skewie09 Posted March 4, 2008 Share Posted March 4, 2008 ok, i got the Z up and running and its been a project for awhile. my 280 sounds and idles perfect, except for.... my very very slow take off and all together hp is pretty much gone. A stock lil geo storm was being stupid on the freeway so i went to pass it and they hit the gas and i couldnt keep up. so i started tinkering with the Z. When i did the head one of the water pump bolts had broke off into the block, so i do have a very small leak in it and it doesnt overheat either, so for the time being until i have the time to fix that i decided to flush the radiator, so i drained it and refilled it and but some Bars leak and when i started up the Z. it had SO much more response and take off just like new, then after about 10min. of driving it went back to the slow lag of power. Is it possible that the leak is causing my loss? I also know i do need to change out my fuel injector connectors for sure, but they are holding a good connection. I just replaced vacumm lines, oil change, tune up, Maf rebuild. So what can it be? Your help and ideas will really help, also if anyone can possibly look at the Z and help troubleshoot it with me i have a couple things i can barter with for your help...thanks Quote Link to comment Share on other sites More sharing options...
woldson Posted March 4, 2008 Share Posted March 4, 2008 How is the voltage. My 280zx runinng of the battery voltage had about 1/3 of the power. Fuel pump? Get a pressure gague, cheap trouble shooting tool for fuel pumps that get old in these wonderful cars. Quote Link to comment Share on other sites More sharing options...
skewie09 Posted March 4, 2008 Author Share Posted March 4, 2008 i can check the pump in a couple days, so when your talking about the voltage, your saying it might be a ground? i did just get a new yellow top cost me 200, stupid batt. but a nice differ. than my old one Quote Link to comment Share on other sites More sharing options...
Matt K Posted March 4, 2008 Share Posted March 4, 2008 Adjust your valves lately? What's your timing set to? Have you done a GOOD tuneup yet? TPS connection good? Fuel filter? A lot of little things can contribute to it running sluggish. Quote Link to comment Share on other sites More sharing options...
woldson Posted March 4, 2008 Share Posted March 4, 2008 Your gauge should read around 14+ volts when running with no big loads on it. If that is fine, then your fuel pump could be a problem all by itself. A pressure gauge will tell you if you are a full fuel pressure at the fuel rail. Quote Link to comment Share on other sites More sharing options...
DuoWing Posted March 4, 2008 Share Posted March 4, 2008 Definitely check your timing. On my turbo when I tightened up the dizzy after setting the timing, I had accidentally knocked the timing back a degree or two from 20. This was noticeably slower on take off, under boost, it even felt longer for boost to kick on. I upped my timing from about 18-19 which I accidentally set it at to 24 before TDC and that made a huge difference. Also depending on the year, check your O2 sensor. I remember when my O2 sensor didn't work the car's lower end response was really dull. It seemed really slow to respond until I hit around 2000-closer to 2500 RPM then it would start to go better. Finally when driving wiggle the wiring to the ECU, there's been a lot of cases with this old wiring being corroded, and I've had problems where my car would be slow to respond, sputter, hesitate, pop. Then I shook the wiring coming out of the ECU and the car suddenly jumped alive. Quote Link to comment Share on other sites More sharing options...
skewie09 Posted March 5, 2008 Author Share Posted March 5, 2008 ok, within the last two weeks, this is what i fixed/replaced. the head gasket went out a month ago. that is when the power went way down of course. so right now replaced timing chain/gasket, chain tensoner, head gasket and got the head shaved and fixed two cracked valves and had the lifters set. Also had the Distributor set right b4 the head went out i replaced all fuel injectors, fuel lines, vacuum lines, spark all basic tune up parts. New CAT and full exhaust and exhaust manifold. when i did the head i did have a waterpump bolt break. i still havent fixed it, i put some sealer in the coolent and all the power came back and went away withing about 10min. so i thought it may have been a seal, but idk. i also know that when i went to get smogged i couldnt pass, so im thinking about just changing out all emission controls on the whole motor. also i wont be able to do a lot of the troubleshooting till this wkend. thanks for everyone help so far. Quote Link to comment Share on other sites More sharing options...
skewie09 Posted March 7, 2008 Author Share Posted March 7, 2008 ok, i think i know what the problem is......right b4 i had the head gasket go out i got the exhaust done. new cat and everything else. well i think its the cat. 3 days after the exhaust was on i noticed that the car had a weird smell and it seemed to get a lil hotter then normal then the gasket went, and today i walked by the muffler and noticed im not getting much exhaust flow, but it sounds ok. then tonight when i came home i got the clue, it smelt like rotten eggs not too much but just enough to notice, i think the new cat is either cheap or my car is running so rich it burned/backed up a new cat in 3 days. im gonna have it tested tomarrow, does anyone think this is a poss. now im worried i might burn the gasket again. Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted March 7, 2008 Share Posted March 7, 2008 rotten egg smell not unusual with cat converter. Some maker had a big problem with that years ago. My subaru does that going to the mountains in the winter when I hit the long uphill to the ski area. Sometimes get a whiff in the Ford Ranger. Both vehicles less than five years old. My 83 doesn't but I don't push it up the mountains either. this happens when engine is running high load. perhaps you are running lean and exhaust is getting hotter than usual. Quote Link to comment Share on other sites More sharing options...
skewie09 Posted March 9, 2008 Author Share Posted March 9, 2008 played with the Z a lil bit more, im going to check the pressure on my fuel pump. but i was driving down the street and decided to push it to the floor to see how it would act about 4000 it started to bog out and lost all power and when i took it to second it just didnt wanna go. also on friday..... Quote Link to comment Share on other sites More sharing options...
woldson Posted March 9, 2008 Share Posted March 9, 2008 That is what my zx would do when the alternater was bad. Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted March 9, 2008 Share Posted March 9, 2008 Yeah zx electronics are real voltage sensitive. I had a brand new battery that was bad out of the box. If fully charged and started right off it was okay. But a little extra cranking or sitting a couple days would do weird things. After much cussing and hair pulling saying can't be the battery it is new I took it to a battery place and had them do a load test sure enough. replaced with another under warranty. check your battery cables for corrosion. sounds electrical either that or some sensor is putting you in the go home mode of the computer which only allows the engine to rev so high. Quote Link to comment Share on other sites More sharing options...
silver280zx Posted March 11, 2008 Share Posted March 11, 2008 before you go replaceing alot of epensive struff, i would rplace the cheap stuff, like the fuel filter. I had a clogged fuel filter, and it did the same thing your describing. The problem, is that the car sat for a while and the inside of the tank started to rust, and it clogged the filter. When i took it out, th einside of the filter looked like brown paint primer. What it did, is when the fuel pump move gas through the filter, all the debree that moved down the lines when it wasnt pressureized would move back up into the filter, thats why it runs fine for 10 minutes, its not clogged yet. Around 3-4k, the engine should flatline, and wont really accelerate when pushed hard. Quote Link to comment Share on other sites More sharing options...
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