Starting problem only when engine is hot

Hi everyone!

Backstory: As you may have seen in my last post, I had an overheating problem and a leak in a hose (you guys so kindly helped me to determine it was a heater hose). So, I made the connection in my brain that we should fix the leak/replace the hose! It all made sense.

So then, I drove the van! I drove it for about 30 minutes at about 9:30 P.M. (~60 degree weather) and no problems in a drive through picking up food for, stopping at the mailbox, and just cruising! And the leak was gone! I even drove it about an hour and 10 minutes one way, and back, so about 2 and a half hours at about 9 P.M. and then at about 11 P.M. back! No overheating at all, no leak, working beautifully. needless to say, I was thrilled!:yes:

BUT then on Friday, I went to a local CVS, about a mile away on a hot day at about 3 P.M. I saw that the temperature gauge started creeping up again! I was so sad :( To confirm, on Saturday, I tried driving the van to a job that I had for the day, and it was overheating again! But I noticed that it would go back to the middle of the gauge when I would be going 40 - 50, and creep up at long stoplights.

My question is, does this mean it is the radiator fan?: I know that on most cars if the overheating happens at stoplight this is the reason, but I wanted advice and thoughts from you Toyota van pros! :wnk:

**Here is the real kicker: The van made me late to the job! ;( Because when I got to a light I know is very long, to avoid overheating, I turned off the engine. When the light went green, I turned the engine back on: or should I say TRIED to! The van would not start!? What does that mean?! I had to have some nice people help me push it to a parking lot and leave it there while getting another ride to the job! BUT, double-kicker!: When I went back to the van at about 11 P.M., (it sat in the nearest parking lot for about 9 hours), it started right up fine! Does this have to do with the overheating or the battery? I am so confused :dizzy:

Well I know this is a storyfull so thank you SO much for any and all help! I just want to get my vanny running great! Breaks my heart! Aside from these small things, it has so much life in it!

Your van probably wouldn't restart because of Hot Soak, which could be exasperated by the fan not kicking on. Flip the drivers seat & start your van. Does the fan kick on?

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Originally Posted by foreverly

Your van probably wouldn't restart because of Hot Soak, which could be exasperated by the fan not kicking on. Flip the drivers seat & start your van. Does the fan kick on?

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Thank you so much for your reply. What is Hot Soak? I am not familiar with it. Yes! The big fan in the front is moving!

Hello im on a road trip Seattle to central Baja in my 87 4x4 van.
I'm havin an intermittent no start problem. We're traveling around 800 miles per day. Van is running great! Other then a high temp guage /: (going to address that next /thermostat / radiator). But once or twice a day the van doesn't start after being shut down.

It turns over once but then dies immediately. After that the starter cranks but doesn't turn over. So far when I wait about an hour it starts again.

Anytime I start the van I have to push the gas after the starter cranks to get her going. Sometimes she 'chugs' a bit before she will start idling. Seems like a fuel issue.

i replaced the fuel filter (no change).
i jumped the fuel pump / runs fine when jumped.

i checked the diagnostic code. I am getting an even 10 flashes. Then pause and repeat even 10 flashes.
i don't see this code in the pdf for an 87?

291k on the body. 110k on the engine according to previous owner.

any help would be greatly appreciated!!!

Actually it's 11 flashes!
And also the rad light / batt light and oil level light are all on always (been that way since engine swap according to previous owner).

iimagine those lights being on will effect the diagnostic codes likely making it inaccurate for trouble shooting my current intemittent issue

I am having trouble understanding what you are saying here.
"It turns over once but then dies immediately. After that the starter cranks but doesn't turn over. So far when I wait about an hour it starts again."

If the starter is cranking the engine, then the engine is turning over. Can't have one without the other.
I suspect you mean the starter is cranking the engine but the engine is not firing up, but clarity of terminology will save much time and aggravation.

Maybe do a search for "Heat soak" and see if those threads match up to your experience.
Failing that you may also want to search threads on ignition problems - think igniter, coil....

There should be a link kicking around to the 87 manual where you can decipher code 11 or just do a search for said and you will also find many threads.
As far as your dash lights go, search for the term "Christmas lights" and you will find many more hours of reading enjoyment.
Those dash lights are a separate issue from the rest and likely won't be causing any issues with engine fault codes.
BB

Thanks for the advice!

thank you for the terminology clarification.

Your suspicions are correct. Once or twice a day the van will crank and fire up, but die immediately. Then I try again and it cranks but doesn't fire at all.

