Need Help w/no-start and 511 code

[RacingNotPacing]

**Sorry for the lack of clarification it the title! I just came back to edit it & it wont let me.**

So my baby wont start, & i belve I'm getting the 511 code. it always drove great then just the other day I went to start it up & no fire, I have fuel at the rail, but no spark according to my timing light.

do you all have any sugjestions as to why the 511(no power to PCM) would be coming on? I also belive its pulling 116 ETC sensor.

Its a 93' MTX, but i also have a running 89' MTX for parts, could i possibly use the PCM from the 89?



Thanks in advance for the help guys,

 

[AREA 91]

Check the ground strap on the rear of the intake.
Check the bolts on the crossover tube.
Check the dis module connectionsas well as the 5.5mm mounting bolts.

 

[Mr Anonymous]

511 is a ROM test failure. Usually it's caused by the installation of a chip, so that would be the first thing I would check is if there is a chip installed and if so, make sure it's seated properly. Actually, just removing it would be better to start, then you can reinstall once you verify that the PCM is OK.

Disconnect your battery before touching the chip if you find one installed.

If there isn't a chip installed you may have a fried PCM.

 

[projectSHO89]

Any after market chip will cause a 511 code. As Chris said, often they come unseated and end up killing the PCM's operation until the chip gets removed.

Steve

 

[RacingNotPacing]

Does it matter if i actually have an aftermarket or a reprogramed PCM, IIRC i sent it into the guys at SHO Shop about 9 years ago & had it programed.

 

[Mr Anonymous]

I can pretty much guarantee that SHO Shop didn't have the technology to re-flash a EEC-IV PCM 9 years ago since that technology still doesn't exist today. I'm willing to bet they opened up the PCM and installed a chip inside the case -- probably the old "ribbon" style.

If the rubber cover is still installed at the rear of your PCM, pull it out and see if their is an edge card connector there. Again, disconnect your battery before even breathing on the PCM, if there is a chip in there, and it's not seated properly, moving it the slightest while the PCM still has power risks frying both the PCM and chip.

Oh, and to answer your earlier question, yes, your '89 PCM should work fine.

 

[RacingNotPacing]

OK so i got to the PCM & yes it did have the chip, I pulled the chip & since i had the wire loom off the PCM (in order to check for voltage to it) i went ahead & pull the PCM out of the dash & pluged it back into the loom but sitting at the fire wall instead of going through it, Is this hurting anything?

While following voltages I did confirm that i have 12 volts at the PCM & at the box thats at the RAD support. Still no fire.

Another funny thing i noticed, when i crank on the starter it just turns over & turns over,BUT if i crank & hold the gas down then it will act screwy, like its losing it voltage for a .002nd of a second, & the lights & everything dim for just that brief fraction of a second, but ONLY when I'm holding down the gas pedle.

 

[RacingNotPacing]

OK & I'm perty sure I screwed up the PCM & Chip, cause,,,,,,,,,,,Yes i disco'd both with the battery connected:banghd:

the chip doesn't worry me at this point, & if the PCM from the parts car works then I have that option, also I might just order a new one in & have it ready to go if i need it.

 

[Mr Anonymous]

Sounds like the PCM may be done for. Here's a tip, if you can pull codes from the PCM, it has power.

Try the PCM from the '89 and see what happens. Obviously, don't even futz with trying to use the chip. Even if it was still good (I'm betting that's fried too), it wouldn't be compatible with that PCM.