very rough idle, cutting out immediately: distributor? vacuum?

[jbrush]

geez, that was annoying! must have pulled and redone 6 times or more. but finally got it, and the advance works fine too.

for anyone else wondering: one of my issues is telling when i'm at TDC and have compression: feeling with the finger in spark plug hole 1, wait for the "pushing" feeling quite strongly in the period immediately before the notch gets to 0. i repeatedly got foxed by some amount of air moving near or after the wrong TDC.

secondly, i found one has to be really really precise in setting up the distributor drop, and go straight down without touching the sides as much as possible, and i think the angle of the slot is slightly less than 30 degrees (but i didn't have a protractor!). anyway, finally finally got it.

so now it's idling fairly well at 750! pretty major accomplishment. there are still some slight misses and irregularities in the engine, and it sounds like my power steering pump is going (though no problem turning the wheel -- maybe "just" a pulley), and the transmission fluid is leaking somewhere, but perhaps those are all for other threads? trying to keep this all tidy.

i also went ahead and replaced the radiator with a salvage yard one, which was almost straightforward compared to all this other stuff. but that's for another thread as well.

but basically, for this main issue -- i think we can declare victory and move on! thanks tim, a remarkable help you've been.

[timsrv]

No problem, glad you got it all figured out. I know it was a PITA but this is how we all get experience (if it were easy everybody would be doing it). Another way to tell if you're TDC on the compression stroke is to check the valve positions on #1 (of course you need the valve cover off for this though). If you don't have the valve cover off (and don't want to take it off) you can put a compression gauge in the number one hole and watch that to find the compression stroke.

If you happen to get lucky and randomly drop it in "close enough" for the engine to run, then you know you're on the right stroke. Adjusting the distributor a tooth or 2 is easy and doesn't require repeating the entire procedure. Just grab the rotor and articulate it back and forth as you're lifting the distributor. As soon as you "feel" the teeth becoming disengaged, slowly rotate the direction you want until you feel the next tooth begin to engage. Then just drop the distributor as far as it will go. If it doesn't seat all the way don't worry (it's just the oil pump shaft not lining up). Don't force it down, just rotate the crankshaft until it drops the rest of the way. I usually just crank the starter a second for that part.

Sorry I didn't walk you through all this in the beginning, but sometimes I forget not everybody knows these tricks. Tim

[jbrush]

thanks again, tim. yes, those suggestions make tons of sense, would make it all a lot easier! i was on my way by trial and error.

often in other technical contexts i have a hard time putting myself in a newbie's shoes, so i know what it's like. it's humbling to be learning more or less from scratch, but your help makes it much more rewarding and worthwhile!

more questions, in other threads.

[toytime]

I’ve been reading this post and #12 has a part #89422-30020 for the ECU temp sensor, I’m having the same problem I changed out the alternator with a Denso because it died plus as normal maintenance I also did an oil/filter change and changed the plugs and fuel filter. When I was done and started the van it acted just like the post stated, shut down on idle have to keep RPM’s around 1100 to keep running engine is very rough so I started searching the forum and found this post I have three sensors on the neck of the radiator fill port does anyone know what the second temp sensor is for, should I order both? if so would you happen to have the # for the other sensor which is more toward the driver side and is larger than the ECU temp sensor I’ve been going through the Chilton manual but can’t find either part listed my manual which is #368352 and is for the Cressida and Van and it’s a real PITA to find anything also where do you find the Toyota OEM numbers I tried online but had no luck. By the way I sometimes see something about donations what are they used for and where can I donate I sure would miss all the knowledge if it disappeared like so many others definitely worth a few bucks if needed. Thanks Ralph

[timsrv]

It would be helpful to know what year van you're working on. If it's an 86 - 87 van, the ECU temperature sensor failing would typically be associated with a code #4. This sensor is very important to the correct running of the engine. Since the sensor is inexpensive and easy to replace I recommend replacing it ASAP any time a code 4 is read. Here is a picture that shows it's location:



The sensor is Napa part #TS5520 for around $15. If you're rolling in the bucks, then it's Toyota part #89422-12010 for around $80. The part number you stated (89422-30020) is the old number..........was superseded by #89422-12010. The other sensors there would not likely create a problem to the degree of which you describe. The one in the very front is a switch and will have no effect on a cold start. The one on the driver's side is the "cold start injector time switch" and would only create hesitation issues while the engine was cold. I think I would recommend checking the engine closely for loose and/oror damaged vacuum lines. Especially check the big ones like the brake booster (towards the back of the engine) and the PCV valve. Another thing to check would be the condition of the intake air tube. If it were removed or tugged on during the service it's possible it developed a tear or perhaps the air valve tube became disconnect from the tee at the bottom of it. Good luck, please let us know what your find. Tim

