Feels sluggish but no proof

[Hotrdd]

So I've tuned the 99 Yukon with new air filter, plugs, oil change, transfer case change, new serpentine belt and tensioner. BUT when I first start driving it just feels like the power isn't being transfer to the ground. I can hear the engine, rpm don't seem high, but just no guts. What should I look for? Can I get any proof on this?

 

[Freedom Motorsports]

I know this sounds simple, but have you checked the level of the fluid in the tranny? If it is low you may not have enough pressure in there for it to hold the clutches.

 

[Hotrdd]

I'll have a look. If it's that simple I'll be very happy and then kick myself for being so stupid. Will keep you posted.

 

[SunlitComet]

inspect your cap, rotor and wires for pitting or tears. And check for a clean maf sensor.

 

[Hotrdd]

When I inspect the wires and cap am I looking for a short in the wire? If I run my hand around them will I feel the spark? Is there such a thing asnsetting the timing on these machines or is it all computerized?

I checked the trans fluid after driving home, according to the owners manual, and everything was within the hash marks.

 

[SunlitComet]

You would be looking for tears, cuts, burn or arcing marks and what not. On wires in good condition you should be able to move you finger over them but that is never recommended when engine is running.. Timing is computer controlled but a base alignment between the cam and crank sensor is needed. However if it is out of bounds the pcm would spit out a p1345 code on you. For the cap look for crack, carbon tracking and pitted and burned terminal. Also make sure there is no big moisture build up in the there.

 

[Hotrdd]

I checked the MAF sensor and it was extremely clean and everything seems to be perfect. I also checked the cap, wires and rotor with my hands and then the mist test both during the day and at night. None of these seem to be suspect.

 

[SunlitComet]

If this happened after the tune-up then the parts you did are probably creating a weak ignition for which your plugs will start showing soon.

 

[ezdaar]

What you will see on the rotor tip and cap contacts inside will be burnt black crusty stuff.. think welding slag.
The rotor will have it bad on the leading and trailing edges of the copper contact.
The cap, just the same but sometimes they get so bad the entire contact is coverd in corrosion.
Cant seem to find any good images of a trashed rotor.

This cap is trashed

this is a well worn distributor cap insides,

This is typical wear inside...

---------- Post added at 07:02 PM ---------- Previous post was at 07:00 PM ----------

IF you decide to replace that cap and rotor (its very easy) BEFORE you go pullin wires, if you dont know how.
Come back here and ask, Theres plenty of guys here that can walk you through the wire transfer from one cap to the other. Or I will be glad to assist you over the phone..

---------- Post added at 07:04 PM ---------- Previous post was at 07:02 PM ----------

If you can get ahold of a timing gun, You can check your base timing and see how far off it is..
At the same time You can put a few degrees into your base.. Up to 3 on stock engine (safely) and get alil more power. This does require staying with good gas tho.

 

[Hotrdd]

The sluggish feel has been around for a while hence the reason I replaced the plugs and did a compression test. It's nothing serious but it's there. The cap on my Yukon isn't the typical round one I was use to as a kid. It's more flat. Plus when I looked in the Haynes manual for timing there was nothing showing and I couldn't find any timing marks. I'm assuming its all computer controlled. I might have to pull the cap later this week and see what it looks like. There isn’t anything serious enough that it’s throwing codes though.

 

[haks310]

Timing light is a no go for a 99. 96+ Vortrcs will need a scanner to adjust the timing. I doubt that is your problem though, you would would of had stumbling if the timing was off.

How's your catalytic converter and muffler doing?

 

[vincent m]

I'm new to this I have a 98 Yukon it ran sluggish had it check by a macanic at a diler ship I had a burned engine. After I spend close to a grand to find out what was wrong with.

 

[ezdaar]

Aahh yea, didnt pay attention to the year of OP's vehical.. >Dumb<

 

[SunlitComet]

I'm new to this I have a 98 Yukon it ran sluggish had it check by a macanic at a diler ship I had a burned engine. After I spend close to a grand to find out what was wrong with.

---------- Post added at 02:33 PM ---------- Previous post was at 02:31 PM ----------

forget the timing issue unless you have a p1345code.

Can you get access to a scanner to see real time activity of O2 sensors?

 

[king_yukon]

Im curious to an answer for this issue, I have the samething by the sounds of it. I noticed it before I did any of the following.

plugs, wires, cap, rotor, spider injectors, cats, custom exhaust, fuel filter, water pump and coolant flush.

I can feel a light almost stumble in the engine while at idle, driving I can hear what seems to be like a stumble in the exhaust, and if i'm just cruising it almost feels like it's held back sometimes, then goes back to normal but if I get on the throttle then it runs fine.

 

[SunlitComet]

have you cleaned your egr ports and valve before?

 

[king_yukon]

How might one go about doing that?

 

[SunlitComet]

removing the valve and clean it out reinstall. use a small scraping tool if carb cleaner does not work.