Bronco Forum - Full Size Ford Bronco Forum banner

1 - 18 of 18 Posts

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #2 ·
All this is due to a high idle still after iac replacement. I capped off the thing in the pic and still drives at high idle
 

·
Registered
Joined
·
4,970 Posts
The correct PCV doesn't have two ports (like yours has), plugging the top port was a good thing. Getting a new PCV couldn't hurt, they do get gummed up and at idle, because of the high manifold vacuum at idle, they are pretty much closed.
 

·
Registered
Joined
·
515 Posts
It wouldn't hurt to see about replacing your vacuum lines with rubber if you don't mind the hassle, especially since if you still have the original plastic lines they are going on nearly 30 years old. Just take it one at a time and with the vacuum canisters one side has a check valve while the other doesn't.
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #5 ·
Ya just picked it up Sunday with a high idle issue! been 3 days trouble shooting it! new tps, iac and pcv!
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #6 ·
replaced a good portion of my vacuum lines and I still have the high idle issue. Now I plugged in my egr delete plug and it dropped down but once i drive it, it comes right back. Now I can only assume this is due to the faulty egr if it is indeed faulty. Any input?
 

·
Super Moderator
Joined
·
27,400 Posts
Yo Xploda,
See my Vacuum leak test in post #11

@ Help with dtc codes and idle

Includes such as;
EFI High Idle Tips by Mikey 350:
"Take off the air intake hoses so you can access the throttle bores. Start the engine and place a piece of stiff cardboard over the throttle bores. That should NOT change a correctly configured engine, as the idle air is only from the opening of the IAC, and nothing through the throttle bores.
If that make a difference, then the throttle plates are slightly open due to the removal of the Teflon coating, or the linkage/return spring/throttle stop is screwed up.
If the engine still runs too fast with the throttle opening blocked, try taking off the IAC and blocking those openings.
What you have done is (supposedly) removed all the "normal" air intakes, and if the engine still runs, you have a vacuum leak.
You could then try leaving the air intakes (throttle and IAC) blocked and cap off the vacuum lines coming off the vacuum tree. (except the MAP line) If one of those makes a difference, investigate the leak.
Check the vacuum line from the vapor canister (on the left side of the throttle, when facing the throttle assembly) (cap it, on the outside chance that the solenoid has failed open) (if equipped)
Pull the EGR connection to the intake and plug or cover it. (if you have wide duct tape, use that to cover the hole)
If it still is running with the throttle blocked and the IAC and the lines from the vacuum tree capped, then you have a manifold or PCV line leaking. Plug the PCV line to the intake, then the vacuum line to the brake booster (if it has it's own fitting on the manifold)
Something is causing that high idle, and 95% of the time it is a vacuum leak."
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #8 ·
Aye brother, so I had a mobile.mechanic outfit come by and work on and was suggested that the purge valve was the culprit and guess what WASTED more money. Holy shit I explained everything that was mentioned here and had suggested I do cap plugs and coil also. Man I'm just going to the dealer I don't have time to keep messing around, I didn't tear it apart as suggested but will prolly try it tomorrow and check. He even said when he removed the purge valve and capped the lines it would idle like it should.
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #9 ·
it will drop idle when I plug in the egr delete plug so maybe its the egr? I need to find my vacuum pump to test some of this stuff
 

·
FSB Pimpster & Recruiter
Joined
·
5,714 Posts
Dumb question but any CEL on ? Also, as mentioned above that's definitely the wrong PCV valve. I'd start by replacing all those rotten looking hoses. You also mentioned you have an egr delete plug. That just has a diode in it. Could have gone bad.

Good luck,
Allcruisen
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #11 ·
ya could be, yes with the egr delete will generate a cel but aside from that no. No cel with the egr plug removed!
 

·
FSB Pimpster & Recruiter
Joined
·
5,714 Posts
EGR Delete shouldn't throw a CEL. That's why I was saying it may be bad. Another way to check is use your oem sensor and push the needle half way in, this will trick the ECM to think the EGR is working.

Allcruisen
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #13 ·
I also ordered a bunch of nice silicone lines to replace the old crummy pvc lines and wow what a difference lol. just wish they had the colors i wanted instead of black and blue!
 

·
Super Moderator
Joined
·
27,400 Posts
Yo x,
EGR Eliminator Installation Manual by Ryan M. @ Wayback Machine
Excerpts, "
Disconnect EGR Valve Position sensor (EVP), and inspect the harness connector. Make
sure it’s free of corrosion and still has dielectric grease on the terminals.
Plug the Eliminator into the EGR Valve Position sensor (EVP) harness connector.
Zip tie the eliminator to the engine to protect it from vibration.
This product only eliminates the EGR electrically. Please take the time to remove and cap off
vacuum lines. If you are leaving the EGR valve on the intake confirm that it is fully closed. A
leaky EGR will cause more engine problems. It’s best to remove the EGR spacer, or put a
block off plate over the opening.
When performing computer Self-Test after installing this kit it is normal to get code:
33 / 332 EGR valve opening not detected.
The computer is acknowledging that the EGR is permanently closed. This is your desired
result. However if you get the following codes:
31 / 327 - EVP circuit failed below the closed EGR limit of 0.24 volts
32 / 328 - EVP circuit failed below the closed EGR limit of 0.24 volts
34 / 334 - EVP circuit failed above the closed EGR limit of 0.67 volts
35 / 337 - EVP circuit failed above the open EGR limit of 4.81 volts
Check your connection again; make sure there is no resistance in the harness.
NOTE: This device is not intended for pollution controlled vehicles. Local, State, and Federal
laws may prohibit the removal or disabling any emission control device on any emission
applicable vehicle."
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #15 ·
Couldn't install a new cat that doesn't have the air pump hook ups and just remove the air pump?
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #16 ·
Replacing the egr valve and sensor on top of it today. I drove it around yesterday and parked at home to troubleshoot some more and as soon as I hit the valve it dropped in idle. So I'm assuming it's the issue. Not an appropriate way to troubleshoot but it definitely seems like the issue now.
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #17 ·
Removed the egr but the bottom part going into the exhaust manifold broke completely off into the b nut!
 

·
Registered
91 bronco xlt OJ edition. 5.8 auto
Joined
·
42 Posts
Discussion Starter · #18 ·
replaced and seems to run better, I pulled the battery terminals off and touched them together and reset the ecu and drove tons better but the idle kinda takes a little time to get below 1200 when i put it in neutral? I know I'm prolly reading into this more than I should but damn it bugs me. The original issue was the idle was too high and would make stopping a little akward and now it seems 100% better after putting in a 2nd egr
 
1 - 18 of 18 Posts
Top