To all TBI owners

[VorTecxas]

I'm pretty new to the site, primarily because I never had the time to actually join. Any time I needed info I would browse through and get what I need, but just never really thought to join. But since joining in Sept I am seeing a trend

All of you TBI boys are having a lot of the same issues - hard starting, stalling, sluggish, poor acceleration, difficult to maintain speed, poor economy, etc. What I have to say is -

CHECK. YOUR. DAMN. TIMING.

No, it's not always the issue. No, it will not always make a difference. But it's a very good place to start. I have worked on MANY, MANY of these trucks (and only god knows how many carbureted vehicles, which aren't much different) and the timing is almost always significantly off. The distributors are inconsistent and unreliable, so it's a safe bet that if your truck has over 75,000 miles, your timing is probably out. Even it's only off by 2 degrees, that makes a difference in the combustion cycle, especially at higher RPMs

So please, before making ANOTHER post with the above issues, check that first. It may save you you some time and grief.

That's my rant. Good night Vietnam

 

[93blackthunder]

Idk how to check timing

 

[Old Goat Ninja]

Haha, thanks


That wasn't sarcasm by the way. Good to know in the future because I am no mechanic. I know how to turn a wrench and follow direction (like a Chilton or Haynes), but that's the extent of my mechanic prowess.

 

[VorTecxas]

Idk how to check timing

Valid point. I will do my best this week to do a write up with clear pictures. I should have it ready by the end of the week, but my job keeps me very busy Mon-Fri, so bear with me

 

[outalne94z71]

Idk how to check timing

super easy on these trucks, run them up to temp, shut the truck off and then locate the timing wire, 88-93 has it behind the plastic cover on the firewall pass side, it a single light brown wire with black stripe and has a disconnect to it, it will be in the group of wires that are all bundled coming out of the bottom of that cover, for 94-95 it is inside just below the glovebox, you disconnect that and start the engine, with a timing light on cyl 1 you set the timing to 0 on the timing tab(the big indent is 0 if you cant read the tab) by turning the distributor(loosen clamp first), turn off engine and plug timing wire back in and the ecm takes over from that point.

this is for stock small block, for stock 454 you set the timing to 4*btdc

 

[VorTecxas]

super easy on these trucks, run them up to temp, shut the truck off and then locate the timing wire, 88-93 has it behind the plastic cover on the firewall pass side, it a single light brown wire with black stripe and has a disconnect to it, it will be in the group of wires that are all bundled coming out of the bottom of that cover, for 94-95 it is inside just below the glovebox, you disconnect that and start the engine, with a timing light on cyl 1 you set the timing to 0 on the timing tab(the big indent is 0 if you cant read the tab) by turning the distributor(loosen clamp first), turn off engine and plug timing wire back in and the ecm takes over from that point.

this is for stock small block, for stock 454 you set the timing to 4*btdc

Kudos on the short version

 

[94Sierra4x4]

Just for s and gigs..
Is there anything you can do to check the timing, or advance/retard it to 0* without a timing light?
Like mark the dizzy, loosen it and turn it a c-hair, drive it to see if symptoms cleared up/changed?

Is it even worth screwing with, without a timing light?

 

[88GMCtruck]

Another thing I will add to this, if your motor is higher mileage it's worth replacing your timing chain. They do stretch over time and it can make the timing walk around.

 

[96k1500]

I always had the truck running and climb up so that i could twist the distributor while running, once the idle smoothed out i would give it some throttle and see how it responded, once it ran how i felt was how it should be i would tighten the distributor back down, this only works if you dont have to pull the distributor out to adjust it

 

[94Sierra4x4]

I always had the truck running and climb up so that i could twist the distributor while running, once the idle smoothed out i would give it some throttle and see how it responded, once it ran how i felt was how it should be i would tighten the distributor back down, this only works if you dont have to pull the distributor out to adjust it

This is what I was thinking about doing.. don't want to put anything to far out of whack though.

My trucks sitting around 150 000 miles now, wondering if it'd be worth getting timing chain done & a new dizzy. Both have never been replaced