Yes sir, it's relatively easy to verify timing. All you need to do is to remove the black cam covers and turn the crank to "0" degrees. If the timing is correct, the marks on the cam gear will correspond to the crank at 0.
Multiple issues, need help diagnosing 4.7 V8 (1 Viewer)
- Thread starter gthoman
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- #42
And just an FYI, this is the video I used for the timing belt/water pump replacement.
At around 13:38 is where he goes over the timing marks, so hope thats right...
At around 13:38 is where he goes over the timing marks, so hope thats right...
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- #43
OK, I wasn't sure if I could just remove the covers without having to remove alot of other things, will give it a try.
I'm with you.
Cheap diagnostics are smelling the exhaust as its running trying to detect a coolant smell, check oil for coolant, and check coolant for exhaust gas presence (loaner test kit from local auto parts store).
I did not notice any compression test results. It seems to me there should be a coil pack diagnostic bench test you can perform with a multi-meter.
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- #45
The biggest problem I have at this point is getting it started and keeping it running. I've been able to get it to run and hold the gas at about 2k rpm, but would turn off as soon as I let go of the gas pedal. While it was running the last time, I really didn't smell anything but gas(had the car in the garage with the door open) but assume I would have to be closer to the exhaust to really see or smell anything. I didn't see the "milky" look when I checked under the oil cap and when I checked the oil, it wasn't obvious it was anything but oil. I guess to run those tests I'll have to find someone to hold the gas while I check to see if exhaust fumes are in the coolant.
The fact that you have to keep your foot on the gas to keep a fuel injected car running indicates a major issue. I was reading through the thread here a bit and did all these issues only surface after the TB/WP change? Assuming the timing is on and there is no headgasket issue, this is seeming more like an electrical issue. Sure, coilpacks can and do go bad, but 4 at once seems unlikely. Have you checked all the fuses? You might have to start tracing wires and checking voltages at those cylinders. Perhaps a broken or loose ground somewhere?
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- #47
No change since this all started on the way home from the lake. It still seems to have the same problems as when it first happened(hard to start and when it does-need to keep on the gas to keep it going) and I've changed the TB/WP/radiator/upper and lower radiator hoses/coolant temp sensor and spark plugs. I'll take a look to see if I can see anything out of the ordinary, maybe disconnected something by accident when doing any of the above changes?? I can try to check the fuses, which ones do u suggest? Thanks for the suggestions, keep 'em coming 
Ok so the issues started before the TB/WP change?
My wife's 04 Sequoia started to misfire at about 245K. Checked the code and it said "misfire cylinder 1". Switched the coil, Said "misfire cylinder 3". Simple right? Replaced the coil and it still missed. I chased coil misfire all across the engine. Turned out to be the injectors. I bought some remanufactured densos from a guy on eBay for about $100. After a month of frustration, its running like new. The injectors were probably getting bad for a while.
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- #50
I should now be completely caught up on maintenance, replaced the ignition coils over the weekend.
There was no change after changing the ignition coils, car still hard to get started, once started need to keep the gas to keep it running, once I release the gas it cuts off) I borrowed the tool to check for exhaust fumes in the coolant and that seemed to still be blue(no exhaust fumes in coolant), caught my son on his way out to help me since I needed to keep on the gas while he did the test. Going to do the test again tomorrow since I'm not sure we did it for a full 2 minutes.
I had cleared the codes once I changed the ignition coils, got it started and let it run for 5-10 minutes, temp showed between cold.hot(normal). Once i let go of the gas, the car stalled and I checked for codes. No regular or pending codes were foind.
The injectors might be next to check, but has anyone used torque OBDII app to try to narrow the problem? Or a way to tell if its actually the injectors? I had a problem similar to this on my BMW and it was the idle control valve. Haven't done research on that for this car, but anyone have issues with that? and where its located and if that can be tested?
There was no change after changing the ignition coils, car still hard to get started, once started need to keep the gas to keep it running, once I release the gas it cuts off) I borrowed the tool to check for exhaust fumes in the coolant and that seemed to still be blue(no exhaust fumes in coolant), caught my son on his way out to help me since I needed to keep on the gas while he did the test. Going to do the test again tomorrow since I'm not sure we did it for a full 2 minutes.
I had cleared the codes once I changed the ignition coils, got it started and let it run for 5-10 minutes, temp showed between cold.hot(normal). Once i let go of the gas, the car stalled and I checked for codes. No regular or pending codes were foind.
