timing

Have a '95 4.3 Z pickup and have never been able to figure this one out. In timing my truck both the repair manual and everything else I have read says to "Disconnect the EST (Electronic Spark Timing). It is over on the passenger side and is a brown wire with a black stripe on it." My distributor has two groups of wires attached to it, one with 4 wires and one with 2. Which do I disconnect? Thanks.

So, no one here knows?

why not try each one individually?

Man, I swear, why are people giving advice when they don't even know what to do.

vtmecheng ,

Go under your glove compartment and disconnect the brown and beige striped timing wire from the PCM directly. It is under the govel compartment going under the carpet.

I have looked high and low for that wire BlazerLT with no luck...the molding under the glove compartment is out and carpet up but no single wire to be found.

Hmmm.....

Whoa, hold on, you have a 1995.

Do you have a computer on your passenger tire wheel well?

yeah, it is a 1995 S10, 4.3 Z manual trany and 4x4. There is a computer on the wheel well.

Ok, I just talked with a GM tech at a dealership. He says the wire should be under my carpet on the passenger side. I guess I will be pulling all the carpet up now just to try and find that one f$%cking wire. How stupid.

Whoa whoa, no, it won't be there.

I think you have the odd change over year with the OBDII computer.

Ther won't be any wire under the glove compartment. Check to see if there is one on the computer in the passenger side wheel well.

Update, the wire can not be found under the dash. I have looked at the wheel well area and it isn't there either. I do have a PCM under the dash but also have a black box on top of my passenger side wheel well with a boat load of wires going to it. Unless someone here has any ideas I am going to talk with the head mechanic at a GM dealer where my friend works. If he can't tell me over the phone I will have to bit the big one and take it in the shop. Chevy really f-ed up on this one guys.
P.S. I do have the odd change over model with the OBDII computer, many call it an OBD 1.5. I call it a piece of S#$T.

You might have a OBDII with computer controlled timing that cannot be adjusted.

Have a '95 4.3 Z pickup and have never been able to figure this one out. In timing my truck both the repair manual and everything else I have read says to "Disconnect the EST (Electronic Spark Timing). It is over on the passenger side and is a brown wire with a black stripe on it." My distributor has two groups of wires attached to it, one with 4 wires and one with 2. Which do I disconnect? Thanks.

The wire in question *may* be a wire with an inline connector that was simply pulled out from one of the wiring bundles located on the passenger side of the engine compartment near the firewall. My '93 had the same requirement for timing (my engine "brain" was mounted on the wheelwell housing) and the EST connection was simply a single wire with an inline connector that stuck out of a large wrapped wire bundle. It is easy to miss and the brown/white stripe wire may be hard to notice if its covered in grime. When you find it, simply break the connection and proceed with the timing. Once you're done, you may have a check engine light come on but it should go out.

To make matters worse, the wire/connector may have been tucked in a little more snugly into the wire bundle so that only the connector is visible.


Hope this helps and good luck finding it...


Mike

Please describe the connector for me; things like color, size, and shape will help. Thanks

It is approximately 5/16 " square, small by comparision to other plugs. Everyone I have seen is black. I have seen them Brown/biege, Brown/white, Brown/ black. The wire is a small guage. The brown is not the dark brown but a lighter shade.

Please describe the connector for me; things like color, size, and shape will help. Thanks

Physically the connector is small, no bigger than say an inch long and no more than about a 1/2" square. It is made of black plastic and will have only one wire on either side of the connector. It is an inline connector; you'll have a single wire into the connector, the connector itself then a single wire out of the connector. To make it challenging to find, the wires on either side of the connector may not both be brown w/white stripe. Since the timing on these engines is rarely, if ever, checked or adjusted the wire may be snugged into the black plastic accordian "snakes" used to wrap the wire bundles. These "snakes" are split on one side (to allow remvoal/installation) so I would systematically follow every wire bundle looking/feeling for any small connector that is outside of the bundle. If that fails to work then maybe the whole assembly was covered over by the accordian wrap; probe any gaps/bulges you find in the wire bundles. Yes, it is a PITA but the area you need to concentrate on (passenger side near firewall) is realtively small and there aren't that many bundles to check. When I had my '93, I found the connector midstream in a wire bundle, that is it was not located at one end or the other of the wire bundle I was checking and the bundle was one of the fatter ones.

I hope this helps and good luck hunting...


Mike

if you have a crankshaft position sensor and a camshaft position sensor there will be no timing adjustment at all. the ecm does all the timing adjustments. if you cant find that connector, see if you have these sensors on the engine and that will solve your problem.

it is supposed to warm up around here mid week so I will try to find the wire then. Thanks for all the help and I will let you know how things go.

Sector95, thanks for the help you were dead on. The wire was right where you said it would be, which is good because if I didn't find it I would not be able to replace my intake manifold gasket. Now that I am into it though I am wishing I had not found that wire, then I couldn't have started this long and painstaking process.

Outstanding! It's a little "whoopee" kind of celebration that only someone who works on their cars can appreciate. I'm glad I could help.

Looks like now you're gonna have to complete the hand at task.....


Happy New Year!


Mike

Yeah, pray for me. The intake manifold is no 4 hour job, thats for sure. I just hope nothing gets f-ed up along the way. Have a good new year man.

Well, intake manifold is all done and she is back on the road. I am getting almost 21 Hg of vacuum at idle now so I can't complain (also means my rings are doing well). Thanks for the help with the timing wire, I just hope I won't need it for a while now.

Well, intake manifold is all done and she is back on the road. I am getting almost 21 Hg of vacuum at idle now so I can't complain (also means my rings are doing well). Thanks for the help with the timing wire, I just hope I won't need it for a while now.

...yeah but think how easy it'll be to find "next time" ;-)

Mike