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16 valve TPS Question
I'm the guy in the middle
me, ( i can know what he did wrong but I say he did,)
and your so called engine builder

never put any unknown engine
in you car
unless you do the on pallet engine compression test. I'd you install it or someone else?

show me his build list. (all steps done in the rebuild after all , only that matters, and if things skipped) and was the engine test stand tested,?
and I will show you why he messed up.,

did you put lots of miles on this car?
the first smog test was June 2017, so ? you been driving his engine this long?
what is his warranty.?
1 month,
and miles limited?

sounds to me like bad build.
the 130PSI proves that. x2. (adjacent cyclinders failed?)
one more comment. (how to save time and labor by working smarter)

i get the engine back , it's on a pallet.
i attach my 5sp bell housing to the engine, then starter, then with battery on ground or in car, use jumper cables and crank the engine (yes full oil in engine)
The DECK test, this is not INSTALLED !!!
I crank it, until oil pressure (a tool gage on side of left block , sender out)

i crank for full 55 PSI pressure, that is step #1, if that fails, back this dirty piggy goes to the schlock builder. (he fails to test his engines I BET YOU and is schlock shop, if yes, is.) 50 is ok too, 10w-30 oil not 0w , ok?
passes. say if not, then any or all bearings are shot..!!@!!! or pump regulator stuck open and is BAD !

test ,# 2
I get PSI near above, good ! even cranking for 5 full seconds wait 1min crank again, do not overheat any starter, ok?

test 2. pull valve cover, and crank until i see oil flow , if not?, then tell the builder no top end oil flow, he failed, (head 0.050" bottom left orifice clogged, or gasket wrong. If not top end flow the cam seizes driving around the block what a tragedy that.
Ok top end test passes ....
test 3: compression test on the pallet , spark plugs out, throttle blocked open or TB missing.
passes say 180PSI , sealevel , tell me altitude I tell you this number.

now install the engine, i just saved you 10+ hour or more hard labor by doing the job right first. above.

a top builder has build sheet attached to the engine
at the end are test 1,2,3 above with data.
and test 4 on super pro builder with long warranty (top clue there), the dyno test, or engine run in test stand test. amazing no, they test it before shipping it.
end facts on engine builds.
I bet the head was not milled right (or shaved, even flat head we do tiny clean up cut , or it fails down the road)
or cheap $5 head gasket no felpro
then pressure test the head, did he, a real machine shop does that step 1, after all why dump cash/labor in useless head, answer they dont.

RA resurfacing rules. head and deck.
. The typical recommendation today for an aluminum head on an OHC bi-metal engine is a surface finish of 30 to 60 RA, with the preferred range usually being from 50 to 60 RA.ot milled same as head to the same surfacing spec.

a great page covering details like this is here
you heard him squawk SNAKE OIL. (bottle of instant engine overhaul in can BS)
that means he is a schlock or the warranty ended. (im not sure)
1 or the other.
Take the engine to a real machine shop, with lots of toyota engines being worked on,,,, bingo!!! they know what to do and not skip steps.
you didnt run pure water in that engine last year,did you? last winter? for coolant/ 50% is good 0% not.
Sorry for minimal info in recent post, lots of that is buried in the thread. I checked compression on first build—195 across all four. Motor seemed great other than the stumble I was talking about and the fact that it wouldn’t pass at the smog referee. I was chasing down a gremlin with your help when one of the smog reports prompted me to recheck compression...that’s when I found 3 and 4 way low. Motor only had 1K miles when I found the compression issue. Motor builder has a great reputation and has built 10+ motors for my Dad’s race shop without incident. He took the motor back, checked everything, and did the hone and rings at no cost to me. I know that doesn’t mean much, just wanted to give you a little background...still could be a schlock!!! I’ll send you the build sheet on the first build when I get back home from this forest fire I’m currently stuck at. 50% coolant since day one. I feel like whatever gremlin we were hunting did his damage before I got him and I want to make sure it doesn’t happen again. As a recap: fuel pressure checked and is spec, ect at spec, your egr tests all pass, new O2 sensor, new 3-way cat, new oem TPS calibrated with your instructions, IAC tested good but maybe sticking?, injectors sent off for testing at both builds. I don’t know if you still work on these, but if so I’m ready to get it to you.
1986 Samurai with 1993 1.6 16V
1.6 completely rebuilt, Trail Tough harness modification and ECM bench test, injectors tested and cleaned, Thorley header, new cat, 2”exhaust
Trail Tough Epic Trek SPOA on 33” BFG KO2’s
how sad it went bad in 1k miles. super sad.
he honed it , it would never need that with only 1k miles, ever,
3/4 low , smacks to me if only bad head gasket, or head and block not milled.
or cheap gaskets, not Felpro.
so let me be clear, engine was total engine rebuild 1,000 miles ago , head and block and is called a longblock rebuild, valve and seals rings and bore/ hone to fit new rings
and not 1000miles later rings failed, no way? no way that huge drop in PSI, never. (or ran out of oil or used 0w oil or some crazy oil additive snake oil there.
or OIL pressure at 5psi at 5000 RPM ,
ok Ive no clue why it failed, but head gasket failures are #1 and for sure , bad mill or wrong gasket used. (or wrong head torque, using inch lbs not foot /lbs and staging it per FSM.
many times with head pulled that gap between cylinder tears hiding the real cause, easy as pie.

ok new engine
do the FAM test,parked .
key on , 1.0–1.6 volts dc
idle hot, 1.7–2.0 volt dc
and gunned. it can hit 3vdc easy or more 4v be like super hard to hit unless flying up a large hill at full 95HP load on the engine.


