Rebuilt 82 280ZX Turbo did first start, now does nothing

[Ineptitude01]

I'm pretty much stumped. I did first startup yesterday on my freshly rebuilt engine, and it ran great. Got it up to temperature, did a little shakedown, looked for leaks, etc. Everything sounded fine. I had it running just fine for 25 minutes or so, keeping it between 1500 and 2000rpm as I've been told to.

 

I tried to take it for a first drive, but it stalled. Going downhill. In gear.

 

When I try to start it now, instead of making the normal 'starting noise' (RRrr, RRrr, RRrr), I'm getting a constant whine, and it seems like the engine is spinning faster than usual, but I'm really not sure. Every ZX I've ever worked on had a different 'starting noise'.

 

I am getting spark based on what I can see with a timing light. The plugs were fouled a bit, but I replaced them with a known good set. I've got good fuel pressure, so I'm stumped. The distributor is brand new, I just cleaned every EFI electrical connection including all the injector plugs. Injectors are also brand new. Fuel filter, ignition coil, plugs, everything is new.

 

If I entertain this weird whining noise, I get a giant blasting noise out the tailpipe after about 15 seconds of trying.

 

Has anyone ever had this problem before? I'm just worried that I've wrecked the rings somehow, and now have to start all over. The only compression tester I have sucks, and I wouldn't expect to see normal compression numbers before the rings set anyways.

[Ineptitude01]

Update!

 

The new plugs are ALSO wet with oil! Have I destroyed my rings already somehow? Or maybe my stem seals are leaking?

 

I pulled one of the plugs, B-12'd it, and grounded it while cranking. Nice spark, once the oil was off of the electrode.

 

Any help is good help!

 

Thanks.

[Ineptitude01]

Okay, further update. The first set of plugs was fouled by oil, no question.

 

The second set was fouled by FUEL. I took them inside and got a better look (and smell).

 

The car still won't start. I used a compressed air hose to blast out the cylinders, and correctly so. There was a lot of unburnt fuel in the cylinders.

 

Did a basic compression check with a crappy tester, saw about 95psi on all cylinders, which is what I would expect for unset rings.

 

So I have compression, fuel, and spark. Maybe my AFM is welded shut? I guess we'll have to find out the hard way...

 

Still hoping for a simple solution. Can't touch the car again until next weekend, though, so this is going to be a long and frustrating week.

[roger.svoboda]

You may have flooded the manifold with fuel. did that on an 83. Be sur you have a good (been load tested) battery and cables (no corrosion on the ends). Disconnect the fuel pump. With a fully charged battery hold the accelerator pedal to the floor and start cranking - KEEP THE PEDAL TO THE METAL. Give it a good long crank and see if you get a few pops and even might run a few seconds. Repeat a few times until no action. Reconnect fuel pump. Kill a goat in the name of the Z gods. It will probably start up assuming you have put the oil pump in correctly and the distributor is properly positioned to deliver spark to the number #1 cylinder at the correct time and the fuel injectors are doing the same.

[Ineptitude01]

That's a good point, I hadn't thought of that. I'll definitely try that this coming weekend. I feel like I did try cranking with WOT, and I seem to remember it backfired into the intake, or from the exhaust. It was very very loud.

 

Worth noting also that my alternator didn't seem to be working. Either it was bad when I got the car (barely ran, so I have no idea) or maybe just that I got it nice and wet filling the radiator on first start (pretty sure I did. Spilled lots of water into the fan - you know how it is. ).

 

The oil pump and dizzy thing was what killed me the first time. First I didn't prime the pump. Then I was 180Ëš off. Now it's perfect, since I actually overcame laziness and removed the valve cover like a good boy. I had it at exactly 23ËšBTDC, and I'm pretty sure that's no problem anymore. Be that as it may, I AM using an aftermarket coil, so I'm a little worried about the spark. It's a FlameThrower, if that's something I should avoid in the future. I loved the one I had on my 82 NA, so I dunno what to think.

 

What would have caused me to flood the manifold like this? The injectors are brand new, the O2 sensor is brand new, etc. I've never heard of this happening before, but now that you bring it up, it seems like that's what the problem must be.

 

And I'm going to be disconnecting the electrical in the rear, at the pump, right? and just whatever fuel is in the lines does whatever? I guess without pressure, it won't do much...

 

Is it possible my FPR is toast?

 

Time for a pallnet and a RRFPR?

[roger.svoboda]

I did it by not thinking. Pulled the plugs figuring I'd crank the engine over and get oil started to all the galleries. That was fine but fuel was pouring into the manifold because the injectors were working fine. Had I just jumped the solenoid instead of using the key no problemo. perhaps when you had the timing off you tried starting it and got a lot of fuel then. Anyway try that if nothing happens one way or the other at least you have eliminated that as an issue. what finally kicked my old overworked brain into gear was asking myself why did I smell raw fuel at the exhaust. Had already checked spark, fuel pressure and air flow. Then came the dawn - too much fuel just as bad as no fuel.

