Measurements to take:
1) cylinder leakage test (not a compression test)
2) vacuum reading at idle (does it fluctuate too?)
3) results of spark output test per plug wire (also test ignition coil separately)
4) exhaust backpressure test per side (in PSI)
5) fuel pressure KOEO and KOER (does it bleed down?)
get lisle #20700
Attachment 14841
get backpressure tester
HTB1A3vyHf1TBuNjy0Fjq6yjyXXaF.jpg
And......remove nothing except the spark plugs and o2 sensors to do the tests. Be efficient.
Last edited by vilefly; 11-24-2019 at 06:05 PM. Reason: tweaking the display
I really appreciate the help here.
There is a new water pump that was installed when the new Opti was installed. Yes there was a huge oil leak in the Opti because of a bad seal. I didn’t actually see it however. Looks like a gasket set is in order at least. We’ll get to the Opti as testing progresses.
My son has an adjustable spark tester as well as a leak down tester he uses on the funny car. So we can do those tests we’ll have to get the car on his hoist so we can mark the damper or at least measure it and I’ll get a tape. I don’t have a back pressure tester but I think a very low pressure gage could be fitted toe exhaust pipes. Jut drill for 1/8 npt and carefully tap. Easy to plug afterwards.
I’m concerned with intermittent spark. So some way to check that. There’s about one spark per second (check my math) so it’s possible to see a misfire at idle if you watch the sparks carefully. You could get with a timing light if you can guarantee the pickup.
My son has fuel pressure tester kit. So we can do that.
Some of the other tests are going to be a bit more involved but we’ll try our best to to run each one and document results.
I know this is going to be a tedious process but I want this car fixed, once and for all.
I’m just getting ready to run the car out to my son’s shop.We’ll try a few basic tests today. He may want to do a preliminary road test to get a feel of the issue beyond my description.
Byron
The o2 sensor threads are 18mm x 1.50mm pitch. Find a bolt, drill a hole in it, npt tap, install brass nipple....done. Tool for life.
woah there.... back up. how did you determine it was a miss simply while driving? what does a miss feel like? and then how did you determine what bank was missing?It’s got a dead miss on the right bank.
do one test at a time in logical order, you're already completely polluting your diagnostic process by assuming you know what's going on or where the problem might be located it. you've already whizzed right past the cause several times.
i'm not convinced its a miss. convince me.
maybe through convincing me you'll realize some things you need to check
also you have eehack, right? where are the logs? show us a log of where it's acting up and we'll rule out a lot of stuff for you.
yesterday I drove the car out to me son’s shop. It’s 65 miles mostly freeway. I was able to run solid 70-75 mph excep a few miles at 55-60. I used cruise control for the first time as an experiment to see how it handled the lack of power. You could feel a shudder on the level and when it required power to go up hills. Sometimes down shifting to direct. It took a lot of throttle to maintain speed. About a mile from the shop the check engine light cane on.
We let the car cool off before checking it over.
Drove it into the shop with a heavy miss. The car was shaking and very smelly exhaust from the right side.
We decided to just look over the motor for errors.
Found EGR vac line disconnected.
Fuel pressure regulator disconnected.
MAP sensor gasket mangled and leaking.
The three vac lines that run from the manifold right side to a connector block have cracked and leaking connectors.
Three wire harnesses were not routed correctly so we fixed that . Not a performance issue.
The O2 and spark testers were loaned out, they will be back today. Then test each separately.
Cyl 2 and 4 are weak. We’ll test the injectors tonight of tomorrow. The
Vacuum tested at 16 inches at idle. Rock steady.
The Optima yellow top is going to be gone. It’s weak.
I admit to not having a lot of experience with this system. That’s why I’m here. I've already learned a lot from y’all and I appreciate the help.
As far as scans I’m new to that too since I haven’t had the car for over 6 months. We spent a good part OF the afternoon going over EEHACK. My grandson who is a mechanic and body man grasped it pretty quickly. Once we get these basics fixed we’ll create some usable scans. I have a neat memory stick that works on my iPad plus a dedicated one for thr buick and EEHACK and it’s computer. I’ll post them as we get them. It may be the week end before I get out there as I have doc appointments this week. I have one shortly so I must go now
if cylinder 2 and 4 were truly weak, why no fluctuation in vacuum? how are you testing them as 'weak', by pulling plug leads off?Cyl 2 and 4 are weak.
yeah that vac line to the regular does needs to be connected, and vacuum leaks are badFuel pressure regulator disconnected.
MAP sensor gasket mangled and leaking.
you have lots of vacuum line issues and the visual inspection might have missed something. disconnect everything that's connected to the intake manifold and test each item for vacuum holding (mityvac or similar). if you don't have that, disconnect everything from the intake manifold and cap them off securely. you only need fuel pressure regulator and pcv but you could leave the pcv hanging temporarily, it wont hurt anything.The three vac lines that run from the manifold right side to a connector block have cracked and leaking connectors.
what's the error codeAbout a mile from the shop the check engine light cane on.
#2,4 were shown weak on the test using EEHACK. Interesting that the other guy said 2,6,8 were weak with #4 not far behind.
We haven’t pulled the plug wires off yet but will. Their spark tester should be back tonight so that will get tested soon too.
I’ll ask also if my grandson noted the manifoldvac on EEHACK And if there was a number. I noted 10 inches earlier in my own test
We were doing as you noted, checking every connection. Both ends where possible.
Unfortunately I didn’t see the error code. It may have been cleared while I was doing something else. I’ll ask tonight when I call out there.
They will continue on it while I’m gone. I asked that they record everything no matter how small.
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