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Is it possible your ECU got wet or something? Maybe a voltage spike?

We had an '86 Ford Taurus when I was a kid that we used to jump start another car, the Taurus never ran right again after that until we had the ECU replaced. Sh!t happens man!
 

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Discussion Starter #222
Ecu has never had a chance to get wet in the last 10 years. and the one time it did have the chance, it didn't get wet just close.

I am not sure if maybe the ecu crapped out due to the timing box attached to it for the supercharger or what. but I think that maybe the first place I start looking now
 

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bear,

at this point, if I were you, I would start to look into long term, meaning taking the motor out. it has been a long time you try to solve the engine stumble problem, now for sure you know it's not something simple.

since money, time, garage space are all tight, plus your plan for the new rear linkage, I would, first get rid of the FJ project, free up some money, and space. meanwhile, you are on the road a lot, start to look for parts, hit the junk yarks, specailly the exhaust, ECU and wire loom.

your engine has good compression, so internally is sound. you need to target on the corrosion, plumbing and and electrical.

I saw a lot of crimpped wires, solder is the only way. take out the aux accessories first, keep them in storeage, simplify the circuitry. clean, seal, replace the wires, connectors, harnesses.

sorting out the plumbing, vaccumm lines are hell lot easier when you have the engine on a stand.

one other reason you need to get the engine out is when people beef up the frame, often they forgot about the motor mounts which can kill a lot of things.

my 0.02
 

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Discussion Starter #224
Tony, I appreciate you coming over as well as your insight. I agree that I have a lot of electrical "housework" to do. I hate the appearance of all the wires running everywhere. Up until recently I had all that mess buttoned up and looking much cleaner.

as for pulling the motor, I am already making plans to seal up the exhaust as the patch work behind the muffler and around the O2 sensor did not hold. I am also going to change out the vacuum connection we had issues with yesterday. With that issue we couldn't test drive which I wish would have been able to. After that I think the PO120 code may not be such a big issue (not consistant~I can live with it if it only happens once in a while as I suspect it happens)

IF these plans do not solve the issue, then I will seriously consider pulling the motor.

NOt sure what you are saying about the motor mounts though, unless you mean a weak mount will cause the motor to move around excessively. In that regards. the motor is pretty sound. that I have been able to test as I have "rocked" the motor quite a bit wrapping the rev limiter searching for the overall problem.
 

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Can't a leaking exhaust lower the exhaust pressure and screw up the intake mixture?

And since the exhaust pressure changes with RPM I could see a good idle but bad performace at driving rpms.
 

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NOt sure what you are saying about the motor mounts though, unless you mean a weak mount will cause the motor to move around excessively.
yep. that's regarding your future plans of beefing up the frame. the factory mounts ain't the strongest and the rust isn't helping either. all frames flex under load. frame flex absorbs some the shocks but when frame got stiffened up, the motor mounts are taking large portion of that shock. probably some of the bushing are already crispy after 15 years.
 

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...frame flex absorbs some the shocks but when frame got stiffened up, the motor mounts are taking large portion of that shock...
I never thought of it that way...

I've realized the same thing in many other projects, just not in a vehicle frame.
 

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it's none issue for a daily driver, but on an off road rig, you are working against heavy load, strong impact, age and corrosion. you can make that engine runs like a champ, but if it's not sitting at the right place at the right time lining up with the right things, it's not doing you any good. vibration alone can kill so many things.
 

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Discussion Starter #229
yes, a leaky exhaust can cause low back pressure, effecting the Hp.

in my case the exhaust leak did not start until after I changed out the o2 sensor and muffler so I can't really see that being the original issue. But it will be addressed soon regardless. It's a cheap fix in the scope of things and it is only responsible, "green" speaking.
 

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Discussion Starter #230
7/28/10:

picked up a new vacuum connector today. When I replaced the check valve that was installed in conjunction with the supercharger. I found this "y" connector that goes between the heads that leads up to the throttle body was cracked and broken.

I tried replacing it with a generic aftermarket tee, but the truck will not run as the generic is too restrictive.

Although I did get a Po120 code which is the TPS circuit code. I am hoping that it was a fluke from just changing out the TPS and that this vacuum line crack has been a contributor to the problems.

Here is the basis to my reasoning. 1)When first installing the supercharger,I had to wait to install the check valve connnected to this line. When the line did not have the check valve, the truck ran similar to how it runs now, just not as excessive as it is currently. 2) even though vacuum lines have been checked repeatedly since this problem started. This "y" connnector lies in an area on the manifold that is hard to get to and even harder to see. So this could have been repeatedly overlooked.3) These vacuum lines have effected the performance of the motor so severely that the truck will barely idle as is.4) this connector lies in an area that excessive heat has caused this plastic part to become brittle over time. the vacuum lines do not move per sey, but when the motor warms up the crack could have changed, opening & closing which would have resulted in the truck running good after start up and then poorly once the motor warms up. Which is exactly how the motor operates currently.

