As in the title, I have a 2002 Blazer 4.3 with 245k miles. I bought it from the previous owner with the knowledge that it only starts with starter fluid when cold. Once it gets up to operating temperature, it starts on the first crank. It also runs fine once started, no misfires or hesitation.

Attached are the codes from my ultra gauge:


The first thing I noticed was that the coolant temperature sensor was unplugged, so I plugged it back in, disconnected the battery, and tried again. No dice. I've ordered a genuine Delphi CTS which I will install.

Anything else I can check? I've seen lots of stuff on the fuel pump or the spider injectors, but it's odd that it will fire up on the first crank when the engine is hot and also when starter fluid is sprayed directly into the throttle body (I know this is a bad idea and I will not be doing this).

*Edit* Reading around the forums here, it really sounds like I need to be looking at the fuel pump. What tools will I need to check the pressures?

 

Fuel pressure testing kit is available at the auto parts stores and there is a fitting in the fuel line on top of the engine. Testing it is a breeze. Have you checked any compression?

 

Good point, I'm planning on testing compression and checking the plugs next weekend when my brother in law brings over his compression tester.

 

THats quite a collection of codes.

p0102: MAF sensor output is in error. This measures the amount of air entering the intake manifold to help the ECM decide on fuel delivery. This could be your problem. Check the connector and try cleaning it. If you still have the code, consider replacement

p0118: temp sensor. Did this code clear up when you reconnected the sensor? This will cause faulty fuel delivery but propbably not a no start


P0155: heater circuit for an oxygen sensor has failed. This will cause the oxygen sensor to take longer to get to proper operating temperature and will affect fuel delivery and emissions but not enough to cause a no start in my experience

p0341: camshaft position sensor. This can cause the truck to run like crap and in the extreme, not start. Check the wiring and if nothing, consider replacement.


P0449: evap vent circuit malfunction. This might cause you to have problems filling your gas tank but should not cause a no start

P0452: usually the ECM has detected a leak in the evap system during test caused by a hose leak or gas cap leak. This should not cause a no start

with this many sensor failures you need to check your 5v reference circuit voltage. Let me know if you need help with this.

how do you get the truck to run long enough to warm up if it only starts with ether?

George

 

One more question, does it run better at the moment it transitions to closed loop from open loop or at some other arbitrary point in the warm up cycle?

George

 

Thanks for all your help George, I'll be checking the sensors listed above next weekend when I get some time to work on it. After reconnecting the CTS the temp gauge is working again. However I haven't had a chance to pull the intake off and try starting it again so I don't know about codes.

The funny thing is the truck runs great once it has started. It feels smooth and doesn't seem down on power. The only other abnormality I've noticed is the oil has a VERY strong gas smell to it.

I'll update once I've had a chance to test the various sensors listed above.

 

So its just the initial start that needs help. It runs great as soon as it starts even when its cold and continues to run great when its warm?

George'

 

Btw: I hate to intrude since you look like you’re trying to get a good handle on your no-start issue.
However, MAF has absolutely nothing to do with starting a vehicle. You could unplug it and throw it in the garage and your engine will still start.
If you want to learn more about open loop and closed loop, pick up an ASE advanced engine performance study guide by Mitchell, or spend some time reading over at the hp tuners gen III forum.

Good luck with your repairs. “Cold” issues can sometimes be a bear to diagnose due to expansion/contraction issues mostly in electronics, including fuel pump or injector connections, grounds, etc.

It certainly wouldn’t hurt to spray some contact cleaner on the main injector harness connection and to throw a new GM fuel pump in it.

 

That’s why we need to determine if the OP means he has issues until it warms up or if he has issues at initial start only regardless of engine temp.

Is throwing the part in the garbage part of the diagnostic process?

George

 

...😂

Like I said, the MAF has absolutely nothing to do with starting a vehicle

​​​​​​...you disagree?