Check Engine..

I just got in from a 1300 Mile Round trip, it was a marathon run to say last goodbyes to a very special person. My 1990 has been running great with no issues of any kind and engine wise, all hoses replaced, complete tuneup, new injectors etc etc.

About 600 miles from home the check engine light came on, my 4Runner continued to run great I couldn’t feel any changes in anything, stopped 3 more times for gas to get home.

This morning, I left to get milk and came right home, check engine light on, truck started right up no issues. Later in the morning I backed it down the driveway without starting to level so I could check all the fluids and top off anything that needed it. Used about 1/2 quart of oil, everything else was good.

Went to start the truck and it just turned over, refused to start. I used my winch to get it back up the driveway. As soon as I unhooked and wrapped everything up I tried starting it, fired right up. Check engine light still on.

It did this a few years ago, but the check engine light never came on. I don’t remember exactly what I did, I think I replaced the Cap and Rotor and that seemed to cure it until now.

It’s never since I’ve owned it had a check engine light...so from my join date here until now and maybe 25,000 miles.

It does smell somewhat rich from the tailpipe, and with my hand about an inch away from the tailpipe I don’t feel any misfiring, just a nice smooth pulse.

I know I’ve got to go back and read a few threads on how to jump the deal to get it to show codes. I did call my mechanic and he has the deal to read the obd-1, he says I’m going to have to leave it a few hours for the thing to read it because this system is old and very slow to read and may not pinpoint exactly what it is.

I’m trying to be as thorough as I can, I know it’s a bit long of a post. Anyone have maybe some idea of what it could be ? Would the 02 sensors do that ? Make it where it occasionally won’t start, throw the check engine light on.

Thank you for any help.

I did replace the electrical deal that rides on the coil, I have a spare and it made no difference. Also I’ve gone out and it’s fired right up twice more, I waited about 2 hours between starts. Check engine light still on.

 

It has the potential to be so many cotton picking things that any attempt to identify it from 50,000 feet would be quite simply a...... W A G.

Hope when it's located it's minor. Let us know.

 

A guess would point towards the O2 sensor, let the mechanic "read" it, it may not be bad, have him reset the check engine light. I've heard that some O2 sensors throw a code at around 60k miles, I do NOT know this to be true.... just what I heard.

 

Take an unpainted paper clip and short TE 1 and E 1 terminals in the diagnostic port, located on the right side of the engine compartment. Turn the key on and count the check engine light flashes. The table will show what system has the fault.

 

Thanks all and Thank you JTM, very much appreciated that you posted that. I thought I was going to be upside down under the dash somewhere. I’ll give that a try Sunday. I was reading some older post’s and I’m seriously thinking it may be the O2 sensor down near the CC and maybe the distributor is worn out. The cap and rotor are fine but the guts that send signal may be going out.

So a combination of the two. The distributor replacement comes from reading one of atgparkers post having what sounds like the same issue.

I’m looking on eBay at distributors and the possibility of trying that 02 sensor delete. Not sure if want to do that.

I’ll report back Sunday Afternoon.

 

Hello bthp223,
Some of this will be a rehash of my other post so here goes:
The O2 is out of the equation until the ECM goes into closed loop after its warmed up. So that will not be a factor in it not wanting to run. The knock sensor can be a real bummer too if its broken or becomes disconnected from the ECM. But the most important signals the ECM needs are the engine position and the speed of rotation. Both are sensed by the distributors signal coils that are in the bottom of the distributors die-cast housing.
The only time so far that I have had the check engine light to stay on on my 91 was when the 30 year old distributor finally quit. The firing signals for the cylinders from the sensors in the distributor are the OBD-1 version of what all OBD-II engines use as crank triggering for timing and fueling the motor.