Now it's evolved a bit and when it does fire up its just barely firing with my foot on the gas for Mayb 45 seconds. The 'firing' slowly increases and she starts running and continues to run fine.

this only happens after I've been driving. Each morning (after sitting all night) she starts just fine.

another possible clue to mention. The idle is high around 1.5 - 1.7 which makes it tricky to shift out of neutral to first or reverse. I was thinking Mayb this 'no start' issue was from me struggling to change from neutral to first and getting too much fuel 'in the system' and then needing to wait for it to 'clear out'.

the van is running warm / hot
but I've kept an eye on the temp and I don't believe I'm experiencing 'heat soak'

thanks again for any advice / input!
ill search for code 11 info now / Ignition problems

I think you need to review the threads on heat soak, as it sounds a lot like the problem you're experiencing.
Don't confuse heat soak with running hot, as they are 2 different things.
Heat soak refers to the fuel boiling in the fuel lines, essentially creating a situation where you have insufficient fuel pressure.
This can happen even when the engine is running at normal coolant temps.

All that said, if it were mine, I would take the other issues first.
The way I see it you have at least 4 things all happening at the same time (excluding the hot starting issue):
High idle, running hot, Code 11 and christmas lights.
There may be more, but you won't know till you dig into it.

Seeing as the PO replaced the engine, I would start with rechecking all of the stuff involved in the swap, from electrical connections to vacuum leaks to whatever. I wonder how they even managed to set the timing, given that its "idling" at 1500+rpm??

Out of curiosity, does it have a fan shroud?
If it does, I would replace the T-stat with a new factory one, then go through the rest of the cooling system to verify that everything is as it should be.
Christmas lights are simple enough to sort out, same goes for Code 11.
BB

PS - That high idle speed is very hard on the drivetrain parts, but shouldn't have anything to do with it stalling out

Code 11 is the same as 51 on the 88-89 vans, "switch signal". This is likely the throttle position sensor but could be something else. There are a number of threads regarding that. I would start with checking the connector. If this is not working it could be causing the high idle. It also affects the ignition timing which could affect the operating temp. If the timing was set to compensate for the TPS not working that could also cause the high idle. The higher operating temps could be contributing to heat soak which is definitely what your hard start issue sounds like. Like burntboot said I would start with reading the heat soak threads but also the TPS threads. I suspect a number of your problems may be related.

Thanx for the replies! The no start issue definitely seems to be 'hot soak'. The Yota made it down to central Baja and home to the Olympic peninsula :) the 4x4 and narrow wheel base / turning radius was great for navigating off road to the surf. Unfortunately we were in a hit and run accident on i5 at 75mph :/ and my cherry van now has a very sad back end /:

Sorry to hear about the crash, nothing worse than having that sort of thing happen.
And while it sucks to be hit, hopefully no one was injured.
Is the damage repairable?

So I've been having this problem for over a year and just need some direction of where I should be looking to fix it. Only Randomly, and only after driving it and warming it up, if I go to drive it again while its still warm, sometimes it will have serious trouble starting. its not a starter issue. it seems like its running super rich or something just at startup. it will start super harsh and the idle is very low and rough. I'll have to give it a lot of gas to not stall out, and it will stall out sometimes if I need to reverse. once I'm moving for a few seconds its back to normal. no problems...could this be an O2 sensor that needs replacing. just trying to get some insight on where to start replacing things. thanks!

I'd be tempted to start with checking for stored codes and take it from there.

I am having the same EXACT problem. Sometimes when the engine is hot I have to turn the key while at the same time go into drive and give it gas or else it just stalls out. Starts up fine when the engine is cool. And it helps when I add water to the radiator while the engine is hot (I guess this is just speeding up the engine cooling). This has been a mystery problem and no one I have talked to has any idea about it. Any help Please!!

Sounds like heat soak, but it's the middle of winter. Was it worse in the summer?
Codes!!!?(clear and recheck).
After warming it up try opening the "hood" and leaving it open while you do whatever you're doing(errands eh?). After you're done with your errands try to start it and is it easier?

It only started happening about a month ago but it definitely is worse on the hotter days. And yes thats what I do when I do errands, open up the 'hood' and sometimes put cool water in the radiator.

Attachment 6556

try grounding whats labeled as the idle up temperature switch wire and see if that helps..
its not advisiable to ad cool water to a hot engine.

Also to the original poster, have you tried giving it gas while starting it up? while still in park.

Yes. this is usually what I need to do to get going or it will stall. sometimes its worse then others and takes up to 10 seconds or so at full pedal down to even engage to revving up. then its jumpy and erratic for a few seconds till I actually get moving then its back to normal.

Thanks guys for the responses. outside temp doesn't really make a difference did the same thing all through the summer and winter. how would I go about "clearing the codes" ? this is something I don't have any experience in. also I will try the whole grounding the switch thing. thanks ! also attaching a photo of my spaceship cause threads without photos are boring :p
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Here is the "heat soak" thread:
http://www.toyotavantech.com/forum/s...ight=heat+soak

Aside from the fact that adding cold water to a hot engine isn't a good idea, why is the coolant low?

