[ckalous]

Hey there,

Just finished a full engine rebuild on a 94 Previa sc AWD (2tz-fe) predicated by a cracked head. My first full engine rebuild, though I have done tons of work on 22r engines in the past. After putting 500 miles on it around town, drove it from Colorado to Chicago. It ran fine over-all but I have a few questions if anybody has the time.

1. It had somewhat low power on mountain pass climbs- couldn't stay at 60-65mph. Is that normal for the little 4 banger with a super-charger? I know my trucks with 22rs couldn't stay up to speed either. I did not own the van pre-rebuild so I don't know its performance.

2. Its running rough (and a little high) at idle and sometimes has a bit of a stall when accelerating cold. Que paso?

3. Just recently, the oil light (not oil level light) blinks when accelerating from a stop or turning hard. Plenty of oil and no light even during hard acceleration at speed. Oil viscocity too low? I may have put in 5-30 , I can't remember. The book recommends 10-30 in summer.

4. How do you know if the super-charger is working or needs maintenance?

5. Check engine light was on for at least a year before the head cracked. It was not on for the first 5 minutes of its new life, but I ran it out of gas (freaked out about that for 45 minutes before realizing it- ha ha) and then it came on on the next start. Maybe unrelated. Probably ought to have that looked at, eh? I don't have any experience with checking or reading diagnostic codes (or the gear), should I have a mechanic run it and get a final check-up on everything?

5. Finally, all the engine (except pistons, crankshaft, block) and timing components are new. Anything else I ought to replace, maintain along with the rebuilt engine?

Thanks- I will post pictures of the rebuild soon and explain some mistakes/solutions that I ran into, because if I can do it, anybody can and it may inspire some newbies to dive in.

 

[zythr]

To answer question 1, even with the Supercharger the 4 cylinder still has to pull a heavy vehicle, so it will be kind of slow uphill, though not as bad as the regular 4 cylinder. Was it just you, or did you have passengers and luggage?

 

[compusatman]

1. In NE Tn and NW NC the Appalachian Mountains are probably considered rolling hills compared to CO. But returning from the SE coast summer beach vacations back to TN I26 is the preferred route to NE TN. I bought my '92 Previa ALL TRAC new and it now has 265K miles. The section of interstate climbing Chimney Rock mountain on the return trip is probably 10-15 miles. We would always be in 2nd and 3rd gear with the pedal to the floor to get to the top. Loaded with luggage,coolers etc for a family of four. So your experience doesn't surprise me.
2. Rough running. What is your timing set at? What plugs are you running?
3. Try 20W50 for the rest of the summer and see what happens. I know, thicker oil is not supposed to be better. The oil sending unit controls the fuel pump so it could be an electrical issue.
4. No experience with pressurized engines.
5. This will tell the tale. You need to verify the codes that have been set.
6. Are the sensors new? Did you clean the MAF? Any vacum leaks?

Under the drivers seat is the diagnostic box. With engine and accessories off open the cover and short (TE1 and E1). Then turn key to on (not start) and the codes will flash in the dash. Post back your results.

 

[ckalous]

Thanks for the replies so far- learning a lot!

Zythr: Not too heavily loaded, me and my tools and a bit of luggage. Could run about 50 on steepest parts. Its really what I kinda expected based on my other 4 cyl toyotas.

Compusatman:

2. Timing is not adjustable on this as far as I can tell. Cap is not movable. Manual says that the computer does it. I didn't drop in platinum plugs, but not the low end either.

3. No oil change yet. I'll get back to you. But the idea that I stated that it does it turning is wrong- I'm simply accelerating then, too. More info: light comes on only off a stop, does not seem to coincide with a certain rpm, shuts off BEFORE the downshit into second. Can flutter a little. Never after the initial start, even under hard load. When I rev in neutral- nothing, When I rev against the brake- nothing. Starting to check the sensor which is NOT new. MAy just get a new one if they are cheap.

4. Thanks to you, I delved into codes. Didn't realize that I didn't need to use a handheld. I reset the codes, engine light shut off and hasn't come back on after about 35 miles. We'll see if it comes on under harder driving. Seems to have helped with the idle, too, but it might be my imagination and I haven't hooked up a tac yet to see what's happening for real.

