Jump to content

Recommended Posts

Actually come to think of it this wasn't a stand alone event, when I first got my car moving under it's own power I had vitually no understanding of how the wiring worked and so I bypassed the fuel pump relay with a fuse to prime the engine, took out the fuse stopping the fuel pump and drove the car exactly 3.6 miles before the engine died of fuel starvation. The only issue I had the whole way was if I took it above 4k rpm the engine would start to die out. Eventually I came to a stop sign and made a turn and for whatever reason the car stalled and continued to do so no matter how high I reved the engine up or how slowly I let off the clutch.

Share this post


Link to post
Share on other sites
My car's a 280z, so it has EFI instead of carbs
Yeah, I saw that. I mentioned carbs because they have their own local reservoirs and will continue to work until the reservoirs empty. EFI only has residual pressure in the fuel supply line which isn't going to give as much as carbs.

Share this post


Link to post
Share on other sites
3 hours ago, siteunseen said:

Efi fuel filters hold about a quart. :ph34r:

yes but they use fuel pressure to atomize the fuel, no pressure no fuel for EFI.

Share this post


Link to post
Share on other sites

I think its safe to say the running/non running fuel pump is a rabbit hole not needed to go down. OP did you check the CTS (coolant temp sensor) per the FSM? do the check at the ECU connector.

Share this post


Link to post
Share on other sites

Here's a nice unsafe way to determine if fuel is somehow being pumped into the engine without your knowledge: unplug the fuel hose between the hardline and engine bay fuel filter, put it in a bucket, and have someone try and start the car (with the fuel pump switch off) and see if you get gas.  You'll know real quick if theres some hidden pump somewhere (or if your switch isn't working/wired correctly)...

Share this post


Link to post
Share on other sites
5 hours ago, chaseincats said:

Here's a nice unsafe way to determine if fuel is somehow being pumped into the engine without your knowledge: unplug the fuel hose between the hardline and engine bay fuel filter, put it in a bucket, and have someone try and start the car (with the fuel pump switch off) and see if you get gas.  You'll know real quick if theres some hidden pump somewhere (or if your switch isn't working/wired correctly)...

Well at least I’d know lol

  • Like 1

Share this post


Link to post
Share on other sites
On 6/24/2019 at 7:46 PM, chaseincats said:

Any luck finding the issue?

No, I haven’t had the chance to mess with it anymore I’ve been pulling doubles everyday in addition to replacing the clutch and flywheel, hopefully I can figure it out today. Now I’ve got another issue as the clutch grinds going into gear even though it’s brand new 

Share this post


Link to post
Share on other sites
55 minutes ago, Jack Pearcy said:

No, I haven’t had the chance to mess with it anymore I’ve been pulling doubles everyday in addition to replacing the clutch and flywheel, hopefully I can figure it out today. Now I’ve got another issue as the clutch grinds going into gear even though it’s brand new 

If you installed a new clutch master cylinder you need to swap the pusher rod (the metal bit that goes into the cylinder) because the reproductions are shorter for some reason (this was my problem).  Also be sure its fully bled.

Share this post


Link to post
Share on other sites

I do have a new master cylinder, but I installed it a while ago, it may need to be bled again, as far as the pushrod goes do you mean use the original push rod? I still have it so it shouldn’t be an issue but right now it has the reproduction push rod in it

Share this post


Link to post
Share on other sites
51 minutes ago, Jack Pearcy said:

I do have a new master cylinder, but I installed it a while ago, it may need to be bled again, as far as the pushrod goes do you mean use the original push rod? I still have it so it shouldn’t be an issue but right now it has the reproduction push rod in it

after swapping the master cylinder, did the clutch work at all w/o grinding?

Share this post


Link to post
Share on other sites
9 hours ago, chaseincats said:

after swapping the master cylinder, did the clutch work at all w/o grinding?

It didn’t work without grinding, it would go into every gear fine except for 1st and reverse but that was with the old clutch, now with the new one it’s doing the same thing but worse. I decided to test if the clutch was the culprit so I put it in reverse with the engine off and then started it with the clutch fully in and sure enough it just started driving.

Share this post


Link to post
Share on other sites
3 hours ago, Jack Pearcy said:

It didn’t work without grinding, it would go into every gear fine except for 1st and reverse but that was with the old clutch, now with the new one it’s doing the same thing but worse. I decided to test if the clutch was the culprit so I put it in reverse with the engine off and then started it with the clutch fully in and sure enough it just started driving.

In that case ya, it's your clutch master cylinder's pusher.  Swap it out with the stock one you still have (I think you just need a pair of needle nose pliers that you can use to take off the snap-ring retainer clip).

Share this post


Link to post
Share on other sites

When you changed the clutch. Did you compare the two pressure plates. There are basically four different heights available. The magical number between the flywheel and where the clutch fork contacts the collar is 92mm.

