Questions with my 6.2L '88 K5 Blazer

[smith64ja]

New member here, hoping to get some help!

The first problem that I need help with is... temperatures have fallen here in Indianapolis, and the glow plugs are not functioning properly. When it's really cold out, I turn key on, glow plug light does not come on and glow plugs are not functioning. I have to sit and crank the engine several times. What are the first steps to try to fix this problem?

Second question... truck has 180,000 mi. At 155,000 mi. replaced manual fuel pump, injector pump, and injectors. Had to take back several times for severe smoking problem. Finally reduced smoking to a minimum, but now I have to replace air filter every month or two. Now, service engine light comes on and stays on while driving. Goes off when accelerate hard, plus, engine not smoking, and air filter staying clean. I feel that the engine is not "breathing" or getting the correct amount of air flow. What can I do to try to fix this probem?

I love this K5 4X4 6.2L truck, and want to keep it for a long time, and I want to start maintaining it better and fix these problems.

Any help and/or advice would be GREATLY appreciated!

[britannic]

Check the timing chain if it hasn't been replaced since the engine was new. It's probably worn to the point your cam timing is off and stopping the engine from breathing properly. The IP timing will also be too retarded, if hasn't already been adjusted to compensate.

If you do end up replacing it, I recommend the dual idler gearing set for keeping the timing locked in for life. The gears last so long, that they can be transferred to the next engine or retained during a rebuild.

[CleviteKid]

For your glow plug problem, take advantage of your membership and go to the ON LINE TROUBLE SHOOTING GUIDE (http://www.thedieselpage.com/members/guide.htm) in the Member's Area. There is a whole chapter on the 1985 - 1993 glow plug system that should get you going again.

If problems persist, repost in the Forum with an update on the tests you have done and the results you get based on the info in the Troubleshooting Guide.

Dr. Lee http://www.handykult.de/plaudersmilies.de/xmas/gespann.gif

[gmctd]

Assuming frequent air filter replacement is from soot, and engine runs better at higher rpm, might check the EGR circuit, noting vacuum levels.
Leaks in vacuum hoses from splits, deteriorated rubber, etc.
Failing vacuum pump = very low vac at low speeds, increasing at higher speeds, but not up to specs.
Should be around 20" at 1500rpm.
The one-way valves stiffen with time and heat, resulting in less vacuum.