Hard start on 89' chevy 6.2l
 

Hard to start, but runs good when once started. No problem with glow plugs, but am uncertain about TPS setting and adjustment.:ouch:

How fast is your starter turning over? A fast starter really helps these engines fire up. Sometimes it's hard to tell how fast it is without having another one to compare it to. Have you changed your timing? Is your engine stock? Have you added a turbo?

The starter is only 1 yr. old, so it is turning at a good rate. The timing is 0 degree TDC, and the engine is stock without a turbo. I was mainly concerned about the Throttle control valve setting, suspecting it may be the cause of the hard starting.

Are you talking about the cold start solenoid that pushes the throttle open a little? You could advance your timing 2 or 3 degrees and it will help it start better. Before I put the turbo on mine I had the injection pump advanced as far as it would go.

Hard start on 89' chevy 6.2l
 

Sorry Red, I meant to say the throttle position sensor, not valve. I have found that mine performs best all around if the timing is set where it is at 0- +1. I moved the position of the throttle to be more open at start, and it made it a little easier on the valves, but still hard to start so I may move it back. I have to assume that the TPS is working properly because of the way it runs once started.

The throttle position sensor is not used for fueling on your engine, since it has a mechanical injection pump. It would be used to determine shift points for the transmission. However the different openings of the throttle affect starting and idle. I found on my truck when it was cold it liked just a little more throttle than idle for cold starts. My truck started pretty good when I had the timing advanced, but when I put the turbo on I moved it down to 1-2* and it had a harder time starting after that. Do you have the cold start solenoid on your throttle bracket? You could try adjusting that.

Thanks, I'll try the cold start solenoid adjustment. Also, there is an adjustment screw on the side of the injector pump and between the TPS. Does that change the position of the throttle? One more thing: where can I purchase a new cold start solenoid for the 89'?