1977 280z 2+2 Posted February 2, 2015 Share Posted February 2, 2015 (edited) Hey everyone I'm having problems with my 280z. It will start up cold no problem. After it gets warmed up it will run fine for a while then bog down. Any gas more than 15% pedal down will cause it to bog worse. If it does still limp it sounds like its misfiring. Other time I had it stall on me I was pulled on the side of the road with hood open. Let it cool down and tried it. Started but with misfire. I looked around the engine bay and suddenly it ran like a top. I didn't touch a thing. Currently it won't start;I think I'm out of gas. There is a gaping hole in the exhaust manifold on the 6 cylinder. Things I've replaced: AFM Distributer (e12) Distributer cap & rotor Spark plugs Spark plug wires Water temperature sensor Fuel filter Things I have coming on the way: Pallnet fuel rail Injector o-rings I have new injectors and another stock fuel rail. Oh and 6-2-1 Monza header. Edited February 2, 2015 by 1977 280z 2+2 Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 2, 2015 Share Posted February 2, 2015 . Let it cool down and tried it. Started but with misfire. I looked around the engine bay and suddenly it ran like a top. I didn't touch a thing. Currently it won't start;I think I'm out of gas. There is a gaping hole in the exhaust manifold on the 6 cylinder. Could be the ignition module. They get hot and go bad, cool down and fix themselves. You didn't say when or why you replaced all of those parts so no way to make a cause-effect assumption. I copied the other stuff just for the amusement. Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 3, 2015 Author Share Posted February 3, 2015 All those things that have been listed as replaced have been replaced within 2 months. Sunday I replaced AFM and water temp sensor. Spark plugs/wires, distributor/cap/rotor maybe a 3 weeks ago. Fuel filter in December. I replaced them because I thought it'd fix the issue. But I have it narrowed down to cold start valve or injectors. Also when I have the key in the 'on' position, I can hear the fuel pump whining. This is odd because I have never heard it run with the key in the 'on' position. Is it time to replace it? Also since I'm so low/empty on gas i want to clean it out and replace any old fuel lines. Although I believe the p.o did a lot of maintenance to it. Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 4, 2015 Share Posted February 4, 2015 One of the first thing many people would do with a problem like yours is to measure fuel pressure while the problem is happening. There are many threads describing having a fuel pressure gauge attached while driving. Proper fuel pressure is critical to proper operation for any fuel injection system. It affects how much fuel is injected. You could save a lot of money by more reading. The injectors aren't going to stop working while driving then fix themselves when things cool down. Neither is the AFM. Or the coolant temperature sensor. And the cold start valve is just another injector that only gets power when the starter is engaged and the engine is cold. You've narrowed the problem down to parts that you haven't replaced, not potential causes. Odds are high that it's your fuel pump. A measurement would confirm a pressure problem. And your fuel pump should'r run when the key is on unless the engine is also running. Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 4, 2015 Author Share Posted February 4, 2015 (edited) the fuel rail i ordered is a pallnet and it has the fuel pressure gauge built in. so i think ill just replace the fuel pump until then. any recommendations as far as brand? and as far as the misfire? would a band pump cause that too? Edited February 4, 2015 by 1977 280z 2+2 Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 15, 2015 Author Share Posted February 15, 2015 I replaced the fuel pump with a msd 2225 . I even went ad far as insulating it per Atlantic z's method. Car won't start at all now. Pump still comes on very clearly with key in on position. When I try to crank it sounds like it wants to start but not on all cylinders. What do you guys suggest I try next? Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 15, 2015 Share Posted February 15, 2015 One of the first thing many people would do with a problem like yours is to measure fuel pressure while the problem is happening. Since it won't even start now, and you've already spent your extra money on a new pump, a can of starting fluid might tell you something. If it starts, fuel supply problem, if it doesn't, spark problem. Pull a spark plug and see if it's dirty. Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 15, 2015 Author Share Posted February 15, 2015 (edited) I did a compression test and all cylinders are 120-125psi. Spark plugs were black and smelled of gas but the contacts were good. Edited February 15, 2015 by 1977 280z 2+2 Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 16, 2015 Share Posted February 16, 2015 (edited) Has any actual testing of these components been done to justify their replacement or is this just going down the checklist of components replacing them sequentially until a solution is arrived at? Have the contacts been cleaned on the ECU and Harness Connector Ends? Typically when the car dies with lower Pulsewidth signals to the injectors (warmer as opposed to colder) it's resistance in the connections... If it's flooding out, a loose connector on water temperature sensor is the culprit. Without some basic OHM checks from the FSM...were grasping at straws here, same as you! The documentation is downloadable free now. There really is no need for this kind of blind shot gunning... Edited February 16, 2015 by Tony D Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 16, 2015 Author Share Posted February 16, 2015 I downloaded it earlier today however I wasn't able to pinpoint the cause. Tony would wd40 be an aporpriate cleaning agent for ECU contacts? Also where do I start for harness connectors? I've never messed with any ECU or harness stuff. Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 16, 2015 Share Posted February 16, 2015 WD40 would be protectant afterward. Radio Shack (now in Bankruptcy...) had CAIG DEOXIT in the small bottles which worked miracles on the buildup you got on the injector connectors, etc... Generally, when problems arise in the EFI system, especially when in reference to "my car won't rev over XXXX rpms" issues, the first thing you do is just clean all the connectors and get them back together with protectant and some grease to keep moisture and air off them so they won't corrode again. If you clean with Deoxit, the metal is pretty much raw virgin metal, and it will quickly corrode without WD40, or dielectric connector grease packing the connector to keep out corrosive components like water and air. E-Bay has pigtail connectors, but I've always salvaged them out of Volvo and BMW's in the junkyard. I am partial to Toyota AFM connectors as they used gold-plated contacts. With a pin tool, you can repin the AFM as needed for your car, and the Toyotas have a nice 90 degree boot they use which seems durable. The Volvo and BMW connectors have nice rubber back covers which seem more durable than the original JECS. The two-pin connectors for injectors and sensors from the Volvos are quick-release type which really makes it nice for cleaning and troubleshooting. If you get into a Volvo 240, make sure to cut the O@ connector off as well as as much of the heater wiring along the firewall as you can get.... It's nice Tefzel Insulated wiring, and the MALE connector (what's in the injector) makes a valuable connector to plug into a harness connector with a resistor on it for a dummy signal, or to make a NOID light with a 3W LED for troubleshooting injector pulses.... My personal best was harvesting close to 3' from one. Nice to be able to put your gadget on the fenderwell rather than laying out on the engine during testing (or let it outside the closed hood while doing a driving test. Some extension wires and you can run a 10 turn resistor to simulate hot-to-cold or vice versa when plugged into the Coolant Temperature Sensor harness plug. The GM AMP Connectors will show up on an E-Bay search, and if you look in Vendors Forum here, there is a member that builds up kits with all the required new connectors and pins which you can not beat at any price (I hope he's still making them, I bought several and attest they are great! May need more!) Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 16, 2015 Author Share Posted February 16, 2015 (edited) Thanks for the detailed replies. Ive heard only great things about deoxit. I'll see if my local radio shack is still in business and go stock up. For the injectors I'll take a look at the junkyards around the area otherwise I'll probably go for the GM AMP connectors. Also a side note, what year Toyota AFM will work? Edit: Just checked out the site wiring specialties but they don't have anything for L28 specific engines. What engine had the same style injector connectors? Edited February 16, 2015 by 1977 280z 2+2 Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 16, 2015 Share Posted February 16, 2015 Any of the AFM and even some of the MAF's will work. You need the same number of pin spots. They all plug into each other, it's all Bosch License. I cut pigtails out of the Toyota AFM's and then repopulate them the way they are needed for the Datsun Application. Two plugs will easily allow for some mistakes. Plus you can get generous pigtails to cut back and get rid of corroded wires in the process as well. Check out the Vendor's Forum, the set sold by the guy here is really complete, using new GM AMP connectors and the ability to get the pins, or pigtails. I prefer pins as I rewire the circuit myself and don't want the splice. Just go straight to the pin with the wire just like stock was! Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 16, 2015 Author Share Posted February 16, 2015 Is the kit you're referring to called 460/755 piece weather pack kit by diyautotune? Quote Link to comment Share on other sites More sharing options...
Tony D Posted February 16, 2015 Share Posted February 16, 2015 No,that's a Weatherpack kit. Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 16, 2015 Author Share Posted February 16, 2015 Well the search function won't allow 4 characters or less per word lol gm amp are ignored when searching gm amp connectors lol mind linking the thread? Quote Link to comment Share on other sites More sharing options...
NewZed Posted February 16, 2015 Share Posted February 16, 2015 The Hybridz search engine is worthless. Use Google. Type in the words "site:hybridz.org" before your search terms if you want to stick to the Hybridz forum. FricFrac. Find a spot where the car can sit for a long time while you install the new parts. Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 16, 2015 Author Share Posted February 16, 2015 (edited) Thanks I'll do that. And the car has been in the same spot for 2 weeksEdit: did the search all I got was alternator upgrades edit: found the thread..left a post but that thread hasnt been active since 2013. Edited February 17, 2015 by 1977 280z 2+2 Quote Link to comment Share on other sites More sharing options...
1977 280z 2+2 Posted February 17, 2015 Author Share Posted February 17, 2015 Ok so update I found the guys contact and I PMed him. So got that kit on order. So if I replace injector connectors and it still doesn't start what could be the cause? It will turn over and catch once in a while but other than that, just turns Quote Link to comment Share on other sites More sharing options...
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