5. Gonna do the MAF (which I didn't know exsisted until you brought it up), and check vacuum...thanks a ton

 

[compusatman]

Thanks for the replies so far- learning a lot!

Zythr: Not too heavily loaded, me and my tools and a bit of luggage. Could run about 50 on steepest parts. Its really what I kinda expected based on my other 4 cyl toyotas.

Compusatman:

2. Timing is not adjustable on this as far as I can tell. Cap is not movable. Manual says that the computer does it. I didn't drop in platinum plugs, but not the low end either.

3. No oil change yet. I'll get back to you. But the idea that I stated that it does it turning is wrong- I'm simply accelerating then, too. More info: light comes on only off a stop, does not seem to coincide with a certain rpm, shuts off BEFORE the downshit into second. Can flutter a little. Never after the initial start, even under hard load. When I rev in neutral- nothing, When I rev against the brake- nothing. Starting to check the sensor which is NOT new. MAy just get a new one if they are cheap.

4. Thanks to you, I delved into codes. Didn't realize that I didn't need to use a handheld. I reset the codes, engine light shut off and hasn't come back on after about 35 miles. We'll see if it comes on under harder driving. Seems to have helped with the idle, too, but it might be my imagination and I haven't hooked up a tac yet to see what's happening for real.

5. Gonna do the MAF (which I didn't know exsisted until you brought it up), and check vacuum...thanks a ton

2. Timing is adjustable. Look under the hood at the emissions sticker. Or go here: http://www.autozone.com/autozone/re...-TUNE-UP/Ignition-Timing/_/P-0900c15280089eef Read through a few times. There is no substitution for NGK platinum plugs in this engine. I would not take a chance.
3. Oil light could simply be a low idle speed. See link in #2.
4. You did not record the codes before you reset the 'puter?
5. Be careful with the MAF. Do you know where it is? There is a spray cleaner just for the MAF at popular parts houses. I find it hard to believe that this cleaner is anything else besides a degreaser. But I have not confirmed it yet. I do know a replacemant MAF is expensive.

 

[outsider60]

Just make sure the cam timing is on. If not will just about the same symptoms you mention.
Poor power, mil on, rough idle.
Oil light blinking??????
s/charger almost never needs maint. just make sure theres oil in it, theres a dipstick on the back of the s/c.
If you rev the engine past 1350rpm the compressor should kick in and engage the clutch.
Hope this helps you some.....
If you could post the dtc codes would be great.......
Any further questions just fire way..............

 

[ckalous]

Thanks for the advice, everyone.

Funny thing about compusatman's comment on the MAF cleaner- even before I read that, I held up a can of throttle body/carb cleaner and the MAF cleaner to the NAPA guy and said "a difference, really?" and he said "Oh, yes, you'll ruin yer sensors with the carb cleaner..." with a tone like I was a total douchebag. I'm not in my hometown, so NAPA guy elitism has not been broken down, yet.

Codes: Initially got code 23 which was oddly absent from my chilton's manual- just skipped from 22 to 24? Another source said its some fuel thing and could have been triggered when I ran it out of gas and then tried starting it over and over for 45 minutes before realizing the problem. So he said, in light of the fact that the check engine light was on prior to rebuild, off on first start, then on after repeated dry start attempts, reset and see if it comes up again on the broken-in engine (containing that magic gasoline).

Another oddity, the Chiltons (I know, I know Chiltons blows, etc. etc.). Its says no MAF on the 2tz-fe, yet I look and there it is (or something that looks like it).

Proceeding on all other suggestions, will update as I go...this is super-fun, thanks again!

 

[AlaricD]

Just finished a full engine rebuild on a 94 Previa sc AWD (2tz-fe)

You sure it's supercharged? The supercharged engine is a 2TZ-FZE, not the 2TZ-FE.

If you have the 2TZ-FZE, then there will be an ODB-II connector under the lid for the fuse panel in the middle of the dashboard. Far easier than using the diagnostic connector under the seat. Also, the -FZE has a MAF.

 

[ckalous]

okey-dokey- right about the S/C (its in there and on the label). Wrong about the 2tz-fe?...that's what the block has stamped on it, but I guess the fze comes from everything else? Its weird, though because some things (like the diagnostic connector) look like the diagrams for the tz-fe, not the fze, but other stuff fits diagrams for the opposite.

And no, I'm not in third grade if you are starting to wonder...

