95s-10 hard starting when warm

[dad2kylie]

my blazer starts like a dream when it is cold. if I trying to start 20 min after shut off, if i dont give it some gas it wont start and sputted out, sometimes not starting at all till a minute later. Sometimes problem seems totally intermittent. I have replaced plugs, wires, cap, rotor, coil, coil module, both HO2 sensors, camshaft position sensor, and EGR.Truck also has new starter, alternator,and batterry.
Service engine codes i am getting when the truck don't start are
Inigtion control {IC} has hogh voltage
HO2 sensors cross counts to few

Truck engine code is {w}

Can anyone help? Thanks!

[rlith]

More than likely you have a leaking CPI unit and once it heats up the diaphram leaks more causing excessive fuel dump which makes it harder to start.

[BlazerLT]

Also, stop pressing the gas to start the engine, it only floods the cylinders.

You never touch the gas pedal on a fuel injected vehicle.

[rlith]

Pressing the gas doesn't really do anything to a fuel injected engine. (this can easily be shown by pulling a poppet or an injector on a regular car and pressing the gas. Nothing will come out as the car is not on, the fuel pump isn't on and the throttle plate doesn't affect what's pulsed to the injectors.

Now, even pressing it during start while you're cranking the engine won't do anything as the computer is only reading enough of an air/fuel mix to kick the engine over.

[BlazerLT]

When you step on the gas pedal, the throttle valve opens up more, letting in more air. The engine control unit (ECU, the computer that controls all of the electronic components on your engine) "sees" the throttle valve open and increases the fuel rate in anticipation of more air entering the engine. It is important to increase the fuel rate as soon as the throttle valve opens; otherwise, when the gas pedal is first pressed, there may be a hesitation as some air reaches the cylinders without enough fuel in it.

http://auto.howstuffworks.com/fuel-injection2.htm

[rlith]

there is almost no air coming in regardless when the engine first kicks. once it catches it then goes into full operation... This can also be shown in the ECM programming (see s10wildside for more info) as well as a general scantool.

[dad2kylie]

Originally Posted by BlazerLT

Also, stop pressing the gas to start the engine, it only floods the cylinders.

You never touch the gas pedal on a fuel injected vehicle.

If i dont press the gas the car wont start! i was wondering if maybe my cranksharft sensor is bad not giving accuarte rpm because in the chevy manual inigtion control enguages at around 400 rpm thus press the gas would raise engine rpm causing ingtion control system to operate

[dad2kylie]

Originally Posted by rlith

there is almost no air coming in regardless when the engine first kicks. once it catches it then goes into full operation... This can also be shown in the ECM programming (see s10wildside for more info) as well as a general scantool.

i do have a gerneral GM scan tool called tech 2 i just don't understand all the readings my father used to be the person that would help me with these problems

[dmbrisket 51]

is it a scan tool for obd1 obd 1.5 (i think thats what you have being a 95) or obdII?

[movin2stereo]

Let me know your findings.My 98 does this sometimes not as extreme as yours though.When mine is warm sometimes it takes like 4-6 seconds before it fires,when it's cold it fires right up.

[dad2kylie]

Originally Posted by dmbrisket 51

is it a scan tool for obd1 obd 1.5 (i think thats what you have being a 95) or obdII?

I am not sure what version code it is, but my scan tols reads it the codes i get are
P0172 fuel trim system rich bank 1
P0300 engine misfire
P1133 HO2S cross counts bank 1 sensor 1 to few
P1221 fuel pump feedback circuit low voltage
P1351 ingition control(IC) circuit high voltage
will that help find what code it is

[rlith]

those are the codes... Sounds like an injector problem... You actually have the 1st revision ODBII. But by all the codes set, it looks like you're dumping fuel. Pull the upper plenum and check for washing.

[dad2kylie]

Originally Posted by dmbrisket 51

is it a scan tool for obd1 obd 1.5 (i think thats what you have being a 95) or obdII?

I am not sure what version code it is, but my scan tols reads it the codes i get are
P0172 fuel trim system rich bank 1
P0300 engine misfire
P1133 HO2S cross counts bank 1 sensor 1 to few
P1221 fuel pump feedback circuit low voltage
P1351 ingition control(IC) circuit high voltage
will that help find what code it is

[BlazerLT]

Remove the top vortec name plate and the round black IMTV valve underneath it and take a strong flashlight and shine it down into the plenum and look for washing and the strong smell of fuel.

Washing will be shiny metallic spots whereas it should be black and dirty.

Seeing that you are getting the rich codes, you injector is probably dumping fuel into the cylinders.

You need to get this checked out ASAP.

Also, pull the oil dipstick and check to see if the oil is really high and if the oil on the dipstick smells of gas.

[movin2stereo]

Blazer,any idea why mine would do it?I don't have the nice Vortec cover though.