So as soon as I get the chance I will change out the vacuum lines. Unlike most vacuum lines though these are not easy to get to. they are on the back side of the top of the motor, buried under the wire harness for the supercharger and injectors. The vacuum port for the drivers side can't even be seen and can only be accessed by feel.

IF this does not effect a positive result, and against Tony's suggestion of rebuilding th motor (which is out of the budget for quite some time) I will remove the TCM 1.1 timing controller from the Ecu. and remove the wire taps employed by the TCM. This should resolve the Po120 code as I think I narrowed downn where the short/open condition would be.
 

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Discussion Starter #231
Latest update on BearAttack is: It is still sick! While Andrew was up working on his bumpers, He did have a little time to check some sensor readings and check the coil packs with a spare that he brought with him. So far everything checked out.

I completely removed the TCM 1.1 module off the Ecu and soldered the wires where the taps were placed.

The spark plugs were also checked again for new plugs they had too much carbon build up on them. WE got another set of stock NGK's and discovered the bosche plugs installed by a shop I had taken it to were somewhat shorter than the NGK's. Although the truck did not restart afterwards, it did sound like it was getting a better ignition.

The latest guess is the fuel regulator. although I am pretty sure we already replaced it when at Harlan last year. I am going to swap it out for an aftermarket adjustable inline regulator. What is not making sense is when it does run, at first start up, it acts as if it is getting too much fuel (rich condition) but then begins running lean. The plugs also show evidence of runnng rich by the carbon build up on the plugs.

I am also concerned about discovering an electrical connection hanging down by the transmission. But can not find anywhere it might plug into. The thought on it is that it is actually a "dead" connection from the factory for an automatic transmission. but I have yet to be abe to confirm Toyota actually did that sort of thing as other manufactures will do.
 

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Discussion Starter #234
I have been letting the motor sit. Instead I have been cleaning up a few other issues such as suspension, exhaust etc.

I decided to redo the fuel cell and currently it is preventing me from even starting the truck. But hopefully once I get that back in order the few adjustments we made to the throttle body will make the truck a lot better.
 

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Discussion Starter #235
update!


there is no updatibale progress, without a garage, the temps are too cold to work on it. and Even if the weather permitted, the wallet wouldn't allow it.

I did get the throttle position sensor installed and dialed in, I'm in the process of moving the fuel lines around on the fuel cell again but will have to wait. I also moved some springs around but the front end needs new springs to get the shackle off the frame. Once I do that, I'll have to put a spring back in the rear pack to level the truck out unless I go ahead and convert the rear over to the link set up.

but the motor hopefully will respond to the TPS being recalibrated

Oh and my new odessey battery Sulfiated again (condition of sulfation) so a new one will be needed and I've already been told they will not warrantee the second one.:mad:
 

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Discussion Starter #236
The new "to do list"

1) remove fuel cell to "re-plumb"/ install original fuel cap back on (tired of taking 30 minutes to fill the fuel cell up)
2) re-fill front diff after building new cover
3) replace back brake line (I'm the only person I know that can break a brake line without even moving the vehicle out of the driveway.
4) test drive the hell out of the truck to see if last theory of TPS actually fixed the truck
5) replace battery
6) various other minor crap, I can't think of right now.

The truck feels like I am getting closer to having it running again...but I have felt that feeling before so my hopes are not that high.
 

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Discussion Starter #237
Wow 4-3-2011

That was the date I started this thread.I'm not sure when the last post was made, but it appears this thread can now die quietly into the depths of totally played out threads! It definitely appears the longest fuster cluck in the history or I don't know when is over!!!!

The truck finally drove (WITH UNSEEN POWER) today!!!

The only remaining real problems are the steering system needs to be bled from putting a new hydro assist ram on and the brakes bled from having to replace the master cylinder due to it sitting so long.

I can break down things later if need be but now I must go make some money so I can pay for all the mods I have dreamt of for the last three years!

Happy days! & cheers!
 

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Seems like we have heard this before...jk :D

Hhope you got rid of all those gremlins once and for all! Please gimme the 'skinny on the remedy whenst you get a chance. Good news for sure!

2-12-2009 til 4-30-2013 :eek:
 

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Discussion Starter #239
Seems like we have heard this before...jk :D

Hhope you got rid of all those gremlins once and for all! Please gimme the 'skinny on the remedy whenst you get a chance. Good news for sure!

2-12-2009 til 4-30-2013 :eek:
Oh! I whole heartly agree and had my reservations about declaring the issues to be in the past, but I am extrememly confident the "bugs" at 2500 rpm's are exterminated!i feel this way due to the most successf test drives I have ever been able to perform with the most power the truck has ever demonstrated for the longest duration. Not to mentioned one of the test drives was BEFORE ripping the ignition wires apart over a month ago and the again yesterday!

I'll try to muster up enough guts to eat the crow by giving the entire 411 the next time I'm awake. But right now I just happened to wake up from my post employment slumber long enough to notice the email alert that you repsonded to my post
 
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