Oil warning light on, oil level good...what's my issue?

[alia176]

unfortunately, it's hard to check the fuel pump pressure without connecting a fuel pressure gauge to the fuel system, which is tad fussy. There are threads on how to do this so it might be a good idea to study the process then connect a gauge, and then tape the gauge to the bottom of the windshield (outside). Then just drive around until it stalls, that's when the gauge will tell you things vs you having to guess. Again, the gauge hookup is a bit of a pain but the info it tells you is priceless. @cruisermatt has developed a cool adapter which makes this process MUCH simpler, and it's about to go online soonish from what I hear.

I suggest doing a systematic approach vs throwing random parts at this issue. Everyone here will throw all kinds of ideas at you to help you out, but you need data first and foremost.

 

[94toInfinity]

Id start with the easy / cheap stuff first. Fuel filter is pretty high on the cheap/easy scale. From there try running a quality injector cleaner like redline with the PEA additives and a spirited drive. If that doesn’t help then could be the pressure regulator. The fuel pump isn’t a fun job! Good luck and RTFM

Haha, thanks guys. I won't do it without the manual. I've got it downloaded and am going through it. I just like finding a good experienced thread/video with firsthand hillbilly knowledge and experience when possible.

 

[94toInfinity]

Update time: Here's what I've done so far-problem persists...sort of.

I pulled the fuel pump and changed the fuel sock/filter as well as all the constituent parts (gasket, hose, etc.), fusible link, AM2 fuse, oil change, Sea Foam gas treatment, and Sea Foam throttle body cleaner.

I made two longish trips with no issues but then just yesterday almost recreated the original problem. Pulled away from a red light and when I put my foot on the gas the engine started bogging down like it wanted to die. I let go of the gas and the engine came back to life, put my foot on the gas again only to have it bog down again. When I let go of the gas pedal it came back to life again. But then I hit another red light and when I took off from that light it drove fine.

Could it be some type of fuel sensor, O2 sensor, or otherwise? Any other ideas of what I should check/replace?

It's tough because I can't always recreate the problem-it just happens here and there.

 

[nakman]

As for the low oil light coming on, the solution is (or at least used to be) pulling the sensor from the oil pan, bending it down just a smidge, then putting it back in. My first 80 had this issue and I did this and it worked great. and yes that was 20 odd years ago Low Oil Light - https://forum.ih8mud.com/threads/low-oil-light.24818/ hope that helps!

Good luck with the stalling issue... have you tried looking for any codes?

 

[alia176]

unfortunately, it's hard to check the fuel pump pressure without connecting a fuel pressure gauge to the fuel system, which is tad fussy. There are threads on how to do this so it might be a good idea to study the process then connect a gauge, and then tape the gauge to the bottom of the windshield (outside). Then just drive around until it stalls, that's when the gauge will tell you things vs you having to guess. Again, the gauge hookup is a bit of a pain but the info it tells you is priceless. @cruisermatt has developed a cool adapter which makes this process MUCH simpler, and it's about to go online soonish from what I hear.

I suggest doing a systematic approach vs throwing random parts at this issue. Everyone here will throw all kinds of ideas at you to help you out, but you need data first and foremost.

I'm quoting my own post with a pic. I too am looking into something funky with the fuel system so now I'm driving around with the pressure gauge taped to my windshield.

 

[94toInfinity]

I'm quoting my own post with a pic. I too am looking into something funky with the fuel system so now I'm driving around with the pressure gauge taped to my windshield.

View attachment 4109899

What's going on with your LC? What's the funky thing?

 

[alia176]

that's a fuel pressure gauge taped to the windshield. That's how I'm checking the fuel pump output under load while driving. Anytime I suspect fuel delivery issues, i start with this to see what's going on.

 

[Marvelicious]

I'm quoting my own post with a pic. I too am looking into something funky with the fuel system so now I'm driving around with the pressure gauge taped to my windshield.

View attachment 4109899

This is like the vehicular equivalent to putting one of those cones on your pet after surgery. It's probably helpful in the long run, but man does it look goofy.

 

[alia176]

This is like the vehicular equivalent to putting one of those cones on your pet after surgery. It's probably helpful in the long run, but man does it look goofy.

exactly, well put! It's fugly but it gives me the data I need for troubleshooting purposes.

 

[94toInfinity]

that's a fuel pressure gauge taped to the windshield. That's how I'm checking the fuel pump output under load while driving. Anytime I suspect fuel delivery issues, i start with this to see what's going on.

Understood. Was just wondering how you noticed the issue, as in what's the issue you are having and when do you notice it?

