Mass Air Conversion Problems!!!

[Kdubslugga]

This may be normal I dunno though. I got a MAF Engine Harness from an 89, and I got an A9P Computer. Im using the stock MAF Meter right now with 19lb injectors until im sure all is good. Anyways I fired it up and it was great for about 10 seconds then it stumbled a bit and died. It did this 2 maybe 3 or so times and didnt do it again but the idle seems kinda rough and low to the point where my instrument panel lights dim and then it'll climb a tad again. It seemed to idle real good for a few min. and then have a hickup again, but it never died again. Does the new computer have to relearn itself? Ive doing some searching and have heard the computer needs at least 2 to 3 cool to hot cycles before it has relearned itself. Does this sound what its like to you?? I floored it a few times and its fine no pops ticks, nothing sounds off, just worried about the idle!

 

[horsepower302]

I would try re-learn then go from there

 

[DMAN302]

Pull the codes...after my conversion she simply lit up..no issues. Codes might tell you if anything is needing attention. Watch for and ignore code 95 for 'secondary fuel circuit fault", this code is often found when a wire is not run run from the puter to the fuel relay(not a power wire).

 

[fordman54935]

I would think after some driving the computer should start to re-learn. After I did my mass-air swap, the more i drove the car, the better it ran - not just at WOT, but at idle, part throttle cruise, everything. When's the last time you replaced the oxygen sensors? I replaced both of mine when I converted and the car gets great mileage considering the H/C/I and 4.10 gears. A bad O2 sensor can cause the stumbling you described, or it may be a dirty IAC valve. Sounds like your heading in the right direction, good luck!

 

[vristang]

Pulling the codes is a great suggestion.
Personally, that is the last thing I do before starting my engines after a rebuild or other major work.
It is a cheap/quick/easy way to verify that everything is plugged in, and that there aren't any major issues.



I am not sure how quickly the A9P 'learns', but I have seen my X3Z be fully adjusted after one commute to and from work (about 50 miles total, with some stop lights and highway traffic).

This isn't on the Powerdyne car is it?



jason

 

[Kdubslugga]

Well all was good before i did the mass air swap, Vac was at 19*. I took the Upper intake off just to route the engine harness easier. My Vac guage is really low like at 13* now, I dunno if maybe there is a vac leak at the intake gasket which i reused the old ones or if its an electrical thing I dunno, pisses me off though


No my S/C was waiting for the mass air coversion, its going on as soon as this is fixed!

 

[Kdubslugga]

I need help I dont even know where to start, what would cause a low vacuum other than if the upper intake gasket is the culprit?? I dunno, all I did was put a new engine harness in from an 89 and a A9P Computer. From a cold start it dies all the time now and runs rough. Any suggestions?

 

[vristang]

I need help I dont even know where to start, what would cause a low vacuum other than if the upper intake gasket is the culprit?? I dunno, all I did was put a new engine harness in from an 89 and a A9P Computer. From a cold start it dies all the time now and runs rough. Any suggestions?

Definately pull the codes.
If you don't have a scanner, check my sig for a link, or look up Stangnet member JRichker. He has some very good info on pulling codes.


There has been one member here post that a bad MAF sensor caused the car to barely run, and exhibit low vac. Replacing the MAS solved his problems.
I have no idea how a bad MAF would affect the vac, but that is what was reported.

Start with the codes, even if all you can get is memory codes.



jason

 

[jrichker]

Dump the codes and see what the computer says is wrong…Codes may be present in the computer even if the Check Engine light isn’t on.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Wal-Mart.

Or for a nicer scanner see http://www.midwayautosupply.com/pc-7208-90-equus-digital-ford-code-reader-3145.aspx – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $30.