95 lumina stalls out.... alot

[JohnVanWormer]

Ok, i have a 95 Lumina 3.1... IF you can actually get the car to start it stalls rite back out....Or, itll stay running till you touch the gas pedal... But if you play with the throttle you get it to stay running for awhile... but once you let it go back to idle itll either stall are start chokeing out real bad.... also while giveing it gas, if it dont just stall out it will hesitate real bad or eaven have a drastic drop of RPMs.... I replaced the coil packs lastnight ( it was aound -3 lastnight...burrr) and that didnt help....im sure this is just a continuation of the problems its ben haveing for a couple months, i cant figure it out, my mechanic brother cant figure it out, and owner of JBR Automotive cant figure it out... Today is the first time it ever threw the check engine light though.... So maybe someone can tell me which two turminals to jump under the dash to do a diagnostic test... ive got the paper clip i just done know which two terminals / pins to jump. any help would be awsome.

[meistermind]

Terminals A & B on a pre '96.

What else have you (or your mechanics) done, checked, or replaced? Have you looked at all your plugs to see how each cylinder is running? Are you going through any coolant. Checked fuel pressure? Checked injectors for a bad or clogged one? New plugs, wires, fuel filter, Clogged air filter?

Check for coolant in the oil- Luminas had a common issue to look out for, primarily affecting the 3.1 litre powerplant. This engine is prone to intake manifold gasket failures that can allow coolant to leak into the crankcase, where it contaminates the engine's oil, creating the potential for serious problems if the leak is not caught and corrected promptly. Coolant can also get into cylinders during running and stall the combustion. This problem can seem to appear with little to no notice.

The fact that its running does eliminate some variables, but give a few more details as listed above. If your car is running, but not running well, you should start by verifying the condition of the items you would normally replace during a tune-up, then proceed to more difficult items.

[JohnVanWormer]

The car has 113k on it and at around 80 it blew a head gasket, so had the heads re milled and flow tested, and replaced those gaskets. Replaced the fuel filter and air filter (K&N) a few months back, also did a fuel pressure test, primes consistant and holds a consistant pressuer, and does not drop much at higher RPM... The plugs wires are in good shape but will probably go ahead and replace them... the plugs could probably use replaceing but shouldnt be bad... But will probably replace when i do the plug wires... may as well... Im gunna go outside in a minute and jump the diagnostic harness to see what code it is... but to be honest i think its gunna end up being the ICM... And i know it has a slight valve cover leak but nothing major.... 1/2 qt- 1 qt loss per oil change.

[meistermind]

Try using even a cheap timing light to help you check how each cylinder is firing. You can hook it up to each plug wires in turn and then observe if each has a good steady flashing without any ocaisional "miss" or no flash at all. This could save time by quickly determining the status of saprk on each cylinder. Pulling the plugs and observing them can tell you more of whats happening inside the cylinder.


****Tech Tip 101****

"A good tool this time of year is heated garage"!!!


Ask the 'ol lady for one this Christmas..........Or, just trade her in on one..................



Good Luck!!!

[JohnVanWormer]

ok... I tried a diagnostic test... My book told me to use terminals A and B...The locationi of of the B terminal in the wireing harness does not have a contact in it... infact there where only 3 locatoins on that wireing harness that had contacts, and i could not get any combo of the three to flash the engine code through the service engine light... Are 95 Luminas OBD II ?... I was under the impression that anything pr 96 was the old style diagnostic system... (im pulling my hair out and throwing wrench's across the neighborhood rite now)

[meistermind]

This may explain your '95 hybrid OBD1 code with OBDII connector......................


Some 1995 GM vehicles have the 16-pin connector like the OBDII system, but have acessible OBDI codes. (Check your emission decal for which system you have). On these 1995 with the 16-pin connector, bridge terminals 5 & 6 to retreive the trouble codes. Pin 1 is on the upper left. So on the top row, start at the left end and count over to the 5th and 6th terminals.

I could email a pic if you still have trouble.



Just Do It!!!

[the6]

acording to my manual you can't test the 95 3.1 by shorting it you need an engine anyalizer. or a code reader. this is out of haynes repair man for 90 - 96

[chris13174]

I'm not trying to insult anyones intelligence here so I hope noone takes me out of context here. All of the information that the prior post are definitely great places to start looking but in my opinion they will all turn up deadends. I would suggest you start by checking every vacum line on the throtle body and make sure you do not have any leaks. Due to the sensitivity of the Idle Air Control, if there is a leak in one of the vacum lines, the IAC cannot compensate for the extra air and in turn will cause the engine to either idle rough or stall out all together depending on how bad the vacum leak is. I would bet money that the code that set is either the IAC, MAP (Manifold Absolute Pressure) Sensor or the EST (Electronic Spark Timing) or a combination of the three. I had the same problem you described with my 1993 Lumina 3.1L VIN T. I hooked up my OBDI to check the codes and mine had coded all three of the codes I mentioned above. I started with the MAP sensor since it was the only code I could get to set repeatedly. Well turns out that the vacum line that runs to the MAP Sensor was in need of changing and it did have a small leak. Code fixed but problem wasn't solved. At that point I stopped and went back to the basics and did a thouough inspection of the motor, electrical components and all the vacum lines and found several vacum leaks along the way. All were minor leaks but together they were enough to stall the engine everytime I put the car in any gear other than park. I hope this helps get you moving in the right direction to solving your problem. Merry Christmas and Happy New Year, Chris

[bkro]

Before my current car I owned a 1995 Lumina myself. Shortly after rebuilding the heads the car started doing what you are describing. While driving home one night it started to stall repeatedly and was hard to restart and ran at reduced rpm's when it did run. Turned out the problem was that the catolytic convertors were plugged. If it hadn't happened to me I would never have thought to check it out.

[stormyjoe]

I have a 3.1litre engine in my pontiac 6000 and it gave the same trouble you describe when my fuel injector failed. you can check them for resistance with a good digital ohm meter they should meter between 11.8 and 12.7 if not they can affect the entire performance of the engine including the ecm without a trouble code