# "New" 84 Turbo z31, Won't run... CHTS?



## Xyclonik (Feb 9, 2009)

As I posted in the "What did you pay for your Z?" forum, I just picked up an '84 Turbo z31 for $600. It's recently had a full tune-up, new injectors, new FPR, new clutch set and slave-cylinder. Problem is, it will not run. It's got spark, and fuel to the fuel rails with some pretty good pressure...(So much pressure that a clamp he didn't tighten completely on the fuel rail was leaking.)

I heard the engine turn-over and run before buying it, he had sprayed starting fluid into the TB and turned it over, and it would run as long as you kept supplying it starting fluid, or gasoline with a spray bottle. :balls:

I checked it for codes today and came up with 13, 23, 24, and 31. I imagine number 13, (CHTS) is going to be my problem. But would the CHTS malfunctioning really keep the engine from running? Any other ideas as to why it won't run? Any helpful input would be appreciated.

P.S.- With the the ignition in the on position without turning the engine over, the fuel pump runs continuously. I may be wrong, but it seems in my NA model the fuel pump will run for a few seconds and stop if I don't try to turn the engine over... Maybe something to do with it? I know it has new gas in the tank.


----------



## AZ-ZBum (Nov 21, 2004)

Why do people insist on buying cars if they have no idea how to fix them?

HELLO! Your big clue is that if you keep spraying starting fluid into the intake it keeps running. How much more of a bat to the head do you need?


----------



## Xyclonik (Feb 9, 2009)

Your comment is useless and unhelpful, and as per being unhelpful, it is unappreciated. I bought the car because, 1. It is one of my favorite cars of all time, and 2. Do I need any others reasons, or your blessing to buy the car? 

No.

If you aren't going to post something helpful, don't post at all. From the countless forums posts, I've read tonight... it sounds like it is either the CHTS, or the MAF. I imagine the CHTS, and MAF are the same be it a turbo or NA car?


----------



## Xyclonik (Feb 9, 2009)

"Disclaimer:
One thing you'll find about me is that I can be very helpful to people who take their time to ask complete questions with good grammar and punctuation. I'm also a real ass to people who don't show at least a little effort in their posts.
Z31 Registry
Z32 Registry"

^ Besides, what is your signature... a joke? From what I've read in most of the forum posts, you used to be helpful but here lately... heh, not so much.

Are you saying that the small hole used to spray the starting fluid the previous drilled into the 3" rubber hose between the plastic intake piping and TB is the cause for it to not run? Is so, just say so. I'll try replacing that piece tomorrow and see what happens.


----------



## AZ-ZBum (Nov 21, 2004)

You idiot. You're spraying raw fuel into the intake to get it to run. You take away that source of fuel and it doesn't run.

Now... How stupid are you that you can't figure out it isn't getting fuel into the cylinders?

Yes. I think you are an idiot for buying a car that needed work if you don't know how to work on it. Why would you buy a project if you aren't capable of using tools?


----------



## Xyclonik (Feb 9, 2009)

What a surprise, another useless and insulting comment. You must have plenty of time on your hands. I, on the other had, do not. 

The point of my post was to try and save time, seeing if anyone could point me in the right direction versus me spending 10+ hours removing the plenum and TB to re-do everything the previous owner did with the injectors and tune-up.

I am quite capable of using tools, and fixing the car myself. Since I am going to be removing everything from the lower intake up now, I suppose I'll go ahead and throw the VG33 plenum, and distributor I having laying around from the spare 2002 Xterra motor.

AZ, I guess you don't understand saving time since you seem to have so much of it on your hands...


----------



## VMX12Rider (May 3, 2010)

13: Cylinder Head Temp Sensor
23: Idle Switch
24: Neutral Switch
31: Air Conditioner


----------



## Xyclonik (Feb 9, 2009)

I know what all the codes stand for, VMX, but thank you anyway. I have all of the FSM's and there is a de-coder on the ECU itself.


----------



## Spongerider (Nov 18, 2002)

Xyclonik said:


> I know what all the codes stand for, VMX, but thank you anyway. I have all of the FSM's and there is a de-coder on the ECU itself.


You should replace the sensors/switches and be done with the codes. After you replace the parts and your problem still is occurring then report back.


----------



## skittle (Apr 27, 2010)

^^^ only if you want to waste money. Follow the FSM it will show you how to test each individual component. After doing so you will see if any of them are the culprit. 

Have you even done a fuel pressure test yet? Also check all the grounds and clean all the conections. Some time a loose one can create this problem.


----------



## Xyclonik (Feb 9, 2009)

Spongerider said:


> You should replace the sensors/switches and be done with the codes. After you replace the parts and your problem still is occurring then report back.


The only code that concerns me is 13, I've already ordered the CHTS and Sub-harness, I've just not had the time to replace it. Codes 23, and 24 showed up because I didn't check them to make sure they were working, I know they are. I'll post back when I have the time to replace the CHTS, do a fuel pressure test and solve the problem.


----------



## Xyclonik (Feb 9, 2009)

So I've finally had some time to pull the car back up on the pad, just to do a compression test. From what I gathered in the FSM on an '84 Turbo model, standard compression should be ~165 P.S.I. Now, is that with everything connected or with the entire Plenum removed?

I did my compression test with everything north of the lower intake removed, and got these results.

Cylinder 1: 173 P.S.I.
Cylinder 2: 180 P.S.I.
Cylinder 3: 185 P.S.I.
Cylinder 4: 180 P.S.I.
Cylinder 5: 170 P.S.I.
And Cylinder 6: 176 P.S.I.

Now I would imagine with the Plenum and entire intake system in place the compression test would show lower pressure, but how much? Also, the engine was cold during the test, since it doesn't run, I couldn't warm it up.


----------



## Xyclonik (Feb 9, 2009)

Little by little, more progress is attained. 

I made a fuel pressure tester today and was able to test... With the ignition on, but the engine non-running I had a constant fuel pressure of 40 P.S.I.

It would drop from 40 P.S.I. when vacuum was applied to the FPR. I know that when I turn the ignition on the fuel pump should only run for 5 seconds to prime then stop until the engine is turned over and fired, but, my fuel pump runs constantly with only the ignition open at 40 P.S.I...

My questions are, is it possible that my fuel pump relay has arced and welded itself constantly open causing the fuel pump to run, and if it has, would it keep the E.C.C.S. from spraying fuel into the cylinders?


----------

