4.6L General Discussion This section is for non-tech specific information pertaining to 4.6L (Modular) Mustangs built from 1996 to 2004.

Hesitation and EGR Question

Old 01-11-2014, 01:27 AM
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Default Hesitation and EGR Question

I've got a lot out of these forums so thanks for that. Now I have a question.

2000 GT 4.6L stock, 98,000 miles.
I had a cracked intake manifold so I replaced it with a Ford Racing manifold with the aluminum runner. I also changed the plugs and injector o-rings.
Now I have a severe hesitation during acceleration. I'm thinking vacuum leak but the idle is good (I'll do the carb cleaner test tomorrow).
No codes, no pending codes. Hoses and connectors are all in place.
Checking out the emissions system, I check the EGR valve. Putting vacuum on it causes a bad rough idle so I assume that It's working. I put a vacuum gauge on the EGR valve vacuum line: Cold, no vacuum. Warm idle, no vacuum. Warm at 2000 RPM, no vacuum.
Is this normal or is my EGR solenoid bad. Under what conditions is the EGR valve supposed to open?
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Old 01-11-2014, 08:31 AM
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Carb cleaner test?..just delete the EGR
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Old 01-11-2014, 12:10 PM
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Originally Posted by CobraFrenzy View Post
Carb cleaner test?..just delete the EGR
carb cleaner test for vacuum leaks.
I can't delete the EGR, CA smog.
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Old 01-12-2014, 06:30 PM
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Problem fixed.
It was the EGR solenoid. I suppose that it was just a coincidence that it happened days after I changed my manifold. Perhaps I bumped something lose inside.
I found this site that has an excellent step by step troubleshooting guide. It walked me right to the problem. While driving, I was getting a ton of hesitatation and misfire when there was 0 vacuum.
In case this comes up in a search, look here for troubleshooting help:
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