HossZ28

iTrader: (5)

Hey guys, I have got a strange symptoms going on with my car and am not sure what is causing the problem. The car will be driving fine and will randomly die for a very short period of time and then resume to normal operation. If I am at idle the car will die. If I am cruising at speed of 10 or higher the car will jerk from the cutoff real quick and then resume to normal operation. There is no telling how often the problem will happen. The car is a 2001 Z28 A4.

My question is what is most likely to cause this issue? I am guessing it is either the fuel pump or something that controls the ignition. Is it normal for the sensor that does control timing to fail? If anybody can help I would deeply appreciate it.

JasonSS2000

iTrader: (1)

Get the codes scanned and post them. Thats the nice thing about these cars, they keep track of what is happening.

HossZ28

iTrader: (5)

Thats the thing, no unusual codes. Have the ones for the AIR system being removed and the codes for removing the rear O2s. I did have one saying the front O2 on one of the banks had slow response or something like that but that still would not produce the problems I am having.

2000 SS #1305

iTrader: (2)

How long has this been going on? Bad gas? Something in your fuel system? I've never heard of anything like it before.

Trevor.j

iTrader: (10)

sounds like the knock sensor is throwing off the car for some reason. like you are getting low fuel and is causing the motor to get way to much vibration which then the knock sensors step in. but it could just be bad gas, or ground, or clogged injectors. just start some where easy like gas, injectors. then work your way form there. i have never had a fuel pump go out like that. when they go out the usually just die( but thats what ive only seen) also i know you dont have a cam, but when you have a good size cam with the a/c on sometimes the car will shut off.

HossZ28

iTrader: (5)

Yeah, its def not the gas. This has been going on for prob about two months, but it was barely noticeable before, it would happen once every couple drives but very slightly. I got very bad today and I barely made it into work, the car was driving fairly well but about twenty minutes into the drive it was wanting to die every twenty seconds or so.

I had the same experience last week and took it into a mechanic. When he got around to working on it he took it for a test drive and could not duplicate the problem it was driving perfectly. I couldnt believe it so I went for a drive with him and ofcourse, it was driving perfectly. I drove it normally all last week with no problem and not it is starting to show itself again. This is making me lean more toward a sensor issue.

I am starting to rule out fuel pump just due to the sporadic nature of the problem. I also thought they would just die. I dont think it has anything to due with the fuel system at all now, because when the problem does happen it seems like all cylinders are shutting off, but when it is running normally it runs perfectly. When a fuel injector is clogged or failing it is consistently happening.

Also, the car has 111k miles on it.

Thanks for the replies guys. I really need to fix this as it is my daily driver

HossZ28

iTrader: (5)

Alright, so i spent some time googling around and determined that this problem is most likely caused by a failing ignition control module, the symptoms sound exactly like what I have and it makes perfect sense. The only problem is I cant find an ignition control module for an LS1 on autzone, advanced, or even summit. So I am assuming LS1's dont have ignition control modules. So what does control the ignition on these cars? Is it in the ECM and does the whole thing need to be replaced or is there something I dont know of?

jimmyblue

iTrader: (11)

I think throwing money at an ignition module is a bad bet.
Personally I have never heard of anyone needing one (not
like the LT1 Opti situation, which is maybe contaminating
your search results).

Now problems with the alternator and that L-terminal
connection, those are not so uncommon. Can you see the
voltmeter dip when this dying goes on? Any way to borrow
a scan tool so you can catch sensors & such, in the act?

HossZ28

iTrader: (5)

Yeah, just put a new alternator on a couple weeks ago and the problem was started happenning before the swap. I am almost positive it is something with the ignition.

JasonSS2000

iTrader: (1)

Sounds like the contacts in the ignition switch. There are a bunch inside and mine had burnt ones that caused issues. Was dissasembled, shown to me, and cleaned. Has worked fine since.

toplessHO

iTrader: (25)

Had a similar problem with a GTP.
short version was it has 2 circuits on the ignition switch and one was only getting 8 volts.Replaced the entire switch/harness and it works fine again.

Mike Norris

iTrader: (10)

The first thing I would do is check all power and ground connections at the battery, starter, fuse blocks and the block. There are grounds on the back of the heads and a couple to the body (one at the RS fender near the battery and another from the block to the frame on the LS).

Besides checking them with a test light, be sure to ohm them as a test light can show good, but an ohm meter can show a high resistance.

After that, I would check for a good light fit for the IGN fuse and the Igntion Relay in the underhood fuse block(s). I have seen the terminals not be very tight and cause an intermittent open or high resistance.

To test each terminal you need to do a terminal tension test. This involves having a single male terminal on a wire and insert into each female terminal for the IGN fuse and Ignition relay one at a time and see if any of the connections feel "loose" as you pull the terminal out. Find a loose terminal and you find the issue.

Hopefully this makes sense and helps.

Mike Norris

RyanSws6

iTrader: (72)

I agree with Mike, could be a loose ground. I've seen it happen just like you describe. I forgot to tighten up the screw in the back of left head once and had a similar problem.

HossZ28

iTrader: (5)

Alright, I really appreciate the replies. Ill start checking these things out tomorrow and let you know what happens.

Thanks again

Ced55

Ya I say check power & ground & the fuel pump.

bobodog

nobody has suggested changing the fuel filter? sometimes it could be the something as simple as that idk, thats where id start.