motomanmike Posted August 26, 2012 Share Posted August 26, 2012 (edited) I'm getting closer to being able to drive the car but wanted to ask a few questions. Current status of the car is as follows. 1. L28ET swap from a 82 280zx, Engine has all sensors and plugs that come factory. 2. 280z fuel injected tank. New Walbro GLS392 pump with -8AN line run back to front, one-8AN russel filter before the pump and an izuzu rodeo V6 fuel filter after the pump its the 5/16 size of the factory fuel rail and I have it right at the rail. 3. Ignition spark is stong, car runs fine at idle. 4. 6 brand new fuel injectors. I'm really getting close to driveability. The car will start. After a few failed attempts at cranking it will start. Once it starts it sputter sputter sputters and then will idle but it idles high i'd say roughly 12-1500 rpm(I don't have a tach hooked up yet). I have 2 vacuum leaks on the intake manifold but plugging them increases the roughness of how it runs terribly to the point it will die. The factory vacuum solenoieds are hooked up, as is all the other appropriate sensors wires and plugs. AFM is mounted good with nice tight seals. Knock sensor, tps sensor, head temp sensor etc etc. What I think is happening is the walbro pump is overpowering the stock fuel pressure regulator and choking it out. The reason why I say this is I put alligator clips on the fuel pump 12v feed and started the car, when it started running rough i'd take the clip off the battery that i was feeding the fuel pump with, it would settle and level out, then start to run rough as it started to run out of fuel, i'd put the clip back on the battery the car would then level out and idle then back into its cycle of idling high but still won't take throttle and would choke under load. I know I have the firing order right. I left timing where it was and it should remain unchanged but I havn't toyed with the distributor. What I want to know is, do you need to run a separate fuel pressure regulator before the rail, the FSM shows a fuel dampner by the pump in the rear of the car what is its importance as i've seen guys run just a pump and the stock rail regulator. I have no way of telling at the moment what the fuel pressure is, I have no gauges to test and I have just the pump running to the stock rail. Plugs are wet after the car runs. When I shut it down, they are wet. Also, do the injectors have a specific firing order, it doesn't appear they do since nothing in the FSM mentions the firing order if they do so i'm assuming they all fire at once. I appreciate any direction. I've had enough this weekend but made leaps and bounds of progress and just want to get back on the road. I'm tired of paying insurance on a car I can't drive! Edited August 26, 2012 by motomanmike Quote Link to comment Share on other sites More sharing options...
JSM Posted August 27, 2012 Share Posted August 27, 2012 To me it sounds like your fuel pressure is way to high. I would run to harbor freight and put one do their cheap fuel pressure gauges inline right off the fuel rail. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 27, 2012 Share Posted August 27, 2012 I would also check CHTS resistance at the ECU connector. Make sure resistance is right for its temperature. There are charts of resistance v. temperature in the 280Z FSMs if the ZX FSMs don't have them. The injectors have no order, it's batch/simultaneous injection. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 27, 2012 Author Share Posted August 27, 2012 I ordered an external fuel pressure regulator, I should have it by next weekend, comes with a gauge so we will see how it goes, man they aren't cheap either. Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 27, 2012 Share Posted August 27, 2012 Might be wasting your money. You have a stock FPR on the rail now, right? Many auto stores have a "loaner" program for tools - http://oreillyauto.custhelp.com/app/answers/detail/a_id/150/session/L3RpbWUvMTM0NjAzNDY4My9zaWQvWV9UX3NJNGw%3D Quote Link to comment Share on other sites More sharing options...
rejracer Posted August 27, 2012 Share Posted August 27, 2012 The fuel damper is not required to run, but it's a good idea regardless. All a damper does is smooth out the fuel pressure from the slight pulses from the pump. In my experience the AFM not being connected causes symptoms like this. I would pull the AFM plug to ensure all the pins are intact and check all grounds. Check the basics, compression, fuel pressure, ignition. With the wet plugs it appears to be either the AFM, fuel pressure, CHT. Also clean the ECU pins. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 27, 2012 Author Share Posted August 27, 2012 All the "basics" have been methodically tested. Compression is great on all cylinder, new plugs, wires, new cap, spark is extremely stong and firing order is correct. The only unkowns are this is a second hand engine as many of us have had the experience with. I don't know if the AFM is any good, I have it hooked up and the flapper moves, I popped the cap off it and its very clean inside, the contacts are good, the wires to the plug are good and the plug from the harness is good and continuity to the ecu is good. I will test it per the FSM. The only reason I think its all fuel related is for one the pump is bigger, the feed line is bigger and I get a strange hissing sound at the rail when the fuel pump is running and its not a consistant whine its random. I'm not sure this is normal as it doesn't sound normal. I'll get the fuel pressure solid and report back. It will be about a week or so. Thanks for everyones input, I really want to drive this thing!!! Quote Link to comment Share on other sites More sharing options...
Nigel Posted August 27, 2012 Share Posted August 27, 2012 I don't see that you've mentioned the size of the fuel return line. If your still trying to use the original 1/8 or 3/16 (whatever it is) return line this will cause your fuel pressure to be way too high! You need at least a 5/16" return. Nigel Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 27, 2012 Author Share Posted August 27, 2012 The return is the same size as the rail/ 5/16 straight from the rail to the tank, -6AN fit great I didn't use any of the factory 240z hard lines but left them on the car in case I ever go back to carbs. I'll try this regulator when it gets here and report back. It shipped today so I should see it by the weekend. Quote Link to comment Share on other sites More sharing options...
