93 GAGT testing patience

[Violator]

I currently have been trying to resurect this car from the world of the dead.
Well at first the car just ran like crap.. recently I changed the intake gasket (common problem on 3.3L with factory gaskets) and what not... Everything was fine a moment. Yesterday the car wouldnt idle down so I tool out the IAC valve and had my wife turn the key on and nothing no movement at all. I cleaned it up and still nothing So I got a new one 55 dollars I had got one 3 years ago and it was 32 dollars, for the same part number.....

Anyways I get it in and the car idles about 925-950 rpm but with it that low I sometimes here a popping sound under the hood like the PS pump pops at the lower rpm, its annoying, is there anyone else on here that has suffered from this or has fixed the prob

[antoniobanderas]

first time i hear the LIM being a problem with this model year ,never have had any with mine ,it runs just as strong like new check your sensors and codes

[Violator]

No codes just the codes when I unplug the TCC. I never got a code even when I unpluged the IAC is self and let it just run a sec without it.

[93GASE3300]

is your idle erratic? I know when I had a bad 02 sensor when the engine was hot it would surge and almost stall out and the tensioner made a popping sound just like your describing.

[Violator]

I replaced the O2 sensor about a month ago. I was getting a rich lean reading and the old one was beat up. Anyways I had adjusted the thottle set screw (yes there is one on the back side of the thottle assem) I set it so it would stay at 990-1000 or so, no popping but it still would run rough. Like if I was to let off the brake is would pluse forward a bit. The only thing left that hasnt been changed is the TPS and Fuel Pump. I check the Fuel pressure and it checks out at idle, although it does whine at times. Well I just put a IAC in and changed the idle screw back to spec's and it idles at about 950 or so but again it runs rough when warm I get that popping, now if I took it out and hammered it hit the highway 70--90mph its alittle smoother but when I put in park it hunts for a sec.

To be it does seem like a sensor but without a good good scanner Im in the dark. As I get no codes. I plugged my TCC back in and reset the codes, and recive nothing after a run, as if nothing is wrong......

[bigjayzizzle]

my 93 gagt used to do the same thing idle wise. i turned my idle up and it stop making that knockin nosie. but when in park it makes a ratling almost like ps pump, but when i tap gas it runs regularly. u said o2 sensor can make it act like that? i havent checked mine, change ps pump 3 times and still get that low almost rackling nosie while in drive or park even with turned up idle. i idle round 1000.

[antoniobanderas]

well....next i would suspect a bad computer,you state it will not set a problem code even while unplugin a sensor,it seems to point to be a bad puter,,,my hunch? a bad MAF there is no tps in this model year v6 :)

[rixGAphx]

Originally posted by antoniobanderas
first time i hear the LIM being a problem with this model year ...
He didn't say 'LIM gasket', he said intake gasket.

BIIIIG difference.

EVERY modern engine has an intake manifold, and thus a gasket between the manifold and the head.
This gasket can always give problems, and the problems are more frequent on V- engines than Inlines.
I have no idea whether 3.3's have an endemic problem in this area; glad that antoniobanderas has had none, tho.

GM and LIM's:

The lower part of the manifold is almost part of the head, since the push rods go thru it and the valve cover spans across it.
On earlier versions of this GM 60* V-6 (in 2.8, 3.1, and 3.4 form, carb'd and FI'd), there was a single cast-aluminum Intake Manifold that set nicely in the 'Vee' almost like a normal engine ('cept for the damned pushrod locations).

The 3.1/3.4 V-6, in '94+ form, uses one of the stupidest intake manifold designs, IMO:

An upper half (UIM?) and a lower half (Lower Intake Manifold).

It is the gasket between the lower half and the head which is the notorious LIM gasket problem.
The gasket between the UIM and the LIM is pretty simple and trouble-free in my experience.

So, a 3.3 with a single-piece manifold can't have a 'LIM gasket' problem, but it can have the same intake manifold gasket problems as other engines.

Just a little terminology clarification, tho I'm sure it won't help with Violator's engine problem :roll2:

-Rick

[93GASE3300]

My engine runs a bit rough at idle still but no longer searches like yours does. My 02 sensor fixed the surging problem. I remember in the past I had started a post on my cars erratic idle problem and one person who replied to my post said he had the same problem and he replaced the ignition control module. That fixed it for him. Im doing that next due to my rough idle and the fact that I have a stumble off idle in gear. From what I understand the coil packs and ICM's on these vehicle are very sensitive and can cause problems that may not seem like they would cause it. You said you replaced the 02 sensor, tps and iac so your getting pretty far into this problem money wise. I dont think that it is your fuel pump because normally when you have a weak pump its getting power above idle that is the problem, as for the whining mine does that too and Im sure thats due to age and location of the tank. How do your plugs look?

