CARBON DEPOSITES??

Warrior of the rising sun · 07-24-2006, 05:33 PM

Hey guys, so I just bought a comp. tester and tested my car this weekend.
The results were 200-205-205-205. I read on this forum that "normal" was 142-172+ , but how much plus is OK?It seems kinda high to me. The instuctions say that very high pressure could indicate carbon deposites. The valve cover gasket, and I think the haed gasket are leaking (there's oil ALL OVER the block)- also the throttle body is full of crap. Could it be oil seeping into the cylinders and not getting burned all the way? I've got another head
w/a ported intake that I want to put on, so I'm thinking about pulling the old head, replacing all the seals and cleaning out the pistons.

So if anyone knows whats going on, or has a suggestion, or some advice:
I would REALLY appreciate it.

CyFi · 07-24-2006, 11:05 PM

The leaking and oil in the intake arent related. The car has a bad recirculation system and takes a bunch of crap back into the throttle body. Those numbers are high, but i cant see why it would really be bad. You can water clean or seafoam your engine if you are worried, just do a search and you will see what im talking about.

Warrior of the rising sun · 07-25-2006, 08:59 AM

I wouldn't really worry about it, but it runs like crap- and somtimes not at all!
The idle is very erratic and the plugs get black almost immediately. After the comp test, I cleaned the plugs, and now it won't start!

Jason.MZW20 · 07-25-2006, 09:15 PM

Did you remove the EFI fuse when doing your compression test? If not, your cylinders are flooded with fuel, and that'll cause your issues with starting.

Your engine has accumulated carbon deposits. You may need to switch to 89 octane to smooth your idle. The increased compression of the engine is causing some slight detonation at idle. Also ensure your ignition components are in good condition. Blow-by from the engine is escaping through the PCV system, which is why your intake manifold is dirty. The only way to reduce blow-by is to change/rebuild the block. Cylinders wear as do the piston rings.

Warrior of the rising sun · 07-26-2006, 05:38 PM

The car is a 91. Mr2.2 said that early mr2's don't have a pcv valve, just a breather hose

. And by the way, it has an HKS intake, so there's no breather valve anymore.

Jason.MZW20 · 07-27-2006, 07:53 AM

The 5SFE still has an active PCV system. The hose from the valve cover to the intake manifold vents the engine's internal gases. The suction from the intake does its best to get most of the blow-by out of the engine.

An HKS intake shouldn't have anything to do with your PCV hose. The hose connects directly to the throttle body from the valve cover. If you removed that, the PCV system will be passive instead of active.

Warrior of the rising sun · 07-27-2006, 08:58 AM

Gotcha! Thanks.

07-24-2006, 05:33 PM	#1 (permalink)
Warrior of the rising sun 4 cylinders of fury baby! Join Date: Jul 2006 Location: Atlanta GA Posts: 29 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	CARBON DEPOSITES?? Hey guys, so I just bought a comp. tester and tested my car this weekend. The results were 200-205-205-205. I read on this forum that "normal" was 142-172+ , but how much plus is OK?It seems kinda high to me. The instuctions say that very high pressure could indicate carbon deposites. The valve cover gasket, and I think the haed gasket are leaking (there's oil ALL OVER the block)- also the throttle body is full of crap. Could it be oil seeping into the cylinders and not getting burned all the way? I've got another head w/a ported intake that I want to put on, so I'm thinking about pulling the old head, replacing all the seals and cleaning out the pistons. So if anyone knows whats going on, or has a suggestion, or some advice: I would REALLY appreciate it.

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07-24-2006, 11:05 PM	#2 (permalink)
CyFi Moved on Join Date: Oct 2005 Location: Phoenix Posts: 1,401 Thanks: 12 Thanked 38 Times in 35 Posts iTrader Rating: (11/100% )	The leaking and oil in the intake arent related. The car has a bad recirculation system and takes a bunch of crap back into the throttle body. Those numbers are high, but i cant see why it would really be bad. You can water clean or seafoam your engine if you are worried, just do a search and you will see what im talking about.

07-25-2006, 08:59 AM	#3 (permalink)
Warrior of the rising sun 4 cylinders of fury baby! Join Date: Jul 2006 Location: Atlanta GA Posts: 29 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	I wouldn't really worry about it, but it runs like crap- and somtimes not at all! The idle is very erratic and the plugs get black almost immediately. After the comp test, I cleaned the plugs, and now it won't start!

07-25-2006, 09:15 PM	#4 (permalink)
Jason.MZW20 Pig Snout Join Date: Jul 2006 Location: Victorville, CA Posts: 1,373 Thanks: 15 Thanked 111 Times in 102 Posts Blog Entries: 6 iTrader Rating: (2/100% )	Did you remove the EFI fuse when doing your compression test? If not, your cylinders are flooded with fuel, and that'll cause your issues with starting. Your engine has accumulated carbon deposits. You may need to switch to 89 octane to smooth your idle. The increased compression of the engine is causing some slight detonation at idle. Also ensure your ignition components are in good condition. Blow-by from the engine is escaping through the PCV system, which is why your intake manifold is dirty. The only way to reduce blow-by is to change/rebuild the block. Cylinders wear as do the piston rings.

07-26-2006, 05:38 PM	#5 (permalink)
Warrior of the rising sun 4 cylinders of fury baby! Join Date: Jul 2006 Location: Atlanta GA Posts: 29 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	The car is a 91. Mr2.2 said that early mr2's don't have a pcv valve, just a breather hose . And by the way, it has an HKS intake, so there's no breather valve anymore.

07-27-2006, 07:53 AM	#6 (permalink)
Jason.MZW20 Pig Snout Join Date: Jul 2006 Location: Victorville, CA Posts: 1,373 Thanks: 15 Thanked 111 Times in 102 Posts Blog Entries: 6 iTrader Rating: (2/100% )	The 5SFE still has an active PCV system. The hose from the valve cover to the intake manifold vents the engine's internal gases. The suction from the intake does its best to get most of the blow-by out of the engine. An HKS intake shouldn't have anything to do with your PCV hose. The hose connects directly to the throttle body from the valve cover. If you removed that, the PCV system will be passive instead of active.

07-27-2006, 08:58 AM	#7 (permalink)
Warrior of the rising sun 4 cylinders of fury baby! Join Date: Jul 2006 Location: Atlanta GA Posts: 29 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Gotcha! Thanks.