QuestionDear Mr. Jacobson
I am having troubles with my 1986 full sized Blazer with a 6.2 diesel and only 76,000 mile.
When you turn the key to the on position the glow plugs will cycle as they should and then when you turn the key to the start position it will sometimes hesitate for a second or two before it will energize the starter and start, and finally a couple of days ago it would not start at all when you turned the key to the start position. I also had the starter rebuilt with a new solenoid a few weeks ago to make sure the starter was not the problem. When it quit a few days ago I took a tester to make sure it had power to the cable and then I put a tester to the one wire that goes to the solenoid, after someone trying to start it finally started. Where else should I look.
Second question is fuel run out problem with this truck. If I park with the front end uphill when I go to start this truck after sitting for several hours it will start and run a couple of minutes and then shut down. Then I will have to crank, crank, crank until finally it starts again. If I park this truck with the front end downhill it will not do this. Also it does shut down a few times even when it is sitting level. Whats up with this problem.
Thanks so much if you can help with these 2 problems, it is driving me crazy.
AnswerJohn,
Two part answer and two items to check in each part.
Starting: Check all the battery cables and connections. The double connection on the passenger side battery is especially prone to cause problems. Cables can corrode under their insulation, so replace any that look suspicious.
The other possibility is the ignition switch. GM vehicles in the 1980s are known to wear out the switch contacts. The switch is operated by a rod from the lock cylinder and the switch is perched above the steering column down near the firewall.
Fuel supply: Early 6.2 diesels use a mechanical pump to transfer fuel from the tank to the injection pump. I just bought a 1985 Suburban with a bad 6.2 (overheated) and it has a mechanical transfer pump, so your 1986 may have one, too. If it does, it is located on the passenger front side of the block, down near the frame rail. It looks like a fuel pump from the days of gasoline Chevy V-8s with carburetors. These pumps are known to lose their prime and allow fuel to run back towards the fuel tank. They also run at camshaft speed and are not very efficient at moving fuel to the injector pump (which wants a constant supply of air-free fuel). Parking nose up does not help the problem.
The problem can also be a fuel cap that does not vent and causes a vacuum in the tank. Try driving the vehicle with the cap removed and see if the problem goes away.
I have converted my two other 6.2s to electric fuel transfer pumps and I will convert the Suburban as well.
I will not post an e-mail address on this forum, for obvious reasons. If you would like to contact me and/or read further about these problems, I suggest going to www.gm-diesel.com and joining the forum. It is free and you can send me a private message with your e-mail address so that I can offer further assistance. I am listed under my name "HJacobson" on the forum.
