- Thread starter
- #21
Just did the leak down test on a warm engine. Curious to hear what everyone thinks bc I’ve had enough of consulting Chat GPT…
Thoughts on this compression test.
- Thread starter landcruisertx
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
20 or less is a pass. you need a valve job to make it right. piston rings burning oil is still not out of the question.
mass air flow sensor under reporting will also cause lean and pinging.
Compression test doesn't really raise any eyebrows
Plugs look okay.
Oil consumption and smoke at start up sounds like valve stem seals.
My 1fzfe was burning about 1litre every 1500km or about 1 quart power 1000 miles.
With new valve seals, oil consumption went to almost zero.
Another thing to look at that indicates worn valve seals is when you're driving, let it coast down a long hill, at the bottom, look in the mirror when you get back on the gas. If you see blue smoke, good chance it's due to valve seals.
As for timing, I advanced the static timing on mine to 10⁰ BTDC.
It ran noticeable smoother, better throttle response, and more power at take off.
You could try advancing your timing a bit and see how it changes.
Some 1fzfe won't be happy with 10⁰ BTDC, but even going to 6 or 7 may change things
Plugs look okay.
Oil consumption and smoke at start up sounds like valve stem seals.
My 1fzfe was burning about 1litre every 1500km or about 1 quart power 1000 miles.
With new valve seals, oil consumption went to almost zero.
Another thing to look at that indicates worn valve seals is when you're driving, let it coast down a long hill, at the bottom, look in the mirror when you get back on the gas. If you see blue smoke, good chance it's due to valve seals.
As for timing, I advanced the static timing on mine to 10⁰ BTDC.
It ran noticeable smoother, better throttle response, and more power at take off.
You could try advancing your timing a bit and see how it changes.
Some 1fzfe won't be happy with 10⁰ BTDC, but even going to 6 or 7 may change things
Last edited:
- Thread starter
- #25
Thank you, will clean it today and report back.
1,4,5 air in oil filler is what makes me pause. I daily the rig and will keep it forever. If the bottom end even looks like it’s on its way out I’d rather shell out the dough for a new bottom end from Toyota.
Will take a look at timing again if I can get the pinging to chill out.
Thank you, all!
cleaning MIGHT work but best to get some time on a scan tool and graph out the data, see what your calculated load is at WOT under load. check Grams per second at idle.
- Thread starter
- #27
Cleaned the MAF. The fuel trim long is slightly lower (maybe). Also filled up with premium which helped decrease pinging. Most of the day had little pinging and in the Texas heat in the afternoon the pinging came back a bit worse on a highway run.
This is idle. Will try to get the engine to reproduce the pinging and capture the numbers at that time.
RevISK
SILVER Star
Nevermind. I'm out of my league now.
- Thread starter
- #29
Slight pinging happens at around 70 with light throttle
Your engine should not ping under just about any circumstance. You're probably beating up up your piston rings and pistons with all the pinging. Your exhaust valve seals/guides are totally shot if the exhaust valves are that wet and oily. I don't know if it's possible to pump a quart of oil every 500 miles through valve guides though, so I suspect other issues.
When you did the leak down test, you made sure each cylinder was TDC compression, right?
15.6% long term fuel is a lot. I suspect you have fuel injector issues, and some of your cylinders are running very lean.
When you did the leak down test, you made sure each cylinder was TDC compression, right?
15.6% long term fuel is a lot. I suspect you have fuel injector issues, and some of your cylinders are running very lean.
yea fuel trim is pretty damn high. what's your calculated load at wide open throttle? does it ping at all then?
Fj80oregon
GOLD Star
How’s your fuel filter? You could try pinching your bigger hose on the fuel pressure regulator and see if the fuel delivery is the issue. Detonation is not a common issue on these trucks pretty much unheard of. I would make sure your fuel delivery is up to spec. The knock sensors should be kicking codes if you’re pinging that bad.
- Thread starter
- #33
Yes, every piston was measured with a homemade tool to be sure they are all TDC. This is why I am a bit concerned if I was to just do the head I have had pinging for quite a while... Don't want to seal the top then have the bottom go boom.
- Thread starter
- #34
Fresh filter, have not done any maintenance to the in-tank pump. No codes, no auto-retard either. Just be beans in a can sound when I let off the throttle a little or really let it get up in the RPMs
- Thread starter
- #35
Have not run the test with wide open throttle yet. However it does ping a little if it gets high in the RPMs
When was the last time you dropped the oil and inspected the old oil?
Your description of pinging on letting off on the throttle seems odd to me. Pinging usual happens under load of acceleration.
I had a head gasket failure that hydrolocked the engine.
I repaired the head gasket, and thought the bottom end was OK. It wasn't.
In very short order (maybe 1500 miles) I started hearing what I thought was pinging, then I though it was an exhaust leak under acceleration and mid range - high rpm.
Turned out to be sslight rod knock that i was hearing. The engine seized but long after hearing this.
On tear down, bottom end bearings were shredded.
If your timing is actually at 3⁰ BTDC, you shouldn't be having any pinging. These aren't high compression engines. They are engineered to run on standard gas in basically any weather conditions.
Texas heat ain't any hotter than an Aussie summer, or African, Middle Eastern summer etc
The only time premium gas should be warranted is if you have forced induction raising compression. Generally, running premium in these is just burning more $$ for no gain.
Another simple thing to look at, use a tool to bring cylinder #1 to TDC and check that your harmonic balancer/crank pulley timing mark is still showing you an accurate TDC.
Then confirm your timing is actuator 3⁰BTDC
- Thread starter
- #37
I have not taken a close look at the oil recently however will this next time. Will double check my timing with the method you recommended. I really appreciate all the guidance
The reason for checking if TDC is accurate is because the rubber in the harmonic balancer is likely to be rock hard and cracking. They can separate, and the outer pulley section can rotate out of position.
The first thing I would do is verify the timing accuracy as mentioned above. Then, I'd yank the injectors and send them out to be flow tested and cleaned if necessary. Generally fuel trims can max out at +/- 25% before a check engine light turns on. The ~15% means the computer is able to "correct" the fuel trims, but it's adding quite a bit of fuel to do it. If you have one or two cylinders with partially clogged injectors, those cylinders will be running lean, while the other will be slightly rich.
I believe the FZ engine has two banks, so there should be a bank 1 and bank 2 fuel trims.
I had a mild panic driving our ‘94 DC to Denver last summer. Midway across Nebraska I saw blue smoke and got a low oil warning. The worst of the smoke came on start-up.
Long story short compression and leak down were fine and valve seals were the issue. @Kernal suggested I move to Deleo XSP 400 in a 15w-40. My daughter reports that 3,000 miles later it remains full. I will change it when I fly out next week.