Help analyse spark plug pictures!

[Jan Larsson]

Pulled 3 spark plugs so far to see what they look like, first 2 looked fine and gapped them down to 0.035 as they were around 36-37

3rd one I pulled (passanger side, back next to firewall) looks really bad ... probabrly no spark and it looks like the header might be leaking there as well as it's all black and the plug booth is black as well ... please take a look at the pictures and let me know what you think might have caust this, just a bad plug wire or something else.

 

[Grumpy]

well first thing ... coil pack good ??? wires ??? make sure the ends arn't crappy+rusty ... the car did sit for a while right ??? prob startin and shutting off to move it around ??

 

[Jan Larsson]

Wires are good, just measured them and no corrosion etc on the terminals. Coil pack and module just installed brand new GM pieces so they are defenitly good now. Gapped all plugs (replaced the "ugly" one with a new one) to 0.035" (all 6 are Delco R42 LTS).

Car been sitting on and off sometimes for up to 4 weeks but usually no more than a week or to .... some short trips in between.

 

[Jan Larsson]

By the way, if it not been running properly on all 6 would this cause false knock?

 

[Jan Larsson]

So took it for a test drive, and it's a bit rough I must say. Running rich and still have some knock retard while putting some light load on the engine .... Guess I'll hook up my laptop with TurboLink as well to get some more data.

 

[Razor]

Does the car hold fuel pressure when you shut it off?

Hows the gas mileage?

Possible bad injector's'.. post back the FP reading. Post back scantool data at idle. Like BL

 

[Razor]

Wanted to add.. looks like oil burning on plug. Your probably sucking down a lot of oil through the PCV or have bad seals onthe heads. If its only one cylinder, then more than likely bad valve stem seal or oil ring issue.

Run Top Engine cleaner through the motor to clean it out.. then change the oil. Keep an eye on that plug. It is heavily fouled.

 

[Jan Larsson]

Julio,

Just checked, BL is 120 in closed loop (engine warm) and steady at idle.

Fuel pressure is gone the second I turn off engine (bad?) but have no issues with flooding if I start it right away again or if it sits for a while ...

Idle warm is pretty steady at 925-1000 rpm and TPS seems correctly adjusted (at idle).

Any suggestions ...

 

[Razor]

Julio,

Just checked, BL is 120 in closed loop (engine warm) and steady at idle.

Fuel pressure is gone the second I turn off engine (bad?) but have no issues with flooding if I start it right away again or if it sits for a while ...

Idle warm is pretty steady at 925-1000 rpm and TPS seems correctly adjusted (at idle).

Any suggestions ...

BL at 120 means its a little on the rich side, but not much.

Losing pressure when you turn the key off.. thats a problem. If you flood one cylinder.. it will still fire rite up. But the issues of one cylinder magnify onto the performance of the car. Pressure should hold on the rail for at least a few minutes. A bad fuel pressure regulator can also cuase the pressure to bleed down, and I would look into trying and seeing as to why this is occuring.

You can listen to the injectors using a mechanics stethescope.. they should all sound the same, any chattering will show up as a bad injector. Aside from removing them, I dont know of any simple tests to find which one is leaking. Guess you could pull the plenum, using a flashlite look down the ports, and then place the key in the run position to lite up the fuel pump or use the port on the aldl to run the pump and look for any injector thats bleeding down. There should be no fuel coming from the tips of your fuel injectors.

The fuel pump can also cuase the pressure to bleed down. Tho having drivability issues.. I would look at fuel injectors.

HTH

 

[Jan Larsson]

I got a brand new fuel regulator sitting around so guess I could swap that on in as a starter as that is fairly easy to do. I'll see if I can listen to the injecotrs as well and compare, so this would be while the car is at idle right?


Would a leaking injector be connected with my knock issues you think Julio?

 

[Razor]

Would a leaking injector be connected with my knock issues you think Julio?

Anything can cuase knock. We need to fix everything we can see pop its head up.. then work on the things we cant see. The motor not being smooth is the first concern. Obviously your having a fuel system issue Regulator would be an easy first, careful dont strip the fuel line nut underneath it.

Yes listen while car is idling.. that way they go tick..tick..tick..

 

[Jan Larsson]

I'll change the fuel regulator and then see, also try to listen and compare the sound of the injectors. Will be later in the week as I need to prepare for some meetings tonight ... pulled the fuel pump fuse and cranked the engine a couple of time to releif pressure so should be fine to swap the regulator out within the next couple of days.

 

[Razor]

Jan.. if your losing pressure.. that means you have no pressure.. why did you have to pull the fuse :wink:

 

[Lunkan]

If You haven´t done it, ohm-measure the injectors to. If I´m not wrong, they should be around 16ohm´s.

 

[83ttypecooled]

Troubles

Hi,
I really doubt you will find an resistance issue with a bosch injector, but anything is possible. Flow problems with these 28 pounders are quite likely, however. From your photos,I see rich mixture, not oil consumption.Obviously, the plug had been in there for a while. Let's say 10K miles or so. Do you know of anyone in your neighborhood who might be able to clean and flow the injectors?If not, replace them, they are cheap on ebay.I have a set of 30 pounders, considered the best stock replacement,in good condition,for sale.
Regarding the immediate fall off of fuel presure, you need to pursue this problem vigorously. If the regulator swap doesn't fix the problem,try blocking off inlet AND outlet hoses after pressuring up the system,see if you REALLY have dribbling injector(s). By the way,the fuel pump is also a possibility, internal check valve can fail. What a PITA those are to replace.
As your problem seems to be on #6 cylinder,the bastard child of the fuel system, and because our cars are getting old, consider corrosion as a possible issue. Ethanol and Methanol are pretty corrosive chemicals, and our cars were not set up to use a bunch of this stuff.
These are just my observations from a lifetime of car repair. I hope that some of what I have said is helpful. Good luck with your trouble!

 

[Jan Larsson]

So ohmed the fuel injectors and all 3 (including #6) on the passanger side are all the same 16.0 ohm.

Replaced fuel pressure regulator with a brand new billet I had and same problem, pressure goes to zero as soon as I turn off the key.

Plugs been in there for maybe 1000-2000 miles at the most.

Fuel pump was replaced about 2 years ago (at the most 3) with a Walbro one.

My injectors are 42lb ones and the chip (Jay Carter) been made for my setup, should I just order a new set or should I see if I can have the bad one cleaned (not sure if there's someone here that can do that for me but I'll ask around).

Not sure how to block inlet and return fuel hoses to maintain pressure ... don't want to squash the rubber hoses as they might become damaged...

 

[turbobuickman]

Your problem might be fuel related but like razor said, it looks like you may be burning some oil. Check the compression on that cyllinder against the rest. Also, it might help to read that plug if you had a picture of the end.