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Showing results for tags 'compression'.
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I'm trying to diagnose a few things on my 75 280z 2+2, and I'm wondering if they might be related. Any help would be appreciated. Also, does anyone know why the section of my camshaft above cylinder #2 is red? Video. In summary, I can't seem to get power out of my engine. It used to run "great", but now I can barely get the car over 30mph. I ran a compression test, fearing a blown head gasket, but though the readings aren't great, I would have expected to get over 30mph with them (1: 170, 2: 156, 3: 167, 4: 169, 5: 160, 6: 165). That #2 cylinder seemed especially low, so I ran it with a tsp of oil in the cylinder, and no change - still 156. My vacuum is measuring low at about 13 in of Hg. I replaced all the old vacuum tubing, but it's still running low, even with most subsystems' vacuum lines blocked off. Fuel is spraying well out of all injectors. Fuel pressure is at 38 psi with the fuel pump on, but engine off, then drops down to ~30 psi when idling. Using a timing light, I adjusted the distributor til the engine was at exactly 10 degrees by the timing mark. I lashed the valves back in the day at cold, but I definitely hear a clicking from the engine that I don't love. Based on that and everything above, I imagined that I must have just screwed up the lash, so I opened the valve cover and checked, but no, the lash was exactly where I left it. So I don't know. Any pointers, ideas, or other debug steps would be appreciated. And yeah, if anyone knows why that section is red on the camshaft, I'd love to know! Thanks everyone. Valves in action
I generally keep my car in the garage in the winter. So far, it has only had the occasional struggle starting when left out in the cold. However, this last weekend it was down to -37C, and I was over at a friend's place now it's Tuesday, -10C, and it still wont start (cranks but no firing at all). I have heated it well beyond what it should need to start (using several devices). with no luck. I have found the following, the pump still works, there is spark, it cranks just fine, and it won't start even when jumped. It runs and starts just fine above +5C (with no external heater). There is a possibility the fuel lines have frozen but that seems unlikely, and I have no way to test compression, but I hear that is another possibility. Does anyone have ideas or suggestions?
So I finally got my hands on an early 74 260z. I've had several z31's and an s130 so I'm not new to the z game... I just have some things I need advice on. I received a solid rolling chassis, boxes of parts and one l28 na (n42 block and n47 head) that has an l26 intake and what looks to be earlier SU carbs. I also received an l28t (f54 block and p90 head) that's missing the turbo but not down pipe... I was told both were good engines turbo coming out of a wrecked car with right at 100k, and na being an l26 (incorrect) that was a fresher bottom end. So let me drop in a few pics to keep some attention... Original color, Ok now for the questions, I'd like to build the na block with higher compression. I'm coming across conflicting info... Can I pick up some flat top pistons and that up the compression to around 10 to 1? Along with a lumpy cam (not so much to sacrifice power or push it to far up in the rpms). Also some port work on the heads with some valve seats/seals. And of course a full gasket kit, timing chain and bearings if needed. I've read the block is fine to build and the head is an ok flow'er plus I'm not looking for anything wild. I'll figure out what I will do with the l28t later. I'm aware of the potential just have an 88 na2t z31... The usual places for parts are turning up null. Recap, Pistons where? ITM can be had on eBay, good/bad? Compression numbers with nothing but flat tops... Cam suggestions, supporting mods? N47 tricks? Parts sources... My z31