[Violator]

Plugs are new. ICM, Coils, I havent changed the TPS though. As far as the computer though I have put three different ones, and same outcome... So its deffently something on or in the engine.
well....next i would suspect a bad computer,you state it will not set a problem code even while unplugin a sensor,it seems to point to be a bad puter,,,my hunch? a bad MAF there is no tps in this model year v6

All Fuel injected cars that I know of has a TPS sensor that tells the computer when and how much gas to send. As for the MAF its a working one off my Skylark and that engine work flawlessly..

A IAC code doesnt set it I unplug it...... anything else will set a code. I thing Im gonna try the TPS seems about the only thing that I havent changed.

I listened to it more that popping and I do think its a tensionor because I remember it being alittle tight when I took off the belt when I changed the Intake gasket.

[1FASTGTP]

You also tried the MAF ?

I will be pulling my hairs too, this 93 Century that I'm working on is doing the same thing.

:???:




All Fuel injected cars that I know of has a TPS sensor that tells the computer when and how much gas to send. As for the MAF its a working one off my Skylark and that engine work flawlessly..

[/B]

[bigjayzizzle]

on my 93 i went to the junkyard for a new iac, cleaned it and pulled my old one. my old one was caked with black stuff it looked horrible. put the use done in an it ran perfect no searching and idle the way it was supposed to. but like a week later the problem came back and car started stalling when warming up and searcing / slight knock while in drive (sitting at a light or sumthing) do u think it was just a bad senor? i prob should buy a new one but there like 80$. but could it also be that there a lot of carbon build up under the manifold (where the iac plugs in it looked black) if so would cremoving and cleaning my tb fix it or do i have to take the whole mainfold off and clean everything... it has to be iac or tps (havnt touched tps yet) what do yall think?

[bigjayzizzle]

so far ive put new o2 sensor in, fuel pump, new delco plats plugs, new s. plug wires, and a used iac. still acting up.

[Violator]

Im having a missing problem but its intermediate. When I start up the car the engine runs decent, until it warms. I have a bucking sensation at about 40 and 45 is the worse. The higher the speed the less action. I just had the TCC replaced and trans refreshed so much difference. Anyway in drive at a stop the car shuddlers alittle, and as I said the bucking at around 40. Funny thing though is I hammer the gas at 30 to shift it to 1st, the car will act fine for the time being (Idle is smooth in park or in gear) untill I shut it off and restart later. Thing I have replaced
TCC
TPS (made a differece as well)
ICM +Coils
IAC
O2 sensor
Plugs (Rapid Fire #14)
Intake Gasket
Fuel Filter
Injectors

There was a post on here before somewhere about the module(gear indicator) in the console about that being the cause of alot of the engine misses, Well I took mine apart and saw that the circut board had evidence of liquid in it at one time, some of the traces are damaged. So I ordered a new one from GM parts direct. See if that fixed it...... If anyone has anything to add let me know.

[Violator]

I replaced the gear selector and now I dont worry about the thing shorting out. I also heard about the ECM getting water damage from the leaking Air inlet. So I thought hey let me take a look... I took out the ECM and looked at the connection and sure enough on the connector was corroded, so I cleaned it up with electronics cleaner and I let everything dry.

Plugged it back in and hooked the battery.... Started the car and bam man I had smooth idle and no bucking when the TCC engages. I though yeah it worked was this the problem that solved my yelling and screaming? Well I took it out to work and no probs drove it a few days and still nothing (no hard running) Decided to run it down the highway I think I drove about a 4 mile strech when I got off the off ramp the car was missing so bad, man WTF!!!! I was hot....
The rough idle and missing still occurs(kills my gas when it does), but if I get the engine hot and start hard accelling from 30mph(at least 5 times) the problem goes away. Sometimes it goes away when its still cold depends really.

I think one of two things Crank Postion Sensor is loose or damaged, or the cat is plug slightly. I say this because if I get the missing to stop after awhile the problem returns slowly.


I just changed my Belt Tensioner....... goodby popcorn sound.

The engine has 115000 on it and does have some lower bearing wear on startup, but this problem is intermediate and seems more electrical.

When it misses like that I notice that the 4cyl is missing, and the CS is what sends the signal for spark, if damaged maybe it is not sending a strong signal.















Im still having that intermediate problem, I just changed my Belt Tensioner....... goodby popcorn sound. The rough idle and missing still occurs(kills my gas when it does), but if I get the engine hot and start hard accelling from 30mph(at least 5 times) the problem goes away. Sometimes it goes away when its still cold depends really. I think one of two things Crank Postion Sensor is loose or damaged, or the cat is plug slightly. I say this because if I get the missing to stop after awhile the problem returns slowly, Unless I get on the highway where Im at constant 70-80 mph the roughness returns sooner.
The engine has 115000 on it and does have some lower bearing wear on startup, but this problem is intermediate and seems more electrical.

When it misses like that I notice that the 4cyl is missing, and the CS is what sends the signal for spark, if damaged maybe it is not sending a strong signal.