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Help please engine cranking/running issues


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Good Morning fellow Z'ers, as you can see im having issues with my Z let me say i looooove this car so much but i haven't been able to enjoy it since I’ve owned it. The previous owners was a nice couple in Wisconsin and all they really asked was that i drove the car and enjoyed it "which i plan to do once its running good", anyway onto my issues let me list what i have done and i hope someone can point me in the right direction on what could be the issue. Oh and if anyone lives near or passes through Augusta, GA and wouldn’t mind putting an eye on it that be awesome also.

 

1978 Datsun 280z "stock"

 

Maintenance done so far:

 

Replaced Alternator, plugs, wires, fuel filter, and all vacuum lines. Sea foamed fuel tank and replaced fuel with fresh fuel.

 

Cleaned all connections to the body of the car including scrubbing areas for all ground connections, replaced battery terminals and battery.

 

My Z did run before but had the symptoms of dying out and hesitation and stalling out during driving which i thought was tied to some of these pieces. I have cleaned the AFM and throttle body. The fuel pump is working very well and the injectors are getting voltage from what i seen last night. I am kind of stumped at this point im not new to tuning cars, i did the swap on my 2jz FD on my own and before that I’ve swapped a 2jz into a sc400 "nightmare for wiring let me tell you" but on this im stumped. I do have both the FSM and Fi bible and have read them religiously if anyone could point me in the right direction: preferably with pics or video i learn easier that way :) that be great my plans for my Z is to run the l28 stock until 2015 and build up on body restoration and full aftermarket suspension until then. I would like to stick with the L28 maybe stroker motor maybe L28et swap im not sure yet but i am considering other engines. Anyway for now I’d just love to drive this Z around please help and thanks. Oh and yes i have searched and read and re-read maaaaaaaaaaany threads from different forums still no dice. Thanks in advance....

 

With warm regards

 

Andrew

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Edited by 2jztank
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yes it did as i mentioned but it would cut off and stall out at random times during driving. When it died everything in teh car would work except the engine cranking but if i jumped the engine it would crank. so after doing maintenace that ive done now it cranks fast adn strong electronics look great. but it just stays cranking and now starting so i thought vacuum leaks replaced all the hoses "some was cracked and some was frayed bad. still crank crank crank no start. Now i tried to do a starter test last night "negative jumped to battery from other vehicle and postive to starter" but still just cranked. i know my plugs are right but before and this is weird the plugs on my car was totally wrong.

 

Is there any way to tell if maybe the distributor needle is off-set and maybe my plugs need to be done differently. "w/pics"

 

Another thing i noticed is when i go to crank theres a small voltage dip "small" and if i have the lights on they do dim some, but not to a effect that there off.

 

thanks for a speedy response really hope to enjoy my Z soon...

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Ill buy some starter fluid this evening after work and try that if it doesnt start where should i look next, also side note sometimes when i dont attempt ot start it usually for a couple hours and come back the car will crank and start/die immediatly but soon as it does that back to crank crank crank.

 

Also if it is a fuel supply or injection issue whats steps could/should i take next

 

thanks again really appreciate the assistance...

Edited by 2jztank
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The side note implies that the engine is flooded.  Total opposite of what your first description suggested.  Pull the plugs and see if they're wet or dry.

 

" I do have both the FSM and Fi bible and have read them religiously " - stop reading and start doing.  Good luck.  Tuning and swapping are two different things.  This is an easy problem.

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ok i know the last plugs i took out was damp so if these new plugs i installed are wet then its flooded also i have been doing and i relaize swapping and tuning are two different things but im willing to try and willing to learn. thanks again for the info quick question if the plugs are wet and this leans towards the engine being flooded whats the best route to handle this situation on our Z's...

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We learn the same way as well, some pictures or videos of the problems will help go a long way towards diagnosing problems as well. A picture of the car is nice, but a picture of the wiring, engine, etc would be much more useful.

 

If you just added power to the starter the ignition circuit would not be engaging and thus the engine would not start regardless of the starter cranking.

