I am curious if someone could say why i have a respectable amount of carbon build up on pistons 1 and 4 but not on 2 and 3? Is this a sighn of anything or style of runing condition.. ?? It is the first time i have seen my pistons since purchase last year any info is good info.

Oil leaking past the rings?

o.k. waht if it is that? new rings??

FI or carbs?

74 2.0 fi.. It is just the 2 foward pistons #2 and #4 . The build up is hard dry crusty not sticky tar oily.. so if this is because it was running rich then why not all 4 cylinders??

Hard dry crusty carbon sounds like cooked oil.

Several causes.

1. bad valve guides leaking oil into the cylinder

2. oil rings didn't seat

3. score mark in the cylinder wall? (oil path)

4. Rings not staggered on the piston (all in a line on the bottom of the cylinder provides an oil path)

Any smoke on startup or driving?

It may also be that the injectors are not balanced properly..
Send them out to be rebuilt and balanced.

Check your cold start injector and send that out also..they do drip and leak..

Rich

Thanks tOWLE.. ACTUALLY INSTALLED A NEW COLD START LAST WEEK AND JUST GOT MY INJECTORS BACK FROM SERVICE TODAY.. aLSO HAVE A NEW FI HARNESS TO BOOT .. I WAS LEANING THAT WAY..

did you hopefully re-ring the motor???
You might as well get new FI trigger points and clean and rebuild your distributor.
Rich

i have electronic igniton but it used to have points.. i have not learned yet how to rebuild a distributor.. my heads are getting cc'd should have them tommorow then number crunching.. new rings make sense.. how would i know what rings to get? It is a stock 74 2.0 wish dished pistons and a "supposedly rebuilt motor done by the po mechanic" so if anything was honed how would i know??

take a very focused, high resolution picture of the cylinders with the piston out, or all the way down. post it here.

Get rings from Jake..I think he sells hasting rings...they seal quickly.

Rich

Click to view attachment
i can see cross hatching thats all i know.. nothing leaking and i did clean off all the carbon earlier today..

Click to view attachmentanother one..

Click to view attachment

When was this motor rebuilt? how many miles?

Your rings did not seat...but you still need to put in new rings.
I cant really see those pics that well...they need better focus and each cylinder needs to be shown with the piston at the bottom of the stroke.

Rich

cell phone camera is all i got.. so where do you recommedn i get rings??

supposedly rebuilt 6 0r 8 thousand miles ago, i have had the car a year and when it was rebuilt sometimes maybe year and 1/2 or 2years ago.. this car was not someones daily driver.

how could you tell.. so iu know how to tell..

http://www.aircooledtechnology.com/store/home.php?cat=278

Perfectly done towle.. why not.. nice lead they have orignal germans and 33% off too..

Those are 2.0 bus pistons... are the rings the same? I'm not sure, but I seem to remember that bus rings are different than 914 rings.