EGR problems

firecadet613 · July 12, 2004

95 4.3 is the engine. If I unplug the EGR valve it runs great, without a problem at all, albiet the SES light is on due to the DTC code P1406 because its not plugged in. If I plug the EGR valve in, it stumbles and misses quite a bit. It misses enough at speed that it causes the torque convertor to not lock up. Any ideas? This is the third brand new A/C Delco EGR vavle I put on there so far, and the problem still exists. New TPS also.

Joe

snoman · July 12, 2004

95 4.3 is the engine. If I unplug the EGR valve it runs great, without a problem at all, albiet the SES light is on due to the DTC code P1406 because its not plugged in. If I plug the EGR valve in, it stumbles and misses quite a bit. It misses enough at speed that it causes the torque convertor to not lock up. Any ideas? This is the third brand new A/C Delco EGR vavle I put on there so far, and the problem still exists. New TPS also.

Joe

How about the module that control the EGR valve vacum? It sounds like it is opening too much too soon.

firecadet613 · July 12, 2004

Where would this module be at? There are no vacumn lines going into my EGR valve, just the electrical connector.

Joe

citydriver · July 13, 2004

The EGR is controllred by the computer (ECM/PCM) the engine computer uses info from various sensors (MAP,TPS,Transmission gear selector,O2,etc...) only way to check it all is w/a Scan tool(TechII or equivelent) and follow the diagnostic flow chart.......... as far as I know of

firecadet613 · July 13, 2004

Thats the thing, the EGR valve is not bad, I'm on the second new one in two weeks and the same problem exists...

Joe

snoman · July 13, 2004

Thats the thing, the EGR valve is not bad, I'm on the second new one in two weeks and the same problem exists...

Joe

I agree, it is not the valve, it is what is controlling the valve. I went to look at my 2000 5.7 to get a picture of it in my head but it does not have a EGR valve on it.

firecadet613 · July 14, 2004

Any ideas on what else I could check or what it could be snoman?

Joe

snoman · July 14, 2004

Any ideas on what else I could check or what it could be snoman?

Joe

I have to take my kids to library tomorrow, I will do a bit of research for you in AllData on it. I know it is a 95, what is make and model?

firecadet613 · July 14, 2004

95 Chevrolet S10 Blazer 4x4, with the "W" Vin.

snoman · July 14, 2004

Okay, I did a little checking and you have what is called a Linear EGR valve. It is eletronically controlled by the ECM (or PCM as some call it) based on data received from TP (Throttle Position sensor) the ECT (Engine Coolant Tempature) and the MAP (Manifold Absolute Pressure) . I would rule out ECT because it only enables or disables its functions based on engine temp. This leaves the TP, MAP and ECM left and the wiring as well. My first guess would be the MAP sensor then TP sensor as they may be sending bad data to ECM. If they are good then you need to replace ECM unit.

ryan632 · July 26, 2004

i have a 94 gmc jimmy with the vortec 4.3 same problem. carbon is breaking off from inside the engine and sticking inside the engine. you will nee to get your intake cleaned, fuel injectors replace along with the fuel line inside the manifold.

and a egr screen http://www.tomco-inc.com/