Just a bad wire

[Camino LS6]

...at least I hope so.

The Tahoe suddenly started acting like it was only running on seven cylinders today - so I ordered new plugs,wires, cap, and rotor. Sure hope that solves it, but the truck is almost at 200k so who knows.

[A Horse With No Name]

I hate automotive electrical problems.

[Camino LS6]

Actually, I'm really hoping that it is electrical.

The alternative could be unpleasant.

A quick check showed me a suspect plug wire - so I'm hoping that that's the culprit.

[A Horse With No Name]

I'll keep my fingers crossed, Bob!

[daves87rs]

I hope so too...

[67impss]

Yeah the alternative like my 1994 ROPOS reliable 330K mi 1500 is lo compression on one cylinder. It has a slight miss at idle but not above idle its a slow death I pray for not a sudden one.

[Camino LS6]

I'm heading out for the parts shortly.

[Camino LS6]

Things are not looking good.

Oh, it needed all of the ignition parts, but the symptoms are even worse with the new stuff installed. I'm thinking timing chain or cam.

I am holding out a small hope that a clogged fuel filter is responsible - but I doubt it.

The Tahoe may be dead.

Right now, it is undriveable.

[A Horse With No Name]

Yeah the alternative like my 1994 ROPOS reliable 330K mi 1500 is lo compression on one cylinder. It has a slight miss at idle but not above idle its a slow death I pray for not a sudden one.

Your doing better than the Fords...we've had thee Ford work trucks blow up within the last week...a diff..a motor...and another motor. (one motor is just a 5.4 that blew out a plug but...still)

Things are not looking good.

Oh, it needed all of the ignition parts, but the symptoms are even worse with the new stuff installed. I'm thinking timing chain or cam.

I am holding out a small hope that a clogged fuel filter is responsible - but I doubt it.

The Tahoe may be dead.

Right now, it is undriveable.

This has been a really crappy two or three weeks for me also....starting a "bitch" thread so we can all commiserate...

[Camino LS6]

Had to rush and make the wagon legal so I have something to drive. A former GM tech friend of mine is coming by tomorrow morning to help me diagnose the Tahoe.

But I'm not optimistic.

[ocnblu]

:-/

[A Horse With No Name]

Had to rush and make the wagon legal so I have something to drive. A former GM tech friend of mine is coming by tomorrow morning to help me diagnose the Tahoe.

But I'm not optimistic.

Hopefully the wagon won't be going through a pee ayy winter...

But then again....ughhh...is the RPOS drive able?

[Camino LS6]

Ugh.

I sure don't want to put the wagon through winter, but no, the ROPOS will never be street legal again. It's just a work truck on the property.

[A Horse With No Name]

I just bought a decent 97 Chevy Astro cargo van that runs well...if you can make it to Ohio, i might be able to arrange a "loaner" to keep the wagon from being destroyed.

[Camino LS6]

Thanks for the offer - I'll figure something out.

Have to see what tomorrow brings for the Tahoe.

[ocnblu]

Things happen for a reason... FIVE SEVENTY-TWO!!!

Sorry, Camino, you know me, just trying to make a smile. I hope it's not as bad as you fear, sir.

Edited October 5, 2011 by ocnblu

[67impss]

Things are not looking good.

Oh, it needed all of the ignition parts, but the symptoms are even worse with the new stuff installed. I'm thinking timing chain or cam.

I am holding out a small hope that a clogged fuel filter is responsible - but I doubt it.

The Tahoe may be dead.

Right now, it is undriveable.

1.) Timing chain will affect all cylinders equally

2.) Cam could be responsible but you'd hear a bad lifter and a roller cam seldomly wipes out a lobe.

3.) Fuel filter will also affect all cylinders equally in all but the most worst case which might be a semi plugged injector, also the fuel regulator could mimic the bad pump.

4.) If popping through the intake that valve is bad

5.) Ditto with exhaust hold a dollar bill(any denomination you wish )& if it sucks the bill into the pipe then bingo it's a bad exhaust valve.

