1997 mgm gs loping idle and drive

[Renegade8100]

Hey guys! Newbie here with a new interesting issue. My car started having a real rough idle with loping (high/low rpm jumps) on christmas eve of all times. I had the check engine light on for the intake manifold for 3-4 months until I finally buckled down and replaced the intake manifold today expecting to fix this issue. Unfortunately that didn't fix it and I am at a loss. I have the haynes repair manual for my car and it helped me a bit but now I am confused. I think its the iacv but I get the same issue when the rpms go up until finally it stops when I give it sufficient gas.

What i've done -
replaced intake manifold - dorman (nifty, came with gaskets built in, i supplimented further with gasket maker). I found one cylinder 8 was full of antifreeze so I drained and let all the rest of the liquid burn off when I hooked everything back up. This solved my check engine light and high rpm when starting the car.

replaced the belt - figured alternator wasnt gripping because I saw it stop for a nano second often when the car was on. Now that does not do that.

cleaned out the air filter and checked intake hoses.

cleaned fuel injector o rings

replaced spark plugs

Ok guys soooo now I am stuck. I have been googling and referring to my manual so now I think its either my idle air control valve, something with my fuel system, or my head gasket because my prior anti freeze before I drained it was kinda cloudy but that could have bin because It was night and I was shining spot lights.

I need help ASAP as my rides to work are running out soon and I need to be able to get to work and make my fire calls (volunteer). I can't afford a mechanic and every mechanic I know who CAN help is a flake.

[bunchacrappyfords]

I'm thinking IAC, fuel pressure regulator, stopped up fuel filter, or insufficient fuel pressure from the pump. I'm new here myself, but these forums have lots of info for testing fuel pressure. Consult your manual for testing the regulator. I'm not very good with EFI components.
SAMSUNG-SGH-A177/A177UCIC3 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/6.2.3.3.c.1.101 (GUI) MMP/2.0 UP.Link/6.3.1.17.06.3.1.17.0

[Renegade8100]

Originally Posted by bunchacrappyfords

I'm thinking IAC, fuel pressure regulator, stopped up fuel filter, or insufficient fuel pressure from the pump. I'm new here myself, but these forums have lots of info for testing fuel pressure. Consult your manual for testing the regulator. I'm not very good with EFI components.
SAMSUNG-SGH-A177/A177UCIC3 Profile/MIDP-2.0 Configuration/CLDC-1.1 UP.Browser/6.2.3.3.c.1.101 (GUI) MMP/2.0 UP.Link/6.3.1.17.06.3.1.17.0

Thanks for the re-assurance. your help is appreciated.

Bump!

[Blue)(Fusion]

I'd suggest starting off easy and cheap.

First, get any codes read. Even if the Check Engine Light is not illuminated, it does not mean there are no codes stored. Most auto parts stores will read these for free, although not all codes can be read by these universal scanners (for example, ABS and transmission codes, but these should not be your problem anyway).

Clean your MAF sensor! These are often overlooked. Get a can of CRC MAF Cleaner at an auto parts store. Remove the negative wire from the battery terminal. I do not bother removing the MAF from the housing, but just remove the air intake tube from the car and spray the hell out of the MAF. Let it dry for about 15 minutes and re-install the intake tube into the car. After atleast 15 minutes, re-attach the negative cable to the battery and start your engine. See if it's improved at all.

When was the last time you changed your fuel filter? It's a cheap part (under $15). I am not sure on the install procedure for a 1997, but my 2000 requires only a screwdriver and the fuel lines are held in place by two plastic clips.

If that solves nothing, remove the IAC valve from the plenum (two bolts). Clean it out with carb cleaner as best you can and re-install. I did that which helped for about another 2 months but ended up having to replace mine in the end with a Duralast one for about $80.

To help identify the problem a little better, does it drive okay? If you accelerate hard are there any misses? Hesitation? If not, the fuel pump is providing enough fuel for proper operation so it should be crossed off the list of possibilities. The fuel pressure regulator may still be a problem, however, and fuel pressure should be tested at the rail.

[Renegade8100]

Well.. I cant drive to any parts stores. What is a MAF Mass Airflow Sensor?? I have not checked the fuel filter but I will in a bit. I will take off the iacv and clean it out and if that resolves the issue, I will just replace it.

[Renegade8100]

ok so I cleaned the maf and installed a new fuel filter and I got farther than before but now I am leaking antifreeze in my exhaust and.. engine so I have to remove my intake manifold again and check the gaskets. l;'jfsdgbsdf/jbf

[danielsatur]

Did you replace the heater coolant tube going through the Intake?

[Blue)(Fusion]

If you cleaned the head surfaces well and tightened the bolts down to specifications and in the proper sequence, there should not be any coolant getting into the cylinders from the intake. If coolant is getting into the cylinders, it might be a blown head gasket.

Also, if it's the intake gasket, you will see coolant in one of the four corners on the heads. For coolant to get from the coolant journal in the intake to the intake port, it would have to bypass two separate gaskets (the one on the coolant journal AND the one on the intake).

Is the coolant still clean?