The injectors might be next to check, but has anyone used torque OBDII app to try to narrow the problem? Or a way to tell if its actually the injectors? I had a problem similar to this on my BMW and it was the idle control valve. Haven't done research on that for this car, but anyone have issues with that? and where its located and if that can be tested?
Sheesh...down to injectors I guess, but I am shocked you don't have codes?!?! I would think the timing would be off and you would still have misfires due to misalignment to be honest, but I guess injectors? This is sort of a great story to follow though! Keep it up!
Hmmm.. maybe a bad fuel pressure regulator? is the throttle body dirty? I'm trying to think of issues that can cause this that won't throw a CEL....
I had the exact problem on my 97 Lexus ES300. One day it just wouldn't stay "started". It would start and run completely "normal", no codes, nothing.....as long as I was giving it a little throttle, as soon as I let go of the gas, it would die. I thought it might be the battery, fuel pump, starter, you name it. Took it to a friend mechanic who checked it out and couldn't find anything wrong with it. He recommended the Lexus dealership that would have more diagnostic tools. To get me there he "fixed" it with a bandaid. He got under the hood and slightly tightened the throttle cable so the car idled a little faster therefore never dying when I let off the gas. I never went to the dealership, and drove 150k more miles like that with no problems or codes. The higher idle was only 1 or 200 rpms faster, didn't even notice it. But the symptoms we're the same as yours, I'll be interested to know the cause.
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For the price of ignition coils I'm thinking you could have bought your own compression tester, leak down tester, block fluid tester, and maybe even a coolant system pressure tester and decent multi-meter and ruled out all of the basic diagnostics. Obviously its your rig to do with as you please. Your approach to tracking down the problem is essentially backwards though. If you rule out the basics first, you can save yourself a great deal of time, money and effort on things that aren't fixing your issue.
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- #56
Thanks for all the replies, so I redid the test to check for exhaust in the coolant for a FULL 2 minutes(had my son keep the gas at around 1200 RPM's) and it came back yellow(positive for exhaust fumes, so in the end looks like the head gasket.
I know I should have done more diagnostic at the beginning, I guess I was just following what others were thinking and hoping for the best, but live and learn. Multiple opinions have been great and even though it ended up being really bad, I learned alot along the way and appreciate everyone that helped.
Anyone replaced the head gasket and know of a good diy?
Would that be the next best step? after the compression test to verify(if I want to keep the car??)
Will still do a compression test(borrowed the tool) and see where its leaking, and verify what the block test came back with.
I know I should have done more diagnostic at the beginning, I guess I was just following what others were thinking and hoping for the best, but live and learn. Multiple opinions have been great and even though it ended up being really bad, I learned alot along the way and appreciate everyone that helped.
Anyone replaced the head gasket and know of a good diy?
Would that be the next best step? after the compression test to verify(if I want to keep the car??)
Will still do a compression test(borrowed the tool) and see where its leaking, and verify what the block test came back with.
I would do a compression test for sure, and a leak down. That is crazy as I have never seen a head gasket go bad on a 2UZ (at least not common, AT ALL). 2001 Blown head Gasket
Sucks!
Sucks!
alia176
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I'm trying to understand why the engine wouldn't idle, even with a spark plug getting doused out with water, it should idle roughly at least. When the spark plugs were swapped out, the OP didn't mention anything about wet or steam cleaned plug(s) so I feel like something else is amiss here.
I wonder if the IAC is the culprit and should be swaped out with a known, good unit just for S&G? I know that no CELs are popping up but something is going on with the idle circuit. If all vac hoses are good and connected, that leads to the IAC unit.
OP, please update your signature line with location, mods etc so that someone close to you can help out with a "control" engine that is running normal.
I wonder if the IAC is the culprit and should be swaped out with a known, good unit just for S&G? I know that no CELs are popping up but something is going on with the idle circuit. If all vac hoses are good and connected, that leads to the IAC unit.
OP, please update your signature line with location, mods etc so that someone close to you can help out with a "control" engine that is running normal.
Definitely do a leakdown/compression test to confirm. If it is the headgasket, in my opinion it's not worth fixing and here is why. I just blew the engine in my GX. It had 120K miles and I bought a used pullout from a truck with 74K miles for 2K shipped. You would still need some gaskets and nuts and such, but overall, you are likely better off spending the same amount of effort and the same or less cost and getting an engine with far fewer miles. Once you pull your heads off, you would want to send them to a machine shop to verify the mating surface is totally flat and that is another couple hundred bucks + the cost of all the gaskets and head gaskets. The engine swap is time consuming, but not difficult. PM me if you're curious on the procedure.
