dustyeye

1991 Camaro 3.1L

Okay, so the car ran fine, but would die after 10 minutes, ended up being the fuel pump.
I replaced the fuel pump and it ran great, idled it for twenty minutes. Next start up it was idling a little rough.
Third start and it was horrible, 500 RPM idle. Took the EGR off and it started up and idled good.

Today I replaced the EGR and it still won't run! It will start and idle at 500 RPM or just stall.
Now if I hold my foot down on the gas it fires up and will idle smoothly at higher RPM's, but will take FOREVER to climb up in RPM.

What the heck is going on?! Someone help me! Haha, I can't think what is wrong.

Its the fact that it ran good before the pump change and now suddenly it doesn't, but it runs with the EGR off?!

One thing to note, I filled up the fuel tank after changing the pump and added a whole bottle of injector cleaner, maybe carbon got stuck somewhere?

Thanks for any help!

fervernt

If it ran better with egr off but replacing it didn't fix it, I would look at other stuff in the egr system. Maybe the egr solenoid? Vacuum lines? Id check that stuff

dustyeye

Hey thanks for the reply!
I'm thinking it must be something to do with the EGR system.

This is an electronic EGR though, so no vacuum lines.

Where is the EGR solenoid you mentioned?

fervernt

Unless its been modified to be an electric egr it should have a vacuum line to it. Mine is also a 91 and I know it has a vacuum line. The solenoid is basically just a valve that opens and closes to let vacuum through to the egr. I'm not sure where the solenoid is on a v6, but on mine its on the pass side on top of the engine. Should have 2 vacuum lines and an electrical connector on it I believe. I don't know how to upload pics on the site but ill give it a shot in a little bit

fervernt

Heres a link to a pic of what it should look like. You can buy it here too but I would STRONGLY recommend testing yours first. And your egr should definitely have vacuum to it. If it doesn't you could very well have a vacuum leak that isn't helping how it runs at all
http://www.rickscamaros.com/camaro-s...1985-1992.html

dustyeye

You have a V8 right? The V8's have vacuum EGR's, the 3.1 V6's have electronic EGR's, no vacuum.

fervernt

ah. did not realize that. guess I learn something new every day XD. sorry about that. maybe there isn't even a solenoid for a v6 then? wow I hope someone jumps in here to help out. I thought they all were vacuum operated. do you have any SES codes? looks to me like there isn't any solenoid, in the shop manual it talks about 3 solenoids, but they all appear to be part of the egr valve itself. have you gone over your wiring to the egr? to check if there's any shorts or breaks, anything like that?

dustyeye

Hey no problem, haha. I know I learn something new everyday!
Got it running by cleaning the spark plugs, they were fouled.
But it still won't stay running unless I'm on the gas.

fervernt

alright. well if there's no codes I would take a look at the IAC and TPS next. maybe cap & rotor, and plug wires. just your standard tune-up stuff might do wonders

dustyeye

Yeah I picked this thing up recently as a project and haven't done a tune-up yet, wanted to get it running first.

For some weird reason I'm not getting any hard codes, everytime it runs bad and stalls the service engine light comes on, but when I jumper it I only get code 12 repeated over and over.

I believe the plug wires are good.

So how would I go about testing the IAC and TPS?
I can hear the IAC clicking when I jumper the A+B terminal and put my ear to it, they say that means it's good?

Thanks for all the help, I really appreciate it.

dustyeye

Update:
It is running super rich, that is my problem.
I pulled off a vacuum hose and it idled great, but stalled if I put my finger over the hose.

Now to find what is causing this rich fuel mix? Have any ideas?

Thanks.

dustyeye

It is officially derivable with the vacuum hose off.
Unfortunately the gas mileage sucks because it is running SO rich.

What should I check? Maybe the O2 sensor got carbon coated?
I really don't think it's the fuel injectors, but I haven't tested them.

fervernt

Code 12 is normal. Basically means computer is functioning properly. I've never had to really test the IAC or TPS so I'm not sure. I would just search it there are TONS of threads on how to do it.
O2 sensor sounds like a great place to start. It only costs around $20 so just go ahead and replace it. even if it isn't your root cause I can almost guarantee that it will help with your gas mileage and how it runs. It gave me an extra 5-7 mpg when I replaced mine and it ran soooo much smoother.

90rallysport60

I recently replaced EGR on my 90 RS with 3.1 again no vacuum on that one....3 electronic centroids. and I checked the wiring as well....Still runs like *&%$ HELP anyone?

dustyeye

Wow, forgot about this thread....
My 91 3.1 ended up pissing me off so much I sold it, but I did get it running a lot better.

Have you tried running it with the egr taken off? Have you done a general tuneup? Definitely replace the spark plugs if you haven't and check how the old ones look, is it running rich? What really ended up helping mine run better was replacing the O2 sensor. They are only $20+

Start with that and keep us posted.