 

Simple combustion.

 

Air

Fuel 

Spark/Timing

Compression

 

You have replaced the vacuum lines, did you make sure they were plugged correctly? 

You seafoamed the tank, do you have a fuel filter inline? How did you check the flow? Did you check that the injectors were firing actual gas?

You replaced the spark plugs and wires etc, have you confirmed an actual spark? 

(I hope this goes without saying, but don't check spark and fuel at the same time)

If the car was running before, compression could be less of an issue, although definitely something to check once the other main concerns have been addressed.

 

You can disable the fuel pump and run starting fluid/ether to see if the problem is related to fuel delivery. If you can get the car to turn over on ether, definitely a fuel problem, if the car won't turn over on ether, then either a spark/timing/compression problem.

 

If you are not getting anything with ether, let the fuel vapors evaporate and then test the spark by using an inline tester 5$ at harborfreight, or if you want you can pull the spark plug and leave it on the valve cover/next to a bolt and visually observe spark. If it is not firing, you will have to work your way back to the distributor (rotor and cap, as long as it is not the et distributor), then to the coil, then to the ignition signal for the coil.

 

If it is a fuel supply issue you just have to go as far back until you find the problem. Start at either end and work your way until the fuel stops/starts, take one step back/forward and there's your problem. Most likely will either be a blockage from rust/dirt or a weak/dying pump. The fuel system is easy enough to take apart on these cars. 

 

If the engine is flooded, remove the spark plugs and you can let it air out overnight as long as it doesn't rain etc, if you are more in a hurry, you can crank the engine over with the coil disconnected with the spark plug out to push the fluid out, this will get gas everywhere depending on how flooded it is, but if you have indeed really flooded the cylinder there may be a lot of fluid in there.

 

It seems you have an underlying problem if you can't get the starter to crank without bypassing your electrical system, some basic fact checking will help us either rule out or direct your attention elsewhere.

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lots of great info there thanks so much man I performed a couple more test tonight but still no answer, I bought some new plugs "NGK BPR5ES" and some starter fluid and a siphon to see if if the engine was maybe flooded with fuel. When I pulled the plugs though they was dry as a bone barely look used and since they was new some of them look like I just twisted them in. Either way I put the new ones in attempted to crank no dice. then I sprayed some starter fluid in the AFM area and boom she starts and a couple seconds die. So that leads me to fuel delivery so I will check the fuel system next again when I checked the injectors I plugs I was getting a reading from all of them so im a little lost on if there not firing but I would say maybe so tonight ill pull the fuel line on the fuel filter "brand new filter also" and see what comes out and all. to answer some of your questions that I can right now.

 

 

1.I believe I did from what I have seen yes I could be wrong I will take pics of my bay tonight after I check the fuel filter for flow so someone can verify

 

2. I bought a new fuel filter a while back when I first started working on my Z when I went to replace it fuel flow was fine and considering the car ran before I figure that's ok

 

3. No but I will do that here in a few minutes and report back

 

If anyone knows anything or have no issues wth a quick phone or Skype call to help id greatly appreciate I know im asking a little but im really hitting a brick wall, also where is the Cold start injector located I heard you cant unplug it and maybe that will help "not sure just from reading forum threads"

 

Ill be right back with more information...

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So just came back from testing fuel on the Z *sigh* pulled line from bottom of fuel filter and let drain then put the car to the on position and yeah soon as I did no fuel came out so no fuel is flowing through the car at all which would explain the no cranking or running. This is very discouraging and really hmm anyway stiff up the lip and drive on so yeah here are some pics of my bay please tell me if anything is out of order and how should I go about running this issue down, im thinking drop the tank and and all fuel lines im assuming or pump and first?

 

Sorry in advance for the pic quality is is very late here and thanks to any help in the situation.

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Edited by 2jztank
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The fuel pump doesn't run when the key is On unless things have been messed with.  The pump gets power when the key is at Start, or when the engine is running.  So, what you saw is correct for an unmolested stock 1978 280Z.

