No power after head gasket replacement and valve job!!!

[Vegas4Runner]

In the interest of time I will keep the details to a minimum, but after having my rig in the shop for six weeks to replace the head gaskets, do a valve job, replace the water pump and timing belt, and replace a faulty injector, I finally got my baby back. And it now has the torque of a Jazzy power chair.
It is a 3.0 with a manual transmission, and while it was never a beast off of the line, it now takes nearly a mile to get up to 55 on the highway. There is almost no power between 2 and 4K rmps (where it usually pulled the most).
The shop swears that they did a compression test after reassembling everything and they are telling me that it must be a clogged cat. I pulled the O2 sensor in front of the cat to see if I would notice a boost in power (as that would theoretically minimize the obstruction from a clogged cat by allowing the exhaust to vent trough the O2 sensor port). Other than a lot of noise, this made no difference. I have a compression tester, but no time and I don't want the shop to hide behind a "well you messed with it after we got it back to you" claim.
Can anyone think of a reason that would account for the loss of power across the board if the shop is correct and there is no loss of compression? They are closed for the weekend, but I would like to better understand the options before I take it back in there on Monday morning.

 

[penbergm]

One of your brakes dragging? Lift up each end and spin the tires.

Does it idle & rev normally?

Did they or you check the TPS adjustment?

Is timing set correctly?

You doing a compression test should not void their work if it was done correctly.

 

[89FourRunner]

Was timing adjusted properly with belt change? Need correcting?

 

[clunker]

Not sure why the shop would immediately jump to the conclusion that you have a clogged cat. The fact that you went from normal power before the work to low power after the work suggests that they screwed something up. Could be as simple as a one of the hundreds of vacuum lines or electrical connections that was missed in reassembly. Could also be that the timing belt is off by one cog. How much do you trust your shop?

 

[Rodnic]

Most of the time I have seen these symptoms it has been a timing issue, such as a tooth off. Hope this helps and let us know what you find.
Rod

 

[Bad_Vision]

Sounds like you should have that shop put a new cat in. If that doesn't solve the problem then it is still there responsibility to fix it!
When you pay to have something done it should be done right and if they screwed up then they should fix it.

 

[theking11863]

Sounds like you should have that shop put a new cat in. If that doesn't solve the problem then it is still there responsibility to fix it!
When you pay to have something done it should be done right and if they screwed up then they should fix it.

I agree with Vision. If they messed it up they should fix it free of charge. That reminds me I still need to go kick up a shit storm at the shop that messed up my charging system... Might be too late now though...

On another note I now have one more thing to be scared of when I do my HG job :crybaby:

 

[Bad_Vision]

My philosophy is to never waste the money on a 3.0 because they are like the 22re you can dump a bunch of money on them and they still don't perform well. So I spend the money on better engines.

 

[theking11863]

I know everyone shits on the 3.0 but honestly until the HG blew i had no problems with it. For what I used it for it was more than enough and I was happy with it. If i could afford a 3.4 swap I'd do it just for better power and fuel economy but I can't so I'll just fix it. Also I'm only putting $700 into the repair so its not the worst thing in the world

 

[gtgt_bangbang]

I doubt it's the cat, all of a sudden anyway, but you can test for it. Probably for free since there's a muffler shop who will stick a manometer just ahead of the cat to look for excessive pressure while peeking if you need a muffler or cat.

No way I would buy a cat on a "troubleswapping" mission. big $$ for nothing

As a matter of fact I just had my cat checked the other day; the shop simply pierced holes in the pipes with their torch, pressure tested it, And welded it right back up. 10 minutes & gratis. Said there was 1psi in front and 1/2 psi behind for reference, and that it was OK.

If you have a infrared thermometer, you can shoot the front and the back of the cat also. If it's working right the exit is hotter than the inlet. If that's true I doubt it's bad, because it's doing its job. Make sure you're scoping the cat and not the heat shield.

I'm kind of upset with the results of my 3.0 after a rebuild. Don't think I have it all yet, but I put Bosch plugs in. Not exposed fine wire type, instead it was a fine wire supported by ceramic. I checked them after a couple of tanks and the gap was 40 (don't remember but box probably said "do not re-gap". Lots of bosh platinum with special electrodes are 40 or simply not adjustable, ).

However I didn't see why these shouldn't be the standard 032 , so I closed the gaps. The truck ran a lot better immediately. I'm going to get rid of those fine wire plugs in favor of some more conventional looking Platinum ACs and go by the book

"0.032 or fight" .

Sounds like you definitely headed for a compression test ON THEIR DIME. It will be a Royal Pain, especially on the pssgr side, but thats the gold standard. I don't know if you can discern a valve timing problem from a compression test, But that does make sense. Remember it could be either or both cams. Super easy to get set up out of whack when working with engine installed.

Hows your gas mileage ? I would want to bring that figure to any argument with them, especially if you have before and after data.

I presume spark timing was checked ? My spark is kind of jumpy ( usually a sign of a worn distributor shaft, but I don't believe it on this motor) so I have to center "the light band" at around 10deg, with the advance jumper inserted.

I like the timing belt / tooth off idea; that can happen easily. not too damn hard to check either.

I'm still digging around mine and see if I've got everything. I just took it over the Sierras with a modest utility trailer, and I did not become a big 3oh fan.
Damn truck was so slow, The trailer got there before I did.

