Ignition Timing not responding SOS

[Arivalsend]

1988 4Runner 3.0 3vze engine.

Ok fellow members I am hoping for some help on a timing dilemna. I recently replaced my timing belt, top dead centered the engine...ect. Its all back together and it fired right up after remembering to reconnect my MAF wire. So now generally after timing belt work I have had to advance the engine back to 10 before top dead center. As the engine generally starts up at 0 degrees btdc. In this case I checked the timing and it was already at 10 degrees btdc. So I was a bit stumped on this and the engine was running alright. I then went ahead and shorted the check connecter as per the manual instructions and the engine speed remained the same. So the RPMS did not decrease when I shorted the check connecter. So now I am stumped on where to go with this. Is it my EGR valve? Anyone run into problems of this sort. I just timed a friends 94 4Runner and it went just perfect. So this one has me stumped. To top things off I need to get this out on the road, carrying me to Colorado in about a week. So the clock is ticking for me and I hate to drive it without it being timed. Hopefully you guys have some insight on this. Thanks all and I will keep working on it.

 

[Tucson T4R]

When we rebuilt my son's 1990 3.0 we thought we had the timing correct. We drove it for 10K miles and finaly had our machanic check it out. He noticed that the distributor adjustment was all the way over to one end of the adjustment slot. If everything is correct, when properly timed, it should be mid way in the adjustment slot.

It turned out once the engine turned over a few times and belt self adjusted, the cams were a little off. One cam was 1/2 tooth advanced and one cam was 1/2 tooth retarded. :elkgrin:

He retimed the belt and all fell into place perfectly. This may not be your problem but it's easy to look at the distributor adjustment to ensure it's mid way in the slot.

 

[Grim Reaper]

Wouldn't be EGR. EGR has to due with mixture. If the EGR was open at idle it would attempt to stall.


I'd set it TDC on the crank and double check the timing again. Should be able to get the covers off the cam gears to see the timing marks without pulling a lot off.

I haven't messed with the 3.0 but on my 22RE and the 7M in my supra has similar FI. When you jump the diagnostic plug for timing you should get a steady blink on the CEL if it has gone into diagnostic/timing mode and did not have a code stored. That would confirm that you have indeed got it into test. Did you get the blink confirming diagnostic mode?

What speed is it idling at?

Check for IDL on the TPS. If the TPS does not make the IDL connection you may not get the RPM drop.


edit:

Didn't I read you left something unplugged when you tried to fire it off? Try resetting the ECM (pull the FI fuse for a couple minutes). It may be stuck in a limp mode from the missing signal the first time you tried starting it.

 

[DaveInDenver]

Haven't worked on many 3VZ, but see if I can help.

With the engine fully at operating temp (so take it on the highway), turn off the truck and put the TE1-E1 jumper in. Then start the engine and let it idle. The check engine light will be flashing, which tells you it's in diagnostic mode. The idle RPM should about 800 and your advance should be 10 degree TDC. Spin the distributor until you get there and snug the hold down bolt. That's the extent of it and like T4R says, should be somewhere close to the middle of the slot.

I'm not 100% sure what you mean by the RPMs changing with the jumper in. This is the base idle advance and it should be the same as your regular warm idle. The advance will be disabled, so the engine won't run well when you rev it. If disabling the advance makes the RPMs go up or down, then you might have the screw on the throttle body wrong and the idle speed is set too low or high.

If all this checks, you should be within a tooth of having the right cam timing.

It's also possible you just put the distributor in one tooth off.

 

[Arivalsend]

He noticed that the distributor adjustment was all the way over to one end of the adjustment slot. .

thanks for the post, I have also had a similar problem and it was one thing I checked right off. Mine is right in the middle.


Guys thanks for the fast posts and I will be sure to get a more detailed overview in the morning.

Grim- after doing some more checking I found that my idle speed is also low once it really warms up. I am dipping from 7500 to about 5000 when its really warmed and has been run around town. So I am wondering why all of a sudden my idle speed has dropped off. I am going to pull the covers off tomorrow morning to just double check. I must have checked those suckers around 4 times before reassembly though. I also hand cranked the engine over a couple times and then checked another time before I put it back together. I did try to start the engine without remembering to reconnect the wire to the MAF sensor on the air intake tube. Your suggestion is a good one about resetting the vehicle and I will pull the F1 in the morning. I am a in the dark on the IDL and TPS, could you elaborate? Cheers

Dave-I am not sure that my vehicle is entering the diagnosis mode. I will double check that in the morning as well. It would seem that nothing changes when I short the two connecters. I just know that generally when I put in the short my engine RPMs change and in this case they do not change at all. I guess what really threw me off was that according to my timing gun my vehicle was already running at 10 degrees btdc. I guess what I am confused on is what the short really accomplishes? I know that it effects the auto engine advance, but how do I check if my engine's advance works? This has always been a hazy area for me and I am hoping to diagnoss this once and for all.:REOutShootinghunter

Thanks for the input and I will be sure to get some more info for you guys tomorrow.

 

[DaveInDenver]

How's the diagnosis going?

I guess what I am confused on is what the short really accomplishes?

