Van sputter and hesitation after hauling a##.

[timsrv]

It's a keyed connection to the TPS, so it won't go on wrong unless there's damage to the connection. The last time I did this (the one where I shot the video) I also got a TPS code afterward. I then checked the timing and checked for it to advance when I pulled the jumper out of the "check engine" connector. The timing didn't advance so I was like "damn, did I get a bad TPS?". Upon further inspection I realized I had forgotten to plug the harness into the TPS . I'm happy to report the problems went away as soon as I plugged in the TPS. You should definitely check the condition of the harness connection there. I'm not sure what else to tell you. Sometimes these type issues can be a real PITA to diagnose and repair. The good news is you're starting to run out of things to fix. Once you find and fix the real issue you'll have a practically new van . Tim

[Cornato]

You're telling me. Jesus Christ.

Well how do you check the ignition timing? And I also think maybe not all the VSV's are working correctly. Which I turn the key I can only hear the one near the filter box click.

[llamavan]

Check the O2 sensor wire to make sure it hasn't been compromised. If there's a break in the connection, the ECU will throw the O2 sensor code. That may not be your van's problem, but it's always best to check the easy things ...

Gwen

[timsrv]

I had missed the post you made about it not being the TPS..........I think we were posting at the same time. So anyhow, that's good the ECU is no longer throwing the TPS code. Did you clear codes AFTER you installed the new o2 sensor? Keep in mind the ECU needs to be cleared after repairs or it may continue to display the same code (even after the fault is gone). If you verified the o2 code was gone then came back AFTER the new o2 sensor was installed, then it's very likely the harness connection to it is messed up. Inspect it closely to make sure the wires and connectors are in good shape. Tim

[Cornato]

Yeah I didn't inspect the harnesses, TPS or 02 sensor. I'm getting so tired of spending every weekend working in my van.

And it would be pointless to take it to a mechanic because I've run every test and replaced everything he would. SO I'm so far into repairing it now I might as well finish it.

Good god how great it is gonna feel when I finally get it fixed. Tex will be invincible when I get him fixed. That's the only hope I'm holding on to.

[Cornato]

So I just went to a Toyota Specialty mechanic just to get an opinion, and he said they don't even work on these vans anymore! He said his mechanics would go on strike if they took another van in for repair. Haha.

He said to check the MAF though. He said they wear a grove in them from constantly moving and can stick. He said to open the part on top that you're not supposed to, and just caulk it back. I don't really like how that sounds. Thoughts?

[Cornato]

Ok, distractions this week prevented me from getting anything done. So tomorrow I'll swap out the igniter and maybe check the timing. After that I'm completely lost. I ordered a shop manual from ebay. So maybe that can help.

And by the way, right when I bought the van there was a van that just got to the pull a part by me. So I checked it out not knowing anything about the van just grabbed a cupholder. I went back yesterday after 6 months thinking I'd grab a few parts to keep in reserve....

Good God.

It looked like a burned out car in Iraq. That thing was bare metal. I don't know know how someone pulled a motor, tranny, a/c, suspension, etc with cars on all sides 2 feet away on gravel. Somebody really wanted EVERYTHING. Guess I underestimated how rare these things are.

[RawbSpear]

Here's a video I took the last time I replaced a TPS. Enjoy

I love you Tim!!!. My 87 4wd van, 160k miles, "Sola Thumper" has been having the Hesitation when cold issue. i started checking everything and it came down to my TPS, code 11. (i keep thinking about TPS reports)....anyway i got mine out today and it sounded like a baby rattler. This vid was instrumental on the repair. I'll find out tomorrow morning if it all worked out. Funny part is van seems to run great after it has 20+ miles on it and is completely warmed up. The first 20 miles i thought the van was going to stall out if i hit a stop sign.