When one of the signal coils in my distributor was failing and finally went open circuit the engine would turn over but it would not start and rumble to life. I remember during the weeks which led up to this event the engines snap to running was getting worse requiring me to hold the starter motor for longer before it would catch and run. Then on the morning it finally failed I was fortunately at home and it would not run no matter how long I cranked the starter motor and spun the engine. With no spark coming from the ignition coil I used A DVM and as it turned out one of the signal coils had finally failed inside the distributor (there are three) which was quickly diagnosed as the problem. If the ECM cannot sense the engine is turning it won't sent a pulse to the ignitor on the ignition coil. You can check the signal coil resistances at the connector on the distributor that sends all these signals to the wire harness and the ECM. The FSM has values for verifying if they are within specification for the respective resistances of these coils. The problem is that as these copper wires in these signal coils get older and older and see yet another thermal cycle the resistance will change over time and that is two fold in both relative age and operating temperature. The signals generated in these coils will be small current pulses because they are inductive sensors that receive pulses from lobes and teeth that spin with the distributor shaft. I think that because the check engine light is illuminated the code has been set in your ECM's memory because the occasion were the signal failed to be strong enough was sensed in the ECM. Old age with hot and cold operating temperatures and there in you have the making of a potentially intermittent problem. Mechanically, if the lobes and the toothed wheel are wiggling about because the distributor shafts bearings are shot this will effect the signal quality and if the air gap gets big enough the signal would be lost completely perhaps but just for a moment long enough to set the code. That is an easy thing to check with the distributor removed the play on the shaft should be non-existent but must easily rotate. My oldest boy Blake has an SR5 1990 Extra cab and his 3.0's distributor bearings seized and snapped off the teeth on the distributor shaft when his finally quit at >300K. Thank goodness the cam 's gears did not suffer.

For me as you may recall a quick trip to O'Reilly's and $190 later the new distributor was installed and sure as anything it immediately roared to life with a flick of the key. It was quite a difference in how it would start up with the new distributor and the check engine light was gone. I also replaced my thermal sensor that tells the ECM that the engine is not cold anymore and that triggers for the ECM to go into closed loop so the O2 can help manage fueling the injectors correctly and the knock senor can help allow the ECM to advance the ignition timing to just short of pre-ignition all in the name of increasing fuel efficiency and reducing emissions while at partially open throttle settings where the AFM's flapper and the TPS are not at WOT. So know that when the engine is dead cold and hasn't been run the ECM uses a preset algorithm to administrate the timing and fueling of the engines running and is referred to as running in open loop. It also uses a pre set algorithm when the TPS senses you have the throttle plate wide open and you are flooring the accelerator. For all the other operational conditions when the engine is warmed up all the sensors are used to administrate the ignition and fuel injection pulse times to maximize fuel efficiency, horse power and general drivability and this is referred to as closed loop operation.

Dang now that is another chapter!
Cheers,
ATGP

 

I’m going to go straight in and replace my distributor, unhook the battery and let everything reset and see what happens.

The question is, what’s the difference between the Orielly or Napa $230 dollar distributor and the new eBay units for $60, aren’t they all coming from the same place ?

Update, I ordered a new, not remanufactured distributor from eBay. Napa Auto only had reman units. So when it gets here I’ll install and reset my truck by way of battery disconnect. If the check engine light comes back on, JTM I’ll follow the steps you posted.

And Thank you atgparker for posting that response.

 

My pleasurer bthp223,
The O'Reilly unit is their brand and has a life time guarantee that I know of for sure. The first one I got from them the distributor cap cracked in like a months time. So I returned it and got a refund and ran the original till it died a few months later with the bad coil wire in the sensor. So now I'm on O'Reilly distributor No 2 and so far so good. How old are your ignition wires, they do not last for ever and the distance to #5 cylinder is a long run of ignition wire? Good luck with your prognosis!

 

Everything is all original wiring wise, so far I’ve been blessed to have no issues or trouble with anything. Are you talking about plug wires ?. All new kit from LCE engineering and then I typically will only use Napa Auto Parts electronic wise. Caps, rotors, switches etc.

Plug wires are routed for least contact. I did that back in October.

Distributor will be here tonight, seems like I’m always close to the last stop for UPS, they say by 9pm and I can guarantee the truck will be here at 8:59 pm LOL. So Thursday morning I’ll be out changing the distributor, I’m guessing that 190,000+ is pretty good life from the original.

