car runs rough when it gets up to operating temp

Hey all, I finished my front brakes yesterday and went out for the first ride in six months since I've spent time fixing it up.

It has a new starter, plug wires (acdelco), plugs (acdelco), new air filter, PCV, idle air control valve, throttle body was cleaned as well.

It ran a little rough at first, but it got worse as the temp went up. It isn't terribly noticeable while accelerating, it starts bucking and the idle is super rough.I changed my idle valve so I'm not sure why this is happening.

It has a full tank of 93 gas.

It ran like that six months ago, and I thought the tune up would have alleviated the issues.

I keep thinking that its the injectors.I changed out the injector filters and o-rings.made a huge difference in idle quality.I could not afford to have them sent out for sonic cleaning but I bet that would solve My rough idle issues ,maybe yours too

That makes sense.My exhaust smells like chit too.


I'm not sure if there are cats on this car, I have to check.

cats get clogged over time.Mine were.If you dont have smog in Illy,take 'em out.

Here's hoping you're right, Robo.I took it in to Firestone, they're putting it on their injector cleaning machine.

Hopefully one day I can send the injectors in to get cleaned sonically.

sniperdude wrote:

Here's hoping you're right, Robo.I took it in to Firestone, they're putting it on their injector cleaning machine.

Hopefully one day I can send the injectors in to get cleaned sonically.

Hope that works.

Yeah, they used a kit by QMI.



It didn't work out too well. The idle was slightly better afterwards, but it still has a really bad idle. Felt like a waste of money. Seriously out of ideas on this damn car.

sniperdude wrote:

Yeah, they used a kit by QMI.



It didn't work out too well. The idle was slightly better afterwards, but it still has a really bad idle. Felt like a waste of money. Seriously out of ideas on this damn car.

Well, alright then, I guess it is time for grease-under-the-nails troubleshooting.

When you replaced the IAC did you remove the Throttle body and clean it? You will need a TB gasket (make some phone calls, in my area most parts places don't stock them but the one that does only stocks ggo felpros and keeps 6 or more on hand).

So. Let's start there. Did you remove and clean the throttle body?

Yup. IACV, cleaned throttle body, new gasket.
New Fuel filter, pcv, spark plugs, wires, vacuum lines, air filter.
Basically everything that could be related.

I would still try and find a set of injectors from a junk yard and have them sent out for super cleaning and blueprinting.Or buy a refurbished set from Rockauto.It's an expense for sure but if you calculate the cost of running around and the hassle of diagnostics a new set of injectors dont sound so bad.Having a spare set is allways a good idea.The modern fuel injectors do clog up pretty bad and no amount of bottled cleanser or on the car cleaning will make them good again. I've been putting off buying an extra set to focus on other systems,but I think now that I've got my rad and suspension mostly squared away a set of injectors might be worth another think.

Does anybody have instructions on removing the fuel rail?

Theyre pretty easy to remove. Looking at the injector you can see a shiny wire clip



push that wire clip in towards the injector.Once the clip is completely compressed pull and tug on the electrical connector gently,remove from injector.Repeat for all injectors.

Nect turn you attention to the Vac tree atop the S/C.loosen the 10mm bolt and remove after disconecting all Vac lines.There is a wire harness that runs to the EGR valve,disconect that by prying open the plastic clip that holds it to the fuel rail.Just push the electrical harness out the way.



Now concentrate on removing all the 10mm bolts that hold the rail to the S/C body.



Gently pull and tug on the rail,it it will pop off.On reassembly you must replace all the injector orings.Go to the VatoZone and buy a set.On reassembly coat the injector o-rings with petroleum jelly to facilitate instal and prevent tearing of the o-ring.

The injectors just get pulled out.

And that is how you do it.Piece o cake.

Go back and check your work. Make sure all vacuum lines are secure. elec connections are plugged in, clean and tight. Is your CEL on or off? , Are you able to scan?

Don't keep throwing parts at it. Checking codes or monitoring a datastream on a scan tool may give you a better idea of what is causing the problem. May be something as simple as a faulty coolant temp sensor.

you'll need to pull, clean and reinstall the plugs, too. Look for differences between plugs - not the condition of each plug.

..next question, whose (new) wires did you install? Delco? Belden? Autolite?

...The point is, the odds of 18 year old injectors being fouled beyond conventional means of cleansing is high. Kinda like having a spare tire.Allways good to have a spare.

There's a thread here about using "Mr Injector" service that I believe was about $15-20 an injector which seemed like a reasonable deal. I'm thinking about that myself.

Thanks for all your helpful suggestions.

I have an appointment at a Buick dealer on Saturday morning to get it checked out professionally and scanned with the Tech 1 and all that nice stuff.

Hopefully I can find out what I'm dealing with.

Good luck to you. I hope they find it for you and fairly inexpensively!

robotennis61 wrote:

Theyre pretty easy to remove. Looking at the injector you can see a shiny wire clip



push that wire clip in towards the injector.Once the clip is completely compressed pull and tug on the electrical connector gently,remove from injector.Repeat for all injectors.

Nect turn you attention to the Vac tree atop the S/C.loosen the 10mm bolt and remove after disconecting all Vac lines.There is a wire harness that runs to the EGR valve,disconect that by prying open the plastic clip that holds it to the fuel rail.Just push the electrical harness out the way.



Now concentrate on removing all the 10mm bolts that hold the rail to the S/C body.



Gently pull and tug on the rail,it it will pop off.On reassembly you must replace all the injector orings.Go to the VatoZone and buy a set.On reassembly coat the injector o-rings with petroleum jelly to facilitate instal and prevent tearing of the o-ring.

The injectors just get pulled out.

And that is how you do it.Piece o cake.

Thanks for this, Robo. If it ends up being injectors I'll follow this info.

I'm wondering what will come up tomorrow with their inspection. I am guessing my TCC solenoid is bad because the shaking at 45MPH sounds exactly like that issue.

..It's gonna be good to find out! I have similar issues but I put up with them maybe more than I should.

For 126 bucks, I really hope they find the issues.

Also I asked them to diagnose that gear shift indicator issue with them all being lit up simultaneously and blinking.

Will share whatever info I get.

sniperdude wrote:

Also I asked them to diagnose that gear shift indicator issue with them all being lit up simultaneously and blinking.

Will share whatever info I get.

That sounds like it could be a PCM problem.

wow man, they saw you coming