Hi Everyone,

My 89 suburban with the 6.2L diesel is feel like it is getting tired. On the flat it runs not too bad but is slow at accelerating especially between 40 and 60MPH. It will struggle at accelerating while climbing even a moderate grade, simply forget it on a steep grade. Though once up to speed it will cruise easily at 80MPH. If I really put the pedal to the floor it will down shift and have a little more power but it does blow some smoke as long as I keep the pedal down. Normal driving does not cause hardly any noticeable smoke.

I am wondering if this lack of performance I am describing is typical of a tried DB2 Injection Pump? Is there any chance of improvement by advancing the timing a few degrees. The truck has 210,000 Miles on the clock but I have no idea if and when the IP was ever replaced. I also don't know the condition of the injectors. Could they cause this lack of performance? Is there any use in pulling them and having them pop tested before going for a new IP?

I know the fuel supply is good and that the intake screen on the IP is not restricted. The fuel filter is new. There is good fuel pressure at the IP.

Any suggestions or additional questions are most welcome. I really want to be sure before I layout good money for a new IP.

Don't buy a new injection pump until you have tried advancing the timing a bit.

If that doesn't work, don't buy a new injection pump until you have the injectors tested/possibly replaced.

It is possible that the pump is going out, but with the amount of money a new pump costs don't buy one until you have checked everything else.