Just had the engine pulled in order to change all the gaskets since the rear seal was leaking. While the engine was pulled I had them install a new distributor rotor and cap. They also took off the smog pump.

Changed all the broken hoses and that seem to help my rough idle and the car does not want to die at red light now. This purge sound "rooomp" is only heard from inside the cabin and is very faint. I can hear the sound every time the car is idling. Car idles around 700-800 rpm, each time this purge happens it drops rpm to 600 and oil pressure a couple of psi at the same time. Oil pressure is very low around a quarter gauge to about 30 psi when warm and idle. Reason why I say the pressure is low, since I had the car (1year) It has all ways been between 30 - 60 psi. Never dropping lower than 30 psi.

Tried locating the sound from the engine bay but it can not be heard. One time I was able to hear it under the car coming around the torque converter. OP rebuild the transmission a year before I brought the car. Car shifts very smooth.

Any ideas what it might be? Only error codes I have now is 12 and 24. I don't have the gauges to test the fuel/vacuum pressure. Hopefully I find some on Amazon.

 

Today I decided to change the oil and filter hoping it will give me better oil pressure. While I was there I took off the rest of the Air pump tubing going down to the cat. Check the spark plugs to make sure they were ok. Found a splitfire spark plug, weird thing is I did not add this plug. The rest of the plugs are AC Delco. Changed the splitfire plug to an old NGK I had laying around.

Oil pressure seems good, but I have not driven the car around yet to make sure. The car also had a knock noise once in a while. Near the driver side firewall there is two sensors a grey one and a black one. The grey one was going crazy and making a **** load of noise. Trying to find out the name of this sensor [412210] 199 INDIA E ---->C, D---->A,B. The sensor looks fine but the connection inside is burnt.

 

Yesterday we check the timing and it was set to 8. If we cranked up the number the louder the noise got. In the end we dropped it down to 6. Still able to hear a faint sound. Was told that the code 24 could be messing with the idle. Going to try to fix the VSS then check to see if that fixes the low rpm issue.

 

Possible Misfire?????

*Fuel Pressure is at 11psi
*New CTS
*New EGR
*New TPS
*New IAC
*New Pcv Valve
*New Distributor cap and rotor
*Changed Fuel Filter
* New VSS
* New MAF
* New Fuel Injectors
* tbi rebuild kit
* Took out AcDelco spark plugs and replaced with NGK's.
* Tried 89 to 91 Octane Gas (Various stations)

The missfires is only once in a while now. When I change out the stock airbox for a open element filter type setup. I hear the missfires constantly therefore at this moment only using the stock setup.

The only way it does not missfire with the stock airbox is if I raise the idle speed to about 1100/900 rpm. But i'm worried it will kill my mpgs. This there any thing else I might be missing?

Thanks in Advance.

 

the purge sound that i usually hear is the fan kicking on, it drops the idle down to 600 and bounces back up to 7-800, its kind of a hard sound to describe but sounds like when i say your "rooomp"

its normal to see your gauges do that, and you cant trust the reading from a stock oil pressure gauge(same with voltage or any of them really)

typically i verify my engine RPM with a laptop


the missfire is something else, but i know a stock L03 motor should be at 0* BTDC base timing(connector unplugged) I've never had to run anything more than 87 in the gas tank

this is the fuel pressure gauge you want

most guys will tell you to buy the 0-15 psi gauge kit(same money but only has the TBI adapter) but ive never had an issue reading the 0-100 and i also have a TPI iroc so i needed one that worked on both,
as long as its reading around 10 PSI(hopefully over) you are fine

 

Thanks for the reply,

The fuel psi is steady at 11. The fans are wired to a switch in side the cabin. As for the rpm I'm using an after market gauge since the oem gauge is way off.

I'm going to change out the 160* thermostat back to the stock 195* and lower the timing.