 

Take the small wire off of the starter solenoid (it's a male-female press fit), place it where it won't ground out and cause a spark, then turn the key to Start.  The starter won't turn the engine, but the fuel pump will get power.  Be ready for fuel to flow.

 

 

Edit - the first few pages of the Engine Fuel chapter will tell you how things are supposed to work.  It can take some time to absorb it all but if you go back to it regularly, things will start to make sense.  For example, "where is the cold start injector?"  It's described, with a drawing, in the Engine Fuel chapter.  Go look it up.  It's also mentioned in the first few pages of the chapter.  You'll waste a lot of time and money if you don't take a methodical approach.  

Edited by NewZed
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Ok will do that also one more thing when i had the fuel line off i also cranked the car as well and still no fuel came out. My Z is stock for the most part that i have seen and the fuel that drained "which was a very small amount" out fuel filter was very murky looking. When i put the car to the on position i do hear the fuel pump engaged "but no fuel flow" and when i tried to crank it with the fuel filter going to a bottle to see if flow was good still no fuel.

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The "one more thing" and "I forgot to mention" are progress killers.  You just need to test each component, one at a time, and make sure they're doing what they're supposed to do.  Dropping the fuel tank when you're not even sure if the fuel pump works doesn't make sense.

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Roger that i will test the fuel pump today and open the AFM to also i dont believe tested its points inside or inspected the gear in there "ill also take pics to have a another set of eyes verify". but im pretty sure there some nastiness in my fuel tank based on the small amount of fuel that dripped out the fuel filter was like a mudd color and you couldnt see through it and had small particles floating around also.

 

 

For others reference i found this site which shows some good info/maintenance walk through's with pics...

 

http://atlanticz.ca/zclub/techtips/

Edited by 2jztank
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Ah should have checked last night, could have assisted you with trouble shooting.

 

Highly agree with newzed, work on one aspect at a time. Trying to solve multiple problems at the same time will be overloading.

 

Getting the engine to turn over on ether definitely points towards a fuel problem, the clogged filter confirms the problem. 

 

You know you aren't getting fuel past the filter, are you getting fuel right behind the filter, if there is no flow, work your way back to the pump, if there is no flow at the pump then it is either a bad pump, or a blocked/short pickup, its just a matter of going back till you can find your problem. Don't mean to point out the obvious, but is there sufficient gas in the tank I know you said you added fuel, how much did you add?

 

Honestly I would drain the tank and clean it out via whatever method you can and flush till clean. The old rock tumbler method, is a good cheap choice. If you want to see if it is the only problem you can try the old drink out of a gas can trick, but you would have to run more lines, or buy an efi fuel pump to try that out.

 

Just stay safe, you are clearing things up, just keep at it.

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yeah tonight I pulled the fuel pump and dropped the tank the way I see it might as well clean it to be extra safe in the long run an you know what emptied the tank and a first fuel looked normal, when it got to the last bits was like sludge so glad I did that. However working 9 hrs then pulling a tank at night alone was a little overwhelming those old clamps was no joke lol. tomorrow after work ill clean the tank and test the pump and pull the old lines so that I can replace them just to be safe. and ill report back with results.

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Working on these old cars requires some discipline and effort to get things right.  I can't help but notice the degradation of this thread as it progresses, both in writing style and accomplishments.  It's just not good.  You've pulled the tank and the pump and you still don't even know if the pump works.  And who wants to read text-speak, really?  Anybody?  Bump the effort level back up to Post #1.

 

Edit - actually I may have offended some people that do text.  I know that when I text a message I actually hit the little button for capitals.  So "text-speak" is probably the wrong term.  I don't know what the word would be for what's going on here....

 

Post #1 sample - 

 

"Good Morning fellow Z'ers, as you can see im having issues with my Z let me say i looooove this car so much but i haven't been able to enjoy it since I’ve owned it. The previous owners was a nice couple in Wisconsin and all they really asked was that i drove the car and enjoyed it "which i plan to do once its running good", anyway onto my issues let me list what i have done and i hope someone can point me in the right direction on what could be the issue. Oh and if anyone lives near or passes through Augusta, GA and wouldn’t mind putting an eye on it that be awesome also."