 

[alia176]

Understood. Was just wondering how you noticed the issue, as in what's the issue you are having and when do you notice it?

Thanks for clarifying.

I'm chasing a "extra long" cranking before starting condition. Which is leading to m to check if the fuel line stays pressurized after the engine is shut down. Just for warm/fuzzy, I also wanted to see how the fuel system is delivering fuel during WOT since I have a turbo.

 

[94toInfinity]

Thanks for clarifying.

I'm chasing a "extra long" cranking before starting condition. Which is leading to m to check if the fuel line stays pressurized after the engine is shut down. Just for warm/fuzzy, I also wanted to see how the fuel system is delivering fuel during WOT since I have a turbo.

Ok cool, thanks for the explanation.

I don't have a cranking issue-fires up right away every time, even after it has the shut off problem. That's why I'm thinking this is a fuel issue. Maybe a vacuum issue?

 

[alia176]

Ok cool, thanks for the explanation.

I don't have a cranking issue-fires up right away every time, even after it has the shut off problem. That's why I'm thinking this is a fuel issue. Maybe a vacuum issue?

This is why i suggest doing what I did so that you can look at your fuel pressure.

 

[94toInfinity]

Update: So I ended up doing lots of things and think* I finally found the issue. Here's what I did just in case anyone else has the same issue.

I started by making sure my fuses were good. Had some corrosion on the AM2 fuse so I replaced it. Also did the fusible link at the same time. Problem persisted.

The I changed the fuel filters just to make sure I was getting good fuel flow: changed the fuel filter and hoses in the tank under the rear seats. Also changed the fuel filter on the engine. Problem persisted.

Used Seafoam throttle body treatment to clean my throttle body. Problem persisted.

I bought a fuel pressure adaptor from @cruisermatt and drove around with a fuel pressure gauge on my windshield for a week but the pressure never dropped. Problem persisted.

Then I changed the distributor cap and rotor as there was some obvious corrosion. The engine still shut off randomly but it would start back up again more easily.

Finally started thinking about the idle valve control after finding a thread on that, so I got a new one and replaced it along with all new spark plugs and plug wires. I think that was the issue. I've driven it 5 times now without it stalling out on me. The vehicle only shut off after taking off from a red light and so I think the idle valve control wasn't working properly. Fingers crossed that takes care of the issue from now on.

Hope this helps someone else in the future. I'm ready to enjoy the vehicle now rather than just working on it all the time.

 

[alia176]

Update: So I ended up doing lots of things and think* I finally found the issue. Here's what I did just in case anyone else has the same issue.

I started by making sure my fuses were good. Had some corrosion on the AM2 fuse so I replaced it. Also did the fusible link at the same time. Problem persisted.

The I changed the fuel filters just to make sure I was getting good fuel flow: changed the fuel filter and hoses in the tank under the rear seats. Also changed the fuel filter on the engine. Problem persisted.

Used Seafoam throttle body treatment to clean my throttle body. Problem persisted.

I bought a fuel pressure adaptor from @cruisermatt and drove around with a fuel pressure gauge on my windshield for a week but the pressure never dropped. Problem persisted.

Then I changed the distributor cap and rotor as there was some obvious corrosion. The engine still shut off randomly but it would start back up again more easily.

Finally started thinking about the idle valve control after finding a thread on that, so I got a new one and replaced it along with all new spark plugs and plug wires. I think that was the issue. I've driven it 5 times now without it stalling out on me. The vehicle only shut off after taking off from a red light and so I think the idle valve control wasn't working properly. Fingers crossed that takes care of the issue from now on.

Hope this helps someone else in the future. I'm ready to enjoy the vehicle now rather than just working on it all the time.

congrats on fixing the issue by approaching is systematically. Where did you source the IAC and was it an OEM one? They're quite spendy these days!

You said The vehicle only shut off after taking off from a red light and so I think the idle valve control wasn't working properly. Fingers crossed that takes care of the issue from now on..

your engine stalled AFTER taking off from a red light, which is interesting. The IAC valve is responsible for not stalling the engine after you take your foot of the gas before coming to a stop. I'm curious if the IAC was indeed your culprit!

 

[94toInfinity]

congrats on fixing the issue by approaching is systematically. Where did you source the IAC and was it an OEM one? They're quite spendy these days!

You said The vehicle only shut off after taking off from a red light and so I think the idle valve control wasn't working properly. Fingers crossed that takes care of the issue from now on..

your engine stalled AFTER taking off from a red light, which is interesting. The IAC valve is responsible for not stalling the engine after you take your foot of the gas before coming to a stop. I'm curious if the IAC was indeed your culprit!