[toytime]

Thanks Tim, it's a 1987 2wd auto I've already ordered that sensor, The first thing I checked was the vacuum lines but I didn't know about the tee at the bottom of the air intake tube I will not get a chance to work on it until Wed. Eve. will report what I find thanks Ralph

[timsrv]

The 90 deg molded air valve tube on the back of that tee is easy to miss, and will totally make the van run like crap (ask me how I know). Tim

[toytime]

Tim, I don't have to ask because now I know …... how you know, Thanks Ralph

[timsrv]

Awesome! That's one mistake you'll only make once. Sure, you might knock it loose again, but it will be one of the 1st things you check Tim

[toytime]

Other than the plugs, fuel filter and Radiator hose is there anything else I should look into before putting passenger seat back in Thanks Ralph

[timsrv]

Distributor cap? rotor? plug wires? AC belt? etc, etc, etc....... I guess it depends on condition of these items & last time they were replaced. Tim

[tmiron]

No, the one circled in your last picture is your BVSV (Bimetal Vacuum Switching Valve). Another common name for this is the "Oh crap I broke it valve" . This is because the plastic nipples get brittle over the years and will break if you look at them wrong. This valve's job is to inhibit EGR operation until after the van warms up. With it broken like that the EGR won't work and you'll have a small vacuum leak. You may also get a trouble code in your ECU and the van may not pass emission testing. I doubt you'd be able to find a good one in a salvage yard, so your choice will be limited to bypassing or replacing. If you replace it's Toyota part #90925-05017 and has an MSRP around $50. If your on a budget, you could bypass by looping a vacuum line from one metal tube to the other. In theory this will make the van run a little rough when cold, but I doubt you'd even notice (considering you'll be trading up from a vacuum leak).

The ECU temp sensor I was talking about was the one in your 1st picture. This sensor being broken will make the van run like crap. I took your picture and marked it up (so there's no confusion). It's Toyota #89422-30020 with an MSRP around $80. Tim

What is the sensor on the right side of the coolant cap? Mine broke and I can't find a part number or name to order a replacement part

[brentlehr]

I believe that is the Idle Up Temp Switch - Toyota part # 89428-20050.

[tmiron]

I believe that is the Idle Up Temp Switch - Toyota part # 89428-20050.

Thanks. I don't need the actual sensor, just the plug on the end of the wire that plugs into the sensor. Anyone know that part number I can't find it anywhere

[timsrv]

That switch (Pressure-up Temperature Switch) is worthless anyhow. There was a service campaign back in the day that replaced that switch with a lower temperature one. Very few vans had that service campaign completed, and now the new switch is NLA. You're better off to just cut the old connector off, then put an eye terminal on that wire and ground it out. I usually extend the wire and put in on the front stud of the intake plenum along with all the other grounds. Doing so will activate your "pressure-up" system for 2 minutes after every start. This will help combat the Heat Soak issue. Tim

Here's a thread that further explains the "pressure-up" system of the van: http://www.toyotavantech.com/forum/s...ht=pressure-up

[tmiron]

That switch (Pressure-up Temperature Switch) is worthless anyhow. There was a service campaign back in the day that replaced that switch with a lower temperature one. Very few vans had that service campaign completed, and now the new switch is NLA. You're better off to just cut the old connector off, then put an eye terminal on that wire and ground it out. I usually extend the wire and put in on the front stud of the intake plenum along with all the other grounds. Doing so will activate your "pressure-up" system for 2 minutes after every start. This will help combat the Heat Soak issue. Tim

Here's a thread that further explains the "pressure-up" system of the van: http://www.toyotavantech.com/forum/s...ht=pressure-up

Tim, You just made my day!

[spacecruisers]

looks like you can get the pressure up temp switch aftermarket for about $80. is it worth replacing though, especially at that price? mine might be okay but its hard to tell because the single wire where it runs into the connector is hanging on for dear life lol

[timsrv]

Keep in mind the original specs were worthless (that's why they did the service campaign). If you get one, make sure it's a lower temp setting (like 140 deg F). My way of thinking is that 140 deg switch will activate with almost any start (except when there's more than 2 hrs for the van to cool). Due to that, I say why waste your money and a valuable sensor port? FYI, it's just a temp switch. The Toyota part is NLA, but you can find them for other makes/models. I put one in from a Nissan, but I use it to activate a cooling fan for 15 minutes after shutdown. If you really want one to the specs of the service campaign, go to the heat soak thread, and do what I did there (page 2) except use it like Toyota intended. Tim