[Ineptitude01]

I guess the thing that really threw me is that it was running great, up until I tried to drive somewhere. I hadn't changed anything, and it just stopped working.

 

I still like the theory, since it explains my symptoms, but... What in those conditions could cause this to happen at all?

 

I haven't adjusted my TPS yet, but I don't think that would cause it... Right?

 

 

I did get the engine pre-oiled by pulling the plugs and cranking for a while, but after I got it to fire, I ran it in neutral at 2000rpm for 25 minutes. Could there still have been fuel sitting in the manifold at that point?

[roger.svoboda]

no no fuel left after running unless you got a leaking injector that pours what ever is under pressure in the fuel lines into the manifold. this one is kind of a stumper. Have someone watch the engine to be sure the starter is turning it over. you said you hear an odd whine now. Maybe the bendix went south and you hear the starter motor running but it isn't actually turning the engine. I'm out of ideas after that. Remember that zx don't like low voltage. A weak battery or corroded connections can turn over the starter but not provide enough voltage to run the electronics. just cause a timing light works doesn't mean you have spark. Try pulling the plugs and laying them on the block then crank her over and verify they are all sparking. You also said you had unburnt fuel when you blew it out. Things don't compute. what is your fuel pressure I don't see that in your post? TPS on a turbo just says go/no go. Really doesnt' affect starting. Might not like to rev up or might idle rich but should allow you to start it.

[woldson]

Check compression.

[Ineptitude01]

I haven't checked the fuel pressure with a gauge. I did the more lowbrow "If I disconnect this hose, and turn the key to 'ON', does fuel spray everywhere?" test.

 

I did lay the plugs out and verify that they were all sparking.

 

Now that you mention it, though I was having trouble with the battery. It didn't seem like the alternator was working at all, which could very well be the case. I didn't drive this car more than 10 feet after I bought it, so I have no idea if the alt worked. I switched out the negative battery cable, also, because the cable that was on the car was too short to reasonably reach a battery. Now I've got a much beefier cable on there that can certainly reach, and I cleaned the contact surfaces before installing it. I bought a new alternator the other day, and I'm going to install that this coming weekend also. Even if that wasn't the problem, the alternator that's in there now looks to be nice and old, and full of grime.

 

So my to do list as it stands is:

- Disconnect fuel pump and "start" car with wide open throttle until there can't be fuel in the manifold

- Replace alternator with new one

- Check starter for proper operation, verify that engine is turning over (it sounded like it was, and I can't imagine getting spark without that)

 

Maybe after a week of sitting, it'll just work for me.

[roger.svoboda]

what does the positive cable look like? Is the negative cable grounded close to the battery and then to the starter as it was originally designed or did some genius just cut it all off and go direct to the starter. It will work but not the best way to do it. on my first z31 not knowing how it was supposed to be I ran two 10 gage wires from the negative terminal to either side of the engine compartment. Lots of M6 bolts around that go into the body for grounding. Insufficient earthings were what gave early Limey cars and Lucas electric a bad name. not saying that is the problem but every little bit helps. If your fpr is shot the spray fuel everywhere test doesn't tell you much. If you don't have a constant (around 30-35 psi) fuel pressure on the ring your injectors are not performing properly. Too much pressure they shoot in too much fuel. Too little pressure they don't shoot in enough to keep it running. You could try the starting fluid trick if it runs that way then you know (maybe) that timing and spark are right therefore a fuel or air issue. How could you check the spark and not see that the engine is turning over? A huge vacuum leak could also exhibit the same problem you are having. Recheck all the hoses and stuff that could cause that.

[Ineptitude01]

Oh jeez, of course the engine was turning over, duh. I don't know why I said that.

 

The positive looks fine, but the negative was just too short. It looked like someone had cut the old cable by a few inches and installed a new clamp. I unbolted the frame ground (was real close to the battery - just below it) and took off the battery-frame ground piece, and replaced it with a longer, nicer cable. Prior to that, the battery had been able to wiggle around enough to kill the circuit, and after I installed that longer cable was the last time I successfully started the car. So it's like it was from the factory, negative to frame to starter.

 

I'm not sure if I have a spare FPR I can try, but I can scrounge around. I need to read up on checking fuel pressure, also, since that's something I've never done before. Is there anything I could have done hooking up the engine again that would have raised my fuel pressure? Seems like it's just the FPR that would have a say in things there.

 

Frankly, though, the more I think about this, the dumber it seems, and the more likely I think it is that I've missed something really obvious. Maybe I should try going through the whole EFI Bible troubleshooting checklist, if I can't figure this out after all's said and done.