Shorting the TE1-E1 turns off the ECU's ability to advance the ignition, among a few other things. This is your base ignition timing, in other words, how soon before TDC that the position sensor inside the distributor tells the igniter to fire the spark. The ECU will advance the ignition from this point as RPMs increase and so it's important to set it to close to factory because the knock sensors on our old engines (I'm not even sure the 3VZ has one) are pretty much useless.

 

[Arivalsend]

Dave thanks for the 'short' information. That makes a good deal more sense now. Well after some time spent working on the problem today I was able to do a few things. First I pulled the upper timing cover again and double checked my cams. They are good and the timing marks line up just great. So then I pulled the battery leads and let the rig sit for a couple mins to just see if I was off from the MAF sensor issue. After this I made sure that my short was in fact doing the job. When the short was in place my engine check light did come on, but was not a steady blink, although the blink was not completly random. It threw me a bit because it has a strange pattern to it. Not a steady throb. So after this I again hooked up my timing gun and reset the engine at 10 btdc (the recomended FSM setting). At this point my engine seemed to be running ok, seems to be running rich...but no solid evidence yet just a bit higher fuel consumption. The idle was still dropping down very low to about 500RPM and struggling when down that low. After checking my manual I could not find much info on adjusting it. On some it seems that there is a set screw with a rubber cap that can be adjusted. Mine on the other hand does not have this. Although on the front of the throttle assembly there is another set screw which adjusts the throttle. I went ahead and dialed this in for the time being just to get my idle rpms back to normal. Let me know if this is a major no no. So after brings me up to the moment. The engine is running well, but I am worried that it may need further adjustment. Any suggestions or revelations guys? Thanks

 

[DaveInDenver]

I think you got the right screw. I attached a photo showing what the idle screw looks like on a 22R-E and yours will be similar.

It sounds like your idle is set too low. With it jumpered, make sure you're at 10 degree and if so, adjust the idle to 800 RPM. I believe on your engine when you pull the jumper out, it should actually pull back to about 8 degrees at idle, right?

The check engine light should be flashing, that's one of the other features. That pattern that it's flashing is not random, but the stored trouble codes. There are decoders so that you can read them. You count the quick flashes and there are pauses between codes. It's always a 2 digit number. If there are no codes stored, the CEL flashes 2 times per second. If it's telling you a code, it will flash the first digit at 1/2 sec per digit, pause 1.5 seconds between code digits, 2.5 second between stored codes and 4.5 seconds before repeating the stored codes. Make sense? That's all in the manual and on the web.

Keep after it, you'll get it.

 

[Arivalsend]

Dave that picture is worth 1000 words thanks very much. I was adjusting another screw after passing over that one as being a permanent mount for my throttle body. I just put the other screw back to where it was and then dialed my idle right to 800 and it worked beautifully. I have yet to take it out due to my spending the day working on a faulty starter. But hopefully tonight I will have it back together and I will be sure to post up an update. Crossing my fingers Thanks for the post and the code description, making more sense to me now.

Cheers
Lucas

 

[Scenic WonderRunner]

Here is the idle adjusting screw on my 3.0V6

It's right behind the orange boot on my tranny kick down cable......see it?

Sounds above like you got it..........just thought I would share the pic for others to see what it looks like.

My kick down cable looks messed up there because it was! Mr. Sucky laid the cable on my new headers and melted it! That's why I took the pic a while back.

 

[DaveInDenver]

Circled it, hope that makes it a little clearer.

 

[dieselcruiserhead]

the 3VZE does in fact have a knock sensor and it can spit out some issues as well. I'm having a pinging problem currently that I am trying to figure out with one day (Sunday) off before Cruise Moab...

http://www.pirate4x4.com/forum/showthread.php?p=8171699#post8171699

 

[DaveInDenver]

the 3VZE does in fact have a knock sensor and it can spit out some issues as well. I'm having a pinging problem currently that I am trying to figure out with one day (Sunday) off before Cruise Moab...

The general consensus with the knock sensor on the 22R-E is that it looks pretty and that's about it. It doesn't do squat in my experience to keep the engine from actually pinging, particularly with a header and the valve chatter. If you go with forged pistons, forget about it. Maybe the knock sensor on the 3VZ is better.

 

[dieselcruiserhead]

Not sure if it is or not, mine is pinging like crazy unfortunately. Also sounds like a PITA to change...

 

[DaveInDenver]

Not sure if it is or not, mine is pinging like crazy unfortunately. Also sounds like a PITA to change...

Have you checked the base advance? If the sensor is failed, it will set the check engine light. But it's possible that it is not dead, but also not working right. In any case, the ECU for a 3VZ is like the 22R-E and neither try and stop knock under 3000 RPM. So it's possible to lug the engine and get a ping that the ECU does not try to stop anyway. I have to bring my advance back to 4 degrees in the summer to keep from knocking (the base on a 22R-E is 5) and that's how I solve it...

Does it ping at wide open or partial throttle or all the time? Mine never pings at WOT, but I will get a little ping at 5 degree advanced and about 50% throttle if the air temperature is really warm, above 90F, and I'm running cheaper gas. I always use 87 octane (which is our mid grade for people at sea level) and I think it's just at the margin for my engine. But I don't like running 91 because that zaps all my power.