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Heya all, just replaced the fuel pressure regulator and after doing so the car seemed to stutter a little at idle. Gonna do some more checking into it tomorrow by checking ECU codes and whatnot, but it has me worried. Either something else decided to take a crap on me or the car needs something else to tune it up a little.
My question though is about the cable that attaches to the regulator; what does the female connector do exactly? Does it supply power or read a signal? If it just supplies power and the insulated end is just that, an insulated female pin connector? If so then I will solder in a new insulated female connector as the wire seems to have a fair bit of play in it and I can hear something physically clicking when I move the wire around a little.
I tried looking through the FSM but there isn't much said about the regulator or it's connector.Z31 owner as of 27/04/12!!! Sitting in my driveway as of 29/04/12!!!
Let the madness begin! -
the fuel pressure regulator works off vacuum and has no electronics connected to it, there is a vacuum actuator located next to the coil that helps with cold starts but in my opinion it is not necessary its just more electronics they tried to jam into the car, try connecting a vacuum hose straight from the plenum to the fpr you'll only need like 3 inches of hose if that, the fuel pressure regulator has a spring in it that sets it to a certain pressure nothing electronic, if youre having a stumbly idle, check your chts if youre having stumbles at a cold start, they are common to have troubles with, get back to us about it -
On the contrary, there IS an electrical connector at the fuel pressure regulator. The connector is there for the fuel temperature sensor that screws into the side of the regulator itself which could cause the issue as well. Make sure you have a good connection with the wiring to the sensor. As jakz31 said, the chts is also a good thing to check. They often cause odd running issues being that on cold start up, more fuel is dumped to get the engine to operating temperature. If the temp sensor isn't reading right you may be running too rich or too lean at idle on cold startup. -
Thanks for the info guys. That is where my issue is, and it just seemed odd that after replacing the regulator that it now idles badly; before it idled fairly well as it used to stumble and die every blue moon.
Is the connector at the end of the wire, the large black plastic covered connection, anything special or is it just an insulated female pin connector? If I remove the connection, in what way would the car react seeing as it doesn't have a fuel sensor reading? I am working inside a heated garage so I don't really see this as being the culprit but it may very well be; replaced a failing component and another failing component became apparent.
I will check into the CHTS as well, I'll look over the FSM some more this morning before tackling the car again in a few hours.Z31 owner as of 27/04/12!!! Sitting in my driveway as of 29/04/12!!!
Let the madness begin! -
is it only when the car is cold or even at operating temp does it idle poorly? generally the chts connector has a habit of being a bit loose, well mine was a bit flimsy, just give it a poke on the sensor side connector and check the connector for it too the loom itll be somewhere near the pop off valve, generally thats where the connector is due to the length of the loom, i know mine had a broken connector so i crimped one back on plugged her in and all my problems were solved, beautiful idle, but thats just me, check your plugs and leads as well because once its revving it might seem okay but you never know it might be a plug contributing to the issue -
I will definitely check into that jak. I never had a chance to have the car running up to operating temperature after doing the work, she is still sitting in the heated garage.
The off idle seemed like random stumbling moreso than a misfire, although that could be the distributor going out as well; replacing that once I get my next paycheque.
Doing all of the odds and ends on the car now. I will take some pictures of what was done to post in the build thread. Nothing spectacular, but I did put insane new hood shocks on her…lets just say it takes both hands and brute force to put the hood down now; one of these hocks alone was more than enough to lift the hood.Z31 owner as of 27/04/12!!! Sitting in my driveway as of 29/04/12!!!
Let the madness begin! -
Make sure you bolted the fpr firmly to the LIM, and soldering a new female connector for the FTS will be the best way to go. Also after you confirm that, read the stored ecu codes to get a direction on where to go nexthttp://z31performance.com/showthread…2-2-(-now-NA2T
My build thread (: -
Btw I tried starting and running my car (85 na2t) without o2 hooked up, and it was terrible. Almost stalled, vacuum went down to almost 12" hg and miraculously it went back up yo the 20" area, and fluctuated wildly until operating temp Not to mention the car ran like there was a severe intake restriction. Ran codes and retrieved code 44 from the 84t ecu Plugged the o2 back in and immediately the car has all of its power back. So those who say that they never run o2 on their Zs… I think you are full of shit.http://z31performance.com/showthread…2-2-(-now-NA2T
My build thread (: -
Thanks for all the info guys.
I replaced the vacuum hose on the top of the FPR and it seemed to idle very nicely. Everything was bolted up nice and tight, so I'm thinking it was the vacuum hose maybe or it took a while for the system to readjust to the new components. I noticed that the car is idling fairly high though, 900-1000 RPM range, so I am going to tackle the timing next time I go at the car and check the idle settings.
Never got any codes from the ECU, so that's a good thing. Hopefully all is well now. Also managed to fix the power steering leak, at least I think so after replacing some copper gaskets, and some more odds and ends. When I get some more funds to dump into the car I am going to replace some belts and other odds and ends.Z31 owner as of 27/04/12!!! Sitting in my driveway as of 29/04/12!!!
Let the madness begin! -
I dont run an 02 sensor and I have no idle or power issue. 87 ECU with nistune and 460cc injector with adjustabe fpr. Go figure.Cha iro
enjoy building it yourself.
if it fails, fuck it.
at least you gave it a whirl. -
ASCO block off plates as well.Cha iro
enjoy building it yourself.
if it fails, fuck it.
at least you gave it a whirl. -
That's a stupid conjecture. Personally I don't run an 02 sensor in my NA2T nor any idle or emissions control. What I do run is Nistuned 87NA ECU with 460cc injectors and adjustable FPR. Remember the 84/85 is the worse of all Z31 ECUs.les_joey_paul;n769958 wrote: So those who say that they never run o2 on their Zs… I think you are full of shit.Cha iro
enjoy building it yourself.
if it fails, fuck it.
at least you gave it a whirl. -
the car has a valve that raises the idle on a cold start and once its warmed up the idle drops back to 700ish rpm, if you let it warm up to proper temps i think youll find it wont have a high idle issue, also check the tension of the throttle cables because i remember once i set the nuts on my throttle cable at the throttle body too far tight and it raised the idle, so keep cable tensions and idle up valves in mind, generally there is a reasonable explanation for stuff without drastic issue -
If your running a standalone system like nustune then yes I'm sure your car runs fine without o2 But with stock ecu… o2 makes a ton of difference. As for the high idle.. what does your car idle at with all of your accessories on?Augustus Maximus;n770005 wrote: That's a stupid conjecture. Personally I don't run an 02 sensor in my NA2T nor any idle or emissions control. What I do run is Nistuned 87NA ECU with 460cc injectors and adjustable FPR. Remember the 84/85 is the worse of all Z31 ECUs.http://z31performance.com/showthread…2-2-(-now-NA2T
My build thread (: -
I will have to check to see what the idle sits at with the accessories on the next time I am at the shop.
As for the throttle cable, I know there is no issue there as the cable has tons of slack due to a break in the adjuster piece, which I had to fix by means of just rigging it up in a usable way that results in pedal play is all.
I had the car running inside for about 20 minutes and the rpms never dropped at all, so it's something I am definitely going to have to look into. I know before it used to be a little lower, maybe the 800 range.Z31 owner as of 27/04/12!!! Sitting in my driveway as of 29/04/12!!!
Let the madness begin!
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