What happened? Loss of power, shudder. HG? (1 Viewer)

[flintknapper]

I blocked the one side and applied suction to the other and the engine started to stall out.
From what I can see the wiring harness is buried under the throttlebody and other items. Is there somewhere specific I should be looking? Just on the EGR?

Wiring bundle/harness right by the EGR tube is subject to a lot of heat, you can't tell IF any wires are cooked, broken, compromised unless you unwrap the factory insulation around it. It will be evident if any wires have melted or are corroded.
Good thing to check even if it doesn't prove to be the problem.


I have a fuel filter and I am going to try to get it replaced this evening.

Good to change the fuel filter every 75K or so. Be sure to slot the hole in the filter nearest the engine block. Use NEW crush washers on your banjo bolts. It's not a real fun job, but should be done occasionally.

I have not done a compression check, I'm not sure how to do that.

Compression check will be more for peace of mind than anything else (given your symptoms).

1. Get a compression tester.
2. Disconnect the lead from your coil to the Dizzy Cap and ground it.
3. Pull all plug wires and spark plugs.
4. Wedge something (a stick or whatever) between your seat and accelerator pedal so that the throttle is WIDE OPEN.
5. Hook up a battery charger (if you have one) to your battery and set on about 40 amps.
6. Screw compression tester into cylinder one spark plug hole (securely). The one nearest the front of the engine.
7. Crank the engine for the SAME amount of time/revolutions per cylinder (7-8 revolutions should be plenty).
8. Record your readings (psi) for each cylinder. IF you don't have a battery charger don't be surprised if the #5 & #6 cylinder readings are lower than the first four (less battery power to turn the starter).
9. Look to see that there is no more than 10-12 percent difference between cylinder readings. Hopefully you will have something between 185-200 psi per cylinder.
10. Button it all back up.

^^^^^ Expand above

 

[musthave]

UPDATE

Wiring bundle/harness right by the EGR tube is subject to a lot of heat, you can't tell IF any wires are cooked, broken, compromised unless you unwrap the factory insulation around it. It will be evident if any wires have melted or are corroded.
Good thing to check even if it doesn't prove to be the problem. - removed plastic piece covering wires by firewall. Looks ok so far. Next is to remove the tape like stuff right by the EGR, like 7 or so inches of it.


Good to change the fuel filter every 75K or so. Be sure to slot the hole in the filter nearest the engine block. Use NEW crush washers on your banjo bolts. It's not a real fun job, but should be done occasionally. - filter replaced.

Replaced plugs, wires with OEM just because.

Distributor cap had about a half teaspoon of oil in it. There was a leak from the o-ring too. So I replaced o-ring, distributor, rotor.

The inner most belt was very loose and literally upside down, not sure how that's even possible. So, I replaced all 3 belts with OEM.

Used CRC parts cleaner (buy stock in them), I bought 12 cans so far and buying more. Cleaning everything thoroughly so I can find any leaks once I'm done. Hasn't been this clean since 98.

I have not done a compression check yet.

Once I'm doing with EGR wiring I'm going to wrap things up and see attached f issue persists. Hoping that it's good.

 

[musthave]

Wiring harness looked great, undid everything and then wrapped it in high heat tape, then another wrap.

Put everything back together. Started up.

Same problem. Drives to 30 or so then it shudders when given gas. Opened windows and have funky sweet smell.

Oil looks fine, radiator fluid looks fine.

Slight smoke coming from what appears to be back side of engine. Not sure if it's gunk foam wearing off or something worse.

Thorough clean up earlier shows that I'm leaking oil as shown. That wouldn't cause the shuddering though, would it?

 

[OGBeno]

EFI system related.

Either O2's or MAF.

That my guess.

Or the entire engine needs to be replaced.

Those are your next options.

 

[musthave]

Thanks @beno. I appreciate it. It's only got 220K, engine never dies right?

Would O2 or MAF throw a code?

Is there a way to test?

 

[FJP971]

I wonder if your catalytic converters are clogged? Overheating cats (insert joke here) give off a funny smell.

 

[PDoyle]

What about the air cleaners big rubber hose?

 

[musthave]

Air cleaner hose is good. I don't have a way to check the catalytic converter but again I would think that would throw a CEL code.

 

[Irish Reiver]

Air cleaner hose is good. I don't have a way to check the catalytic converter but again I would think that would throw a CEL code.

This might not be the most scientific method but if you have an IR temp gun, measure the temps at the input and out of the Cat. There should a noticeable difference- around 100f.

