wrenchmonster

Glina, I'm beginning to think you may have a mechanical problem. I'd do a cylinder leak down test if you have that available. Basically you'd hook up air into the cylinder through the spark plug hole and then put the cylinder at the bottom of the power stroke, so both valves would be closed. Then you charge the cylinder and try to determine if the air is leaking through the intake side or the exhaust side, or bubbling your oil past the rings. Snap-on and others sell this tool.

Beyond that I'd double check all the previous work done. It's all too easy to miss something the first time around. Also, just because it's a new part doesn't mean it hasn't failed already. Sometimes you get a defective part and sometimes you just haven't dug deep enough to figure out not only what has failed, but WHY it has failed. In any case, I wish you the best and hope you get it figured out soon.

TNRabbit

Here's an easy check; pull your ECU/EFI fuse to reset the computer and see if you still have the problem....
??

Stranger things have happend...! :-)

Glina

Thank you guys for help. I'll check everything once more and keep posting about effects.

Mechanical problem? hmm.... Doesn't it mean that my rig should burn oil or coolant or even smoke just a little bit (but it doesn't)? I don't hear any knocking, and idle is just perfect - on hot engine 800 RPM. Anyway I'll do a compresion test as soon a possible.

I'm using oil (in all my cars) Shell 5w-40 synthetic all year round. My 4R has 180.000 miles on it, HG changed at 155.000.

trythis

You might look into teh throttle body, and see if it it coated in gunk. It may be that the throttle body plate is not closing all teh way, causing the computer to misadjust the fuel mixture. THe TPS wouldnt be closing and that could mess all sorts of things up, including your timing.

FOrgive my ignorance if this idea does not translate from a 22re to a 6 cyl.

mr toytech

i really think if you have the means i would try another coil and ignighter. i have seen many coils act up only when the engine is warmed up. if you are unsure about it running rich or lean, pull the spark plugs and look. and if you can take a pic of them as close as you can to the electrode, [the part that sparks] and post the pics so we can see them. that is if u dont know how to read spark plugs. most people can get a decient idea of what the motor is doing by seeing the plugs. btw, ive seen many bad coil ohm good and still be bad and a good coil ohm bad. ohm ing a coil has NEVER worked for me and i work on yotas every day.

lVlr_87

I am having very similar problems Glina. And I have found a 'band-aid' for the problem as I am looking for the problem. I can plug off the vaccum line that comes out of the top of the EGR valve and mine misses ALOT less, to the point where I can live with it for a while. Disconnect it from the EGR and plug the vaccum line with the end of your finger or a screw. Try this on yours and see if it reacts the same. If it works for you maybe we are looking for the same problem. I have changed EGR valve, O2 sensor, TPS, VAF and my injectors are being rebuilt right now. I have even bit the bullet and took it to the stealership and they got up to $300 before I had to get it back from them as it was obvious they were guessing just like I am. I will post on how the new injectors affect the issue.

I am looking at changing the coolant temp sensor next to see if it is somehow affecting the choking of the engine as it only misses once it is warm? Any suggestions on this anyone? I have been getting Codes 7 and 11, but mostly 11. Any input on other stuff to look at?

I have a remanufactured Jasper engine my truck that only has 15,000 miles on it. My problems started after I drowned out my engine in some water last year.

Glina

I'm not getting any codes. I'll try the EGR vacuum trick and I'll see what happens.

I've checked spark plug twice, they look good enough - thers no sign of running rich or lean, maybe becouse it's not happening all the time.

rdharper

Glina;

Just thinking out loud here. Since the condition occurs when you are at speed, but without backfire, this implies fuel cutoff as has been suggested. The question is, is the ECU doing that, or, is some component in the fuel chain failing periodically.

Since it occurs at speed, and while attempting to maintain a steady state, but not otherwise, this suggests the ECU is doing it. What could be causing that?

The TPS misadjusted very slightly, could do it. Suppose when you get to this failure condition, your throttle position will be quite close to the idle position. Suppose the TPS switch is set just to the wrong side enough for the position to be interpreted as the idle position. What happens? Well the ECU will attempt to cut fuel flow, in order to lower rpm's to a proper 800 rpm.

So if you are with me so far, how about trying this: When I was first troubleshooting my TPS problem I noted two things. When I disconnected the TPS all together, my problem disappeared, performance-wise. I had the opposite problem of you. My idle position was never being seen by the ECU, so at idle, the ECU would continue to try to lower the rpm's, taking it down to 500rpm, which seems to be some limit under which the ECU stops this process. Point is, simply telling the ECU that the TPS is not there at all, by disconnecting it totally, removed the performance problem, although I would get a code, of course. Also, this test made it clear that the TPS was my problem, and not something else.

After verifying the TPS was good (as you have done also), I made a quick test. Reconnecting the TPS, I loosened the two screws on the TPS so that I could hand set the thing while the engine was running. Turning it while idling the engine, I found the knife edge point where idle was just detected. (You can tell this because you will get a sharp rpm shift from 800rpm to 500rpm. You want it to just barely be a normal 800rpm where the throttle is against the idle stop.) Tightning up the screws and road testing confirmed the position was good.

