97 N* Shaky idle

[clarkz71]

OK, so I guess he needs to buy a fuel rail.

[clarkz71]

Part # for that fuel rail is 12499784. You can order it online or go to any GM dealer.

[N*Caddy]

Well, up to the point where they go under the beauty cover is all metal, under I can not tell. The trouble hose was about 4’’ long probably under the beauty cover (I guess at the end of the metal part of the rails). Got to open one of these days to check…
Maybe if it rings a bell, the shop where I fixed the problem told me that GM does not sell this part of the fuel circuit separately and one option is to buy a $200 adapter kit (witch according to them is not worthing). They used an air-conditioning pressure duct (quite stiff) to solve the problem (apparently they use this thing all the time for this kind of repairs).
The bill states (among the others):
”Check for gas leaks remove top cover and replace two lines at injector rail”
1 Fuel pressure hose (from witch they cut the two smaller pieces)
4 Fuel line pressure clamps
As for the random idle drops and misfires (witches now are less noticeable) the hose was not the cause (at least the primal cause). The fuel pressure was never abnormal as the car ALWAYS started on the first key and NEVER stalled (except fort that day, one year ago, when my fuel pump died). When misfires occur is enough to press/release the gas pedal a little and all gone. Definitely the idle thing and misfires are related. On idle looks like every a few revolutions, not all the time, a piston (or two) fails to fire (either no spark or no gas). I can not tell if is the same (probably the spark plugs color could light up this problem). If is/are the same piston(s) all the time the fuel pressure is eliminated from the equation. Misfires are occurring only on a certain engine regime (when accelerating moderately at around 2000 RPM in the fourth speed and again: not always). By “moderate” I understand in such a way that the tranny will not downshift. And another thing, very rarely the idle shakes are noticeable when the car is in neutral (as the engine encounters less resistance) and this adds difficulty to the troubleshooting process.
So many things could be wrong:
- Ignition coils;
- Spark plug wires;
- Spark plugs;
- Injectors;
And so many others than I can not see right now.
Don’t ask about codes because I got NONE (current or history).
This behavior is very strange…I am puzzled.
Probably I will start with some injector cleaning agent (and I don’t believe in fixings coming from a container) then the spark plug wire set (and this is where I have high expectations) if not…I just don’t know…

[clarkz71]

The replacement fuel rail retails for about $200, that might be what they are talking about (adapter?). You can get it online for half that, $90-$100. The beauty cover is easy to remove, 4 1/2 nuts. Can you take a picture? If not, I can take a pic of mine, and you can see if you have the updated fuel rail. I don't think you do, and I don't know that a/c hose will hold up to gasoline.

[clarkz71]

Here's what it should look like, remove your cover and compare.

[clarkz71]

Here's a pic of the defective plastic rail. If you have this one, replace it with the part# I gave you. Don't take a chance with fire for a $100 part.

[dp102288]

& good pics.

Before the fuel rail was replaced on my Eldo, the car did smell like gasoline. Since it was done, no smell or problems. Come to think of it, the car was driving a little rough before the rail was changed...

[N*Caddy]

Oh yeah, that’s the one (second picture), I did removed the beauty cover about one year ago (just out of curiosity) and yeah I remember is plastic alright, I don’t have the nice metal rail all around (pretty neat setup, looks safer to)…
Now I am really curious to se what was replaced and how the heck I did not notice the VERY PINK hose in the first place…
Thanks’ guys

P.S. A thing is sure, so far no more gas smell (in almost 400-km following the repair)

[Ranger]

Judging from your misfire discription 2 posts back, my money is on plugs & wires. Same symptoms I had on my '97. Do a search for "Stutter, engine or trans". It's somewhat lengthy but I think you'll find a lot of similarities.

[1999STSCresskill]

Originally Posted by 1999STSCresskill

I am experiencing a very similar situation. I had a rough idle very soon after buying my 1999 STS. I changed the plugs AND wires (oem) and my problem was solved.... for a few weeks. Now the rough idle is back and a bit worse. A friend of mine that used to own a repair shop took a quick look the other day. He said it sounded like one of the spark plugs was damaged and arcing, causing the rough idle. He cautiously suggested that I since I'm not a Pro (like him) I may have cracked one when I was putting them in. Even though there's NO WAY I could have cracked a plug I'll check them out anyway this weekend. If one's cracked I'll tell him it was defective when I bought it!

I'll let you know if it solved my problem.

I jumped in on this thread about 2 weeks ago with a similar idle problem. I had changed the plugs about 4 months ago so I had ruled out the possibility that the spark plugs were my problem. It turns out that either I damaged a plug when installing (although I don't think that's likely) or one of the plugs was defective. I was reading an earlier thread this morning on this forum about defective AC-Delco plugs so evidently it happens some times. Luckily my damaged plug was easy to get to and replace. I drove the car quite a while today and haven't had the idle issue resurface.

Hopefully your issue is as simple (and relatively inexpensive) too.

[BCRICH]

I'm keeping an eye on this thread. I just bought me a 96STS a week ago. 270 miles later you guessed it Rough idle. I'm gonna do the TB and plugs&wires a.s.a.p. I really hope it works. I'll let everyone know.

[BCRICH]

Originally Posted by BCRICH

I'm keeping an eye on this thread. I just bought me a 96STS a week ago. 270 miles later you guessed it Rough idle. I'm gonna do the TB and plugs&wires a.s.a.p. I really hope it works. I'll let everyone know.

I changed the plugs & wires and cleaned the TB an it runs great again

[hardrockcamaro@mac.c]

Originally Posted by clarkz71

Here's a pic of the defective plastic rail. If you have this one, replace it with the part# I gave you. Don't take a chance with fire for a $100 part.

Holy cr*p!!!

That's the same fuel rail as is on my 2000 (!) STS (the little black tubes between each injector?).

Mine is a European RHD model.
Surely Caddy didn't send dangerous parts out on the euro models when they knew years before that they were faulty?!?!

[clarkz71]

Originally Posted by hardrockcamaro@mac.c

Holy cr*p!!!

That's the same fuel rail as is on my 2000 (!) STS (the little black tubes between each injector?).

Mine is a European RHD model.
Surely Caddy didn't send dangerous parts out on the euro models when they knew years before that they were faulty?!?!

No, GM claims the 98 & up rails used a "different" plastic material that doesn't have a cracking problem.

[hardrockcamaro@mac.c]

Thanks!

Phew!!!

I was just burying my head wondering where to buy the steel one, how to persuade somoene to ship it to the UK (at huge expense) where to find the money for the import taxes on it and all to risk installing it myself...

Cheers for the reassurance!!!

I'm happy again!