This last 2 weeks of trouble shooting i have replaced the Cold start thermo time switch(bad numbers on ohm meter, cheapest on amazon.com), the temp sensor(broke in half when i tried to take the connector off(rock auto), the t.p.s.(amazon.com), and the o2 sensor(rock auto). I also super cleaned out the throttle body, totally dirty, replaced vacuum lines, and cleaned out the egr regulator filter. Van seems to be running better than ever.

other recent repairs (5k miles): swepco oil change with oil improver, cap, rotor, wires, plugs, pcv valve and grommet.

Excited to drive it tomorrow and see if this project is completed.

[timsrv]

Thanks for the kudos. I hope that did it for you. Nothing like a correctly running vehicle. I got a crash course in GMC throttle body injection this past weekend (makes you REALLY appreciate Toyota quality). I challenge anyone to work on a 91 TBI 454 in Chev P-30 chassis. Seems like everything was an "afterthought" on this vehicle. I did finally have success and the vehicle was purring like a kitten when complete (thank God). Now I'm gunna go drive it up to the station and blow $300 on gas .........Tim

[RawbSpear]

van works better than ever but still hesitates. First, it only did it when it was cold. Now it only does it after initial warm up and then works fine after its been driven 10 miles or more. Only hesitates when i first run car that day but not on later missions. Any ideas?

[timsrv]

Vacuum leak? I don't know. Intermittent issues are the hardest to chase down. Good luck. Tim

[RawbSpear]

the MAS was showing bad numbers 28ohms instead of 200-400, on one of the connectors. Replaced it yesterday. Before i bought a new one i opened it up and found a broken solder connection. I repaired it but that did not fix the numbers. Van drove very well last night. Hoping i get better mileage to offset these sensor costs. Have to try it cold and see if still hesitating...crossing fingers.

[RawbSpear]

hesitation problem continues.
Im getting burnt and broke from this project. At least the van runs better even if the hesitation issue persists....

I dont get it. Ill bet its that stupid air sensor that make you have to remove the upper part of the motor to replace. Problem is everything i test says its supposed to be replaced.....

[timsrv]

Oh the joys of vintage vehicles. Things get old & need replacing. You test the things you can & scratch your head on the others. Sometimes these type runability problems are the end result of several smaller issues. I doubt it's the air valve though......unless there's a broken hose or vacuum leak. Sometimes when I get these type problems I just start swapping parts until I stumble across the culprit. I know it's not the most professional way to diagnose but if the part already has a couple hundred thousand miles on it I figure it's time anyhow. If the new part doesn't change anything then I'll save the old one as a spare . Eventually you have enough spare parts that you can swap them around to test future issues . If you have the space, having a parts van around can be very, very beneficial at times. Good luck. Tim

[RawbSpear]

I just found a thread on the other van site and it suggested the ignitor. The thread said it was temp sensitive. 400$ part....jeez.....may go to JY for this part just to try it.

My van has only 161k miles.

[timsrv]

Here's some: http://www.ebay.com/sch/i.html?_trks...nitor&_sacat=0. I always pick these up when I find a van in the salvage yard. Sometimes the yard will get greedy (those times I leave them behind), but I typically pay around $10 for these............and yes, the coil & igniter can be sensitive to heat & or moisture. These however are not the type of parts I'd associate with a hesitation.........but I've seen stranger things. Tim

[RawbSpear]

I got it!!!

it was the "idle up temperature switch". its one of the three sensors next to the radiator cap. The 2 other switches were bad too and have been replaced

Got it for 50 on eBay but 1sttoyotaparts.com had it for $90.

list of parts to make my van run better than ever. Everything here was broken at 160k miles:
M.A.S.- 225 eBay, Python remanufactured
T.P.S- 125 Amazon
Idle up temperature switch- 50 eBay
cold start timing switch- 130 rockauto
temperature switch next to 2 above switches- rockauto
o2 sensor

also cleaned Air filter -k&n
replaced vacuum lines
super cleaned throttle body

The new MAS has a rich/lean adjustment my old one did not have.

For the first time ever I dont have any knocking or pinging.