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Re: Trying to get a stable idle Posted by Gary Stottler [Email]  (#1463) [Profile/Gallery]
(more from Gary Stottler) on Sat, 4 Nov 2023 06:30:46
In Reply to: Re: Trying to get a stable idle, Bernie   [Profile/Gallery]
, Fri, 3 Nov 2023 15:24:03
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I agree with Bernie, a vacuum check is a good overall engine health check and also would identify any air leaks.
Regarding the crankcase ventilation, I recommend you look in the service manual for the correct routing. I feel like on non-turbo cars there's a vacuum line in addition to the larger line that goes to the air cleaner (which does provide a vacuum as engine speed goes up). The nipple on top of the valve cover is a "Y" with a large fitting and a small one, and I think there should be hoses to both. I general the vent system is designed to prevent pressure in the crankcase because that causes oil leaks. If there's so much pressure in the crankcase that it overwhelms the properly functioning vent system, then there's likely an engine hardware problem (such as worn rings allowing excessive blow by - check compression and cylinder leak-down).
As far as the D-Jet itself, I consulted an expert (Doug) since I'm not one myself, and he said it's important to check the fuel pressure and make sure that's correct - if it's too high that can cause rich running. For 1974 the maximum pressure is 28 psi.
I don't think the spark plug wires are the issue here - sounds like getting the vent system straightened out is the first step followed by the basic engine hardware health checks. Then confirm fuel pressure. If there are still issues at that point, then it's time, for better or for worse, to dive into the injection system.
I hope that helps!
Best,
Gary
_______________________________________ Gary Stottler
, Mon, 30 Oct 2023 18:31:34, Fri, 3 Nov 2023 15:24:03, Sat, 4 Nov 2023 06:30:46 <-- Viewing This Message
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