HELP!!! Trying to time my '94 5.7L Sierra 1500

I am trying to time my '94 truck. I talked to a mechanic at GMC that was vague at best. Said something to the effect of disconnecting a wire off the distributor that disconnects the computer. Then using the timing light.

Does anyone have any better description?

You can email me at Jaguars-fan-2@comcast.net if its easier...or if you have written info.

Thanks!!!

Yes, there is a junction box located on the passenger side fire wall. Take off the cover. There will be several wires in there. The one you need will be a single wire, brown I think, that has a connector in it. Noting fancy, just one wire. When you unhook it that takes out all the computer control to the distributor and the timing should read ZERO. If it doesnt then set it to ZERO. You can varify you have the right wire by connecting it and rechecking the timing. It should jump to about 10 deg or so with the wire connected. When you got it set reconnect the wire and you set!

Hope this helps

I can verify the wire color if needed as I also have a 94 k1500

Great! Thanks! I will take a look at it tomorrow and see if I can find it.

If I need addtl help, I will let you know!

Appreciate the advise!!!

Hey there...its me again...I have opened up that junction box, but there are no single brown wires that have connectors. I have taken a pic, but when I tried to send you an email, it advised that you dont accept emails thru the forum. If you dont mind taking a look... :-) Im have 5 connection leads from R to L.

First one (on L) is empty and the other 4 have connections. Any idea which connection is the right one?

My email address is: jaguars-fan02@comcast.net

If you send me an email with your address, I will send you this pic.

Thanks!!!

Steve




Yes, there is a junction box located on the passenger side fire wall. Take off the cover. There will be several wires in there. The one you need will be a single wire, brown I think, that has a connector in it. Noting fancy, just one wire. When you unhook it that takes out all the computer control to the distributor and the timing should read ZERO. If it doesnt then set it to ZERO. You can varify you have the right wire by connecting it and rechecking the timing. It should jump to about 10 deg or so with the wire connected. When you got it set reconnect the wire and you set!

Hope this helps

I can verify the wire color if needed as I also have a 94 k1500

when u take the cover off there should be a large loom with the wires that come into the relays ...........look on the back of the large loom of wires, its normally taped on the back and is hard to see

It's not on one of the screws. Like 72rs says, its in that big mess of wires on the right that come in to the junction box. Its the only one that has a connector in it that will come apart.

If you still have trouble I will take you a picture tomorrow, its a little late tonight.

Alright...keep looking. If you can take a pic, that would be great! I will dig into it tonight and see if I can find this wire. The panel on the passenger side firewall (engine side) only has 4 1/2" leads. 3 of them have 2 14-16 ga wires each and the 4th has a single 10 ga ground wire. Under the dash, there is a large loom of small ga. wires coming thru the firewall and going up under the dash. I didnt see a junction box.

I know this REALLY cant be that difficult and you are all probably shaking your heads...but really...I'M LOOKING!!! :-)

ok ............ lets see here. after removing the cover you will have some relays on the fire wall.......IGNORE THEM. looking at the WIRE LOOM that ENTERS the relay cover there should be a bracket that holds the loom to the firewall ( about 6 inches from the end of the loom). between the end of the loom and that retaining bracket you should find the (EST) electronic spark timing.....plug ( tan wire with a black stripe)(norrmaly taped to the back of the loom) unplug it. now setu rtiming to (TDC) top dead center . when done plug the wire back up. thats it ...................your done.

I sent Jaguars-fan a picture of the location out- side. 72rs, maybe you can send him a pic of the one inside.

wish i could send pics, but cant.......dont have a digi cam or scanner

Im hoping tonight I can tear into it. Wife has had plans the last two nights, so I have had kid duty! With all the info you two have provided, Im sure I can find it. If I do fail to find it, I also heard there was one other way to fix the problem. Basically it only involves driving and a good location...to sink it in the freakin' RIVER!!! :-)

I will keep ya posted!!!

Exactly why do you think its out of time? Did you do any engine work? If it misses or lacks power maybe it just needs a tune up. Just curious.

Well last year I had to replace the intake gaskets. Had to pull the distributor then. Marked it before pulling it, but had issues getting it back in and got it as close as I can. Ran ok so I quit dicking with it. I have been having problems with it running way rich. Will messing with it one night, busted the heater core quick connect on the back of the intake. While fixing that I bumped the distributor hard enough that I lost power. I have moved the dist. back and forth and know its out...but I moved it just enough to keep it from pinging, but Im sure I am not timed.

I tore into it tonight and found the tan wire with black stripe, but have traced it forward and back as far as I can reach and havent found the connector. Im am planning to cut the wire this weekend and see if it effects the timing and then whether it does or not, just put quick connects back on it and use shrink wrap to seal it. I checked the timing tonight with the wire connected. I advanced my gun to about 26 advanced and it is showing TDC...so Im guessing that if the computer adjusts it approx 10 degrees, its about 16 degrees out. Its running ok, but with todays fuel costs, I need every mpg I can get!!!

Anyway...I will post a final outcome as soon as I get it done. I really appreciate all the help you all have given me!!!

Sounds like a plan. You definitly need it timed. That should work. With it cut you should read "ZERO".

Well I found that damn wire! Never did find the connector...but found the wire and made my OWN connector.

I disconnected and i'll be damned if it wasnt freakin' perfect! Dead on TDC. All that work and time to just confirm that it was already on.

The amazing part is the fact that, as I stated in my last note, I had bumped it pretty severly when I was replacing that quick connect on the intake. I was fiddling with it back and forth until I didnt hear a ping and just left it alone. Apparently I hit it dead on...

Anyway...guys, thanks SO much for all your help with this. couldnt have done it without your guidance!

Take care!!!

Steve

wish i could send pics, but cant.......dont have a digi cam or scanner

Hey 72RS, this is a dup of the one I just sent, but wanted to make sure you got it too...

Well I found that damn wire! Never did find the connector...but found the wire and made my OWN connector.

I disconnected and i'll be damned if it wasnt freakin' perfect! Dead on TDC. All that work and time to just confirm that it was already on.

The amazing part is the fact that, as I stated in my last note, I had bumped it pretty severly when I was replacing that quick connect on the intake. I was fiddling with it back and forth until I didnt hear a ping and just left it alone. Apparently I hit it dead on...

Anyway...guys, thanks SO much for all your help with this. couldnt have done it without your guidance!

Take care!!!

Steve

Glad to help.

Alright...keep looking. If you can take a pic, that would be great! I will dig into it tonight and see if I can find this wire. The panel on the passenger side firewall (engine side) only has 4 1/2" leads. 3 of them have 2 14-16 ga wires each and the 4th has a single 10 ga ground wire. Under the dash, there is a large loom of small ga. wires coming thru the firewall and going up under the dash. I didnt see a junction box.

I know this REALLY cant be that difficult and you are all probably shaking your heads...but really...I'M LOOKING!!! :-)

You guys are off the timing connector on a 94 and up is inside the cab on the passenger side below the glove box. There should by a wire bundle that you can see to trace under the carpet. I had the same problems with my friends 94' and thats how I found this out.

already found it...found the tan wire with a black stripe in that bundle after it came into engine compartment. Got tired of looking for the connector, so I just cut the wire and added my own connector. Worked perfectly!

Thanks!

The connector your looking for is inside the cab under the glove box close to the fan motor...