hello guys...

i recently got the ELM Reader.
so im using this device with the PCMSCAN program. and it seems good..

the program throw me the report.. but some things i understand and others dont..
like the Long and sort trim fuel..
the Time Advance on cylinder 1
the O2 data...

if someone can help this guy...i would be thankfully.

thanks

 

so, here's another reading after 10 minutes later..

please view the attached file.

 

no one?

 

Without seeing a graph of how it's cycling I would bet o2 bank 1 sensor 2 is bad and your burning too much fuel.

 

It would be very helpful if we knew the year, make, model & engine? I'm guessin" 99??
Right off the bat though:
Coolant temp is low.
Both LTFT's are low.
Something screwy with manifold absolute pressure.
PCM is applying 17 degrees advance, (normal).
Air inlet temp at 154 degrees???? What was ambient temperature?
Possibly something going on with the MAF sensor.
Depending how many O2 sensors, 96 & 97 had 4, 98 & newer have only 3, can't tell much, and may need a graph?

 

oops..
sorry about that...

its a blazer zr2 2001 4.3 automatic.

i recently cleaned the MAF.

my primary reason it's the Bad mileage..
i recently bought this truck and i been repairing all the faulty things that the previous owner never done...

 

Here are some very basic things that will affect fuel mileage and performance. Each one needs to be addressed before the data that you posted can be analyzed with any kind of accuracy.

Does the check engine light work?
Is the check engine light on when the engine is running?
Are there any DTC's in the pending or memory files?
If so, what are they?
Have you checked fuel pressure and leakdown?
If so, what were the results?
How many miles since the last tune up using AC Delco parts?
Have you checked camshaft retard?
If so, is it within specs?

 

thank you for the fast response.

yes the check engine light works..
sometimes give me the P0300 code, of the Misfire thing..
not all the times giveme that code.

yes, i have done the pressure test.
for the very first time i put the fuel gauge and open the key and the pressure was around 60 , then turn off and the pressure drops to 52 and go up to 55, then after a minute or two falls to 50, then 45 and to cero.. very fast..
one more minute later , open the key and the fuel was 60. the i turn the key and then 54psi then go up to 58 and it remaining to that value for about 8 minutes then start to decline to 55, then 49.. to the minute 13 .

since this is a new truck for me. i change the cap, sparks, and all the electrical stuff.

the camshaft retard.. this is a thing i never done . because i dont have scanner to do this. and autozone dont let me rent it.


you said something about the MAP, could be a problem sensor?

thanks

 

P0300 is almost always caused by a fault in the secondary ignition system, (distributor cap, rotor, plug wires, spark plugs, and ignition coil). These things are very fussy when it comes to these parts, they like AC Delco, not aftermarket stuff. Incorrect camshaft retard and low fuel pressure can also cause P0300.

Fuel pressure and leakdown: Your pressure is borderline low and leakdown is excessive. Key ON, engine OFF, fuel pump running: fuel pressure must be 60psi to 66psi and must remain above 55psi for at least 10 minutes. Leakdown not holding, like yours, indicates a fuel leak. Could be an external line leaking, a leaky line in the fuel pump module, faulty fuel pump check valve, leaky fuel pressure regulator, leaky injector, or a line to an injector inside the plenum. To determine where the leak is, you'll need to check fuel pressure and leakdown at the fuel filter. All fuel flow and pressure must dead end at the tester. Pressure must be 73psi to 108psi and remain above 55psi for at least 10 minutes. Results of this test will tell if the leak is in the tank or in the plenum.

MAP sensor: Your data shows MAP at an average reading of 9.62psi. If the engine is naturally aspirated, the reading should never indicate a positive pressure... zero or negative pressure, (vacuum) only.

 

thanks for the fast response
like you say.. my MAP is an average of 9.62. this mean i have a leak somewhere.? ... yesterday i checked in the plenum for leaks with brake cleaning fluid. and nothing changed. the hoses in the ac fender firewall are ok. there are another hose that goes to the 4x4 that's ok too..

this is drivin' me nuts..

thanks again captain!!