your smog pages do not even hit of rich mixtures, that can wash oil off rings, hint hint.
I say only limphome mode can do that or FI pressure not 30s but 50s; with bad FPR valve.
just lean. and lean is HOT, very hot.
and too lean makes lots of NOX (egr works overtime correcting this)
Hello again, I’m finally back with the vehicle. Immediately did a compression check on the motor per your direction. Motor installed and has 8-10 heat cycles and about 10-15 miles of driving just to seat the new rings. Results: 1,2, and 3 all at 205...4 is at 165!!!(and 175 wet). Sure wish I would have checked before installation like you do!!! Quick backstory on the motor. Bought a 1993 sidekick as the donor. Drove that car for over a year as I did everything else I wanted to do to the Sammy. It ran pretty good, not great and was getting pretty rough before I pulled the motor. First build, the mechanic(I use that term loosely for him now!) found a bent rod on number four and a crack in the block between 3 and 4. Sourced a new block and he built the motor. The car had issues at the smog referee after I installed that motor (that was when I found this forum and started working towards a solution for the high nox with your help). Regretfully, I didn’t check the compression on that first rebuild until well into the process at about 1K miles(as mentioned previously in the thread). That test was: 210 on 1-3 and 170 on 4...suspiciously similar to what I just found today on the newly returned motor. (Sorry for the bad info earlier about 3 also being low...didn’t have my notes with me)
I am going to do a leak down on it tomorrow and see what I can find
I did check the MAF per your direction in the previous post and it is within spec on all tests.
1986 Samurai with 1993 1.6 16V
1.6 completely rebuilt, Trail Tough harness modification and ECM bench test, injectors tested and cleaned, Thorley header, new cat, 2”exhaust
Trail Tough Epic Trek SPOA on 33” BFG KO2’s
that bent rod was a seized crank bearing (ran on no oil or tons if antifreeze in said oil, that is how my 97 came, from young woman that didnt know water can freeze and boom)
engine 1 and 2, is engine 2:>suspiciously similar ? means it was WET too?
and wet with what, oil or antifreeze green water? or soaking in raw fuel?
that is ok, 3/4 confusion.... so easy to do. later

Below is some tests using the leakdown tool, but what I call hiss testing.
yes leak down. #4 tool placed in this spark hole, (the offending cylinder) http://www.fixkick.com/compressiontest.html#leakdown
Do not forget to listen for leak sources.
using a hose to your ear under pressure. (14mm outside diameter hose, so it will fit spark plug holes)
hear hissing in these locations:
#4 at TDC cranked locked there. firing here (rotor on #4 distrib cap off) see valves shut #4, with felt lash loose #4
Hiss test:1: hose placed in.
#3 spark hole hisses (looking for a head gasket leak #4 to 3. or other odd cracks in head)
Hiss test:2:
o2 sensor pulled out listen in that O2 bung hole, for exhaust valve leakings. #4 under pressure, valves bad here.
Hiss test:3:
listen in dip stick tube, top , dip out. hiss? (you will hear hiss here, and is normal ring leakage, but is a very quiet hiss)
the trick is to compare all 4 cylinders under test, see if one hisses way louder than the other 3. (say #4 does, and has collapsed rings carbon stuck)
Lets say #4 cylinder has wall damage. below the rings (picture that in your mind)
so unlock the crank from TDC and ...
( turn the (CW) crank slowly TDC downward the (power stoke) and see if dip tub hisses (MORE) as piston goes down now. cracked
cylinder wall... or warped, or damaged in some way below rings at TDC, this can find bad cylinders not just at TDC, but must be done on the power stock.
under full pressure with the leak down tool.

last hiss test:4:
open throttle valve , and listen there, past the TV butterfly plate (bad valves intake) #4 in this case.

finding a hiss can be a joy, saving lots of head scratching.... good luck !@

as you can see the tool not only shows, #4 leaks real bad (say it does) but now you can hear where that air is going.

there are 2 rebuild classes on engines:
1: the hone and pray. (and throw in STD sized rings)
2: bore and hone and new pistons and rings. (crank shaft grind and bearings too, if the tests fail on it.)

the #1 is very hard to do right, i'd have to use inside mike readings on in 6 places on each cylinder, at the top below the wear ridge.
then 1/2 way down from TDC, and at the bottom where the end of swept ring area is clearly seen. 90degrees apart each reading, (2+2+2)
if the valves on #4 do not leak, then the cylinder walls are not fitting well to the rings.
if wet means antifreeze green seen that is a whole other matter,
(cracks or bad head gasket caused by not milling head, or deck flat or clone gasket crap from china (no name gaskets sets) or warped head or deck.

in s real machine shop the block and head are pressure tested, for cracks, some can be very hidden. so not doing this can be a travesty.
the 16v head has 3? freeze plugs on top of head, and if rusted, and leaks, antifreeze lands in the pan. seen this on 16v.

suspiciously similar ? mean wet? too>?
the #4 spark tip , after running engine is also a good clue.
for sure, if oil , fuel or green antifreeze coated tip.

one poor guy here we worked his engine over and over doing tests. (him in Argentina, sad story there)
but compression was insanely high.
caused by milling head, 10 times DEEP or not de-warping (oven) treating it first and then milling the SNARF out of it.
it pinged like mad, (gross detonation) endless, (NOX too) (engine sounds like bucket for rocks, shook)
and the only cure was (retarding timing grossly) (band aid) (or 2 head gaskets at same time)
no heads spare in that country. zero. (nor shops that know what to do, but too late now...)

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