water in gas tank/lines?

[filterway]

Hi everybody!

yesterday i had problem with the acceleration of the van. When i'm driving, go at a constant speed of 60 miles/hour, then i release the gas pedal for maybe 1-2 seconds, and when i try to push again the gas pedal to maintain the speed at 60 miles/hour, engines have misses. I have to push down the gas pedal in the floor to bypass the problem.

In a stationnary mode (warm engine) , the problem come when the engine is idling around 1800-2000rpm. The idle is perfect at +/- 750 rpm. the problem is when i gradually increase the gas pedal. the rpm increase constantly, but when it reach 2000 rpm, the needle go back to 1800 rpm, then 2000rpm, then 1800 rpm etc... to bypass this problem i'm pushing hard the gas pedal and the engine rpm go 3000 rpm and over, as usual.

can someone help me with this?

The van is used maybe once a week. the gas tank was less than the half (maybe water formed here in the gas tank when temperatures is low like -25 celsius. i forgot to fill it to avoid condensation in the gas tank)

[timsrv]

Did you check for codes? If not, do that and report back what you find. Tim

[filterway]

Did you check for codes? If not, do that and report back what you find. Tim

not yet, this is my next step.

Tim is it possible to upload a video on the forum? (not a link, i don't have any youtube or google acount). i filmed the symptoms and i d'like to share it.

Jerome

[timsrv]

not yet, this is my next step.

Tim is it possible to upload a video on the forum? (not a link, i don't have any youtube or google acount). i filmed the symptoms and i d'like to share it.

Jerome

I'm not sure. I've tried it before but it didn't work. Not sure if the format I was using was supported or not......could have been any one of a hundred reasons. I do know that you can upload to photobucket, then link over (I've done that before). Photobucket has free accounts available. BTW, I doubt your problem is water in the gas. it sounds more like an electronic issue. Tim

[filterway]

Did you check for codes? If not, do that and report back what you find. Tim

No codes. (with warm engine)

i think i hit something underneath when i tried to pass over a frozen snowbank to park in Montreal. There is a prestone line and 2 wires. the symptoms appeared after i tried to park.

You can see where the snowbank hit the coolant pipe (copper) but there is no leak. I don't know what to de next....
21092110

[filterway]

I'm not sure. I've tried it before but it didn't work. Not sure if the format I was using was supported or not......could have been any one of a hundred reasons. I do know that you can upload to photobucket, then link over (I've done that before). Photobucket has free accounts available. BTW, I doubt your problem is water in the gas. it sounds more like an electronic issue. Tim

Tim i think i have found something. On the repair manual, at page FI-79, there is a fuel cut RPM. i don't know where is it what is the purpose, but it cuts the rpm at 2200 and it return it at 1800, the exact area where i have rpm problem.

Here is a pic of the page.2111

I need to know where this thing is.

[timsrv]

It's possible. Disconnect your TPS (Throttle Position Sensor) and take a test drive to see if the problem is gone. If it's gone, then you have a bad TPS. The TPS is mounted to the side of your throttle body. Here's a thread that features the throttle body: http://www.toyotavantech.com/forum/showthread.php?1242-Article-Cleaning-the-Throttle-Body. 5th picture down is a straight on view of it. Near the bottom of the 1st post I have a video link that shows how to adjust it.

There is a little spring clip on the TPS wire connector that makes it difficult to remove. Use a dental pick or something similar to remove the clip, then the connector will pull right off. Tim

[llamavan]

i think i hit something underneath when i tried to pass over a frozen snowbank to park in Montreal. There is a prestone line and 2 wires. the symptoms appeared after i tried to park.

You can see where the snowbank hit the coolant pipe (copper) but there is no leak. I don't know what to de next....

That's the coolant pipe from the rear heater back to the block; fortunate that it's not leaking because those are long ago NLA. For future reference (if it does leak), that pipe can be replaced with bulk hose.

The "wires" are rear HVAC control cables; nothing to do with your fuel issues.

