97 riv sc "chuggles" on right turns and....

[Sigsmaster]

I have a 97 Riv s/c, I first started having the problem a year ago. During right hand turns or curves the engine stumbles. Also I noticed that it stumbles at negative g's like coming over a hill. it is very intermittent, I tried tracking at different outside air temperatures, gas types, oil types, wet or dry outside, I’ve even gone as far as to see if barometric pressure or dew point makes a difference. I have checked all plugs and plug wires. It is most noticeable when the car is on cruise control or when trying to maintain a speed. The car jerks pretty violently at times at other time it is less violent.
A buddy recommended changing the in-line fuel filter, seeing that I had bought the car at 68k miles and there is 137k on it now and I have never changed it.
Some other information that may help is that the rear valve cover is leaking oil. And it collects around the right rear spark plug (#4 correct?) but I have ensured that no oil is getting in under the spark plug cap and interrupting contact b/w the wire and plug.
I have the GM manuals for my vehicle, and have run through most of the trouble shooting steps for “Surges/Chuggles”.
I am a Flight Engineer so I’m not a mechanical idiot but I essentially have no experience working on cars, so please speak slowly and use small words.

[HotZ28]

Have you ever changed the wires? Did you change the fuel filter when suggested? This sounds like secondary ignition breakdown i.e. coils, wires or plugs.

[Sigsmaster]

No and not yet. i was thinking about replacing the wires (any sugjestions on kind and tips on doing would be great) but i haven't yet. and as soon as it stops raining the new fuel filter is going in. by the way do i need any special tools to bleed the preasure from the fuel rail?

[HotZ28]

Belden, ACDELCO, MSD wires are the prefered brands. Just do one at a time and it should be fairly easy. The hardest part is getting the boots off the plugs. You will have to twist & pull at the same time. If it don't come loose the first time, take a Bud break & try again.
It could take several Bud's to get all three on the back!

Nothing special concerning bleeding the fuel pressure, most people just wrap a shop rag around the valve and bleed it. The proper way is to pull the fuel pump fuse and start the engine, it will bleed pressure as soon as it starts. Be careful if you bleed the rail and don't let it spray in your face! (Wear safety glasses)

[Sigsmaster]

Ok back from an out of country trip. Before the trip I replaced the O2 sensors, the car finally through a code and a friend with a code reader let me know it was the o2 sensors. And boy did it work great for awhile. Now that I’m back and it is cooling off I noticed it all back again. Looking at the other posts I noticed something about checking and cleaning the idle air control. Did that and it started pretty hard at first. But I got it started on the 3rd attempt and took it down the highway. It ran pretty good, I didn't notice any "chuggling" in the right hand corner but a tiny bit while on cruise. But what was really noticeable was the stumbling that it does when I apply the brake when I slow to 10mph or less. I still didn't change the plug wires, and it one more thing when slowing down and going slow the rpm goes way down then surges. Any more help please?

[Sigsmaster]

I can't believe I'm still dealing with this. Update to this is, I found a break in the MAF sensor wire and fixed it. But I still have a problem with it during hard acceleration or when the engine is under a load like going up a hill. It still throughs a MAF code. But the MAF is good and wire test good all the way to the PCM. Any more suggestions would greatly appreciated.

[enslow]

I have found that a scan tool that will collect engine data on a trigger is very useful. I use Auto X ray. Hook it up and get it ready so all you have to do is push a button as soon as it throws a code. The scan tool then keeps the previous 15 and collects the next 15 data points. This way you should be able to see if the MAF is faulty, or if it went out of range for another reason.

I have heard that a lot of refurbished MAF sensors are faulty out of the box. It is usually better to buy a new AcDelco one.

Sent from my GT-P3113 using Tapatalk HD

[edwinn]

Originally Posted by Sigsmaster

No and not yet. i was thinking about replacing the wires (any suggestions on kind and tips on doing would be great) but i haven't yet. and as soon as it stops raining the new fuel filter is going in. by the way do i need any special tools to bleed the pressure from the fuel rail?

Yep.. I went through the Riv last summer from end-to-end, inside and out, and took care of DOZENS of small issues. Also have a 97 (non/SC) with 132.5k and love it. Wouldn't hesitate to dive it across the USA again in necessary. So you're a flight engineer? you may be getting a PM from me.

My dealer SM in Leesburg, VA has twice provided a comprehensive "Fitness, Inspection & Treatment Plan" since 2007, and that really helped identify problem areas. They pointed out Fuel Filter and Wires should be replaced. I had the FF and fuel system service done at that time. Five years later, the FF (which is under the rear passenger seat where the harness come through) looks a bit rusty, and they recommend changing it again!! Here is a photo in 2012.. installed in 2007.




And another..




As for wires.. Delcoline has a set for the 97 Riv and they are less that 40 or 50 bucks. I went through and pulled each wire last summer, degreased and rejuvenated them, first the front three, then the rear. The objective of doing this was to.. 1) verify I could reach each plug, and could get a wrench on them all.. 2) check to see if the boots could break free and come of each plug (never been done in 15 years).. 3) to inspect the plug wires inch-by-inch to check for cracks or deterioration.

They all came off the plugs with little difficulty, and I could reach back-the-engine with both arms and get a plug socket on each one!! Great.. that meant the plugs and wires could be replaced at home in the garage w/o tilting or lifting the engine like some mechanics used to scare me.

So I bought new plugs and put them on the shelf.. and reinstalled the inspected and juiced-up wires. It started up instantly and still runs great. Also replaced or added split loom on the plug wires and other wires (getting carried away with it.)




The #1 plug wire and plug wire cover/bracket after inspection. The underside of that plastic "cable guide" was loaded with crud! Not anymore.



Here are the inspected (also inspect contacts inside boots) and thoroughly reconditioned rear wires ready for re-installation..




Well.. it's easy to get carried away around here, and I know the condition of every square cm of the plug wires now.


-Ed