Engine serge and bogging down

[bear151]

I have a 1995 GMC Jimmy 4x4, it is hard to start up but when it starts the engine will serge at 1500rpm. If I let it idle and give it gas for a while it won't serge at 1500rpm but than it will at 2100rpm. Also the engine sometimes bogs down almost to the point of quitting. I have replaced the distributor cap and rotor, air filter and checked spark plugs they look fine and run injector cleaner through it.
And when the engine bogs down the rpms go up 500 and down 500 but it mostly just serge's and does not bog down as much any more.

Thanks in advance.

 

[barks507]

This seems to be the basic answer to your question on this board:
-start with cleaning throttle body and IAC valve
-also try a treatment called Seafoam

 

[Molson02536]

I have a 1995 GMC Jimmy 4x4, it is hard to start up but when it starts the engine will serge at 1500rpm. If I let it idle and give it gas for a while it won't serge at 1500rpm but than it will at 2100rpm. Also the engine sometimes bogs down almost to the point of quitting. I have replaced the distributor cap and rotor, air filter and checked spark plugs they look fine and run injector cleaner through it.
And when the engine bogs down the rpms go up 500 and down 500 but it mostly just serge's and does not bog down as much any more.

Thanks in advance.

Check your EGR valve, it maybe sticking with carbon build up. Clean the EGR valve or replace it if its to far gone to being cleaned.

Good luck and try the http://www.seafoamsales.com/ as mentioned.

Molson02536

 

[bear151]

Do you think it could be the fuel injector?

 

[Molson02536]

Do you think it could be the fuel injector?

Start with the simple and replace the fuel filter and check the fuel pressure at the shredder valve. you should have 62-65 PSI when its priming the fuel lineand should drop 5 PSI when the engine is running.

If its a injector issue, there are DTC codes at associates with a bad injector like the engine running rich or lean. But i would start with cleaning the EGR valve or replacing it if its to far gone to being cleaned.

Molson02536

 

[bear151]

The fuel filter has been replaced and so has the pump. Also there is no check engine light and it surges when I'm driving or giving it gas in neutral.