Gajit Posted February 21, 2021 Report Share Posted February 21, 2021 I have an 85 720 that is still running great. Unfortunately I live in California and it fails smog testing. I traced down the problem to a defective Thermal vacuum valve (TVV). So the EGR is never being activated. However, I can't seem to find a replacement anywhere. Does anyone know where I might be able to locate one? Or a substitute? I think the part number is : 14890-N8500. I've tried the junk-yards in the area and the ones i have found are also defective. I think the long-term solution is to move out of California...but I'm looking for a short-term solution. Any help or advice is welcome. Thanks! Quote Link to comment
datzenmike Posted February 21, 2021 Report Share Posted February 21, 2021 Rock Auto? Want add on here?.... https://ratsun.net/classifieds/category/9-datsun-parts/ Get one from another car or truck that also used it? Was also used on the following... '80-'81 A10 HL510 '80-'81 S110 200sx '84- S12 200sx CA20E '84- 720 Z24 '84- T11 STANZA All the TVV does is prevent vacuum advance and ERG vacuum signal from getting to the distributor and the EGR until the engine warms up. If you were to plug the two bottom hoses at the EGR and connect them to it you would defeat the TVV and have advance and EGR even when the engine is cold. I doubt the emissions test includes letting the engine sit till cold and checking that the TVV works. All they want is the EGR working. Try it. 2 Quote Link to comment
MaxG Posted January 26, 2022 Report Share Posted January 26, 2022 This might be too late, but I'm dealing with this right in CA too - I just found a link to an australian site that I ordered from. 68.00 after shipping, which doesn't seem too pricey: https://abouttimespares.com.au/TimeSpares/ShowParts/32728/Nissan-Stanza-1986-EGR-valve-nos---genuine They're the only place I could find that had the part in stock Quote Link to comment
datzenmike Posted January 26, 2022 Report Share Posted January 26, 2022 Wrecking yards are also a good source for inexpensive hard to find parts. Quote Link to comment
DIY 1985 Posted January 27, 2022 Report Share Posted January 27, 2022 Borg Warner / BWD Automotive Corporation EC987 Port. Vac. SW. I got it from Ebay a couple or few years ago. I've tried to find one since then, but haven't any success. "Ported Vacuum Switch" seems to be a possible search at Auto Zone and O'Reilley, but, I really don't know if the threads are correct, etc. Quote Link to comment
Stoffregen Motorsports Posted January 28, 2022 Report Share Posted January 28, 2022 I just had a crash course in these switches last fall with my new late '70s Jeep Cherokee. I could not find the exact replacement part so I dived headlong into the world of emissions control devices to find the info that worked for me. 1 - Ported vacuum switch, coolant temp override valves, vacuum switching valve - there are a few different trade names for these, but they all work the same. 2 - The color of the plastic body indicates the temperature at which it opens/closes, so if you're replacing a yellow switch with a green one, you may or may not have problems. 3 - Thread size and port size can change between valves, so if you can't find the exact one you need, consider one with a larger thread (you can usually tap the manifold for a larger size) or larger/smaller port sizes (adapters from one size to another or just shove the hose onto the larger size). 4 - Normally open, normally closed, three way with switching ports. The product info usually says what the ports do. Here's a link for many different valves - https://www.summitracing.com/search/part-type/check-valves-vacuum/product-line/standard-motor-ported-vacuum-switches Quote Link to comment
Thomas Perkins Posted January 28, 2022 Report Share Posted January 28, 2022 (edited) Hi,I found this on Ebay,I know the guy,he was a member of 720 World and he sells 720 parts,lives right up the road from me,I bought some great parts from him,A like new hood release cable for 20 bucks,but on this part is as is. Tell him I told you...https://www.ebay.com/itm/185236914338?hash=item2b20fb00a2:g:abUAAOSweVVhzjzq The part has sold... Edited January 29, 2022 by Thomas Perkins Quote Link to comment
720.rdy Posted March 11 Report Share Posted March 11 related/unrelated question, what is the thread size for the thermal vacuum valve? Quote Link to comment
datzenmike Posted March 11 Report Share Posted March 11 Are you planning to remove and plug the hole? Quote Link to comment
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