Setting timing
 

Ive been trying to set the timing on my 90' Suburban for about an hour now, Ive read on many forums to disconnect the "Set timing" wire, but I cant find the right location, some say next to the ecm behind glove box, some say by steering shaft and some say next to distributor. Ive set the timing to 0 and reconnected both wires behind glove box and by steering shaft, and the truck seems to have had lost alot of power and throttle responce. Idle isnt very steady, goes between 700-900. Any ideas? Thanks!!

Re: Setting timing
 

Should be a tan wire under the top of the carpet behind the glove box if I recall correctly. Did it have the idle problem before you set the timing?

Re: Setting timing
 

It had a problem of after starting the trucks idle would be slow, around 500 until I gave it alittle rev then it would idle at 700 perfect. So I checked the timing to make sure it was within spec, and the timing notch on the balancer was about an inch past the timing mark plate. So probably advanced 14-16 btc

Re: Setting timing
 

I've only had one TBI truck that never gave me any trouble so I'm not schooled in trouble-shooting them. But I'd start with checking injector spray patterns. Has it sat up much recently? After you pat the gas and get it up to a 700 rpm idle is it smooth? Also they're real picky about fuel pressure being in spec to run right. EGR malfunction is also common.

Re: Setting timing
 

The timing connector "should" be just to the right of the engine. It is a tan, single wire with a single weather pack connector. That may make all the difference in the world if you didn't have the right connector unhooked.

Re: Setting timing
 

It does have a stumble when i lightly put my foot on the throttle, but drive fine after that. Almost everything on the truck has been replaced about a year ago. Wouldnt rule out any of those parts going bad already, but I was told the throttle shaft that goes threw the TBI after years will become loose and cause a vaccum leak by the throttle blades. And Ived checked the injectors as the truck is running with a flashlight and they seem fine. I will advance the timing to 4 btc and reset the ecu and see if that fixes the problem

Re: Setting timing
 

How many miles are on it? Just curious.

Re: Setting timing
 

Bought the truck in 2009 with 113k, currently has 157k

Re: Setting timing
 

There is a 10a fuse that blows if you reconnect the brn/wht wire with the ignition on, or even sneeze at it for that matter. I can't remember what it's called on the fuse box but its something like "ECM2". Same as running with the wire disconnected, you will have no advance.