Nigel Posted August 28, 2012 Share Posted August 28, 2012 I ran a stock regulator with a Walbro pump and it ran just fine. Could be your regulator is sticking. Or hooked up backwards? I've seen that done before. You really need to get a pressure gauge on there first. BTW, mount the new regulator as close as possible to the outlet of the fuel rail and keep your vacuum line as short as possible (like the stock regulator). I have datalogs showing how fuel pressure response is significantly slowed down with the regulator mounted far from the rail with a long vacuum line. Nigel Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 28, 2012 Author Share Posted August 28, 2012 Any of you using a factory style fuel regulator, does your's hiss? I'm still waiting on parts but i'm just curious whether or not that is a symptom. I pulled the vacuum line on it and its dry. Still to me doesn't mean its good or bad. I'm hoping that is the issue but will also check the cold start valve. It appears to be a common problem also. I'm not even sure if this 82 L28ET has one but I imagine it does. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 29, 2012 Author Share Posted August 29, 2012 Consider the post a dead thread now, I've investigated everything and determined the plug for cylinder head temperature was not working. The ends looked fine, they were clean but the wiring that runs up into the harness was green about 6" back into the wire, I had cleaned the harness plugs up really good before the install but I wasn't getting a signal there, i found one on an electrical rebuilders site we use here at work and wired the pigtail on last night. As soon as I repaired it, the car will take throttle, its not the most responsive, i know if I rev my L24 with carbs its revs pretty quick and responds well to slight blips of the throttle, this engine seems a little more sluggish initially but seems to have more grunt once it gets spooling up, maybe just tuning, maybe just the way they are I have nothing to judge it by but i'm at the point now I have to get it towed to the shop so I can bend the exhaust, right now its shooting exhaust straight down out of a downpipe and I don't want to risk driving it that way. Thanks for all the input it is really appreciated. I can't wait to drive this thing. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 31, 2012 Author Share Posted August 31, 2012 JSM i was trolling through some more posts the other day about this running rich condition and saw the post where the guy had wired the start signal to a switched power and I thought Eureka!! thats got to be it. Well, it was sort of but created another problem. I did have my start signal to my ecu wired to a switched power and the car would fire right up, idle high and barely would take any throttle and once boost hit it would die. Now, i've taken that wire I had to switched power. I've moved it to the starter solenoid trigger wire, and the car started idled up, they suddenly died. Now I have one nice fat spark right when I start to crank and then nothing. Very odd, I only had a half hour or so this morning to toy with it but its very odd and wonder what happened now. Getting a little frustrated. Quote Link to comment Share on other sites More sharing options...
rayaapp2 Posted August 31, 2012 Share Posted August 31, 2012 I read the first post and thought about that start signal wire. I went through the same thing many years ago with that damned wire! Personally Id go through your connections between the car and the FI harnesses. Make sure you have good connections and the correct connections just to be sure. Ive seen these setups do the spark and die. I dont remember off hand what happened for sure to cause momentary power/ground. I dont want to lead you down a worthless path, but I think I started at the ECCS/ignition Relay. Multimeter time Quote Link to comment Share on other sites More sharing options...
motomanmike Posted August 31, 2012 Author Share Posted August 31, 2012 That makes enough sense though, i'll wait until its dark tonight and see if I can find it. Quote Link to comment Share on other sites More sharing options...
rejracer Posted August 31, 2012 Share Posted August 31, 2012 L28ET is not as snappy or responsive as an L24. The compression ratio is 7.4, open chamber head, has a heavier crank, heavier flywheel, heavier pressure plate. It all adds up. Check the responsiveness at 3500 and up and it will be a different story. I connected all the sensors to their factory location. The biggest problem i have is intermittent connection to misc sensors due to worn contacts. Sometimes it's an injector and sometimes its the throttle switch. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted September 1, 2012 Author Share Posted September 1, 2012 I've had carbed motors and they are very responsive with a light flywheel and a good tune. I have nothing to base how the car really runs I can't even drive it yet as it runs so rough. We will see how it goes. How have you like the swap in general even with the headaches? Quote Link to comment Share on other sites More sharing options...
motomanmike Posted September 1, 2012 Author Share Posted September 1, 2012 I worked on it today, put my new fuel pressure regulator on and removed the stock one. Fuel pressue i've got set to a solid 38lbs. Mounted the wire yellow wire I had running to switched power to the start signal permanently. Now the car sucks. It will barely start. It will barely run. SO thinking I had something wrong I put everything back to the way it was. Still runs like crap, barely starts etc etc etc. I'm frustrated and done messing with it for quite some time now. I'm just tired of making so much progress and doing so much work and now it won't even run right or halfway right. Everything is plugged in, i double checked all the contacts on all the plugs. She can sit for awhile. I'm not wasting anymore energy on it. Quote Link to comment Share on other sites More sharing options...
motomanmike Posted September 2, 2012 Author Share Posted September 2, 2012 Really wondering if a megasquirt will solve my problems, just start fresh with new wiring and a new setup. Looks fairly straight forward. Nothing is ever as easy as it sounds. I think i'm going to order the kit and replace all the plugs on my stock harness and see what happens. If that doesn't fix it i'll probably lean more toward MSIII Quote Link to comment Share on other sites More sharing options...
rejracer Posted September 2, 2012 Share Posted September 2, 2012 Megasquirt will be far more complex than a stock system. These Stock L28ET systems are very simple. Go megasquirt if you want to tune, not if you want to get it to run. I like the swap it's better than carbs imo. The problems have been minimal, and those that do pop up are simple fixes. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.