Engine High AFR 5.0 Help!

Fourfourty · Jun 2, 2020

Hey,
I’m from Germany and hope you can help me.
I have a stock 1988 5.0HO T5WC and i have issues with my afr. It’s pretty lean around 17. I checked the vakuum lines and the exhaust for leaks, but there are none. Engine code was 21 which is coolant temp out of range. I changed my coolant temp sensor but still bad afr. Don’t know how old the o2 sensors are... you guys can help me?

Another question:
When i look for wiring plans for the coolant temp sensor, they always have two wires, but i only have one wire going to the sensor and none going to the self service plug. Do i have a Europe model which is maybe different in wiring or why do i have just one wire? (Car is a 1988 5.0HO T5WC)

Thanks for your answers
Danny

General karthief · Jun 2, 2020

Show us a pick of the top of the engine and point to what you are calling the 'temp sensor' , I suspect you are looking at the temp sender,
How long have you owned the car?
Have you checked fuel pressure?

Fourfourty · Jun 3, 2020

Here are two pics of what i call temperature sensor.
I have the car now for half a year and no i haven’t check fuel pressure yet.

Fourfourty · Jun 3, 2020

Here is a pic of the whole engine bay

Steel1 · Jun 3, 2020

That's the temp sender for the coolant gauge.
The ECT sensor is on the passengers side in-line of one of the black heater tubes.

General karthief · Jun 3, 2020

^^^ what he said^^^^

General karthief · Jun 3, 2020

Check fuel pressure, I doubt the ect will effect afr after warm up.
Here is a checklist that may help you:

Help me create the "Surging Idle Checklist"

Updated 26-Oct-2019 to clarify creeping idle RPM increase as the car is being driven. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of...

forums.stangnet.com

Fourfourty · Jun 3, 2020

Thanks for your help
I will buy some new o2 sensors and a new ect sensor.
Today I saw that my steering reck is leaking. I have already tried ones to seal it but it only lasts 2 weeks. Do you guys can tell me which steering rack from rock auto is good?

mikestang63 · Jun 3, 2020

You said you checked for vacuum leaks- did you use a smoke machine? How many miles on the motor. What is your engine pulling for vacuum at idle;

Fourfourty · Jun 4, 2020

No i sprayed brake cleaner on the intake and the vacuum lines too see if the idle goes up or not.
And i dont know how much vacuum my engine ist pulling at idle.
On the odometer are 56.000miles.

mikestang63 · Jun 4, 2020

Fourfourty said:
No i sprayed brake cleaner on the intake and the vacuum lines too see if the idle goes up or not.
And i dont know how much vacuum my engine ist pulling at idle.
On the odometer are 56.000miles.

get a vacuum gauge and hook it up to an intake source. Without that you are guessing. You should be pulling 15 at idle on a stock motor

Blown88GT · Jun 4, 2020

On a speed density car, even a small vacuum leak will affect AFR.
I assume you're measuring AFR with an independent sensor, permanent or temporary?

Fourfourty · Jun 30, 2020

Hey Guy’s
I replaced the ect sensor and both o2 sensors but still running way to lean.
When I read out the codes of the car, it says that there is an issue with the MAP... can the MAP effect my afr?
But this code only was ones. I checked again 15min later and then was everything ok

I checked my afr today again and its still 24.99
Hope you can give me some tips on how to solve this problem.

Danny

General karthief · Jun 30, 2020

what is the code you are getting for the map?
did you reset the computer after changing sensors?
what are you using to check afr?

Fourfourty · Jun 30, 2020

General karthief said:
what is the code you are getting for the map?
did you reset the computer after changing sensors?
what are you using to check afr?

I was at a friend of mine and he told me to check if the „airpump“ which is blowing air in the exhaust system while cold starts is still on when the car is warm up.
So I check it and yes it is still running when the car is warm up.
Tomorrow I will check my afr again and cut the connection from the „air pump“ to the exhaust system. Pretty sure the afr will be ok.
I go to a car repair shop they have an afr tester which is verified.
Yes I disconnect the battery for a few minutes to reset the computer and the code was 22, but it only show up once.
Thanks for your quick answer.

Noobz347 · Jun 30, 2020

Picture of said MAP sensor as it sits in the car, please.

Deleted member 215073 · Jul 2, 2020

The smog pump sends air after the O2 sensors. It won't affect air/fuel ratios.

What is the engine reading for vacuum?

Fourfourty · Jul 4, 2020

Noobz347 said:
Picture of said MAP sensor as it sits in the car, please.

Fourfourty · Jul 4, 2020

JMGlasgow said:
The smog pump sends air after the O2 sensors. It won't affect air/fuel ratios.

What is the engine reading for vacuum?

After I take of the smog pump my afr was around 16 still a bit lean but better like before.
Next problem is the warm start issue
The engine is dying right after start up I have to let it rev around 700 rpm for 1 or 2 minutes till it idles on its own.

Deleted member 215073 · Jul 4, 2020

Vacuum reading?

Engine High AFR 5.0 Help!

Fourfourty

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General karthief

wonder how much it would cost to ship you a pair

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wonder how much it would cost to ship you a pair

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wonder how much it would cost to ship you a pair

Help me create the "Surging Idle Checklist"

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wonder how much it would cost to ship you a pair

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