P0300 & P0316 After Car is Warm

[hotcobra03]

Dropbox - 04-16-1 (1).pdf - Simplify your life


some reading

 

[ERod123]

So it seems like it could be fuel related or EVAP system. My OBD scanner doesn't have the self test option for KOEO/KOER. It also doesn't show value for fuel pressure, boost, LTFT's. Any recommendation for a scanner that would have these options?

I may just take it to a dealer or mechanic shop.

 

[ERod123]

SO just to update:
-I have checked fuel pressure, compression, checked for vaccum leaks (Nothing came of it)
-I have replaced spark plugs, fuel injectors, fuel filter
-I have cleaned the EGR valve, Idle Air Control valve, MAF, and both upstream O2 sensors and have cleaned the electrical connector to MAF, IAC, Camshaft pos sensor, CKP sensor, O2 sensors.

Don't think I can check much else except to recheck fuel pressure, and continuity to fuel injectors and coils.

I believe it is a combination of the low compression on all cylinders, and the tune. Will probably take it to a shop to get a outside opinion, so if anyone has a shop recommendation in the Phx area in Az, lmk.

 

[hotcobra03]

rich codes

something not said /or asked in these test

does car have an intercooler

o2 codes have us check air filter
dirty

mass air dirty

air leaks

restrictions in air inlet

but nothing on our intercooler

this gets very dirty and is an air filter

something to think about

the hose under blower is common for 171/174

 

[ERod123]

rich codes

something not said /or asked in these test

does car have an intercooler

o2 codes have us check air filter
dirty

mass air dirty

air leaks

restrictions in air inlet

but nothing on our intercooler

this gets very dirty and is an air filter

something to think about

the hose under blower is common for 171/174

I would assume that it has probably been cleaned when the previous owners had done a rebuild with the stroker kit. But yeah, I would imagine the heat exchanger in the manifold could get dirty. I can probably check that and the vacuum line later.

I wonder if running lower octane fuel like 89 or 87 would change the way it runs. Cause again, 120psi compression is pretty low so maybe it needs lower octane to combust better?

 

[ERod123]

Here is a vid of what it's doing when I go start it after leaving it parked warm for 15 minutes:

I am also wondering if my vacuum lines are set up right (I heard that the cylinder being pointed to sometimes gets plugged, but this seems to connect to the EGR solenoid and by-pass actuator):

 

[hotcobra03]

those lines are wrong

canister just hangs at the end



https://www.svtperformance.com/threads/03-04-cobra-vacuum-lines-documented.733504/

 

[hotcobra03]

also why are you using a return spring on throttle

makes pedal hard to push

I had a sticking throttle body tried a spring to lower rpms but hard to drive

replaces throttlebody

mine even gave a code for it

 

[hotcobra03]

https://www.svtperformance.com/attachments/vacuumharnessschematicr2-pdf.89144/

 

[ERod123]

Hmmm I will plug the end on the Vacuum Reservoir cylinder and the port on my intake. Probably wont make a difference but I'll see..

Also, the car came this way with the throttle spring. I don't notice any difficulty with throttle pressure.

 

[hotcobra03]

that thing on 300/316
says if any other codes start with those first

rich codes may be caused by hoses being wrong

that cylinder is a vacuum tank

like the one for hvac behind glove box

back side of strut tower

a white push in clip held that cylinder in place
mine is just dangling

 

[ERod123]

Update: After plugging that vacuum tank and the port on my intake, I haven't had any hot start issues for now. It's only been a couple days but hasn't done it once since then.

All my HVAC controls work and function properly. I'd assume those to be correct for now but will double check.

I reset the CEL codes and will see which still are present after plugging the vacuum tank. Car still stutters but only on partial throttle under 3k rpm, hot or cold engine.

 

[hotcobra03]

what about throttle return spring

have you ran without it?

did you check all of the vacuum connection's to be right

I had an issue on a new harness
they had the green egr line in wrong port causing a stall issue

also green egr line is known to melt being close to exhaust tube
vacuum restrictions are harder to find

tested my harness on bench blowing and suckling manual on hose you will feel problem

 

[ERod123]

When you say throttle return spring, you mean this one, right? Or?

I also found this line that seems to be the factory boost gauge line that was not connected or plugged. Currently, there is a line that T's off the Fuel Rail pressure sensor line that goes to the instrument cluster's boost gauge.

 

[ERod123]

Don't know whether one of the previous owners was having issues with the gauge and just ran another line. Might just cap off the factory line. One of the previous owners must have not know what they were doing.

 

[hotcobra03]

not the black spring

long silver going from there to blower case

why are plug covers on wrong

 

[ERod123]

Oh, I've actually left that unconnected once and there was no pressure on the throttle pedal, so I definitely need it, I'd assume.

Driving the car around more and it definitely idles better, doesn't really surge, can hear the cam chop a little, NO HOT START issue at last. I believe my issue is now resolved. Still have rich codes showing up but will drive around some more. That is probably just the tune, Im not sure if they had tuned it with the hoses being wrong--that is a possibility.

 

[hotcobra03]

define no pressure with out spring?

reason I said hard to drive with it ,

is because the weight of your shoe lace should be enough to do 80

if you were to take of cruise cable and throttle

the throttle can than be moved by hand

and should snap back with just that round black spring

there is no spring action on our throttle cable ,just basic cable to pedal

 

[ERod123]

Okay, yeah. It does snap back with the silver spring and throttle cables off. Is that silver spring not factory?

Also, I connected the factory boost line to the instrument cluster instead of the one that T'd off the boost line for the Fuel Rail Pressure sensor, and the boost gauge wasn't working. So that means I probably still have a vacuum leak somewhere. Looking at this diagram, it says the line connects to the lower manifold. Is that the line that you mentioned where it's underneath the supercharger on the lower intake manifold?

 

[hotcobra03]

that long silver spring is not oem
doesn't belong here

black round one is oem and part of throttle body

the lower vacuum port is on back side of blower 2 large ports
top/bottom = upper/ lower

hose under blower is part of pcv system

that link has 8 pages scroll down had color pics of all items and connections