Vacuum question

DarkknightGT · Sep 8, 2025

I have been chasing vacuum lines GALORE trying to find this slight misfire and low idle upon first start up. Ive adjusted the idle and done a reset so many times its not even funny. Ive found some older stuff regarding deletion of vacuum lines but theyre all older threads and most comments are smarty pants responses. I also want to delete egr as well. I wanna know what goes into that as well. Also dont have emissions where im at so thats not an issue, I also wanna know if I do delete this stuff, is the car gonna run if I delete it and cap the unnecessary vacuum off?

Terrorist 5.0 · Sep 9, 2025

Well typically a vacuum leak results in a higher idle that fluctuates. not a lower one. Smoke test the car. That will find your leak if there is one. Check for codes as well. Always check for codes.

EGR deletes are not really possible on these without a tune. You will get a check engine light. No simulator plugs for the SN’s that work, that’s a primitive Foxbody thing. If it is working fine, just leave it. It helps out gas mileage. I had mine blocked off with a piece of soda can because the valve was stuck open and the replacement one didn’t fit.

DarkknightGT · Sep 9, 2025

Terrorist 5.0 said:
Well typically a vacuum leak results in a higher idle that fluctuates. not a lower one. Smoke test the car. That will find your leak if there is one. Check for codes as well. Always check for codes.

EGR deletes are not really possible on these without a tune. You will get a check engine light. No simulator plugs for the SN’s that work, that’s a primitive Foxbody thing. If it is working fine, just leave it. It helps out gas mileage. I had mine blocked off with a piece of soda can because the valve was stuck open and the replacement one didn’t fit.

For some reason the cel hasn't come on in a bit but I would get a 10, 111, 157, 211, 212, 327, and 332. I just replaced the distributor, ignition coil, spark plugs and wires about a year ago, so I dont think its the pip sensor like everyone said it was. 212 was what I was concerned about before, so I replaced it all and it idles but the needle bounces slightly and it idles semi low on cold starts, like 450 to 500 rpm range. Im honestly at a loss at this point with this thing.

96blak54 · Sep 9, 2025

SMOKE TEST!!!

Its cigar time! WOOT!

DarkknightGT · Sep 9, 2025

96blak54 said:
SMOKE TEST!!!

Its cigar time! WOOT!

I went all around the car and capped any open vacuum ports i could find hahaha

tvsn95 · Sep 9, 2025

DarkknightGT said:
I have been chasing vacuum lines GALORE trying to find this slight misfire and low idle upon first start up. Ive adjusted the idle and done a reset so many times its not even funny. Ive found some older stuff regarding deletion of vacuum lines but theyre all older threads and most comments are smarty pants responses. I also want to delete egr as well. I wanna know what goes into that as well. Also dont have emissions where im at so thats not an issue, I also wanna know if I do delete this stuff, is the car gonna run if I delete it and cap the unnecessary vacuum off?

first what year? if its a 94 style it has NO feed back to the EGR as far as flow detection goes. you can just cap the vacuum line. problems come from the valve leaking. it is best to remove and plug or cap the manifold and of course the exhausts. seems like I originally built a block plate, and since have tapped and plugged this in the manifold. the exhausts was welded shut at the screwed connection and reinstalled to seal.

DarkknightGT · Sep 9, 2025

tvsn95 said:
first what year? if its a 94 style it has NO feed back to the EGR as far as flow detection goes. you can just cap the vacuum line. problems come from the valve leaking. it is best to remove and plug or cap the manifold and of course the exhausts. seems like I originally built a block plate, and since have tapped and plugged this in the manifold. the exhausts was welded shut at the screwed connection and reinstalled to seal.

Its a 95 5.0, so is it different?

tvsn95 · Sep 9, 2025

DarkknightGT said:
Its a 95 5.0, so is it different?

Some body will correct me ,, but I believe they are the same.

95opal · Sep 10, 2025

DarkknightGT said:
For some reason the cel hasn't come on in a bit but I would get a 10, 111, 157, 211, 212, 327, and 332. I just replaced the distributor, ignition coil, spark plugs and wires about a year ago, so I dont think its the pip sensor like everyone said it was. 212 was what I was concerned about before, so I replaced it all and it idles but the needle bounces slightly and it idles semi low on cold starts, like 450 to 500 rpm range. Im honestly at a loss at this point with this thing.

With the engine cold, start the car with the iac unplugged adjust the idle stop screw on TB until it idles at about 1000rpm. Shut it down plug the iac back in and see where shes at. The only code i see you didnt address was the 157 MAF.

tvsn95 · Sep 10, 2025

DarkknightGT said:
I have been chasing vacuum lines GALORE trying to find this slight misfire and low idle upon first start up. Ive adjusted the idle and done a reset so many times its not even funny. Ive found some older stuff regarding deletion of vacuum lines but theyre all older threads and most comments are smarty pants responses. I also want to delete egr as well. I wanna know what goes into that as well. Also dont have emissions where im at so thats not an issue, I also wanna know if I do delete this stuff, is the car gonna run if I delete it and cap the unnecessary vacuum off?

For what its worth, Pull the ECU and look inside, there are 2 capacitors that fail. ( they may even have green corrosion) they are cheap and not hard to do, get the polarity right.

DarkknightGT · Sep 10, 2025

95opal said:
With the engine cold, start the car with the iac unplugged adjust the idle stop screw on TB until it idles at about 1000rpm. Shut it down plug the iac back in and see where shes at. The only code i see you didnt address was the 157 MAF.

I also replaced that as well. But that doesn't sound like a bad idea! I will do that and let you know. I'm also gonna pull it and clean it as well so even more of a plus!!

DarkknightGT · Sep 10, 2025

tvsn95 said:
For what its worth, Pull the ECU and look inside, there are 2 capacitors that fail. ( they may even have green corrosion) they are cheap and not hard to do, get the polarity right.

I'm fearing that tbh. When I got the car apparently some wires that went to the distributor were bare and arching against the block, causing the distributor to short out and it actually melted the CCRM. It was a mess!! Im also thinking it could have shorted out my tfi module as well so I may replace that

tvsn95 · Sep 10, 2025

DarkknightGT said:
I'm fearing that tbh. When I got the car apparently some wires that went to the distributor were bare and arching against the block, causing the distributor to short out and it actually melted the CCRM. It was a mess!! Im also thinking it could have shorted out my tfi module as well so I may replace that

just as another note, I personally went through a terrible experience with EMP interference from the alt and the ignition. It got worse over time and was VERY confusing. cost me a fortune in head gaskets and parts.
The short solution turned out to be a new set of FR plug wires and Faraday tape wrapping of the harness. I cant understate what a diff this made.
So yeah, the wiring needs to be good BUT spend the time to Faraday wrap the wires and save yourself the other crazy problems that just don't make much sense . the wrap is cheap.

DarkknightGT · Sep 10, 2025

tvsn95 said:
just as another note, I personally went through a terrible experience with EMP interference from the alt and the ignition. It got worse over time and was VERY confusing. cost me a fortune in head gaskets and parts.
The short solution turned out to be a new set of FR plug wires and Faraday tape wrapping of the harness. I cant understate what a diff this made.
So yeah, the wiring needs to be good BUT spend the time to Faraday wrap the wires and save yourself the other crazy problems that just don't make much sense . the wrap is cheap.

That's a good idea actually, I'll look into that stuff actually!