6.) A bad orplugged injector will cause a miss even if the compression is showing good

7.) Low compression not caused by the valves would be a hole in the piston or broken rings which can be determined if you have excess crankcase pressure(pull the PCV valve from the valve cover

That should be it with the possible problems or as in my case worn out engine but I think yours doesn't go away. Best of luck to ya Camino

Things happen for a reason... FIVE SEVENTY-TWO!!!

Sorry, Camino, you know me, just trying to make a smile. I hope it's not as bad as you fear, sir.

572???????

[Robert Hall]

Things happen for a reason... FIVE SEVENTY-TWO!!!

Sorry, Camino, you know me, just trying to make a smile. I hope it's not as bad as you fear, sir.

572???????

BBC crate motor, IIRC

[67impss]

Wow they've really stroked them up there

[A Horse With No Name]

Good used motors are expensive, they seem to ahve gone up with the price of used cars.

Wonder what a used motor for this thing costs.

[Camino LS6]

A new GM motor isn't bad for this truck, around $1,200-1,400.

But that's about a grand more than I can spend right now.

[Drew Dowdell]

Fuel pump

Fuel injector

[Justin Bimmer]

One thing I remember about the Vortec engines is that the injectors like to get clogged and then the truck runs like $h!.

[Camino LS6]

After checking a bunch of possibilities, the consensus is that the timing chain is shot. We put a timing light on it and it runs best way away from the timing marks - only one thing can really be resdponsible for that.

So, with its other issues, age, and miles, I had to call it. Time of death for that engine: about 1:00PM EDT.

Now I have to think about what to do.

[Drew Dowdell]

Oh come on, even I can do a timing chain on a north/south chevy pushrod....

[Camino LS6]

Oh come on, even I can do a timing chain on a north/south chevy pushrod....

It also needs valve seals, has questionable head gaskets, 200k miles...

Not worth it.

[z28luvr01]

I'm sure if you go to a junkyard you can't swing a dead cat without hitting something powered by a Vortec 5.7.

[Camino LS6]

This is a pre-Vortec EFI engine.

1995 and older.

[A Horse With No Name]

Fuel pump

Fuel injector

Would be my thinking on the matter...

[Camino LS6]

I just checked and the prices on these have gone WAY up!

Even gmpartsdirect.com wants 2k for this engine.

GM part # 12568758

[A Horse With No Name]

Oh come on, even I can do a timing chain on a north/south chevy pushrod....

It also needs valve seals, has questionable head gaskets, 200k miles...

Not worth it.

Yeah...and a junkyard three fifty will cost 6 to 8 hundred, and be of questionable value.

I just checked and the prices on these have gone WAY up!

Even gmpartsdirect.com wants 2k for this engine.

GM part # 12568758

Hope you get some good plowing jobs this winter...

[Camino LS6]

I'm going to have to think this one over carefully.

[A Horse With No Name]

Saw a good driving running 1975 El Camino that was Ohio Rusty but ran well...old skool RPOS as a stablemate for the RPOS?

[BigPontiac]

What about transplanting the motor from the ROPOS truck into the Tahoe? Aren't they the same vintage?

[Camino LS6]

The ROPOS engine is just about as tired - and I'd need to swap the plow over too.

Best deal I've found so far:

http://cgi.ebay.com/ebaymotors/12568758-87-95-New-Chevy-1-2-Ton-5-7K-Crate-Engine-/290545545433?pt=Motors_Car_Truck_Parts_Accessories&hash=item43a5dd30d9

[z28luvr01]

How good are you at rebuilding engines? I only ask because you could save yourself a lot of money and do the hard work yourself

While you've got it apart, throw on a new timing chain and call it a week.

[67impss]

After checking a bunch of possibilities, the consensus is that the timing chain is shot. We put a timing light on it and it runs best way away from the timing marks - only one thing can really be resdponsible for that.

