chaseincats

Weird situation going on here. I'm attempting to charge my factory AC on my '78 280z. There's a non-trivial leak in the condenser but it will hold refrigerant for about a month and a half. I plugged an AC gauge/charger into the low side port and connected a r134a can, but the system only took in enough to get to about 20lb of pressure. After leaving the car running for about 15 minutes and it staying on 20lb, I shut it off and took the can out (i turned the can sideways and upside-down while charging but it never went above 20lb of pressure. When I wiggle the can I can still hear liquid in there. Is there some other liquid in these cans that do not get sucked into the system or is there an issue on my end? Here's what I'm using: Gauge/charger: https://www.amazon.com/gp/product/B00620PXMW/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 Cans without leak sealer: https://www.amazon.com/gp/product/B00WXQBUQ2/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 any ideas?

Since you directly connected the pump to the battery and it didn't turn then the pump is dead. Just go get a new pump or try @psdenno's idea and give it a smack. Also, if you have the ability (air hose) try and blow out the metal fuel line (with the pump and fuel filter hoses disconnected of course.

Sounds good, thanks so much. Will report back.

Hi guys, My pal just got brand new triple webers going (74 260z) and we're having a tough time getting the first carb (one closest to the firewall) to sync with the other two. When we popped the vacuum gauge into the front of each carb, we originally had a reading of "5" for the front two and "7" for the one near the firewall. After turning the screw up on the other two to "7", the carb near the firewall started reading as "10" even though we didn't make any changes to it. Any idea what we're doing wrong here? -chase

I just got off the phone with my old Z mechanic (he exclusively does old Zs). He was saying that depending on which AFM you have, some s30s turn the pump on when the key is in 'on' like mine is doing (with the car off). I am assuming that he is referring to the 1978 air flow meter since only '78's afm had the fuel pump pin removed from the AFM by Datsun (I dont recall why). Edit - it seems that 1978 came with two AFMs depending on when it was made. earlier 1978 models share the universal 280z afm (7 pins) but some 1978 models share the 1979 280zx 5 pin model. weird

lol fair enough. Why would it start the car up immediately after it starts once. I'd have thought that if its electrical it would have a sluggish start each time, no? Edit - ive been looking through the FSM and your chart and am a bit confused - it says 3 out of the 4 situations where the key is in 'on' have the pump being actuated without putting the key to 'start.' Am I missing something here (I'm not the best at electrical)?

Ah, so you're saying that its pressurizing in on where it should be - so maybe its not/or delaying pushing fuel through at 'start'?

Right - it turns on until the fuel pressure gauge gets to 38 then shut off after a few seconds. If it's working (tried this a few times over the course of a few days and pressurized perfectly/within a second or 2 each time), why would the relay be a problem?

It definitely is odd but it's been so consistent that I haven't ignored it. I got vice grips and temporarily clamped the hoses that connect to the fuel rail on the supply and return side (didn't block off the metal lines specifically). I spliced in an in-line check valve between the fuel filter and the rail a while back but that didn't change the starting issue (that should have been in the original post). I'm not sure if somebody wired my car differently, but unlike other 280s, when I turn my key to 'on' not 'start' my fuel pump primes (I did this when I was testing the fuel pressure with the gauge). Whenever I start the car, I usually turn it to 'on' for about 5 seconds to pressurize the rail but this doesn't affect the cranking issue which leads me to believe that its not a fuel rail pressure issue.

Sounds good @Zed Head, see below: Car: 1978 280z stock L28 motor Problem: Long crank times after sitting overnight (>7 seconds of cranking before it will run). After starting, it can be restarted on the 1st or 2nd crank even if the car was only running for a second or two (the car doesn't need to warm up to achieve the 1st/2nd crank start). After sitting for a few hours/overnight the car reverts to the >7 second cranking time before a start Done so far: Checked for low/slow fuel pressure - the fuel pressure gauge shot up to 38ish lbs almost immediately, so the fuel pump is good Installed brand new NGK plugs and wires (they were old anyway) - this didn't fix the problem. (ignore the previous posts about capping hoses, that theory is busted). The CSV is new and worked great in the winter, but is not being triggered now because of the warm weather. Observation: I noticed that by spraying contact cleaner into the fuel injector power connector after sanding them a bit (the connector that comes off of the positive battery cable), the car starts up on the first or second crank regardless of how long it had been sitting - however I need to keep doing this every few days or it reverts to the 7-10 second crank. I also tried the Ox-Gard recommended above which worked for a few days, but I am back to the 7-10 second crank until I clean and re-spray the contact cleaner on those connectors. any ideas?

