86 Stang 5.0L running rich at idle....

[93 LX]

This one has finally come down to running rich now. Many of you have followed me in this journey to get this thing running good. Well after getting all the codes fixed and vacuum lines replaced and the dizy replaced for missing at WOT I am at the last issue. I have a Mark 7 SD computer installed due to problems with EGR and Thermactor issues. Maybe I will swap it back to the stock one if I can not get any help here.

I relaced the O2 sensors today in hopes the rich at idle would go away. No dice. I reset the computer by removing power for 30 minutes and stiil it idles rich.

KOEO codes are:
11
29 - VSS low (This car does not have a VSS)

KOER codes are:
94
44

I will be driving this car this week to see if it gets better but if it doesnt do you thinkI should swap back in the stock ECC?

Allen

 

[93 LX]

btt

 

[jrichker]

What are the symptoms that make you think the engine is running rich at idle?

 

[93 LX]

lets see. watery eyes standing behind the car while its running. I am going to switch back to the stock ECC. Maybe this conputer with the VSS error thinks something is wrong.

Allen

 

[v8only]

speed density cars commonly run rich with low vacuum.

What is your vacuum reading at idle?

 

[jrichker]

Do you have cats with a working smog pump? The watery eyes is typical of a car with no cats or non functioning cats.

 

[93 LX]

Yes the cats are functional and the smog pump works. As I mentioned before I have the codes 94 and 44 which have to do with the thermactor solnoids, Maybe the diverter valve isnt working so no air is getting to the cats. Also when the engine idles down is does run rough after its warm. In my carbed car this is a sign my curb idle enrichment is set too rich.

Allen

 

[93 LX]

I have to wait til the weekend to check the vacuum and to replace the computer back to the stock unit.

Allen

 

[93 LX]

OK did some checking. Found that at idle is between 15 and 20 inches. That seems normal to me. I move the idle up so the engine now idles at 900 or there abouts. This is an auto and in gear its donw around 700. I checked the TAB and TAD to see if they were indeed working as discribed and they are. They do flow vacuum but I still get codes 94 and 44.

I do have one question about the IAC. When I got one from the bone yard it had some sort of spacer between the IAC and TB. This spacer has 2 adjustments whis look like they allow more air then the IAC alone. The car I got this IAC from was a SD MK7. Should I insert this on my car? Do SD cars come with this from the factory? BTW I need to get this smogged sometime this weekend or next week. I am off tomorrow so I am thinking tomorrow. Should I insert this before I take the car to help lean it out?

Allen

 

[93 LX]

This just came to me. I have not verified that the smog pump is actually working. Would a bad pump cause a rich at idle condition? I will pull the hose this after noon and see if it is working and let you know.

Allen

 

[vristang]

This just came to me. I have not verified that the smog pump is actually working. Would a bad pump cause a rich at idle condition? I will pull the hose this after noon and see if it is working and let you know.

Allen

Normally the pump seize when they die. You would know if it had seized.

The vac numbers of between 15-20"
It should be more stable than that.
Maybe I misunderstood what you were saying?


jason

 

[93 LX]

Normally the pump seize when they die. You would know if it had seized.

The vac numbers of between 15-20"
It should be more stable than that.
Maybe I misunderstood what you were saying?

jason

Well the pump turns and as luck would have it I have another interview so the Mustang will have to wait.

The vacuum numbers do vary at idle. I since have brought the idle up to 900 now and it is more stable at 18 inches. This weekend I will check the diverter valve and the flow valve in the smog pump hoses and replace the ECC back to the stock one but after that I may have to pay someone to smog it.

I will be converting it to Mass Air so I hope this will clear up this problem.

Allen