I have a 2000 blazer 4x4.New complete tuneup,new TPS,new IAC,new map sensor,have checked EGR valve for carbon buildup and very little,seems to work fine mechanically,dont know about electrically.When starting in morning on cold startup,idles fine and idles down,but when driving has a severe miss until the engine reaches operating temperature,which afterwards runs great.It shows no check engine light.ANY AND ALL SUGGESTIONS APPRECIATED.THANKS,RobD

 

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!!!!!

 

and what the hell does that reply have to do with anything?????

 

Acting like that will not get you much help around here. He is basically telling you to use the search function, as there probably has been an issue like this before with a solution.

 

I did a search for "misses when cold". Unfortunaltly the results didn't follow the link for some reason.
Just did the same search & you my friend have 2 posts about the same thing.
Read the rules please & don't be so stand-offish.

Rich... maybe he means his reply of...

 

Not sure about the lack of help or where its coming from. That isn't the way this site used to operate. We didnt care how many times the same question was posted, we are here to help. Msot common problems ended up with a DIY thread.

However, my thoughts.
Lack of a CEL indicates the puter didn't pick up a problem and the puter monitors everything EXCEPT fuel, specifically fuel pressure. IT assumes you have proper pressure and that pressure is maintained.

How is your fuel mileage?
Disconnect your O2 sensors and see if that makes any difference to engine performance. Your fuel mileage should go way down, the puter slips into a default mode and everything appears to operate like normal, except your fuel consumption sucks.

I also think your on the right track. The system operates differently in cold start mode. In cold start mode, the puter also disregards the O2 sensors until the engine gets up to normal operating temperatures. Hence my recommendation to check the O2 sensors.

Another thing is the temperature sensor. There should be two sensors, one for dash display and one for the computer. Actually there is a thrid, the overhead outside temp. The ONLY one tied into the puter is the one for the puter. The puter uses it to control engine/tranny performance to maximize performance.

Also in cold start mode, the tranny fluid is used to warm up the radiator temperature to get the engien up to normal operating temp faster. Not much to service here, except to make sure the fluid level is normal.

Lastly is the thermostat, it will remian closed to circulate coolant within the engine to get it up to temp faster. Watch teh temp gage on the dash, it should go up, when the thermostat opens, the temp should drop back down to normal. However, since its not winter yet, you may never see it open, and this not realize the thermostat is stuck open.

To me, search is not the proper response. There is more to this problem than a single simple solution. You need to eliminate each of the potential casues to narrow the problem. Unfortunately, you dont have a CEL. That would make it easy.


NOw, having said all that. You say a miss. Miss until warm. Typically a miss is due to ignition spark. You also mention a complete tune up. This is a high performance engine and GM is pushing everything she can out of her. She needs top of the line plug wires, cap and rotor, and the original plugs. Seen way too many threads where the cuase was the new economic ignition parts. I being one of those who learned that leasson the ahrd way. Cost me a trip to the dealer to tell me that my brand new plug wires were not up to the task. I would start with stuff that has been changed since the last time it ran right.

 

I had done a search & unfortunately the results of searches you copy & paste are only available for a finite amount of time, after which the link goes dead.
(Didn't know that until someone PM'd me & let me in on that lil secret lol)
Seeing as there were 12 days since the OP had checked the thread, the search thread I copied & pasted was kapute.

Just trying to "teach a man to fish...."
I'm washing my hands at this... few misunderstandings/miscommunication & all things go to hell in Rosie O'Donnell's underwear. <--- not a great place I'd assume lol

 

I have the same exact problem after putting a long block rebuilt engine in , as far as codes, all I come up with is a p0440 evap code which I already replaced the fuel pressure sensor , I am now waiting on a Evaporative Emission Canister purge solenoid and
Canister Vent Solenoid , Hopefully this will finally resolve the evap problem and if I am "lucky" it will solve the fouling problem as well, if this does not solve the fouling problem(Which I believe it won't) my next step will be replacing the coolant temperature sensor, I did notice this problem start up after burping the radiator to get my heat working again ..I had a huge air pocket in the system and was still a bit low on coolant so the fouling problem is probably non related to the evap and caused by low coolant levels making the coolant temp sensor not function properly ..I just filled the radiator up and have not had a chance to see if that might have solved anything with the temp sensor so I will have to get back to you on that..The EGR vale will be a last resort , it's not very likely that it is the problem ...Anyway if the sensor does not solve it then I will suck it up and change the EGR along with the o2 sensors ..If all that does not take care of it then maybe a match will be in order...

 

I fixed my 2000 Blazer by installing a new AC Delco distributor cap and
rotor. Be very careful to install them correctly. Note the direction that the
rotor is pointing and make sure the cap and rotor are seated properly
before tightening the screws.