I have an 88 GT 5.0. It has a MSD 6a and MSD coil. Also has a 75mm Throttle body with a Edelbrock Performer RPM 2 intake. The problem I'm having is when coming to a stop if I push the clutch in and stop it will stall. I found if I put it in neutral and rev it a couple of times it will stay idling. Any thoughts.
Stalling problem
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I'm assuming this car has been mass air converted?
If so, did you tap pin 3 and pin 6 on the ECU into the VSS sensor? Have you dumped the codes to see if one code is the VSS sensor?
Your symptoms are common and usually due to a failed VSS on mass-air equipped mustangs
If so, did you tap pin 3 and pin 6 on the ECU into the VSS sensor? Have you dumped the codes to see if one code is the VSS sensor?
Your symptoms are common and usually due to a failed VSS on mass-air equipped mustangs
First thanks for your reply. I bought the car with what on it the only change I made was putting a BBK mass air flow on it. It does have a check engine light on. I had my neighbor who was a licensed mechanic check code but couldn't get any. Not familiar with a VSS can you enlighten me.
Did the issue start after installing the mass air meter? Is the meter calibrated for the injector size on the car?
here’s a good obd1 reader to buy and have. Works well on these cars to pull codes. Some great YouTube videos on how to use (House of Dula) has one.
INNOVA 3145 Ford Digital OBD1 Code Reader Amazon product
View: https://www.amazon.com/dp/B000EW0KHW/ref=cm_sw_r_cp_api_glt_fabc_AP9M4CY45T4FKC84TSR5
So now about the VSS, which is the vehicle speed sensor. Unless your 1988 came from Cali, it was never mass air. It was speed density and was converted. Part of this conversion, that many feel is “optional” is to connect the VSS to the ECU pins 3 and 6. The reason i say this is mandatory is because the ECU uses the VSS to tell if the vehicle is slowing to a stop. A bad or missing VSS can lead to the vehicle stalling out when stopping. 9 times out of 10 when see a 86-88 with this symptom and mass air conveyed, it’s because the VSS was never tied into pin 3 and 6.
in 1988, the VSS was only used for cruise control. In 1989, it was used for cruise and the ECU, so the wiring doesn’t exist.
you can easily run two wires from the ECU over to the pass kick panel and tap into the wiring there. You’ll need two ECU pin connectors though and will need to crimp them into the wire and add them to the ECU harness.
There are some really good write ups on mass air conversion but I struggle to locate them at the moment.
I’d confirm all this before starting by running the codes. Grab that code reader. Obd1 is different than obd2 in that you should actually get 3 different pass code 11s. Two with engine off abs then you need to start the car and pull them with engine running. With the check engine light solid on, it’s a major code
here’s a good obd1 reader to buy and have. Works well on these cars to pull codes. Some great YouTube videos on how to use (House of Dula) has one.
INNOVA 3145 Ford Digital OBD1 Code Reader Amazon product
View: https://www.amazon.com/dp/B000EW0KHW/ref=cm_sw_r_cp_api_glt_fabc_AP9M4CY45T4FKC84TSR5
So now about the VSS, which is the vehicle speed sensor. Unless your 1988 came from Cali, it was never mass air. It was speed density and was converted. Part of this conversion, that many feel is “optional” is to connect the VSS to the ECU pins 3 and 6. The reason i say this is mandatory is because the ECU uses the VSS to tell if the vehicle is slowing to a stop. A bad or missing VSS can lead to the vehicle stalling out when stopping. 9 times out of 10 when see a 86-88 with this symptom and mass air conveyed, it’s because the VSS was never tied into pin 3 and 6.
in 1988, the VSS was only used for cruise control. In 1989, it was used for cruise and the ECU, so the wiring doesn’t exist.
you can easily run two wires from the ECU over to the pass kick panel and tap into the wiring there. You’ll need two ECU pin connectors though and will need to crimp them into the wire and add them to the ECU harness.
There are some really good write ups on mass air conversion but I struggle to locate them at the moment.
I’d confirm all this before starting by running the codes. Grab that code reader. Obd1 is different than obd2 in that you should actually get 3 different pass code 11s. Two with engine off abs then you need to start the car and pull them with engine running. With the check engine light solid on, it’s a major code
The stalling started before MAF was replaced and the maf is calibrated to the injector size. The car originally came from Massachusetts. I'll get the obd1 reader and go from there. Thanks again for your response.
Willybill32
But at least it's tight!
I’ve mentioned this to Mike before, but my ‘86 didn’t have cruise control, hence no VSS. When I converted to Mass Air, I just left those connections open with no issues. After significant upgrades a couple of years ago I had the same symptoms and solved it with a new IAC.
I know it's taken a while but it still cold here in Michigan. So I bought the obd1 reader. When I connected it, the link icon shows then nothing.
I grounded the single wire as shown in the trouble shooting still nothing. Any thoughts
Does the fuel pump continue to run when you turn the key to on (no start) not run for a few seconds then stop?
I didn't think of it yesterday when I was trying the code reader. But I checked today and the fuel pump isn't coming on. Going from bad to worse. Last summer when it would stall you could hear the fuel pump restart.
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