I’ve been out a few times now and the truck starts right up, as it normally does but I’ve noticed she’s sucking the gas big time since that check engine light has come on. Which has me thinking I should send my original fuel injectors out to a cleaning service and then taking the 4 hole ones out and putting them back in.

I’ll snap a few pictures, everything will be dependent on the check engine light. If it comes back on then I’ll do the paper clip deal and start reading codes.

If it does throw anything I’m hoping for a #21 and or #28 those are fairly easy to replace.

 

Well part the Red Sea LOL, it’s here early. Here’s a few picks atgparker. This new distributor was $52 bucks and has the right rotor for the 1990. I’ll have it in, in a few hours and we’ll see.

 

Well bit of a snag, the distributor goes one tooth up or one down. I stopped yesterday as I was getting pretty frustrated. The distributor that came out has reman stamped on the bottom so it’s not original and has been replaced somewhere before I got it. It feels pretty good as far as play goes, bearings feel ok. So I think this morning I’m going to clean mine up and R&R the guts from new to old and see what happens.

I don't have a timing light so I was hoping with marks made I could get the new one in, cheating and not going to TDC on No#1 etc etc.

If what I do works now I’m gonna have to go get one anyway I wanna try the small advancement you guys talk about. If it’s set on 10 degrees I’d like to see what happens at 12-14 degrees. More power/better mileage.

 

A little kitchen counter surgery going on this morning ! You guys ever watch the Pakistani videos where they fix stuff with next to nothing ? Cheers !

Those guys are pretty amazing.

 

Well success as of now, check engine light is gone and she’s running and idling full power and smooth as butter. Barely have to the bump the ignition and she fires RIGHT up. Just did a 40 mile run so I have to wait and see. Definitely tell a difference, still smells a little gassy at the tail pipe though.

 

So since my last post I had set the timing back to the marks I made. My mileage was down and you could smell my exhaust. Today I got a timing light....finally from a new found friend.

I was set at 4*. Pretty far off and since I’ve never had to mess with the timing before I’m guessing it was set at 10* since I’ve had the truck.

Took it straight to 14* and tightened the nut. WOW what a difference, not subtle at all. Exhaust is cleaner and I’m spitting water from the tailpipe again. The BIG difference is in the throttle response and pull in 2nd, 3rd and even 4th gear ! 3rd gear has always been my strongest gear, not anymore. I’m liking the new found power. I can’t wait to get her out in the desert and have some fun. Also my check engine light has not returned.


Now a question if any of you read this, had to take the wife’s Ford to the shop. Dammit, it kept throwing codes and I replaced everything, turns out it was a leaking intake manifold gasket. I’m not a Ford guy so $300 bucks for that one. When we went to get her truck I asked our guy if he could check my timing real quick.

He was busy, said no and I’d have to make an appointment for this week.

What caught me off guard was he said my 4Runner would have to sit until completely cold before the timing could be properly set ???.

Any truth to that on our second gens ?

 

I'm a new member and I don't know beans about the 4Runner other than there is one sitting in my driveway. But I have two distributor ignition vehicles and I don't think you need a cold car to set ignition timing - unless perhaps you are setting static timing. But if you set ignition timing using a timing light, the engine needs to be running and operating temperature seems appropriate. Perhaps the technician was talking about cam timing. I can see were the engine might need to be cold to set cam timing.


See these links which clearly states that the engine needs to be warmed up.

22-RE Wayback Machine (archive.org)

3VZ-E Wayback Machine (archive.org)

 

Yeah, that’s what I’ve always done. Running and up to temperature. On the old school hot rods disconnect the vacuum line and set timing. My engine is in the truck so we’re not coming off a cam replacement.

That’s why I was kinda suspect, I think he may have wanted to run my OBD1 without saying anything.

 

After running around I found for my 4Runner 12* degrees timing is just about perfect and where I set it. 14* degrees it was using to much gas.