As per the title, I've been having this weird issue where my Z (NA) will lose power, the revs will drop and it has started backfiring when I go up a certain hill. It seems to only happen in second (A/T), and it only ever happens at this one hill, and only when it's cold. When the car is cold (just after I've turned it on and reversed out of my driveway) there is a hill that I go up to get to the shops about 10 meters down the road from my house. One out of every three or four times it will run into this issue. Just figured I'd throw up a thread and see if anyone else has had a similar issue? Cheers, Tom
Manual or auto? if auto maybe the box isnt detecting the increased load and is staying in a gear too high causing the issue?
maybe fueld filter/pump, not sure why the hill would change things, but loss of power/backfire at random times in similar situations definately ties in with fuel.
It's an auto, I may have to take it to the auto-trans mech I use if that's the case.. Fuel filter is a little bit old, I can't remember what the service interval is for one, though. Any ideas? I had a similar issue that turned out to be O? sensor related, disconnecting them fixed that issue, then I had them replaced and it was fine. That issue was sometimes hesitating going uphill, but the O?'s weren't replaced long ago at all... it couldn't be PTU-related, perhaps?
fuel filter i think is 30,000km or every 2 years from memory. and O? sensor? you mean oxygen sensor's on the exhaust? having them disconnected will definately make the car run like crap. (they are there to help your car adjust the fuel mixture)
Was an idea for the power loss don't know if it would cause backfiring though, in general when you put your foot down a bit does the zed drop a gear to accelerate harder? and does the car go up the hill any better with the gearbox switched to power? (guessing auto zeds have one of these switches)
Ahh, the forum doesn't parse the "squared" symbol properly. I was indeed referring to the O2/Oxygen sensor. Disconnecting them makes it run in closed loop, eliminating any erroneous readings from them, it doesn't necessarily make it run poorly. I may have to replace the fuel filter, as I'm thinking it's about time. Pretty sure the last time it was replaced was over 30,000k's ago. Yeah, the power switch works fine. It does drop down a gear if enough throttle is applied. Doesn't go up any better with power on though. I don't often go up that hill, so I haven't had much opportunity to test it. This, coupled with the fact that it's only practically possible to replicate once a day has left me with not much actual data about the issue unfortunately A friend of mine has just bought a conzult cable, so I think I'll have to test it one day in the morning with the cable in and record the data when it does it
Dear Mr Tom. If you cant recall the last time the fuel filter was changed. Its probably worthy of a change. Afterall they're not costly. And only beneficial. How long do you let the engine run prior to wanting to drive it. Maybe you have an air lock and the bubble hits the injectors as the nose of the car heads up hill. Not usual to happen though. s1 or s2 PTU? Maybe there is a dry solder joint on iots way out when its cold. Connects properly when warm. Maybe its just the opperator. Trying to WOT a cold car, uphill. Spark plugs? Coil packs. Connectors.... all possibilities when it comes to a cold engine.
I would have to agree with you, Mr Chris. I usually let the car run anywhere from 1 minute to 3 minutes before I drive it. S1 PTU, I was considering replacing just as a preventative maintenance practice in any case. I guess this just gives me a reason to get it done sooner rather than later (for diagnostic purposes). Spark plugs were changed 30,000k's ago, so I shouldn't think they would be the issue, pays to check 'em out though I guess. I have been meaning to get a set of those quick-release injector-style connectors as well... I blame being a poor uni-student. Also; regarding your WOT comment
WOT is the fastest way to warm up the engine (but seriously, a zed which is in good running condition, shouldnt hesitate etc when cold ) if your s1 ptu has been on the way out, your spark plugs will probably also need changing, and should be able to see some sort of fouling on at least some of them.
Ive got a spare s1 ptu from my old black zed sitting around. Im happy to post it to you for diagnostic reasons. As, well, we all know you and i live on different continents. But i would be interested in just checking the condition of the plugs, connectors and similar items, as, wait for it, tricky question... Has the mornings you've been experiencing these problems had a cold, frosted night. Colder then the normal winter nights? As, think about it now, you park and shut down your hot engine for the evening, what happens when you have a hot item in the cold, and visa versa, you get condensation. Maybe you have slight water logging first thing and it takes a bit for the engine to warm up enough to evaporate the condensation. Fixing the problem. Until next time.
Yeah, that's a possibility Chris. Where would the water be going, though, to cause such an issue? Additionally, where would the water condense inside the engine/intake? The nights have been a bit chilly, but I remember it doing it in summer/autumn as well, so I'd be hesitant to chalk it up to water-logging as the definitive answer. BUT YOU'RE THINKING, GOOD WORK. I knew you weren't just a pretty face.
Service it and check your timing isn't retarded. Might be chugging too much fuel when it's cold and your plugs are probably fouled to shit too.
Moisture can reside within the connectors thomas the tank engine. I mean I wouldn't chalk it as a definitive reason why, as you say, but if and when you're under the bonnet eyeballing things, just check all the connectors and look carefully at the terminals for any water droplets. If you find a little bit, check that the weather seal is installed. If not. Let me know as i can grab you some from work. Could be as simple as a loose connector or dodgy ptu connectors. Check check check. Just do it.
Also check that your cats aren't stuffed. I had a similar problem with my VL V8, replacing them fixed it.:zlove:
S1 ptu Hi Saw you had S1 PTU and timing issues - lol "S1 PTU's should be against the law there that f......." Its the first thing to replace, you should't worry about any diagnostics until you rip that S1 PTU out - kill it - bury it - replace it with an S2 PTU. Jamie (linda's hubby)
