spawnywhippet

I sprayed brake cleaner around injector 6, and also changed the crankshaft sensor for fun. Ran the car for 10 miles. It was running fine for about 5 miles, then misfired and check engine light, same codes. What is the brake cleaner supposed to do? It made no difference to the idle, as the car idles perfectly on all 6 cylinders.

I have seafoamed the oil and fuel tank (1 quart in the tank, half a quart in the oil, then ran it for 5 miles. I will let it sit overnight and drain the oil and see if there is any difference. I am now thinking more and more that I have a burnt exhaust valve.

Maj. Dundee

If there was a slight intake leak around #6, the Brake Cleaner would have been sucked in, same as adding fuel, and the idle/RPMs would increase.

spawnywhippet

I checked again with the brake fluid on all injectors, there is the tiniest of fluctuation in revs only when I spray injector 6, but it drops, not increases. The car is running better after the seafoam treatment, it runs without the check engine light on as long as I keep the revs below 2000 rpm. If I go much over that, it flashes on then stays permanently lit. The car has now done about 20 miles since I added the treatment. Perhaps there is heavy carbon build up?
I will do a manual compression and cylinder leakdown test tomorrow.

Maj. Dundee

You said brake fluid and hope you meant Brake Cleaner??????????????????

You have to determine if the Brake Cleaner traveled down to where the intake mates with the head. Seal off the mating area and re-spray.

When you swapped the injectors, did you use new O-rings?

spawnywhippet

Haha, brain fade. Yes I used brake fluid, but did not replace the o rings. They looked in good shape.

Maj. Dundee

I even supplied you with a photo of the product.

spawnywhippet

AAAGH, mistyped again! I meant to say brake cleaner both times. Over-tired and overstressed with this car. Am fixing it after work when everyone else is in bed, trying to type on my laptop in the workshop where I am also doing 10 other things.

To confirm, no brake fluid has been near the injectors, brake cleaner only.

Maj. Dundee

If there was a different response when you sprayed on #6 then there is some sort of leak. Try the spray on cylinders 1-3.

What is you model designation, 164.xxx?

spawnywhippet

Updates on the remedy and the eventual solution.

I initially decided to replace the cylinder head, due to 2 different mechanics diagnosing (guessing) it was bad.

After receiving the ebay unit and taking it for refurb, the cylinder head company told me that it was not able to be rebuilt, so while I decided whether to order a brand new one, I decided to put another $75 of Seafoam through the injectors, inlet and crankcase. I also replaced the o rings on the injectors of that bank just to be safe. I drove the car with the Seafoam for 100 miles, and each trip it got better and better, allowing me to drive for further and harder before a CEL came on. It was pumping out some white smoke, but that cleared up. Then I drove another 100 miles with no CEL at all and I replaced the oil again. The 200 miles old oil came out very black with black specs in it.

One morning a few weeks later, I got another CEL and pulled a code for the crank sensor. I replaced the crank sensor and did a learn-in procedure and it has run perfectly ever since. No check engine lights, smooth, lots of power. I think the root cause of the issue was carbon build up on the valves was preventing proper seating of the valve.

ItalianJoe1

Makes sense, and would explain your issue. If you've got it working well, i'm happy for you.