91 SL Sedan DOHC running terrible, at wits end.
#1
08-21-2010, 08:46 PM
91 SL Sedan DOHC running terrible, at wits end.
This will be a long run down of the problem, so please hang in there with me.
91 SL sedan, 1.9 DOHC, auto. It has a few miles on it, 180,000 and some change. We picked this car up for my father in law for 280 bucks about 2 months ago.
All we knew it needed at the time was a radiator and a new exhaust. Those are now taken care of.
The first issue started when it would not start unless you put it WOT. I know my way around cars and know that means clear flood mood and turns off the injectors. Hooked up my scanner and it said that the coolant temp was reporting -32 or something crazy like that. Replaced the sensor and the connector. All was good....Had to replace the plugs because they were shot from being rich so long.
Few weeks later it is running bad again, this time it threw a CEL, code 23. Code 23 is the ATS low voltage warning. Hooked up the scanner again and the air temp said -52....Again it was running super rich, replaced the connector(it was broken), verified correct readings, and replaced the plugs again. I also threw wires on it at this time.
After all that, now it has a nasty off idle hesitation. The car almost shuts off if you ease the throttle. And today, any throttle kills the motor, impossible to drive. No CEL this time.
Here is a list of things i have done.
Plugs(twice)
Wires
Coolast temp sensor and connector
ATS connector
Fuel filter
Cleaned IAC
Removed EGR and cleaned it
As it sits...it hard starts, any type of throttle will darn near kill the motor, almost like the fuel is washing the spark out.
When i had the scanner hooked up today, i noticed the BLM is pegged at 148, which indicates a super lean condition.
I have not check fuel pressure yet, hoping to do that tomorrow, to be honest i did a quick glance and could not find the shrader valve.
I am thinking if replacing the O2, crank position sensor, and maybe the
coils.
I am running out of ideas...any help would be great!
thanks
tim
91 SL sedan, 1.9 DOHC, auto. It has a few miles on it, 180,000 and some change. We picked this car up for my father in law for 280 bucks about 2 months ago.
All we knew it needed at the time was a radiator and a new exhaust. Those are now taken care of.
The first issue started when it would not start unless you put it WOT. I know my way around cars and know that means clear flood mood and turns off the injectors. Hooked up my scanner and it said that the coolant temp was reporting -32 or something crazy like that. Replaced the sensor and the connector. All was good....Had to replace the plugs because they were shot from being rich so long.
Few weeks later it is running bad again, this time it threw a CEL, code 23. Code 23 is the ATS low voltage warning. Hooked up the scanner again and the air temp said -52....Again it was running super rich, replaced the connector(it was broken), verified correct readings, and replaced the plugs again. I also threw wires on it at this time.
After all that, now it has a nasty off idle hesitation. The car almost shuts off if you ease the throttle. And today, any throttle kills the motor, impossible to drive. No CEL this time.
Here is a list of things i have done.
Plugs(twice)
Wires
Coolast temp sensor and connector
ATS connector
Fuel filter
Cleaned IAC
Removed EGR and cleaned it
As it sits...it hard starts, any type of throttle will darn near kill the motor, almost like the fuel is washing the spark out.
When i had the scanner hooked up today, i noticed the BLM is pegged at 148, which indicates a super lean condition.
I have not check fuel pressure yet, hoping to do that tomorrow, to be honest i did a quick glance and could not find the shrader valve.
I am thinking if replacing the O2, crank position sensor, and maybe the
coils.
I am running out of ideas...any help would be great!
thanks
tim
#2
08-21-2010, 10:19 PM
Find the Shrader valve and measure fuel pressure. At least if it is way low than you can believe the super lean reading.
Seems to me if you check spark and there is some that replacing Crank Position sensor is not going to do any good.
Of course as I am sitting here typing I am also assuming that it is easy enough to check spark which might be harder to do than it is to say.
It is far too easy to assume that there is spark plug wires you can disconnect when the car is out in the garage and I am here on the 2nd floor and it is one of 5 I have all which have spark plug wires, I Think!
Now I hate accronyms, mostly be cause they mean nothing to me, and partly each company comes up with their own thinking it makes them special so to save me from looking that one up, what is a BLM
Seems to me if you check spark and there is some that replacing Crank Position sensor is not going to do any good.
Of course as I am sitting here typing I am also assuming that it is easy enough to check spark which might be harder to do than it is to say.
It is far too easy to assume that there is spark plug wires you can disconnect when the car is out in the garage and I am here on the 2nd floor and it is one of 5 I have all which have spark plug wires, I Think!
Now I hate accronyms, mostly be cause they mean nothing to me, and partly each company comes up with their own thinking it makes them special so to save me from looking that one up, what is a BLM
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