If the system is full, you shouldn't be able to add anything.
If the engine is hot, you shouldn't be able to take off the "rad" cap, at least not without a scalding shower and serious burns.
If you are regularly topping up the coolant then you have a leak somewhere that you need to find and correct. (its supposed to be a sealed system)

An engine thats running too hot will indeed cause "heat soak", but for all the wrong reasons.

How many miles are on the van? My first guess would be a failing fuel pump. I had random weird things happening for months, before I figured out it was a bad fuel pump.
Has the fuel filter been changed? Many times this get overlooked with regular maintenance.
Gas cap seal should be replaced just because...especially if you have never done it.

Sweet van and even sweeter rims!

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Originally Posted by djshimon

Sweet van and even sweeter rims!

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Thanks! the wheels are more rare then the van. they are from a Mitsubishi Starion the weird style the tuner guys don't like hahah. they just required extended lugs but fit good and give me a little more width.

Thanks for the input guys! the problem is most definitely heat soak. I just don't understand why I drove it for a year or so without it happening at all until now. its so bad now that it happens every time. I'm thinking its another component going bad like the fuel pump or regulator. because its happening on like 15 degree days. and every time. but opening the hood and waiting 10 min does fix it. but aint nobody got time for that! also how important is the gas cap when it comes to the pressure system? all this started happening about a year or so ago after my dad left the OEM cap at the gas station. so its an aftermarket fuel cap.

Your picture is kind of making me miss my back window, also loving that blue color!

Totally off topic, but what's going on w your rearview mirror and what was involved in making it work?

I tried some hot rod round mirrors briefly but couldn’t see much. Still looking for a more streamlined solution and dig (what I can see of) yours:thmbup:

Fuel injected systems need to maintain pressure in order to work properly.

If the gas cap is not sealing the system, I would compare it to keeping a balloon inflated that has a hole in it...it may work for awhile if you keep blowing, but eventually you WILL lose pressure.

If you have been experiencing this for a year already, it is very possible that your fuel pump is also going bad, especially if it has been overworking for a year to try and maintain pressure in a leaking system.

I would start with replacing the gas cap. You could have your existing cap tested at a smog shop (possibly at an auto parts store), but if this problem started after you started using the current cap...I would suspect that you have the wrong cap or a faulty cap.

Maybe you will be lucky and the gas cap will solve everything. Keep your fingers crossed.

say what willis?!?! no, not true

CC - Gas cap sealing is very important on new ('95->) cars as the vapour side is sealed and recycled.
Prior to that, you can drive around with the cap off with no drivability effects, won't do much to keep out the water and leaves though

AS to our vans. Yes they are fuel injected and yes they do run at pressure.
Pressure in the system is maintained by use of a 1-way no return valve working in conjunction with the FPR.
The fuel pump supplies the pressure to that system.
If any of those 3 components are weak there will be an issue with fuel pressure.
Less fuel pressure will indeed exacerbate heat soak, thats why the factory fix was to essentially raise FP.

What you really need to do is DIAGNOSE the PROBLEM instead of GUESSING.
This requires actual hands on , getting dirty, kind of labour.
Sometimes it aint any fun at all (though sometimes it can be a blast) at the very least it is rewarding when you finally hit upon the real problem.

You need to diagnose your fuel system, that would mean checking fuel pressure, under several circumstances, to ensure that FP is in the correct range (not too high or too low) and that after the system is shut down that it MAINTAINS that pressure for the correct amount of time.
Heck even the fuel damper can cause a loss of system pressure if its leaking. ANY leak will cause the pressure to bleed down and the less pressure the more likely it is for the fuel to boil in the lines (aka heat soak) it is NOT only the providence of TV but a common affliction of any and all fuel injected engines.

If you had had heat soak since day one, different story, but when it rears its ugly little head after being "fine" for a long time, thats a clear indication that something in the system has become marginal.
So, go find it and fix it and be done with it.

PS it is of course important to have the correct cap in the vehicle, some are vented and some are not, but that has nothing to do with what CC was talking about.

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Originally Posted by boogieman

try grounding the idle up temperature switch wire

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Would someone please explain this process?

Cut the wire going to the idle up temp switch as labeled in the pic in post #17 of this thread. It's the one with a single wire. Attach a ring terminal to it and ground it under a bolt somewhere close by. This will tell the computer to temporarily increase the fuel pressure at startup every time.

Quote:

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Originally Posted by originalkwyjibo

Cut the wire going to the idle up temp switch as labeled in the pic in post #17 of this thread. It's the one with a single wire. Attach a ring terminal to it and ground it under a bolt somewhere close by. This will tell the computer to temporarily increase the fuel pressure at startup every time.

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Thank you! Do I need a "high temperature" ring terminal?

It is not necessary.

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