 

[musthave]

I have an IR gun. In front of the cat it is about 345 to 360 behind the cat it is 240 to 250.

 

[musthave]

I test drove it again this morning and the same thing is occurring. The smell almost seems like it is an exhaust smell.

 

[PDoyle]

Sounds like fuel.

 

[Traakon]

EFI system related.

Either O2's or MAF.

That my guess.

Or the entire engine needs to be replaced.

Those are your next options.

LOL...after fighting a similar problem on my '93 for a year now and spending almost 2k dollars and hours and hours wrenching and still having the problem reoccur (yes, it looks like it is back again on OSO after a month + of no issues.) I am wishing I had done an LS swap at the start of this.

Musthave - What I can tell you is while your '97 and my '93 have slightly different systems, this can make you seriously crazy trying to resolve. Toyota has many systems, that seem unrelated, that cross paths and show up with this sort of drive-ability issue.

To that point, the power brake booster, since it is tied to the vacuum system which is tied to the EGR, while seemingly unrelated to engine idle/performance can have an effect. A bad check valve, bad vacuum line to the check valve or bad booster all effect engine vacuum and ergo effect engine drive-ability. There are two engine temp sensors, one runs the gauge and one actually feeds the ECU, the latter can cause the issue.
You have a different O2 system than my '93 but your system does a comparative sampling of before against / after the cats and a bad connector or sensor in either location can cause the issue. (The system on the '93 just does an air/fuel mixture "sniff" ahead of the cats) not to mention the cats (one or both) going bad.

There is the fuel delivery side. The little filter on the pick-up of the fuel pump can go bad and when the pump sucks hard for acceleration it collapses momentarily restricting flow. The fuel filter (as mentioned), the fuel pump, the fuel pump relay, the fuel pump resistor (which I am not sure you have on a '97 but I am sure someone will chime in). Then we start crossing systems again, the fuel injectors and/or the injector harness (gets you to the electrical system where we start looking at fusable links, EGR harness, engine wiring harness ECU etc, etc.).

I wish I had something from my fight that I could point you to and say "there, do this and you'll fix it" but all I can offer is that I understand the struggle and understand it might be an epic journey and not a quick trip.

 

[Traakon]

I test drove it again this morning and the same thing is occurring. The smell almost seems like it is an exhaust smell.

Exhaust small can take a couple forms. There is a "rotten egg" smell and there is a "rich mixture" smell. In my experience you can get the slightly sweet "too rich" smell without the rotten eggs smell but if the mixture it TOO rich you get the rotten eggs of overloaded cats.

Both, again in my experience, can come back to the O2 sensors/wiring and the cats themselves.

Try unplugging both the O2 sensors and looking at the terminals, they can corrode and the wiring itself can get brittle and cause intermittent shorts. Just somewhere to look that does not cost an arm/leg and could give you a better direction.

 

[Nors]

Ive had this happen
Once was clogged fuel sock but other time was dreaded hg

 

[musthave]

I picked up upside and downside Denso O2 sensors, putting them on today with a little luck.

 

[musthave]

Ive had this happen
Once was clogged fuel sock but other time was dreaded hg

I first thought HG but no codes, no water in oil, no oil in radiator. And terrific idling, and acceleration to 20.

If it were fuel sock I wouldn't be able to rev it to 3500rpm and hold it without issue, would I ?

 

[flintknapper]

I first thought HG but no codes, no water in oil, no oil in radiator. And terrific idling, and acceleration to 20.

If it were fuel sock I wouldn't be able to rev it to 3500rpm and hold it without issue, would I ?

If you can rev the engine (in neutral, no load to 3500 rpm) without it stumbling....but it will not do so under load (driving it) then look to a restricted exhaust system (read CATS).

The readings from your IR gun suggest failing Cats. You should see roughly 100° temp differences after the engine has had to warm up to operating temperature.

Any decent repair shop can quickly do a 'back pressure' test at your muffler (drill a small hole, test, seal hole).

 

[Irish Reiver]

I first thought HG but no codes, no water in oil, no oil in radiator.

It is possible to get coolant in the cylinders without it getting into the oil or vice versa. This would give you a sweetish smell. That said i, would imagine that some amount of white smoke would be present and quite possibly one of your plugs would have looked stream cleaned.

 

[musthave]

It is possible to get coolant in the cylinders without it getting into the oil or vice versa. This would give you a sweetish smell. That said i, would imagine that some amount of white smoke would be present and quite possibly one of your plugs would have looked stream cleaned.

No white smoke. The smell is no longer very sweet at all I think it is more of an exhaust smell.