I did get a Japanese IAC valve from Rock Auto of all places!

Yeah man, I don't know. It only happened AFTER I took my foot off the brake and put it on the gas to take off from a stop at a red light.

Let's just say it happens again...what do you think the culprit is for stalling taking off after a red light?

 

[Old Nick]

I did get a Japanese IAC valve from Rock Auto of all places!

Yeah man, I don't know. It only happened AFTER I took my foot off the brake and put it on the gas to take off from a stop at a red light.

Let's just say it happens again...what do you think the culprit is for stalling taking off after a red light?

The only other thing that I could think of (beyond what you've done) is the throttle position sensor (TPS). But, let's hope that you're good to go now. Happy to see that you're rolling again.

 

[alia176]

I did get a Japanese IAC valve from Rock Auto of all places!

Yeah man, I don't know. It only happened AFTER I took my foot off the brake and put it on the gas to take off from a stop at a red light.

Let's just say it happens again...what do you think the culprit is for stalling taking off after a red light?

no way, a Japanese IAC from Rockauto? Ooooh, let me have a link to yours please in case i need to replace mine. I'll clean it first to see if the random stalling stops.

Stalling after taking off - hmm, let's see what happens. You take your foot off the break, vacuum decreases when the engine starts spinning faster. If you have a vac leak, aka "pirate air" that isn't getting measured by the MAF, you'd think there'd be a CEL code of some sort. Something like running too lean or some thing, but if you're not getting a CEL, and the engine just stalls, could also mean a fuel issue. But you ruled out fuel delivery issue already so perhaps this is an air delivery issue? If this was a spark issue, you'd have a stumble, but a complete stall means lack of proper measured amount of air or fuel going to the engine.

I don't think I read anything about you checking for vacuum leaks. The way I do it is to use a smoke tester from Amazon. Others spray carb cleaner all over the engine, and under the intake manifold to see if the rpm changes while the engine is idling. So, perhaps attack it from that angle? There are few vac hoses under the intake which is a royal PITA to access but they do need to be replaced as they develop split ends over time. See if your brake booster is holding vacuum by using a hand held vacuum tester as that can be a culprit due to the age of the diaphragm inside those things.

 

[94toInfinity]

no way, a Japanese IAC from Rockauto? Ooooh, let me have a link to yours please in case i need to replace mine. I'll clean it first to see if the random stalling stops.

Stalling after taking off - hmm, let's see what happens. You take your foot off the break, vacuum decreases when the engine starts spinning faster. If you have a vac leak, aka "pirate air" that isn't getting measured by the MAF, you'd think there'd be a CEL code of some sort. Something like running too lean or some thing, but if you're not getting a CEL, and the engine just stalls, could also mean a fuel issue. But you ruled out fuel delivery issue already so perhaps this is an air delivery issue? If this was a spark issue, you'd have a stumble, but a complete stall means lack of proper measured amount of air or fuel going to the engine.

I don't think I read anything about you checking for vacuum leaks. The way I do it is to use a smoke tester from Amazon. Others spray carb cleaner all over the engine, and under the intake manifold to see if the rpm changes while the engine is idling. So, perhaps attack it from that angle? There are few vac hoses under the intake which is a royal PITA to access but they do need to be replaced as they develop split ends over time. See if your brake booster is holding vacuum by using a hand held vacuum tester as that can be a culprit due to the age of the diaphragm inside those things.

Here you go: Rock Auto IAC

Thanks for the further instructions! You guys are a treasure trove of information. I did not check for vacuum leaks-the only thing I did remotely close was to tighten up the EGR which was loose. I'll run a smoke tester test like you said. I suppose it wouldn't hurt to replace the vacuum hoses under the intake. That'll be next if needed. Thanks so much for taking the time to respond.

 

[alia176]

Here you go: Rock Auto IAC

Thanks for the further instructions! You guys are a treasure trove of information. I did not check for vacuum leaks-the only thing I did remotely close was to tighten up the EGR which was loose. I'll run a smoke tester test like you said. I suppose it wouldn't hurt to replace the vacuum hoses under the intake. That'll be next if needed. Thanks so much for taking the time to respond.

you're welcome and thanks for keeping an open mind about all this. Yeah, the vac lines get old and with split ends. Toyota sells longer bulk lines which are metric of course, but local auto shops have them too. I just like the looks of oem vac hoses with Japanese writing and lines on them for some reason. I think we have two different metric ID sizes of vac lines under the hood.

Did Matt sell you the fuel pressure adapter thing outside of his website? I still don't' see it for sale on his site yet. Thx for the link on the IAC. Is this the one?