big bear

90 Runner 3vze 4x4 SR5 5 speed stick.

Had my motor rebuilt by a machine shop in San Berdo.

It's never ran right since I put it back in. Been tinkering with it for a while now. Need it to pas smog in Cali.

Low power, I know these motors don't put out a lot of power, but this thing's power sucks, feels like it's putting out less the a 100 horses.


Just did a compression test on it.
All spark plugs removed, throttle tied open with a wire around the dash pot mount, motor warmed to operating temperature, high tension wire from coil grounded. Battery fully charged.

Only getting 120-125 psi across all cylinders

What are your thoughts gents ?

My idea is to pull the motor and take it back to the shop, they can do a leak down test on it.

The work they did.
Heads: micro-flux, new valve seals, valve grind, surface check, and adjust valves.

Block: New pistons, rings, bearings, thrust washer,crank turned and bore.
0.2 oversize.

The work I did: install heads and all accessories with gasket set they sold me, and new head bolts (fel-pro) bought from Napa, torqued to 33 ft#s then turned 90 degrees two times each, following sequence in the Haynes manual. New timing component kit(Gates), new oil pump(Asian),new O2 sensor(Denso),new plugs and wires(NGK), new cap and rotor (Beck Arnly),
replaced all vacuum hoses.

I'm bumming.

Can't figure why the compression is so low in all the cylinders.
Maybe may compression tester is messed up ?

Considering buying a new compression tester and re-doing the compression test.

Marc

I'd try another tester.

RJR

If I read your signature correctly, you're at Big Bear Lake, CA. The elevation there is over 6000 feet, so your numbers are about right. Compression numbers will drop about 3.3% per 1000 feet, so you should be down around 20% from sea level numbers. So, if 150 is normal at sea level, you should be reading around 120 psi.

big bear

Yes I'm in Big Bear, 7000 feet elevation.

Just tested my Pontiac with said gauge, it's reading 120-125.
My Pontiac is running perfectly.

I think the $40 for a new tester will be worth it.

That motor and tranny is a pain to put back in, the transfer case really sucks getting past the front diff mount.

big bear

Never took that into consideration.

big bear

Wouldn't hurt, $40.

big bear

What do you guys think of this set ?

Actron CP7828 Professional Compression Tester Kit



http://www.sears.com/actron-cp7828-p...a=00932992000P

big bear

Maybe I should just suck it up and pay the pros, $85/hour.

maachine

how about "borrowing" a tester from an autoparts store? also......did you have the throttle fully open when doing the test?

big bear

Small town, no testers for loan, and yes throttle was wide open.

Thanks tho.

Kiroshu

May not be a compression problem...?

Another performance/malfunction perhaps...?

big bear

Maybe.

No check engine light.

Ignition timing set to 10 degrees, RPMs 725, jumped the Te1/E1 terminals when I set the ig timing.

Used cold start injector installed, it was cleaned and flow tested.

Forgot to list new Flame Thrower Injectors (6).

big bear

Airflow meter, cold start time switch, and throttle position sensor all within spec.

Kiroshu

Assuming all engine internals are ok.

Exhaust system restriction...?

Intake air hose leaks...?

Dirty air filter...?

Restricted fuel filter...?

Faulty fuel pump(low fuel pressure)...?

Vacuum leaks...?

Intake manifold leaks...?

Air flow meter faulty and or out of spec...?

Worn and or faulty ignition components...?

Faulty and or incorrectly adjusted sparks(plug gap)...?

EGR valve faulty and or open/opening at incorrect intervals...?

RJR

I don't care how you spend your money, but I can't see why you'd want to be chasing a compression further when, as I've pointed out, your numbers are perfectly normal and match those of your perfectly running Pontiac. It seems to me your tester is giving good measurements and you need to look elsewhere if you have a power issue.

What in particular is making you feel like you're lacking power? A 3vze at 7000 feet isn't going to set any acceleration records.

big bear

You sure come up with some good questions

Thank you sir.

big bear

Is it normal to have NO acceleration at 25mph in second gear going up hill ?

No low end power at all, then doesn't really want to go past 5000 RPMs.

Don't get me wrong, I'm taking your guys advice. I appieciate it. I'm not a helpless nubbie, and I'm not afraid to do the work.

Just seems this Runner would be better off with my 03' Echo's engine in it.

RJR

Depends on how steep the hill is, but if it's less than 7-8%, no, that's not normal.

Valve timing could be slightly off. That would impact low-end torque.

big bear

The timing marks are a little ambiguous, I wish they were more precise.

I put it back together with the timing marks as they were when I took it apart, buts who's to say they were correct, it had a replacement timing belt on it.

For instance, the right sprocket tooth will only line up slightley ahead or behind the mark on the timing cover impossible to line it up perfectly.

Do you know of a way to set the valve timing precisely without using the timing cover marks ?

The sprockets were not on as shown in the book, the book shows left sprocket with the flange outward, the right with the flange inward, the sprockets on my motor were the opposite, I returned them to the way I found them.

Maybe I should see what happens if I flip the sprockets and re-time the cams, like I said I'm no afraid to do the work.
Should only take a few hours to do that.

big bear

It starts and idles fine. Sounds like it misses under load tho, could be the muffler, it's pretty well had it.

The dude I bought it from is Korean, spoke very little English, communication was a challenge to say the least.