Re: Bosch VE pump; won't idle after rebuild
Posted: Sun Jul 08, 2012 12:02 pm
Okay guys; I might have something to offer her in way of an explanation. Let's just have a recap on how it all started. The original pump was leaking, I pulled it to renew the distributor head seal. It initially fired up then died again, I thought it just had air in it. But it kept on doing it so I knew something wasn't quite right. Five rebuilds later I had the same problem. Another pump had the same problem, I had done nothing but light modifications to it (stupid I know). Every obscure problem under the sun was investigated-nothing worked.
I had tried the clear fuel lines and although they showed up a few tiny bubbles every now and then, I replaced the lid seal which seemed to stop them, but not stop the problem.
Dare I speak too soon but if would appear some calibrations were thrown out on the original pump. I had no throttle rest screw to begin with on that pump and it worked fine, so obviously no reason to suspect it. It would idle fine if I used the grommet thing on the throttle cable (that you can use to slacken or tighten the cable) but since the rebuild it must have thrown out the calibrations somewhat (I used levers out of another pump) so then I couldn't fine tune the idle enough with the grommet on the throttle cable bracket. All this is what I am assuming was the problem with the old pump, I haven't actually tested it but the new pump had the same symptoms and they seem to have been solved by replacing the throttle rest screw and adjusting it. It offers a degree of very fine adjustment that you can't get even with the splines on the throttle shaft.
I had tried the clear fuel lines and although they showed up a few tiny bubbles every now and then, I replaced the lid seal which seemed to stop them, but not stop the problem.
Dare I speak too soon but if would appear some calibrations were thrown out on the original pump. I had no throttle rest screw to begin with on that pump and it worked fine, so obviously no reason to suspect it. It would idle fine if I used the grommet thing on the throttle cable (that you can use to slacken or tighten the cable) but since the rebuild it must have thrown out the calibrations somewhat (I used levers out of another pump) so then I couldn't fine tune the idle enough with the grommet on the throttle cable bracket. All this is what I am assuming was the problem with the old pump, I haven't actually tested it but the new pump had the same symptoms and they seem to have been solved by replacing the throttle rest screw and adjusting it. It offers a degree of very fine adjustment that you can't get even with the splines on the throttle shaft.