DRex

89 GTU NA, the car idles better with a vacuum leak. Plug the leak and the car surges. Ive done all the tricks, TPS adjustment, idle screw adj., everything. Someone help its pissing me off.

Icemark

Spark plug and plug wire condition???

Have you checked for alternitive vac leaks?

Runs fine while driving I am assuming???

DRex

Yes it runs fine. The plugs and wires are new, and im sure there are no other leaks.

Icemark

and you are not getting any error codes right?

have you checked the BAC and ACV for proper operation yet?

DRex

No check engine light, BAC is OK, have no idea how to check ACV. If you know do tell. Thank You

Icemark

warm the engine to operating temp,
disconnect the air hose (the air silencer to ACV at the ACV)
slowly increase engine RPM. At around 3700, the air should start to flow out of the ACV.

return engine speed back to idle
disconnect the relief solendoid valve connector/wire
slowly increase engine RPM. At around 1200 air should start flowing out of the ACV
reconnect the relief solendoid valve connector/wire

return engine speed to idle
disconnect the split air hose (hose going to the cat), place finger over the hose
disconnect the vacume hose on the ACV from the solendoid valve, air should start flowing out the ACV side of the split air hose.

If any of those tests don't work your ACV or relief solendoid valve may be bad.

rotaryrex7

Icemark, I know you've done this a million times but can you explain your 3rd test a bit more. When you say disconnect the solenoid valve you mean the "switching solenoid" not the "relief solenoid" correct" and the air should start flowing from the split air pipe hose or the silencer hose.

At idle I have very slight pressure coming out of the silencer hose and none out of the split air hose. When I disconnect the relief solenoid valve I get full flow out of the silencer hose. I never seem to get any flow out of the split air pipe to cat hose. I took the short hose off that connects the sir pump to the ACV and I get lots of flow from my air pump. When the ACV is not sending air out the silencer and it's not sending it out the split air pipe hose, WHERE IS IT GOING?!

Icemark

well, out of the ACV, the air can go into the intake tract, the air silencer, the port air (at the exhaust), or the main cat.

The relief soleniod switches between the air silencer and everything else.

The Split air switches the air to the cat.

the switching solenoid valve, switches air to the exhaust port or the cat.