Gwen

[filterway]

It's possible. Disconnect your TPS (Throttle Position Sensor) and take a test drive to see if the problem is gone. If it's gone, then you have a bad TPS. The TPS is mounted to the side of your throttle body. Here's a thread that features the throttle body: http://www.toyotavantech.com/forum/showthread.php?1242-Article-Cleaning-the-Throttle-Body. 5th picture down is a straight on view of it. Near the bottom of the 1st post I have a video link that shows how to adjust it.

There is a little spring clip on the TPS wire connector that makes it difficult to remove. Use a dental pick or something similar to remove the clip, then the connector will pull right off. Tim

Thank you Tim! Now more questions in mind...!

IF TPS is defect, is it possible to drive the van if the connector is unplug? if yes, what is the purpose of a TPS? I really need the van but for now with cold weather and no garage it's impossible to me to do the job.

For my personnal information, what is the utility of a "Fuel cut RPM"? i had a volkswagen golf and the rpm was cut in the hi rpm like 5500, but for the van i don't understand to cut it around 1800-2200...

I looked this morning in my old parts box from the last owner and i found a used TPS. As i saw in your video, i have to remove the throttle body to replace the TPS. I'll look in the repair manual how to check the TPS if it's work.

[timsrv]

I wouldn't waste time with a used TPS. The contact points inside fail (usually around 100k - 150k miles). I wouldn't even trust one that tests good because they usually become intermittent before they fail completely. You can get the Beck Arnley TPS on Amazon for around $35 (free shipping if you have prime), so in my mind it's a no brainer.

As to what the TPS does..........The TPS is a sensor for the ECU. The ECU determines how much fuel to inject based on information from this and other sensors. When the information is good, the fuel mix is precise. With a precise fuel mix the van will run clean and you'll get the best performance/best fuel economy. When a sensor is bad or disconnected, the ECU goes into a default "limp" mode. While in limp mode, the ECU is blind to the actual needs of the engine, so it approximates fuel mix. The TPS is also part of the electronic advance system, (so no electronic advance with the TPS disconnected). The van will still idle and run fairly good, but emissions will increase and power/fuel economy will suffer. Another thing to keep in mind is your catalytic converter. Over long term high emissions can destroy your cat (so it's best to keep your van running clean).

FYI "Fuel Cut RPM" is a mode programmed into your ECU that briefly shuts off injectors when sudden deceleration is detected (it's an emissions thing). If there's a malfunction with this system, it's either a bad TPS or a bad ECU (TPS sending bad information or the ECU is not processing it correctly). The TPS is definitely the most likely cause, however, these ECU's are aging (we're coming up on 30 years) and nothing is exempt from failures due to old age. If you disconnect the TPS and the problem still exists, then I would consider swapping the ECU (for troubleshooting reasons). Since swapping ECU's is easy (compared to replacing the TPS), if you have a spare, you may wish to do that 1st. It's my opinion that if you're driving a vehicle this old, you should keep a spare (known good) ECU as a back-up. Over the last 3 years I've had 3 ECU failures on my 86 van (different type of failure each time). Prior to that I had never seen an ECU failure (even while working for Toyota). Used ECUs can usually be found cheap on eBay. Just get the part number off your old one and put it in the eBay search box. These can typically be found for $20 - $50.

As for your comparison with the Volkswagon, I think you're confusing the "Fuel Cut RPM" with an "RPM Limiter". These are 2 completely different things. Tim

[filterway]

well after removing TPS connector, rpm is good, no misses around 1800-2200rpm. So next step i'll order a new TPS.
code 51 appears also on check engine.

Just curious, rockauto sell this one that don't look to fit...

https://www.rockauto.com/catalog/moreinfo.php?pk=482317&cc=1279818

I already ordered the throttle body gasket from Toyota dealer , 17$ CDN ouch!
I will also order vaccum lines because some looks bad.