If we now assume that fuel in the pistons isn't the issue, any ideas as to what else could be causing the slow first start but easy subsequent ones?

@siteunseen Gave it a shot and while the plugs mildly smell like gas, there wasn't any visible liquid gas sitting in the cylinders (although they were a bit shiny) so I guess that theory is out. In retrospect, gas shouldn't be able to sit in the cylinders since the piston rings are a bit tired and let a mild amount of oil in the cylinders so whatever gas would be sitting in the cylinders probably drains down into the block lol. Any ideas? I'm scratching my head here... Edit: I have no idea if this gives anyone any electrical hints, but the seatbelt buzzer has been beeping a about a 2x faster rate than before this problem started. No idea if this gives any clues but thought I'd add it. Also, the car after being started will only fast-idle to around 950 rpm instead of 1100 again, im not sure if this helps but figured id disclose it (that said it has been warming up here in texas so I'm not sure how affected the AAR is by that). -chase

great idea, I will give that a shot and post my findings.

So I gave the ox-gard a shot and just like with the cleaning spray, it helped for a few days and now I'm back to the labored first start problem again (I also changed the plugs/wires to the proper NGK branded products but that didn't help either). Here's where it gets interesting/possibly have a lead here. I put a fuel pressure gauge just before the rail to see if maybe I was getting low pressure from the pump but within a second or two, pressure shot right up to the high 30s as it should. I then capped off the fuel feed, then fuel return, and finally both hoses and noticed that overnight fuel pressure in the rail dropped to zero. This means that one or all of my injectors leak fuel overnight, right? Could the labored start be due to the cylinders having liquid fuel sitting in there? It would explain why after the first labored start, the car starts up immediately as the liquid fuel has already been burned off. If that's indeed the problem, short of buying all new injectors, is there something else I could do to work around the problem? Any ideas? -chase

I agree with everyone - its most likely the starter switch (same happened with me). $24 gets you a brand new one from your local parts store (example: https://www.oreillyauto.com/detail/b/import-direct-ignition-4489/lighting---electrical-16777/switches-16486/body-switches-25096/ignition-switch-11887/18fc40cb0eca/import-direct-ignition-starter-switch/180325/5731977/1978/nissan/280z?pos=0)

The Kia motor does by far

Another benefit of the Kia motor over the Honda one is that the Kia one requires no soldering. I believe the Honda motor requires a resistor or something to be soldered in as the Honda motor blows backwards when plugged into an S30 without that modification which isn't necessary with the Kia one.

As an FYI, some Sportage blowers have the proper plug/play T connector but some actually have ones that look like a standard wall outlet. Not sure what year made the change over, but ya just keep your eyes out for the one with the right connector.

The blower works/fits all s30s. If you have a 280z, the power connector is plug and play (but with series 1 240s, the connector to the blower motor needs the adapter @jfa.series1 fabricated). While the 280z's blower motor is beefier than the 240's, the sportage motor handily eclipses both. In my '78 280 for example, the level 5 fan speed setting with the original motor is roughly equivalent to level 3 using the sportage motor. These things move A LOT more air and are way quieter like Jim was saying.

Glad to hear it worked out!!

haha thanks, good to be here ?

gotcha, makes sense

Yep it's always done that. Forgot to mention that I have headers too (they may be the same ones haha). Glad to know its nothing to worry about. Why do these cars do it but modern cars don't?

Hi guys, Weird question for you. My car spits out black sooty condensation water in the morning like you can see in the pic (this pic has about 2 week's worth of soot). Ordinarily, I'd think this is because the car is running rich, but I checked the plugs and the spark point on the plug was nice and white. That said, the piston rings are tired and it does burn some oil (wet oil on the plug threads) and doesn't have a catalytic converter ('78 280z) but I am not sure if that will cause this sooty water buildup. Any ideas as to why this is happening/is there a way to fix it? Thanks! -chase

Gotcha, thanks for all the info, I'll go give the starter & solenoid terminals a look!