Toyota Nation Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
#4 cyl code checked coil, ok, checked sprark plug, ok, checked interjector, ok..do not know where to go from here
 

·
Registered
Joined
·
9 Posts
#4 cyl code checked coil, ok, checked sprark plug, ok, checked interjector, ok..do not know where to go from here

Have you pulled the plug to see if the cylinder is flooded or if there is any coolant. Compression test then maybe a leak down test if the code won't go away. You could also have a vacuum leak causing it but I suspect if that were the case, you would have other codes as well.


You know, I forgot to add that I had an Exploder that did that I switched coils around switched plugs around and it still did it. Changed intake gaskets still did it. It was a valve issue.
 

·
Senior TN Member
Porsche
Joined
·
7,508 Posts
Compression/leakdown test would tell if you have internal engine damage such as cracked rings or bent valves which would cause misfire code.

You can also move ignition-coils, coil wires, injectors around one at time to see if code changes to different cylinder. This would narrow down list of possible suspects.

Vacuum leak at intake-manifold gasket for that one runner may cause lean mixtures in that one cylinder only. Would not throw off combined AFR enough to trigger P0171.

Also can’t pinpoint leaks by spraying stuff externally. Only real way is to plug exhaust with banana, potatoe, cork. Then pressurise intake to 2-3psi and squirt soapy water at every single seam, joint, hose-clamp all 360 around from AFM to intake valves. Have to crawl under car with flashlight and mirror-on stick to get to under side of each intake-manifold runner. This test has found leaks where all others have missed it. I then fire mechanic that wasted time and money trying and failing.
 

·
Registered
Joined
·
9 Posts
Plug looked fine, changed any way..sprayed for vac leak, no change..what would comp ckd tell me?
Sorry it took me a bit to reply. Thanks Danno for explaining it to the OP.


See below


Compression/leakdown test would tell if you have internal engine damage such as cracked rings or bent valves which would cause misfire code.

You can also move ignition-coils, coil wires, injectors around one at time to see if code changes to different cylinder. This would narrow down list of possible suspects.

Vacuum leak at intake-manifold gasket for that one runner may cause lean mixtures in that one cylinder only. Would not throw off combined AFR enough to trigger P0171.

Also can’t pinpoint leaks by spraying stuff externally. Only real way is to plug exhaust with banana, potatoe, cork. Then pressurise intake to 2-3psi and squirt soapy water at every single seam, joint, hose-clamp all 360 around from AFM to intake valves. Have to crawl under car with flashlight and mirror-on stock to get to under side of each intake-manifold runner. This test has found leaks where all others have missed it. I then fire mechanic that wasted time and money trying and failing.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #6
Thanks

Thanks all..I only get to work on it weed ends so have nothing new..plug looked as shoud..will try to get comp test soon..
 

·
Registered
Joined
·
9 Posts
Discussion Starter #7
Moved coil around, did not change..checked fuel injectors, they working fine..going to do comp test soon..
 

·
Senior TN Member
Porsche
Joined
·
7,508 Posts
Also swap injectors around and see if error moved to #4 injector's new location.

Could be as simple as clogged injector and moving it different cylinder will result in error-code moving to new location.

If code stays on #4 cylinder even after moving coil and injector, then it's something mechanical with that cylinder. Compression test will give us more data.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #10 (Edited)
comp check

checked com...read #1--160...#2===`160 #3==160 #4==150(175 after drop of oil)
took for run, no misses, that I could feel, ran great??? Bad rings in #4?
am I ready to take to shop for real pro work..I ckeng lite flashing mean do not drive, or what..I have seen it on, and fixed what ever, but the flashing is a new one for me

.thanks for all input, steve in missouri I now see flashing =fix now..........will take to shop for teck tests...
 

·
Senior TN Member
Porsche
Joined
·
7,508 Posts
Try running a bottle of Red Line SI-1 fuel-system cleaner through. There may be some carbon deposits in #4 that's clogging rings and causing mis-fire.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #12 (Edited)
you mean thru gas? I do not have to worry about damage motor (cat converter), while I drive it? I thought at this point I should not drive, tow to shop? Not that serious?
 

·
Senior TN Member
Porsche
Joined
·
7,508 Posts
yes, 1 bottle of Red Line SI-1 in 1/2 tank of gas.
It has PEA which does good job of removing deposits in engine.
Won't hurt cat.

Car should be OK to drive if engine's smooth.
 
1 - 14 of 14 Posts
Top