Jump to content
Sign in to follow this  
tolkaNo

car has been running like shit

Recommended Posts

As per title

 

The 180sx has been running like shit for maybe 2+ years now wanna brainstorm a little to see what the problem might be

 

Used to run like a champ, was incredible on fuel economy and used to light up the tires in 1st/2nd/3rd on boost and could barely keep it straight

 

Now on boost it makes practically no power, boost still comes on quick and holds but no power

 

Triple checked for boost leaks and ignition timing is fine, injectors cleaned and flow tested, fuel pump replaced, fuel pump hardwired

 

Have wideband and runs rich on boost and cruise

 

Comp test is around 120-110-110-110, oil down spark plug holes i get 140-150ish

 

The spark plug tips are always coming out white when they used to come out brown, car has also blown around 3 radiators, is this coolant getting into combustion chamber and onto spark plugs? blown head gasket?

 

Can blown head gasket cause boost to leak out between the head and block? Also can it cause boost to leak into the cooling system pressurising the radiator?

 

Feels like the boost is leaking somewhere after the throttle body because gauge reads fine but translates into no actual power

 

Have had the car around 5-6 years this is the first issue i cant fix

Share this post


Link to post
Share on other sites

https://www.ngksparkplugs.com/about-ngk/faqs/spark-plug-faqs/how-do-i-read-a-spark-plug

 

Good article on explaining plugs.

 

white is not normal... combination of lean + oil perhaps?

 

i would not think its a coolant related issue. as when it burns off, teh steam would clean the fk out of the chambers, and your plugs would look spankers.

check your water levels. if they dropping then yes you have a coolant leak somewhere...

Share this post


Link to post
Share on other sites

https://www.ngkspark...ad-a-spark-plug

 

Good article on explaining plugs.

 

white is not normal... combination of lean + oil perhaps?

 

i would not think its a coolant related issue. as when it burns off, teh steam would clean the fk out of the chambers, and your plugs would look spankers.

check your water levels. if they dropping then yes you have a coolant leak somewhere...

 

Not lean, is 14.5 on cruise and into the 10's on boost

 

take a photo of all the plugs side by side and post it up

 

They're all basically like this

20160331_140924.jpg

Share this post


Link to post
Share on other sites

Spark plugs do definately look clean

I would do a leak down test and see where that loss of compression is leaking out

Headgasket leakage will usually pressurize the cooling system that much that it will be over the rad cap rating and push coolant out the overflow

By you compression test results a jump in compression results wet to normal usually means rings are worn but best to confirm with leak down test

 

Share this post


Link to post
Share on other sites

Spark plugs do definately look clean

I would do a leak down test and see where that loss of compression is leaking out

Headgasket leakage will usually pressurize the cooling system that much that it will be over the rad cap rating and push coolant out the overflow

By you compression test results a jump in compression results wet to normal usually means rings are worn but best to confirm with leak down test

 

I know my rings suck and its a tired engine, but it should make at least some power i feel

 

Anyway ordered a leak down tester off ebay, will try to update this week

Share this post


Link to post
Share on other sites

Leakdown tested

 

Cylinder 1 and 4 were around 50-55%

Cylinder 2 and 3 were around 55-60%

 

I tested a bunch of times and keep getting the same numbers, is it weird my engine wore through so evenly?

 

Looks like im gonna need to replace/rebuild

Share this post


Link to post
Share on other sites

Comp test says it all. FSM says anything below 128 = rebuild.

 

Sounds like a super tired motor.

Share this post


Link to post
Share on other sites

Comp test says it all. FSM says anything below 128 = rebuild.

 

Sounds like a super tired motor.

 

Yeah i know, was still holding onto hope that there's something causing globally low compression because it seems weird that all the cylinders wore down so evenly but its probably wishful thinking and its just tired af

Share this post


Link to post
Share on other sites

jam in loads more boost :)

 

Don't think the rb20 method works as well on the sr

 

Anyway i checked my cam timing as a last resort and that looked normal, no choice now but to rebuild :Drugs:

Share this post


Link to post
Share on other sites

jam in loads more boost :)

 

Don't think the rb20 method works as well on the sr

 

Anyway i checked my cam timing as a last resort and that looked normal, no choice now but to rebuild :Drugs:

 

itll take 22ish psi all day :P

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×