[roger.svoboda]

You can buy a fancy fuel pressure checker from auto parts stores. All you need is a cheap oil pressure gage that is at least 0-50 psi, a tee, some hose, and some hose clamps. Pull the fuel line off the top of the fuel filter. insert short hose there. insert Tee. hose clamps on the new hose. Now connect the pressure gage to the part of the tee that is open. You may have to look around for some adapters to do that. Depends on how good a hardware store you have in your area. I made the whole rig up for less than $20. The reason you had a short negative cable is that someone cut off the original body ground parts and went direct to battery because the original strap clamps were prone to breaking after some usage. Originally the ground wire had a copper piece coming off the cable after the terminal clamp about 6 to 8 inches. This was then bolted to the firewall in the immediate vicinity of the battery. It then ran down and was held by a rubber block and clamp then to the starter. If you can find an original at the junkyard worth the trouble to get it and replace what you have (my opinion). FPR could have failed conincidentally with the rebuild.

Edited March 11, 2010 by roger.svoboda

[Ineptitude01]

Ah, I was saying that I have it the factory way. It doesn't go straight to the starter, it goes to the body, then to the starter. all I did was replace the too-short battery to body cable. I kept the place where it grounds there, because I figured (correctly, you say) that was important.

 

I have a 79 parts car that I can take the FPR from, also. I'm having the weird problem of having bought a car that was barely running. Now that I've rebuilt the enging, I have no idea what else was actually broken. The huge clouds of smoke coming out from the turbo were the bigger concern when I got it, so things like the battery, alternator, plugs... I had no idea if they were good or not. I've just replaced them all out of habit. It didn't smell like it was running rich before the rebuild, but then again, it barely ran.

 

I see what you're talking about with making the fuel pressure gauge. I'll give that a shot this weekend, shouldn't be too difficult. I'm going to get some battery cleaner on all the battery connections, including the frame ground, just to make sure it's all good.

 

Thanks again for all your help.

[roger.svoboda]

when you check the fuel pressure that will verify the FPR. Have you looked at the AFM? lots of posts on fiddling with it. If the ecu doesn't think the engine is getting air it won't give it any fuel. Here is a pic of the fuel pressure rig i made. When i talked about the battery cable I was thinking Z31 but the same thing. On the 280zx it went down from the negative terminal to a bolt that went into frame about a foot below the battery tray. Sounds like you did it right but wanted to correct myself. Been working on a z31 turbo for last two months and sometimes my mind wanders to that. I ask again have you checked for loose hoses that create huge vacuum leaks. The rubber boot from the afm to the manifold is a problem. Examine that closely many folks found it to be cracked. Also there is hose coming off the bottom that needs to be connected (at least I think that is s130 and not z31 I'm picturing).

[Ineptitude01]

Check compression.

 

Whoops, sorry, I missed your post! I checked compression with my dad's tester, but it's kind of a piece. Looks like ~90 on all of them, which is what I've read as being right for un-set rings.

 

 

As far as the hoses go, I've replaced EVERYTHING. Not one original hose is left on the manifold. The only ones are around the AFM. The AFM on my dad's car went out, and it was also causing weird problems. Is it possible that the same thing has happened to me here? is there an easy way to check the operation of the AFM?

[Ineptitude01]

FINAL UPDATE; PROBLEM SOLVED

 

Okay, I got some egg on my face, and I feel real dumb, but if I don't post this, nobody learns anything but me. So on the off chance that this helps someone, this is my contribution to HybridZ today. I really do wish more people would come back after they fix their problem, and tell all about what it was, and exactly how they fixed it. I find myself over and over searching for solutions to problems, and finding that people have had them, and then never reported back.

 

I get it, I get that HybridZ is all about 'search', don't ask, and I try really hard to do that. Still, I think it gets to the point where I have questions that might be helpful to everyone, but I'm afraid of getting shot down, so I don't ask them. I search, find my best guess, and work it all out for myself. We, as a community, have to make sure that we share the knowledge we have, instead of just waiting with fingers on triggers, looking for potential spooners.

 

[/soapbox]

 

Anyways, I didn't tighten the cam sprocket down well enough when the engine was still on the stand. The first peak vac pull downhill loosened it far enough that it came off the cam nose, but not all the way off. so it made no weird noises, and behaved normally enough trying to crank. I finally noticed it when I had the valve cover off. Mechanical timing was still perfect, bright link where it should be. I put it back together, and it started within 5 seconds.

 

Ran real rough, wouldn't rev over 3500rpm. I had the bright idea of cleaning my ECU connectors and wiggling them around. Stable idle, smooth power all the way up. Runs great now, despite T04B naysayers.

 

Shoutout to Roger, who helped a lot, and supported me in all this. Good idea after good idea.

 

And HybridZ... I still love you, but dammit, I'm mad at you right now.

[woldson]

Doing some things the hard way, IE, feeding yourself, can have some fantastic results!

 

It is not uncommon at all that when a problem is found it is simple, finding it can be the hard part. So CONGRATES!

[Ineptitude01]

Definitely it can. Trying to fix this problem, I noticed a few other things I would never have seen - loose hose clamps, etc.

 

Sometimes, though, I just want my car to start.

[AtlantaZ]

+10 for posting your lessons learned! I'm scouring posts exactly like this one for potential issues when I finish my L28ET rebuild in the spring. Thanks for the tip!!