 

[AlaricD]

okey-dokey- right about the S/C (its in there and on the label). Wrong about the 2tz-fe?...that's what the block has stamped on it, but I guess the fze comes from everything else?

This .PDF details some of the key differences between the -FE and -FZE engines, among them being differences in valve timing, oil jets for the pistons, and resin-coated pistons on the -FZE.

 

[compusatman]

OK Calculus, where you at? You bail on us? Find a new woman? Dog die? I hate it when someone asks good questions and gets answers from dedicated posters and gets the problem fixed and never returns to tell us about it. Maybe we could all learn a bit from your experiences, ever think of that? Don't be a Judas. So you gonna' come to my house, drink all my beer, borrow a few bucks for gas, grab a piece of pizza and leave? I thought maybe you would be different.

 

[ckalous]

Oh man, speaking of drinking all yer beer. i been crying in mine. Drove it back form Chicago- no problems other than the little oil light flash discussed above- still there with heavier oil and new sensor. Since it seemed to be running fine, decided I'd ferret out the issue later. Cruising 80mph through Nebraska no worries, for hours and hours. But then...blew at least one piston heading back into the mountains. I haven't cracked the crankcase, but rolled at least one bearing, or broke a rod, or something real bad. So all the above discussion is moot!

Maybe I had a serious oil pressure issue after all. Caused by the bearing starting to go? Oddly, it did also flash on hard LEFT turns only. I just figured it was some wiring/short issue.

Not sure if I have it in me to pull it back out, probably have to get a crank, pistons, new gasket kit...start over. Or the money- the vehicle was free to start with.

I was hotdogging, I knew the risks.

Coulda just bought a new engine by now.

Not sure what I did wrong the first time. Maybe not clean enough? Wrong bearings? Wrong rings? I do seem to be confused about the ft-ze to ft-fze thing. Although the machine shop guy ordered those for me.

If I don't start it on fire just to watch it burn, I'll start a new thread when I find out what went wrong.

:headbang: I've never used these little smilies before, but this one seems too appropriate to pass up!

 

[John A Feider]

Hey there,

Just finished a full engine rebuild on a 94 Previa sc AWD (2tz-fe) predicated by a cracked head. My first full engine rebuild, though I have done tons of work on 22r engines in the past. After putting 500 miles on it around town, drove it from Colorado to Chicago. It ran fine over-all but I have a few questions if anybody has the time.

1. It had somewhat low power on mountain pass climbs- couldn't stay at 60-65mph. Is that normal for the little 4 banger with a super-charger? I know my trucks with 22rs couldn't stay up to speed either. I did not own the van pre-rebuild so I don't know its performance.

2. Its running rough (and a little high) at idle and sometimes has a bit of a stall when accelerating cold. Que paso?

3. Just recently, the oil light (not oil level light) blinks when accelerating from a stop or turning hard. Plenty of oil and no light even during hard acceleration at speed. Oil viscocity too low? I may have put in 5-30 , I can't remember. The book recommends 10-30 in summer.

4. How do you know if the super-charger is working or needs maintenance?

5. Check engine light was on for at least a year before the head cracked. It was not on for the first 5 minutes of its new life, but I ran it out of gas (freaked out about that for 45 minutes before realizing it- ha ha) and then it came on on the next start. Maybe unrelated. Probably ought to have that looked at, eh? I don't have any experience with checking or reading diagnostic codes (or the gear), should I have a mechanic run it and get a final check-up on everything?

5. Finally, all the engine (except pistons, crankshaft, block) and timing components are new. Anything else I ought to replace, maintain along with the rebuilt engine?

Thanks- I will post pictures of the rebuild soon and explain some mistakes/solutions that I ran into, because if I can do it, anybody can and it may inspire some newbies to dive in.

Hey ckalous.....glad to hear you went the extra measure in rebuilding a Previa engine. I'm currently attempting the same thing. Did you ever get to the post on your pix and experiences, etc. I'm anxious to learn more!
Thanx for the post, John

 

[Kurtanius21]

His last post explained how the engine exploded. It's not likely he will post pictures of his long failed project. I suggest you consider a JDM import engine or buy a rebuilt engine by searching this on ebay:

Toyota 90-95 Van Previa 2.4L non-supercharged 2TZFE Engine Long Block TLB2TF