Jerome

[timsrv]

Yeah, I don't know why they display an incorrect picture. Amazon shows the same pic, but that is the correct part number. The one you get will look like your old one. BTW, code 51 is what you'll get on 88 - 89 vans when the TPS is bad or disconnected. Did you have that before disconnecting the TPS? BTW, good job doing your homework and pointing me in the direction of the "Fuel Cut RPM" issue. It's been so long since I've run into and diagnosed that issue I had almost forgotten about it. Please report back with your results.

When replacing your TPS be sure to adjust it correctly. There is a video link at the bottom of that throttle body post that explains it. Tim

[filterway]

Did you have that before disconnecting the TPS?

no, i had no codes before disconnect the TPS.

i'm wondering why the 3 others TPS on Autorock are around 66$ to 88$ and the one with wrong picture is 36$.

i have to use the van maybe twice a week for around 50 miles each time. Is there any risk to drive the van with TPS unplugged? (i'm thinking about the catalytic converter)

Thanks a lot Tim and Gwen for your help. I'm learning a lot here on the forum :thmbup:

Jerome

[timsrv]

It's probably okay. I put a lot of miles on my vans (about 2k miles per month). Not too long ago I was chasing an o2 sensor issue (turned out to be a bad ECU) and put almost 6k miles on my van (in limp mode) before I finally knuckled down and got to the bottom of it. I'm guessing there are rigs out there that have been running in this state for years. Still, I have to admit I was getting nervous about my cat, and that's what finally motivated me to get mine taken care of. Roll of the dice I guess, but I would be surprised if it caught up to you in the next 5k miles. Tim

[filterway]

Here is some pictures of the spare TPS i found in my parts box. I can't compare it with the one still on the throttle body but it look not so bad. Maybe the right blade seems to be dark.

I tested continuity and it's good.

For those who already seen Bad TPS, how look this one compare to a faulty TPS?
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It's a part that does not need as spare on the road, just unplug the wire! (it's easier to drive with more gas consumption then remove the throttle body and change the TPS on the side of the road)

[Burntboot]

I'd have to say the inboard contact is burnt, but I am no expert.

Given what a PITA they are to replace, do you really want to spend a couple of hours messing about only to find you're still having problems?
You won't know if that TPS is bad or if the problem lies elsewhere?
Even if the used one you have functions, how long do you think it will last? Days, weeks, months???
Stuff a new one in there and be done with it for another 20 yrs.

For what it's worth, I had 2 spares of unknown origin, would have been a lot cheaper than what Toyota Cda wanted for a new one.
Hindsight being 20/20, it was still a good call, simply because it eliminated all the guess work and all of the problems.

Just my 5 cents. (we don't have pennies up here anymore)

BB

[filterway]

It's possible. Disconnect your TPS (Throttle Position Sensor) and take a test drive to see if the problem is gone. If it's gone, then you have a bad TPS. The TPS is mounted to the side of your throttle body. Here's a thread that features the throttle body: http://www.toyotavantech.com/forum/showthread.php?1242-Article-Cleaning-the-Throttle-Body. 5th picture down is a straight on view of it. Near the bottom of the 1st post I have a video link that shows how to adjust it.

There is a little spring clip on the TPS wire connector that makes it difficult to remove. Use a dental pick or something similar to remove the clip, then the connector will pull right off. Tim

Tim, the link is great, but it don't show pictures how to remove the TB. Is there a procedure somewhere how to remove it? I think there is coolant hoses to remove (still don't understand what coolant hoses have to do with the throttle body, someone explain to me:cnfsd:). Still a lot of questions about removing the TB.

Jerome

[timsrv]

Coolant is circulated into the throttle body to prevent icing problems in cold climates. For anybody living in a tropical area the entire bypass system is completely useless, but for those of us who need the van to run in sub-freezing environments it's not a bad thing to have.

Not much instruction to give. Basically 2 small coolant lines to remove, one electrical connector, and 4 bolts. Of course there's the vacuum lines and the cables, but this should all be self explanatory. Take a picture or put some tape on the vacuum lines so you can put back in the same position.