So, with its other issues, age, and miles, I had to call it. Time of death for that engine: about 1:00PM EDT.

Now I have to think about what to do.

Not trying to be a smart a$$ but did you pull the timing service pigtail on the firewall before checking timing?

[Camino LS6]

How good are you at rebuilding engines? I only ask because you could save yourself a lot of money and do the hard work yourself

While you've got it apart, throw on a new timing chain and call it a week.

This is sort of tempting.

[Camino LS6]

After checking a bunch of possibilities, the consensus is that the timing chain is shot. We put a timing light on it and it runs best way away from the timing marks - only one thing can really be resdponsible for that.

So, with its other issues, age, and miles, I had to call it. Time of death for that engine: about 1:00PM EDT.

Now I have to think about what to do.

Not trying to be a smart a$$ but did you pull the timing service pigtail on the firewall before checking timing?

Never even heard of it, would it give me a dramatically false reading? No such animal on anything I've ever used a timing light on.

[67impss]

Yeah it's on our trucks and is a must for correct timing as the computer will keep making allowances for adjustments and you wont do any good till the computer runs out of the internal adjustment so the balancer will read way off.

Look here for procedure

[Drew Dowdell]

it..... it's not dead..... it's just restin...... it's pining for the Fords......

[Camino LS6]

Yeah it's on our trucks and is a must for correct timing as the computer will keep making allowances for adjustments and you wont do any good till the computer runs out of the internal adjustment so the balancer will read way off.

Look here for procedure

Thanks!

I'd love to be wrong about this.

[Camino LS6]

Well, I sure can't find the connector they are talking about.

The emissions label reads like it is one of the connectors to the distributer - but that doesn't work.

So where exactly is the damn thing?

At any rate, a further observation with the timing light is that the timing is jumping all over the place constantly all on its own.

Still makes me think timing chain.

[Camino LS6]

OK, found it.

Get this: It is a tiny connector, completely taped over, taped to a huge wire loom, behind the glovebox!

WTF!

Got it disconnected, set the timing (didn't jump all over anymore, ran smoother but still belched through the intake and exhaust. So I shut it down, re-connected the lead ran it a bit (noting that the computer radically changed the timing), and the symptoms remain.

At least it is easier to limp around the driveway now.

Still looks like the timing chain.

Oh yeah, you have to remove the glovebox to access the connector.

[67impss]

Reliable ROPOS's wire was already hanging down sorry you had to search so much. now I might've missed it but this is first I've heard that it's coughing through the throttle & exhaust. Before you condemn it pull the valve cover on the low compression cylinder or both if you don't have a compression tester & look for broken rocker arm's or bent push rods. the rockers won't break due to timing chain on an engine that still runs. The push rods would probably indicate a stretched timing chain that jumped. really the timing chain is an easy fix and the engine should at least have 100K mi left before needing a complete rebuild. That should last your plowing years no sweat.

[Camino LS6]

I am pretty sure that a stretched timing chain is the culprit here. The idea of tearing all that stuff off of the front of the engine (when I've already done a PS pump and a water pump} isn't too appealing on an engine that also needs valve seals and should have the intake gaskets done.

If I do go that route, all three jobs will get done at once.

Ugh. Lotsa crap to get out of the way to do those jobs on an engine I have little faith in.

Still, the parts will only come to a few hundred bucks total.

The hassle factor is huge though - lots of hours and lots of disassembly along with lousy access. If I did all that, and the engine lets me down, I'll be seriously bent.

But I'm thinking about it.

Edited October 8, 2011 by Camino LS6

[Camino LS6]

Oh, and I don't plow with the Tahoe - that's the ROPOS' job.

Edited October 8, 2011 by Camino LS6

[67impss]

Well it's not called sweat equity for nutin

[A Horse With No Name]

If I was in Philly I would lend you a hand...

Good luck!

[Camino LS6]

Thanks, Horse.

I think I'll call the insurance company tomorrow and take the Tahoe off.