Check engine light/engine surges

[Tracey685]

I have had soooo many problems with my 1992 Grand Am that I have resorted to coming on a car forum to try to find the problem. Shortly after I bought the car it started stalling. After the stalling came the idling rough and the engine surging in correspondence to the "check engine soon" light coming on.
I have replaced and repaired everything under the sun on this car including:

Fuel filter (2 times)
Fuel pump
spark plugs and boots
something in the transmission that cost $300
wiring
checked the gas tank and it was clean
Driver belts: Tensioner (which I don't know what that is)

I am currently open to any suggestions or anyone who may have had the same problem and has since had it repaired

Thanks,
Tracey

[messiveian]

what do you mean when you say the engine is surging? do you mean the car is missfiring? that would cause the check engine light to come on. since you say you have replaced the spark plugs did you use AC delco platniums? those are the plugs that anyone on here will recomend our cars dont like the expensve plugs. Did you also gap them correctly to .060?

If you did all that i would start looking at the coil packs

Get the codes checked and before buying anything come back here and tell us what the codes are.

[Tracey685]

I got the codes checked and it was the idle air control, oh ya I replaced that too. A mechanic changed the spark plugs so I'm not sure what kind he put in there.

[rixGAphx]

His engine is a '92 4-cyl, 2.3; that was the older, less-pwerful ignition.
A spark plug gap of .035 is listed by Chilton's for his engine.
We all know that Chilton's is 100% accurate :roll:

There should be an 'emissions' decal on the hood or firewall or passenger front strut.
This will indicate the OEM plug gap, and that should be followed.

IAC has been replaced, in response to the 'srough idling and surging'.

Rough idling and surging are still present, but I *assume* the CEL is now 'off'; is this correct?

Rough idling is very symptomatic of a vac leak.
Lots of vacuum hoses and emissions vapor hoses under your hood, all of which get fragile and leak with age.
Check them all visually, and with 'Winter Spray Fluid'
With the enginewarm and idling and tranny in 'P' (or neutral), spray some fluid at each vac device and connection.
At a vac leak, fluid will be drawn-in and burned.
This will smooth-out the ilde and raise the rpm.

The EGR valve can stick open, and it acts like a vac leak.
But since its passages are sealed within the intake-exhaust system, sparying fluid at it won't have any effect.
I would remove, inspect, adn clean the EGR valve.
This is about a $250 part :eek:

I noticed you have NOT replaced the O2 sensor and the Fuel Pressure Regulator.
A faulty O2 sensor won't cause the symptoms you describe, but you want to keep an eye on it.
It only lasts about 60k miles for your car, and your engine performance and milage will deteriorate quite a bit as it ages.

A faulty FPR will cause exactly your symptoms.
It has a small vac hose going from the top of it to the intake manifold. At idle and low rpm, the strong vac pulls against a diaphragm in the FPR, lowering the fuel pressure in the rail.
If the diaphragm has a hole or tear in it, then the intake manifold is sucking a lot of gasoline, and the pressure isn't being lowered as it should be.
Remove the hose from the intake manifold, and suck/sniff from the FPR.
If you get a mouthful of gas, or strong odor, then the diaphragm is faulty.
Only solution is to replace the FPR.
This isn't a definitive test of a faulty FPR, since there are two other methods by which the FPR can fail; but they have different symptoms, so we won't discuss them here.
The FPR is about $50; it's a PITA to replace in many of the newer vehicles. Might be easier on your '92.

I would definitely check the entire vac system.
Then the FPR by sniff/suck test.
If the problem still remains after ruling those out, I would jump at the EGR valve.

Hope this hleps,
-Rick

[Tracey685]

Thanks a bunch,
It has been mentioned that I should check the vac hoses but I got so wrapped up in people saying other things like the fuel pump and stuff that I totally forgot.
I am not exactly sure what EGR Valve is but I will probably bring it somewhere to get the FPR checked.
If these things don't work I'm just about ready to drive it off a cliff or set it on fire!!! haha, I have had this problem since I've owned the car and no one seems to be able to fix it.

Thanks,
Tracey

[rixGAphx]

Originally posted by Tracey685
If these things don't work I'm just about ready to drive it off a cliff or set it on fire!!! haha, I assure you, that thought is perfectly NORMAL for most GA owners. :eek:

:banghead:

[Nighthawk243]

Originally posted by rixGAphx
I assure you, that thought is perfectly NORMAL for most GA owners. :eek:

:banghead:

X2 :lol:

[pAnDa]

check your crankshaft postion sensor...... mine is doin the samthing and i was getting the same code for iac

[LargeFish]

The Quad 4 does not have an EGR valve. It has a simple oil/air separator which can get pretty filthy so perhaps clean that out.

Has your coil cover been changed? This is a frequent problem part and symptoms can be all over the map.

Originally posted by rixGAphx
The EGR valve can stick open, and it acts like a vac leak.
But since its passages are sealed within the intake-exhaust system, sparying fluid at it won't have any effect.
I would remove, inspect, adn clean the EGR valve.
This is about a $250 part :eek:

[LargeFish]

Platinums were not used until '95. Her car uses plugs that I got for $0.85 each a few years back.

Originally posted by messiveian
since you say you have replaced the spark plugs did you use AC delco platniums?