If this theory is good for your case, you will find the idle position on (at idle) just a bit too far (in throttle rotation), just to other side of where I had my problem, if you follow. A slight error in the setting will cause a problem at idle if too far in one direction, and a problem at speed, if too far in the other.

Ok, back to day-trading... lol.

lVlr_87

I also thought it was the TPS, everything points to it. I tested, set, bought a new one, tested set, positioned it with the engine running. Took it to the dealership and had them set it- didn't work for me.

rdharper

Jake; Your problem is a bit different (and even more frustrating) from Glinas, right? As I recall you have a problem at warm-up, but you have it at idle and under load? This could be two problems, which will always drive one nuts...

Did you give up on getting it diagnosed by a dealer?

Also, you are running a 22re, right? While I've got one of those as well (85), I've never had any of these problems with that guy, so I'm not sure the TPS problem is identical, as I don't see nearly as many comments from the 22re crowd on TPS problems. Could be there are just less of them, but I'm thinking the 3.0 engine had more "feedback issues". Not sure this is right, just an impression.

Btw, you have no coolant loss, right? Have you done a leakdown test, or at least a compression test?

lVlr_87

Mine runs fine UNTIL it warms up. Then it has a slight miss at idle and stumbles under load while driving. It also misses if I just hold it at a steady rev- not sure of the RPMs- no tach. I am not losing any coolant, but I do see alot of "water?" come out of the pipe until it warms up.


YES, I did give up on the dealer. By the time they finished 'diagnosing' it would cost as much as a new engine. $240 to adjust the vavles. They ensured me it would cure the problem, so I picked it up and adjusted them myself and it is still there. As they 'diagnose', they continually call with all these charges of things they have to do in order to keep 'diagnosing', not to mention while they are charging for labor to make the adjustment/replacement the clock is still running on diagnostics labor- WHAT A RIP OFF!!!!!


Sorry- I just noticed GLINA is dealing with a 3.0

rdharper

Jake; How about opening a thread on your problem, restating what you've done. Since I have a 22re as well, I'm just as interested.

One clue has got to be the way you first had the problem... the water thing. If that really is where all this started, it has to be a big clue (as you know).

Have you done a leakdown test... or at least a compression test?

Glina

I've tried TPS trick, but nothing change exept rpms went higher at idle - but it was stumbling anyway.

When I was revving her up I've noticed a little bit of dark grey smoke from exhaust. What could it be then?

Do you think it maybe runnig rich when hot?

TNRabbit

Have you tried a well-placed sledgehammer blow to the ECU??!!?

rdharper

Glina; When you say you tried the TPS trick, are you referring to the disconnect of the TPS connector, or the loosened screws such that you can adjust the TPS while the engine is running? I would be curious as to what happens if you disconnect the TPS and try test driving it.

As to the smoke, I think that the common opinion is that blue is oil, whereas black is fuel. Not sure this is always true, as I believe I've seen bad rings produce black smoke. Maybe before the days of cats.

Btw, the higher rpm case should be either when you have disconnected the TPS connector, or when you've adjusted the TPS so the TPS thinks the throttle is in the idle throttle position, against the idle physical stops. What are the two rpm numbers for both cases?

lVlr_87

Well I said I would post how the injectors did- no help at all. Still have my issue.

Glina

I didn't lose tps srews I just dissconnected it. When I did the rpms went higher, and it was stumbling whet i test drove it. CEL came on ofcourse.

rdharper

Glina; I see. The higher rpm case upon disconnect, suggests the TPS is seeing the non-idle setting at throttle at physical idle stop. But the fact that it doesn't correct your test drive suggests something else is wrong as well. Two problems, probably both minor, can drive one nuts...

I think the TPS setting is maybe not right. In any event, you should be able to get it to run perfectly with the TPS disconnected, or at least I believe that based on my own experience.

You might try rechecking the timing with the TPS disconnected. I set mine at the 12degrees others have used in this forum (instead of 10). If the timing is low enough, it might explain both the stumbling and the grey smoke.

Glina

some more news from battle field.
I was driving today with disconnected TPS and it drives perfectly - no CEL!!!
RPMs when hot are 1000 - 1100 with the rpm screw srewed in almost all the way.

What's wrong then? Why doesn't ECU throw any codes? That's all very strange.

rdharper

Glina: Ok.. that is the way I expect it to perform. Maybe the ECU settings needed to "adapt". Not sure why you don't get an error, I did, but I didn't bother checking what it was. Personally I wouldn't worry about that for now.

Here is what I'd do now.

1. Check your Timing... set it at least at 10, better 12 BTDC, after warmup o course. (or reverify it is set there, I suspect you are a bit low)
2. Next, try bringing down the rpm's (I'm assuming they will still be high, as were mine) using the big flat-blade screw driver slot on the side of the TB. Clockwise should bring it down to 800.
3. Next, hook back up your TPS, and try setting it while the engine is running so that you get the higher setting of (now) 800rpm. This is the "knife-edge" switch setting that seems to cause problems. You want to just detect the idle position, which will be the higher rpm, now 800 if steps one and two went right. If you have succeeded with 1 and 2 above, the TPS out of idle position (throttle still hard stopped at idle) will cause the rpms's to drop to 500rpm. You want the higher 800 rpm with the TPS set properly.

(hope that was clear)