Rep Power: 641

THIS POST IS NOW EDITED TO REFLECT THE CORRECT INFO...

ok, so I've been commuting over 200 miles daily lately, and my car is not liking it, I guess...

Well, I got this car with many problems, and I am still trying to sort them out. First there was a long fight with the Optispark and all the related things. Then I found out that this car has a gutted catalytic converter. The car has been running fine throughout the summer (about 5000 miles), although it had this strange strong vibration going 45-55 mph in O/D at low throttle. My guess was that the turbulence caused by the gutted cat was causing the car shake... but why would that not happen in any other gear???

Now, I got two problems - that may or may not be related...

1 - The car starts, reaches 1000-1500 rpms or so, and instantly dies, within 1second. After doing it over and over about a dozen times, I can get it started, and then it runs like it has been. As soon as it is turned off, cold or hot, it becomes very hard to restart... Only started happenning today, but happened all day long... After reading THIS I found out that PCM starts up in open loop mode, using ECT, MAP and MAF but no O2 sensors...

2 - A few times, at different speeds, my speedometer needle started jumping up and down... It is controlled by the signal from a VSS, so what does such behavior mean?

so far I had some good suggestions:

-check the grounds
-check the MAF
-check TPS voltage
-replace ignition switch on the bottom of the steering column(?)
-i hope its not my PCM itself

 
Rep Power: 878

Yea sounds like your 02 sensor needs to be replaced.

Changing the 02 senor is normal maintenance, With the miles you have been putting on it im sure its up there in miles. Just replace it, I wouldnt worry about checking it since you allready pulled it out and seen it was gunked up and just put it back in. Dont spray them with carb cleaner, they are not ment to be cleaned or messed with at all really.

1. Have your alternator checked at a parts store for free, along with your battery to check you chargeing system to make sure everything is inop. Sounds like something to do with your charging system if its not turning over, you should clarify if it is getting the power to turn the engine over or if your car is just dead.


2. Since your sig says you have the 4l60e The speed is messured by a speed sensor it feeds vehicles speed to PCM then to your dash(I'm not sure on that but I think thats right someone chime in and prove me wrong if i am). Anyway I dont think its likely that it has anything to do with your first question.

 
Rep Power: 1069

almost sounds like a bad pcm

 
Rep Power: 641

edited the original post to concentrate on the problem at hand...

so far I had some good suggestions:

-check the grounds
-check the MAF
-check TPS voltage
-replace ignition switch on the bottom of the steering column(?)
-i hope its not my PCM itself
__________________

 
Rep Power: 1069

ignition module, poor fuel delivery, crank sensor all can cause that, but with the speedo acting up and the driveability issues, that usually means pcm they aren't that expensive just over $100, you may want to see if you can swap one from another car to test it though

 
Rep Power: 0

i was gonna say a pcm isnt that expensive if u get a used one. from a a4 lt1

 
Rep Power: 641

...here is my 5th post so that I could post URLs from now on...

 
Rep Power: 641

So, today I dinked around with a few things:

1 - cleaned the PCM Grounds that are on the coil and my spaced-off ICM
2 - checked both important Temp Sensors, ECT and IAT, as per directions on shbox,
the sensors were ok (0.004 ohms on 2M scale), the harness was ok too (at 5v, no shorts)
3 - tested IAC ok, coil A-B is at 50.0v and coil C-D is at 49.8v
4 - pulled MAF Sensor, it looked ok, I wiped it off with a qtip anyway, dunno how to test it...

so, all the above things checked out ok and can be ruled out for now, in my humble opinion...

5 - finally, I pulled the MAP Valve from the LHS of intake, and it was all gunked up with oil, the rubber gromet is quite squished, and the harness connector is also soaked in oil, indicating that its leaking a tiny bit somewhere... The PCV looks like its leaking a little too, but the PCV was replaced 6 months ago... MAP is kinda concerning here, as, correct me if I am wrong, it is supposed to adjust timing and fuel depending on load conditions based on vacuum iside of the manifold... I found one for $40 at autozone that I can get tomorrow maybe...

