanic should pay special attention to this.

First thing I'd do is get a new mechanic. Someone who can/will do more diagnostics than 'guessing' and parts replacement.

Second I'd have some baseline testing done just so you know the relative health of your engine. I'd have a compression check performed, complete exhaust system inspection, have ALL ground points carefully checked and revisit that engine harness 're-wrap'.

Don't wrap a wiring harness bundle until you've carefully inspected each and every wire in that area. It is VERY common to have wiring issues (some hidden) in the harness right next to the EGR pipe. Have a new fuel filter (under the intake) installed if your is original or very old and have the fuel pressure checked.

Once have the basics above covered you can move on to determining what is causing your issue (if not already remedied).

1. Is it spark related?
2. Fuel related?
3. Sensor related?

A 'good' mechanic will spend his time testing and narrowing down the possibilities as long as testing time is not exceeding the cost of replacing a suspected part/component.

Yup. You and @inkpot bring up some good points. Ive never done a compression check. I'll do that next.

Im not the most knowledgable car guy (hence why im humbly asking you guys), let alone LC specific. Slowly getting around to learning everything. So with that said, I dont think its spark related. Fuel possibly, hence why I went through with all the fuel related work. Had a lot of pressure "whooshing" previously when I opened the gas cap. Doesn't do that now. Definitely could be sensor related too. I'll follow everyone's lead on re-checking hoses, connections and wires.

 

[DrEgon]

When it is running rough, does it only run rough at idle, or through entire RPM band?

Both. When she decides to throw a fit, it'll feel like the engine is fighting to stay on at idle. I try putting it into drive and the thing just jerks around until I come to a stop and shut it off. I'll restart it after shutting off and its like nothing happened. Just runs.

This is a super dumb question but is there some sort of connection or ground or hose that could get pinched or loose when you turn right? The two times that power was loss immediately was when I was turning right. I know, its a dumb question but just trying to find any sort of pattern.

 

[SNLC]

Im considering it. I'm sad. I like these guys a lot.

I know they said they checked a ton of this stuff. o2, EGR, plugs. Haven't specifically asked about dizzy but Im sure (or hoping) that they did.

Yes, I agree, this is a good start. I'll continue on. Fingers crossed.

It is more being familiar with these trucks and engines than being good guys or even good mechanics.

EGR ports in intake get clogged, vacuum lines crack and leak. These cause erratic idling, rough running, ect ect ect. Did they replace the crush washers at the fuel filter when they changed the filter? It is a process of elimination, go over this area/system and make sure it is good, move on to the next.

I think you get my points I am making.

Cheers

 

[sogafarm]

Sounds like a grounding problem. Check around the battery and the fusible link. Replace fusible link if you haven't already, it's cheap insurance around $20 and it's an easy peezy job. Also did the mechanic replace the AFM(maf) with a new one because I don't think toyota makes them anymore.