 

Post #16 (what's different?) - 

 

"yeah tonight I pulled the fuel pump and dropped the tank the way I see it might as well clean it to be extra safe in the long run an you know what emptied the tank and a first fuel looked normal, when it got to the last bits was like sludge so glad I did that. However working 9 hrs then pulling a tank at night alone was a little overwhelming those old clamps was no joke lol. tomorrow after work ill clean the tank and test the pump and pull the old lines so that I can replace them just to be safe. and ill report back with results."

Edited by NewZed
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  • 1 month later...

Hello again fellow Z'ers

 

         First sorry about the long response, just moevd into my new home and family came in from germany also, and my birthday so it has been pretty busy. Anyway again thanks for all the words of wisdom from before after replacing the fuel pump and refurbishing the fuel tank, i also replaced a couple lines. My Z ran well however another issue came up. I notice when my Z is cold she drives and idles perfectly fine but when i drove her to the gas station to fill up i could not get her to start without trying a couple times. Then she drove home and stalled out as i pulled into my neighborhood. I pulled over and didnt notice anything out the ordinary and after a copuple times attempting to crank she cranked up and drove home. Once i got her home i let her run for a bit and didnt notice anything out the ordinary when i went to rev the engine a couple times she died instead of going back to her normal idle and i had to wait to crank her up again.

 

There are no vacuum leaks, car has fresh gas new pump and lines, and when she cranks and runs she runs great but if i fill her up with gas or she runs for a long period of time she will cut off. Is there anyone who has any idea where i should look next i really want to enjoy this Z on a daily basis and dont mind getting my hands dirty on her.

 

Thanks in advance again

Edited by 2jztank
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So after doing some searching and trial and error on my vehicle i think i have nailed the issue down to one problem.  When the car warms up for some reason it will start idling very rough and around 500 rpm's and eventually stall's out. However when it is cold it runs like a champ idles perfect runs great no break ups in the rpm's and full of life. I read this could be tied to a number of things but i wanted to ask some of the season Z'ers what direction would you head first with troubleshooting this issue. Also wanted to ask if anyone on here was in the Augusta, GA area also would be great to know some other Z guys locally.

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Same strategy as above, rule out, isolate, conquer.

 

Right now you have not nailed anything down per say. You know a situation that causes the problem.

 

Once again, lay facts on the table, we can't really help you, if you the one asking for help is making assumptions. We need facts to help isolate any problem.

 

So if the car runs in the beginning, then that means you meet the requirements to start. If it stalls out then that means you are loosing one of those requirements.

 

Air, fuel, spark, compression

 

We lost a week of posts, but I believe you said you acquired a new fuel pump, regulator, and filter? If you have fresh gas and fuel pressure when this happens, then fuel supply is not the issue. It could be a problem with the injector or cold start injector, so there is one place to look. Another thing to check is that you have everything plumbed correctly.

Tank -> pre pump filter -> pump -> filter -> rail -> regulator -> tank

 

Air, you said you have no vacuum leaks, new hoses? or just a general glance? The factory vacuum system is pretty complicated. Something that gives us a little more confidence would be great. A quick squirt with some non-chlorine brake clean would indicate any vacuum leaks, I believe ether would work as well (you would be looking for a rise in rpm)

 

Compression, compression test simple as that, no compression and even if you throw all the air and fuel and spark at it it won't do any good, unlikely situation as without compression it would most likely not want to start. If compression test reads low there are somethings we can try.

 

Now to the most likely culprit, spark. Have you confirmed strong spark? I suspect that either the plugs are fouled, or that your coil is overheating/failing. As the car warms up check how hot the coil gets, get us some multimeter readings from the battery. If you have insufficient charge the engine will eventually stalls as it cannot generate a strong enough spark to light the fuel mixture, which could lead to fouled plugs which only makes the problem worse.

 

Report back with some findings and we can go from there :D.

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