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My EGR doesn't hold vacuum. I put my finger on the vacuum line hole of the EGR, and it doesn't stay in the position I pulled it at. No codes. 93 LT1.
Do I need to replace it?
I'll jump on the agree bandwagon also. You want one of the hand held "Mity Vac" type pumps and to pull a decent vacuum, then see if it holds in without leaking.
Yes, I tried to look for one at auto part stores but never found one. I'll order one. Reason I asked about the EGR is because I have been trying to find out why my left bank is lean, no codes. IAC counts at 0, so there has to a be a vacuum leak somewhere. Does't idle high. But on cold start, the idle settles pretty fast.
Smoke test vacuum leak found, fixed.
New filter, then new injectors.
Exhaust leak at exhaust manifold gasket, fixed.
Last edited by 1993C4LT1; Mar 10, 2016 at 10:01 PM.
10 months old. But I'm gonna double check the left 02, see if it's responding correctly. While doing the oil change last Thursday, I checked to see if the 02 wires were not touching the exhaust, nor where they melted. Forgot to say, on the highway, the car's BLM numbers are perfect.
Last edited by 1993C4LT1; Mar 10, 2016 at 10:54 PM.
Your IAC counts at ZERO. I don't like that. Vacuum leak, odd IAC problem, or someone has been messing with the throttle stop screw.
They are at 0 at idle. Cruising, they go up. But yes, I know they aren't supposed to be at 0 when at idle. Is this the throttle stop screw? The one by the tv cable.
They are at 0 at idle. Cruising, they go up. But yes, I know they aren't supposed to be at 0 when at idle. Is this the throttle stop screw? The one by the tv cable.
Yes, that is the stop screw. If it is still at the factory setting the steel plug/cap will be over the back of the screw at the rear of the throttle body. If the cap is gone, some goober has been in there messing around with it.
I had an idea this morning when I woke up (I solve problems in my sleep) pinch off your vacuum line going to the brake booster. It is totally possible to have a leak THRU the booster but never find it any other way. See if anything changes including the IAC counts.
You did say you smoke tested the entire engine right?
Yes, that is the stop screw. If it is still at the factory setting the steel plug/cap will be over the back of the screw at the rear of the throttle body. If the cap is gone, some goober has been in there messing around with it.
I had an idea this morning when I woke up (I solve problems in my sleep) pinch off your vacuum line going to the brake booster. It is totally possible to have a leak THRU the booster but never find it any other way. See if anything changes including the IAC counts.
You did say you smoke tested the entire engine right?
Yup, still has the steel plug. Yes, smoke tested the entire engine with a smoke machine. Only found a very small leak going to the EVAP and TB. By pinching it, just squeeze it by hand right? Hey, I sometimes solve problems in my sleep to
Yup, still has the steel plug. Yes, smoke tested the entire engine with a smoke machine. Only found a very small leak going to the EVAP and TB. By pinching it, just squeeze it by hand right? Hey, I sometimes solve problems in my sleep to
Pinch off pliers would be nicer so you don't have to hold it and look at your scan tool at the same time. Vise grips will work too.
That stinks. You HAVE to have a vacuum leak. The IAC at zero means the pintle is CLOSED. At least it should be.
Propane and water might be methods to try.
I'm going to link you to this. Watch it. Rather than me trying to explain what else you might do.
You might also try closing your throttle more by pushing on it. See if the IAC or idle changes at all. You could have a leak right around that area if its worn enough.
They are at 0 at idle. Cruising, they go up. But yes, I know they aren't supposed to be at 0 when at idle. Is this the throttle stop screw? The one by the tv cable.
i have L98's but i totally hear a vacuum leak here.
grab yourself a cigar, pull your intake tube and either use packing tape over the tb intake, or if you can stretch a rubber glove over it thats another way, and then pull your brake boost line, and blow cigar smoke into it. blow hard and blow alot. have a buddy or your gf/wife look for where the smoke comes out. works like a charm.
93rubie, that is a badass video. Learned a lot from it, thanks Neighbor helped me do another smoke test just for the hell of it. No smoke came out of any vacuum lines. But I found out that my PCV hose is very hard, no cracks tho. And the brake booster line has a small burn. not sure if you can see it in the pic. Then I found this vacuum line that connects to vapor canister purge solenoid. Should I change them, or keep looking?
That purge hose....I got an idea. Just cap off the inlet to your TB and see what happens.
I remember your trim data being off a bit, if the purge was purging when it is not supposed to.....this can cause the trim to be off. Just a thought.
I also wonder if there is enough air getting around your throttle plates to keep it idling correctly without the IAC. You might want to confirm the IAC is shut like the SCAN tool says it is. Who says it is working 100% correctly? I wouldn't take anything for granted at this point.
YES, Scanner Danner's video are EXCELLENT. A lot of people here would do good to watch them and learn.
Water is an excellent way to find vacuum leaks, you might want to just spray that stuff around and see what happens.
Posting this so people don't get their selves in a wad....
From your video there is clearly a leak somewhere. It sounds like a manifold gasket to me. Have you checked all around the exhaust manifold gasket with a rubber hose to your ear?
Do you still have the AIR system and is it working properly? It's possible the diverter valve is not working properly introducing fresh air into the system.
The air pump turns on every time I start the car. I'd say it turns off in about 3 minutes? Never turns on again once it turns off. I appreciate everyone's helps. Sprayed a good amount of water on every gasket and vacuum line, one at a time. Nothing found. So I guess it's vacuum leak free, and all gaskets are fine. Last thing for me to do is what 93rubie mentions about the IAC valve. Side note, I did change the IAC at start of this year because the car would turn off every time I turned the AC on. No longer does that.
Bad EGR?
Neighbor helped me do another smoke test just for the hell of it. No smoke came out of any vacuum lines. But I found out that my PCV hose is very hard, no cracks tho. And the brake booster line has a small burn. not sure if you can see it in the pic. Then I found this vacuum line that connects to vapor canister purge solenoid. Should I change them, or keep looking?
