EFI question

[kb426]

I have everything hooked up on the 32 so it can run and get up to operating temp. It runs badly. Acts like it has a huge vacuum leak or just doesn't fire when it's supposed to. When I hook up the jumper, the computer won't retrieve any codes. Does anybody know what's next? This is a Painless harness, 92 mustang gt computer setup.

[enjenjo]

I recently had this problem on a 93 Ford 5.8. It was the fuel pressure regulator, so check the fuel pressure. It has to be in a window, neither too high, or too low. In my case it was too high. Acted like a vacuum leak.

[rooster]

You said it wont pull the codes up. A buddy of mine installed a painless harness, but it was it a GM, when he turned his key on he would get the flash,flash flash (12) does yours at least do this? Maybe you have a bad ground or blown fuse.

[kb426]

I'll check the fuel pressure. I don't know the history of the regulator so it's suspect. To pull the codes, you jumper 2 posts on the scanner port. I get nothing. It starts the sequence of running the pump and then is silent. I let it sit for about 2 minutes with no flashing light. I've unhooked the light and it works. When this first fired up, it sounded good. After running around 30 seconds, it started idling  rough and with it fast idling, it misfires badly. It almost sounds like there is an occasional backfire in the intake. Without being able to pull codes, this may be interesting.

[Crosley.In.AZ]

If the sensors are within parameters , no codes will be set.

Is this a closed loop system  with the after market wire harness?   OEM programming?

The ol GM TBI setup would act like it was too rich - bog down. It actually was low on fuel pressure

[Leon]

On a Ford, if there is nothing wrong you should get a code "11".  Getting no codes can be a multitude of other things, check NO CODES?

[wayne petty]

could it be the idle air contol valve....  pull the connector and it should close and the motor should slow down to almost dieing...

there is a screw type speed ajustment on ford throttle bodys.. sometime hidden by a sealing plug...


it the throttle is too far open the idle air control cannot compensate for the air bypassing the throttle blades...



tps voltage also affects the linear motor in the idle air control ....

On efi ford 5.0 there are vacuum ports under the upper intake  hidden...under the front of the upper for the carbon cansiter purge hose.. under the rear of the upper intake for the map sensor..  somewere there is also a port for the vacuum booster......

these ports are either 3/8 or 7/16th  and go down to a 9/32th hose...  do to that hose not being available i use a 1/4X3/8 vacuum hose adaptor and some 3/8 fuel line to the port..



there is also a hidden pcv filter under the pcv valve gromet on the back of the lower efi manifold... (it is actually an anti flash flame filter ) and it gets clogged, it is only a few bucks.. from a ford dealership... or motorcraft...

[kb426]

I figured out my computer has a problem. I found one to borrow and it says I have mass air problems. Back to work, again.

[kb426]

Mass air problems fixed. Up and running.

[EMSjunkie]

Mass air problems fixed. Up and running.

Another fine example of Team Smart in action

way to represent Bill    

Vance

[kb426]

Yo, Vance, you sucking up so you can use my english wheel? Just in case anybody cares, my original computer works ok, it just won't do any codes either with the light or a scanner. I'll send it off when I get everything else done. Tonight I'm wiring lights. I'm afraid Dave is going to finish before me.

[EMSjunkie]

Yo, Vance, you sucking up so you can use my english wheel?  .

is it working :?:  

Vance