Maybe I have to just learn to happy with that big floppy pair of 4.88 axles :girl:

I gapped Number five and six valves at high spec, due to the header heat myth.

I know they were spot on (hi) when I've built it, but After a couple hundred miles one of them got noisy as hell , I have to hate it until I can go in, find it and gap it lower.

 

[flyinhawaiian01]

I too think its mechanical timing-related. Set crank at TCD for timing mark, check intake/exhaust gears for alignment with timing marks. Would not be surprised if one is off by a tooth. Its exactly why, when one puts a new belt on, you rotate the crank 360º and check again for alignment! Because of the timing belt tensioner, one full rotation takes the slack up and shows that someone put the belt on one tooth off.

Compression test will not be able to tell you whether the timing is off at the valves, but it will tell you if they didn't do a good job on the head gasket or valve lash shims are put in incorrectly--IF-- they got it too tight only! Problem is, you'd hear it if they were, that valvetrain noise would be extremely noticeable!

Check the belt first, I don't recall how hard it is to get the cam covers off to check, but this would be a very, very simple process if those covers are easy to remove! Just grab a long breaker bar, a socket to fit the crank pulley bolt (its a 19mm on my supra, not sure what the 3VZE is though), do NOT have engine key on! Hell, don't even put the key in the ignition!

Line up crank pulley mark to "0" on timing mark, look at cam gears. Timing marks should be aligned like so:

If they are not, you will need to redo the timing belt installation procedure-or the shop that did the work on it for you should!

 

[gtgt_bangbang]

Aloha-

I shipped my beast out to CA , got depressed by a noise that developed after the first few tanks of dinosweat, finally decided FIAA ( poke it all anyway) and used it for a 700mi trip. Man it is slow. My truck so slow I got tailgated by a molasses tanker.

theoretically compression test might tell you about valve timing if it weren't breathing right, but I'm sure would be subtle to the point of uselessness so I agree.

I'm curious what the sound of tight valves would be? The only ones I can think of would be sounds a backfire to the intake, or that of dripping iron melted from a superheated exhaust manifold. Lightshow before.

I like your "remove key" warning but let's dial it back one step; MAKE SURE YOU REMOVE THE SOCKET & DRIVER FROM THE CRANK BOLT BEFORE LATER TEMPTED TO TURN OVER WITH KEY. What makes me say that? None of yours damn business.

 

[The Count]

I'm going to add another vote for the timing belt being installed a tooth or two off. That will almost always result in poor power production. I've done ALOT of timing belt jobs over the years and have never had one leave that was installed incorrectly. But I have had quite a few come in that run poorly, and had just had work done recently somewhere else, that turned out to be incorrectly installed timing belts.

 

[flyinhawaiian01]

I like your "remove key" warning but let's dial it back one step; MAKE SURE YOU REMOVE THE SOCKET & DRIVER FROM THE CRANK BOLT BEFORE LATER TEMPTED TO TURN OVER WITH KEY. What makes me say that? None of yours damn business.

BWWWAAAAHAAAHAAHAAAHAAA!!! Scary as fawk when that happens, eh? Don't ask me either how I know about this!!!!

So, bangbang, where the hell are you now? You know you wanna come back to Idaho!!!

 

[delloro]

I agree it's likely that the cam timing is off. Happens to the best of us people.

Won't show up on a compression test.

 

[Vegas4Runner]

Sorry for the lack of updates, I have not heard back from the shop yet. That may be in part because of the holiday, but I also think it is because they move at a snail's pace over there. They have now had the rig for seven weeks and I am sure that if they had figured it out yet, they would have called. It sounds like the consensus is that the belt may be a tooth off. I will confirm that they checked the timing when I call and yell at them tomorrow.

 

[flyinhawaiian01]

Wow, that's just piss-poor service right there! 7 weeks? To rebuild a 3VZE? Shouldn't take more than a couple weeks, max, for a shop to pull, tear down, rebuild, and reinstall an engine, and that's taking into consideration a few days of machine shop work.

I'd say once you get it running correctly, never go back to them again! This should be a simple task for them to do if they're an actual repair shop. They should run through the symptoms in the manual and make the suggested repairs.

Hope it turns out well for you in the end, and definitely keep us updated on their progress!

 

[VA_4R]

Sorry for the lack of updates, I have not heard back from the shop yet. That may be in part because of the holiday, but I also think it is because they move at a snail's pace over there. They have now had the rig for seven weeks and I am sure that if they had figured it out yet, they would have called. It sounds like the consensus is that the belt may be a tooth off. I will confirm that they checked the timing when I call and yell at them tomorrow.

Ask them to do a leak down test, it could be a valve seat leaking

 

[Vegas4Runner]

Update: after nine total weeks, I finally have my rig back. The tps was bad and it took the shop an additional two weeks to figure it out. All told the head gaskets, water pump, timing belt, throttle position sensor, a couple of valves, and an injector were replaced. I am glad to have it done, but will never darken the door of that shop again. I am in the middle of getting a PhD and I still could have done the work faster.

 

[flyinhawaiian01]

Wow, TPS, eh? I would have never guessed that one, but [MENTION=122865]penbergm[/MENTION] did, so he wins the internet today!!!

Strange that it didn't throw code 41 though, did the check engine light even light up while it was running bad?

I'd do one other thing at this point, do a quick code check, write down what's there now, if any, then erase it all and see if any come back next weekend.