This is topic EGR isn't getting vacuum in forum Tech Talk at Northern California Ford Owners  .


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Posted by blind (Member # 3052) on :
 
What to check?

I had a smog pre-test done today and it wasn't pretty, EGR failed due to not receiving vacuum, and the idle numbers were horrible, 2500rpm #'s were bad but no where near as bad as idle
 

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Posted by blind (Member # 3052) on :
 
ttt
 

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Posted by blind (Member # 3052) on :
 

 

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Posted by UNLUCKIER (Member # 435) on :
 
You have got a bad vacum line some where? That is where I would start.

[ May 04, 2006, 04:21 AM: Message edited by: UNLUCKIER ]
 

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Posted by NO MANRZ (Member # 566) on :
 
Can you post all your results? The EGR is only turned on durring steady cruise above somethng like 1500 RPM. If you're failing at idle, EGR is not your problem. Unplug the EGR line and do the engine running EEC test while feeling for vacuum on the EGR line. The engine on EEC test will open the EGR and you'll know if its receiving vacuum or not.
 

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Posted by blind (Member # 3052) on :
 
idle test - 804rpm

%C02 6.8
%O2 8.9
HC (PPM) 1388
CO% 4.23

2500rpm test - 2624rpm

%CO2 10.5
%O2 4.5
HC (PPM) 66
CO% 2.25

HC and CO% fail on idle
CO% fail on 2500rpm
EGR fail on functional test

when the tech hooked up the egr to vacuum it stalled the car, but when he plugged his guage into the vacuum line going to it and rev'd the engine no vacuum was seen.
 

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Posted by NO MANRZ (Member # 566) on :
 
What are the max limits for your smog numbers?

The car should stall if you open the EGR durring idle or below a steady RPM that is above 1500 RPM. Hook up a vacuum guage to the EGR line and run the engine running EEC test. Towards the end of the test the EGR valve will pulse open for two or three seconds if everything is working right.

What codes did the EEC fail on?

[ May 04, 2006, 03:58 PM: Message edited by: NO MANRZ ]
 

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Posted by S351-R (Member # 1605) on :
 
The high carbon monoxide (CO) readings indicate a rich running condition resulting in high hydro-carbon (HC) readings as well. Vacuum to the EGR is controlled by both an EGR control solenoid and a EGR vacuum regulator solenoid (both are controlled by the EEC). Start with the basics and check the vacuum hoses (both the EGR control and vacuum regulator solenoids are located on the passenger side fender near the shock tower),
 

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Posted by blind (Member # 3052) on :
 
I have an adjustable FPR, it's been popping through the exhaust, but every sensor is less than a year old, and the cats are brand new (NOS H-pipe).

I have the fuel pressure set to 39psi with the vacuum disconnected from the FPR and capped, that should be less than stock?

mods are:
255lph fuel pump
kirban FPR
edelbrock performer intake
edelbrock 65mm throttle body and EGR spacer
BBK equal length headers (have carb #)

the car isn't throwing any codes, I hooked it up today, did engine off and engine running to be sure.


I think I fucked up the vacuum routing when I repaired a blown head gasket back in Jan. so tomorrow I'm going to take the upper intake off and go over everything. I am also going to swap the EEC harness.

Currently it has a SD harness and ECU. After I get this smog overwith my S-trim will be going on and I need the MAF for that anyways so I might as well convert it over now. The car is an `89 and I have purchased an `89 MAF engine harness so I should be good to go.


Does the TAB or the TAD solenoid activate the vacuum to the EGR is my main question? They are both basically hooked in to manifold vacuum from the tree.

I don't have any vacuum leaks, it has 19#'s of vacuum at idle (stock cam).
 

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Posted by NO MANRZ (Member # 566) on :
 

quote:

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Originally posted by blind:


Does the TAB or the TAD solenoid activate the vacuum to the EGR is my main question? They are both basically hooked in to manifold vacuum from the tree.

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quote:

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Originally posted by NO MANRZ:
[QUOTE]Originally posted by blind:
[qb] A colorful vacuum diagram was posted here a while ago. I can dig it up if you need it.

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thanks, but I have that saved here on my computer

ok, so the TAB/TAD are the ones on the bottom, and the EGR one is above them, got it.

Can I run the engine running test with my cheap ass scanner that plugs into the test port in the engine bay and has a blinky light all I've ever done with that is checked to see if it blinked a code or not, never has on my car, but it has on my `91.

Do the `87 SD ECU's even throw codes? I dont recall the check engine light ever coming on.
 

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Posted by NO MANRZ (Member # 566) on :
 
So run the engine on test then unplug your EGR vacuum line. Wet your finger and place it over the vacuum line or us a vacuum guage if you're not ghetto. Durring the end of the engine on test you should feel vacuum pulsing for 2 seconds. All EECs throw codes. On MAF cars if you unplug the MAF, the check engine light will come on. On a SD car, try unpluging the MAP sensor and TPS sensor. Unplugging the O2's will take up to 10 miles before the check engine light turns on.
 

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Posted by blind (Member # 3052) on :
 
think I found what was causing the problem.

a couple of the vacuum lines by the passenger strut tower got melted by my headers, they are sealed shut.


 

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