QuestionHi.
I live in Poland.
Could buy modern, 100% healthy and very very very
inexpensive imported car, but Unfortunately, (1+2)
and (3) are mutually exclusive...
Till now I did not find any faulty vacuum
hose, so only upper / lower intake gaskets
left - I will leave the car in a $hop on Friday.
BTW. The problem with RPMs is intermittent,
but the engine tries to stall immediately
after start, everytime if it had a time to
cool down.
Could it be caused by a vacuum leak ?
leszek
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Followup To
Question -
Cirrus 1995, v6 2.5l, A/T A604, ca. 215.000 km.
I am trying to fix three major problems:
- Engine stalls, idle fluctuates,
- A/T goes into limp home mode intermittently,
- A/C is empty – probably evaporator looks like swiss cheese;
without success...
Lets cover the first issue.
If the car was left at parking for at least 1 hour, the engine tries to stall within 1-60 seconds from startup. It usually happens when RPMs do not change from 0 to 1500, and slowly down to 700 during start (sometimes it goes from 0 to 1000, back to 500, and finally to 700).
If I keep accelerator pushed, and wait, it tries to stall too, but I am usually able to keep it running, rising RPMs above 2000 for about 1 minute from the moment it tried to stall. If I am lowering RPMs before that period elapses, the vehicle starts to shake. If I release accelerator – it stalls.
It does not matter what type of fuel I use – I can start on gasoline and switch to Liquid Patrol Gas (LPG) – it does not change anything. What I have noticed is if I switch to LPG, and engine tries to stall, it switches back to gasoline. Another symptom – if I switch cruise on – it switches off when engine tries to stall. It looks like the electric power is turned off for a moment.
In 95 of 100 cases, I am able to restart it immediately, without any problem. After it is restarted, it does not stall.
Sometimes, the car is stalling while driving, but not only when slowing down – at constant speed too. Again, on gasoline, and LPG; same symptoms, as above.
After driving some miles (hot engine), I can observe idle RPMs are changing. Sometimes they are as low as 500, sometimes goes up to 1000, and if I change gear to N/P they rise to 1500.
When stopped, the car shakes (every 0,5-1 second) – more when RPMs are 500, less when 700. Looks like misfire.
Last year DTC 32 (EGR) was stored in PCM several times. Next, another codes come two or three times – 51 / 52 (fuel rich / lean). Now only DTC 13 (MAP) comes on sometimes.
What was done:
- cleaned EGR, IAC, and throttle body,
- replaced thermostat,
- replaced MAP sensor,
- replaced PCV valve.
I did not noticed any improvement.
Last week I disconnected EGR solenoid, and did a test drive – no changes, idle was fluctuating, DTC=52 (five-two). Repeated – results of second trial: no improvement, idle was changing, but this time PCM noticed problem with EGR ;-) DTC = 32 (three-two).
Yesterday, CheckEngine shown up (it usually does not), I continued the drive, and had same RPMs problems when PCM was in limp-in. When stopped, and shifted gear to P, RPMs were fluctuating between 700 and 1000. Checked DTC. Read 13 (one three).
When I visit a shop, scanner shows everything is okay (MAP, TPS output too) , except DTC 13 sometimes shows up.
It is really hard to fix an American car, outside US…
help ! PLEASE
leszek
Answer -
Hi Leszek,
Where are you living? I give you extra credit for owning a modern imported car, which is a bit of a handicap.
What you describe suggests to me that there is a leak in one of the hoses that is attached to the intake manifold (what is called a "vacuum leak" because of the partial vacuum that is created there by the operation of the pistons) and such a leak will dilute the mixture which then is sensed by the oxygen sensors which then causes the controller to lengthen the fuel pulses to make up for the air leaking in but that is imprecise because the amount of leakage varies with the rpm and so it goes on and on causing the variable idle, etc. The 13 code may well be a reflection of this problem because it is saying that the vacuum level is not dissimilar enough from the ambient air pressure as it should be if the only source of air to the manifold was the throttle opening.
Fortunately there is the sticker on the underside of the hood which shows all the vacuum hoses that are connected to the manifold so that will serve as a 'road map' for you to follow as you trace each hose all the way to and through any of the components to which it is attached. You might also check all the nuts and bolts on the manifold and the throttle body to make sure there is not a frank leak inbetween the various parts of the system. The vacuum line could have a loose connection to a nipple, or be cracked anywhere along its length. If you can't find it visually, it is possible to detect it when the engine is idling (if you could get it to do so without varying) by using a spray can of starter fluid to put a very small squirt of fluid on each connection and then listen for a change in the idle speed immediately thereafter. But be very careful because the fluid is flammable, don't use more than a very small squirt which will either be absorbed into the engine thru the crack or evaporate away without catching fire.
There could be other explanations, but the vacuum leak possibility is the first one to eliminate.
Let me know what you learn. If you don't have the vacuum hose diagram on the underside of the hood let me know and I'll xerox copy and postal mail it to you.
Roland
AnswerHi Leszek,
Because of the temperature dependence that you describe, I wonder if the coolant temp sensor might be off value (wrong resistance for the actual temperature of the coolant). That sensor is located next to the coolant filler pipe and you should find if you measure the resistance that it should read 7,000 to 14,000 ohm when at 70F (20C) and 700 to 1,000 ohms at 200F (about 93C).
That recurrence of the code 13 bothers me too. I know you replaced the MAP sensor, but have you checked its wires for damage to the insulation and the plug for clean and tight connections? The MAP signal is the dark green/red wire that goes to pin 36 of the powertrain control module, and the intake air sensor (located near the MAP sensor) has a black/red wire that goes to pin 37 of the same 40-pin connector. The 5V supply for both sensors (violet/white) is from pin 61 and the ground (black/light blue) is on pin 43 of the other 40-pin connector). The air temp sensor's resistance value should be similar to that of the coolant temp sensor.
If you still get the 52 code, then that suggests one of both of the oxygen sensors is faulty. How many miles on those sensors might cause you to replace them (for sure if more than 100,000 (160,000 km) would certainly make one suspicious) but if that is intermittant or associated only with disconnecting the egr solenoid then I would ignore that as the source.
Sure a vacuum leak could be temperature dependent if it involved a large gasket between the manifold and the head if the fasteners were loose and it tended to self-seal when the engine warmed up. So check the tension on all those nuts and screws for the manifold halves and attachments.
These are just a few ideas to consider. Let me know if any of them solve the problem. And best of luck!
Roland
