95 Tahoe Problem

RoyalTermite · Senior Member

95 Tahoe Problem

RoyalTermite · Senior Member

The truck ran OK before the manifold exhaust repair. I changed the plugs and wires AFTER the repair and only after I noticed it was not running right. Planned on tune up anyway.

There was no change in how it ran after tune up. The old cap was burnt to high heaven. No contact left at center. All the points inside cap were covered in heavy corrosion. Plugs were brown on one side of electrode.

Do not think it had to do with the tune up parts. Ran the same before and after.

twomanymontes · Moderator - Monte Hunter Lead Investigator

Being a 95 it's a 1 year only deal. It's not OBD1 or OBD2 kind of like a half and half. This will be extremely hard to diagnose over the net.

1st, is the check engine light on? if so what are the codes?

2nd, is it a light misfire? or does it feel like it's dropping a cylinder?

Seeing as it happened right after the manifolds were replaced, it sounds like a crossed ignition wire, they need to be removed to get the manifold off and could easily be put back on incorrectly, but you said they are not. And changing the cap rotor plugs and wires didn't change anything?

Did they have to torch any of the old bolts out? They could have heated a cylinder head to much to the point one of the exhaust valve seats fell out and is holding a valve open.

Fuel pressure could be too low, Does it have a long crank situation?

One thing that comes to mind with the Vortec motors is the distributor bushing wear out. The distributor shaft wobbles and causes a rolling random misfire. Some or even all the cylinders can misfire. Another thing is the spider injectors clog and stick causing a lean condition on specific cylinders.

Really hard to tell without seeing the truck and not having a scan tool hooked to it.

RoyalTermite · Senior Member

This has the 5.7 TBI. Not a Vortec.

I pulled all the wires and ran them direct from distributor to each plug one by one. Little chance of me running them wrong.

The miss is kind of like a chugging. Nice vibration in the whole vehicle. There are no codes, check engine light not on at all. Once you put it under load, it gets louder. Almost like there is an exhaust leak again but there is not. Runs semi ok till it gets up to operating temp. Then is has hard acceleration, vibration, loss of power. If you eve ran a vehicle with the exhaust off the manifolds it feels like that without all the noise.

I know it is hard to diagnose over the net. Just looking for start point. Taking it back to the shop that did it so he can maybe play detective.

Crusher · Mr Friendly Veteran Member

A coat of Zaino will fix it.....

NYMontess · Administrator

Crusher wrote:
A coat of Zaino will fix it.....

This one might call for 2 !!!!!!

RoyalTermite · Senior Member

Thanks for the tips. Will give it a try knuckleheads.

Lol

twomanymontes · Moderator - Monte Hunter Lead Investigator

Ok, TBI, that's a different story. Most of the Tahoes I have seen got the Vortec motors, Pickups got the TBI.

Running rough sounds like what Jim's truck was doing. But his cleared out.

Is it running rich? The wires that run up the throttle body deteriorate and short out causing the injector to dump fuel.

I doubt you collapsed a lifter, but that's the only thing I can think of that would cause noise as well as a misfire.

Sorry I can't be a better help

NYMontess · Administrator

RoyalTermite wrote:
Thanks for the tips. Will give it a try knuckleheads.

Lol

Get it right, were tumbleweeds!!!!!!!

Crusher · Mr Friendly Veteran Member

NYMontess wrote:
RoyalTermite wrote:
Thanks for the tips. Will give it a try knuckleheads.

Lol

Get it right, were tumbleweeds!!!!!!!

You tell him snapper head!!

NYMontess · Administrator

Crusher wrote:
NYMontess wrote:
RoyalTermite wrote:
Thanks for the tips. Will give it a try knuckleheads.

Lol

Get it right, were tumbleweeds!!!!!!!
You tell him snapper head!!

Don't you have some organic/hydroponic corn to grow or tend to?