6 - I also pulled plugs 1 & 3 from RHS and 4 & 6 from LHS, pix are below:





I also have a few things planned for tomorrow:

- can try starting with a pedal all the way down to the floor
- test the fuel pressure, to check for bad FPR or leaking Injectors
- check the Battery voltage and connectors, as I messed with them recently
- maybe I can look for the rest of the Grounds
- maybe it could be that remote ignition switch on the bottom of the steering column
- someone suggested checking TPS voltage also

and sooner rather than later, I will replace both o2 sesors and put a resonator or a straight pipe instead of the gutted cat...

* * *

Here are 3 of my Datamster .UNI files, two of them (from 11-05) were recorded when the car had no starting issues yet, but wasnt running too good either, and the last file (from 11-16) is from the day when the hard starts started happenning... If you want to view them, you will need the DM35xEE module of TTL Datamster scanner program...

http://www.mediafire.com/?doiamworn4a = 11-05 EUGENE1
http://www.mediafire.com/?4vjrybbnlzt = 11-05 EUGENE2
http://www.mediafire.com/?6fzvyzdtymw = 11-16 HARD-START

*edit: I watched the Datamaster files, and noticed some things:

- it outputs 12.7-13.1 volts running, isn't that kinda low? yet it still seems to charge ok
- the MAP kpa jump up for no reason at 1800 rpm or so, from 18 kpa anywhere to 92 kpa...
- the car apparantly runs 201-209 degrees F when warmed up, isnt it kinda hot?
- by the way, the heater inside is pretty weak warm, but I though that was the heater core

A big thanks to everyone for your time and expertise!!!

 
Rep Power: 1069

if it was the secondary ignition switch it wouldn't try and fire. The temps sound like you have air in the system (209 is borderline warm though 195 is where the t stat should open for best engine efficiency) voltage is low, but not horrible (should be 14 volts) those plugs don't look that bad really, just a bit rich it looks

 
Rep Power: 641

well, I just went and checked the Fuel Pressure, as the car cranks and starts, it goes up to about 48 psi, then, as the car immediately dies, it drops down to 34 psi and stays there - I watched it for 2 minutes and it did not move a bit... so, I say, the fuel system can be rulled out at this point as well...


I am off to the store to get a MAP and PCV and I will post what happens then...

 
Rep Power: 1069

don't forget there are 8 injectors in that fuel delivery, and they are after the pressure valve,

 
Rep Power: 641

so, its not the MAP Sensor, as I replaced that today with no results...

when I installed the MAPS and it didn't start, I tried cranking it over and over again, but this time, not every crank would result in a "start", sometimes it would only click, like with a dead battery or bad connection... however, the battery reads 12v and its an optima... So, I replaced the Battery Terminals, as I wanted to convert to the top mount ones anyway... Still no change though... I noticed that the power wires had considerable amount of corrosion inside, but I dont think thats enough to actually cause the car to die...

It is definitely something electrical... like that remote ignition switch on the steering column or something of that nature... also, where are the rest of Grounds are connected??? any other ideas???

 
Rep Power: 829

Actually they are before it- seems a little low on the pressure, but shouldn't be so low that it won't run.

As far as grounds are concerned, there are only a few. They go right to the frame and the motor. I didn't listen to your files, but I'm assuming that your SES light isn't on? Anytime the motor dies other than the key being turned off it will typically trigger something in the PCM.

It is entirely possible that you got a bad Opti- it has happened to many people before, esp. if you bought something other than dealer.

As far as the hollowed out cat causing the car to shake, thats not possible. I would look into checking your u-joints or suspension/tranny mounts.

 
Rep Power: 1069

injectors can't be after the schrader valve (unless it's in the return line), a fuel pressure test can't verify if one is bad unless it is stuck open (pressure bleeds off)

 
Rep Power: 641

and so it turned out to be the Remote Ignition Switch Module located on the top center of the steering column... it was all burnt up, and was a bitch to get to... now I am back to my other problems... continued here: http://www.camaroz28.com/forums/showthread.php?t=557564