The collar must match the pressure plate. Very easy to mix them up when using aftermarket pressurs plates.

Measure the fork position in rest. From the front of the transmision bellhousing to the clutch fork should be around 115mm. If you measure 120-125 then the clutch fork will bind on the transmission housing before releasing the clutch.

 

ClutchFork-1 280Z en 260Z.JPG

IMG_09230.jpg

Edited by EuroDat
Photo of clutch fork measurement
  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, EuroDat said:

When you changed the clutch. Did you compare the two pressure plates. There are basically four different heights available. The magical number between the flywheel and where the clutch fork contacts the collar is 92mm.

The collar must match the pressure plate. Very easy to mix them up when using aftermarket pressurs plates.

Measure the fork position in rest. From the front of the transmision bellhousing to the clutch fork should be around 115mm. If you measure 120-125 then the clutch fork will bind on the transmission housing before releasing the clutch.

 

ClutchFork-1 280Z en 260Z.JPG

IMG_09230.jpg

I didn’t compare the pressure plates but I did use the Nissan brand clutch and pressure plate replacements that are supposed to be oem quality

Share this post


Link to post
Share on other sites

The problem is that the aftermaket industry doesn't really know the difference between all thedifferent models and pressure plates. 240Z up to 72, 240Z after 72, 260Z, 280Z and 280ZX up to 81, 280ZX after 81 and Maxima 810.

See attached photo's. Btw, They are not my photo's. Other people having similar issues.

240Z_Clutch_series-I-2.jpg..jpg

240Z_Clutch_series-I-3.jpg..jpg

Pressureplate240z_280zx.jpg

PressurePlates zie word doc.jpg

Share this post


Link to post
Share on other sites
2 hours ago, Jack Pearcy said:

I didn’t compare the pressure plates but I did use the Nissan brand clutch and pressure plate replacements that are supposed to be oem quality

The problem is with your new clutch master not slave cylinder's piston length.  Your clutch pedal is connected to a push rod (piston) which directly goes into your master cylinder.  The piston you have is (probably) too short which is in turn not able to push enough fluid through the clutch hydrolic system to fully actuate the clutch fork thus disengaging the clutch enough to change gears.

TL;DR: clutch master (not slave) piston length is most likely the item that isnt matching up to oem length.  Compare the oem one you have on hand.

Share this post


Link to post
Share on other sites
3 minutes ago, chaseincats said:

The problem is with your new clutch master not slave cylinder's piston length.  Your clutch pedal is connected to a push rod (piston) which directly goes into your master cylinder.  The piston you have is (probably) too short which is in turn not able to push enough fluid through the clutch hydrolic system to fully actuate the clutch fork thus disengaging the clutch enough to change gears.

TL;DR: clutch master (not slave) piston length is most likely the item that isnt matching up to oem length.  Compare the oem one you have on hand.

Okay that makes sense, I was only messing around with the slave cylinder because I assumed it would have the same effect, just would be easier to access

Share this post


Link to post
Share on other sites
Just now, Jack Pearcy said:

Okay that makes sense, I was only messing around with the slave cylinder because I assumed it would have the same effect, just would be easier to access

totally understandable, let me know how it goes

Share this post


Link to post
Share on other sites

Just remember Chas (Eurodat) is one of the few resident transmission experts...

Share this post


Link to post
Share on other sites

I thought the master cylinder was replaced earlier before the clutch and pressure plate was replaced. Now reading post #39 I agree.

My internet connection is not the quickest working out of a landcruiser or campsite and I scrolled past it.

Chaseincats has a good point. It looks like an incorrect master cylinder push-rod or adjustment. If it has the correct push-rod it should be adjusted according to fsm. See attachment.

.

Screenshot_20190626-082252.png

Share this post


Link to post
Share on other sites

One trick I've used to verify maximum travel of the master cylinder piston is to adjust the rod so that the clevis pin slides in to the pedal bushing with no effort.  If you have to pull the pedal down or push the rod in or pull the rod out to get the clevis pin in then it's not right.  While you're there you can eyeball the pin and the hole for wear.

I've also used a thread to pull the clevis pin up to the hole so that I can finagle it in the rest of the way with a screwdriver.  I can't get my hands up there.

Share this post


Link to post
Share on other sites
3 hours ago, EuroDat said:

I thought the master cylinder was replaced earlier before the clutch and pressure plate was replaced. Now reading post #39 I agree.

My internet connection is not the quickest working out of a landcruiser or campsite and I scrolled past it.

Chaseincats has a good point. It looks like an incorrect master cylinder push-rod or adjustment. If it has the correct push-rod it should be adjusted according to fsm. See attachment.

.

Screenshot_20190626-082252.png

Oh that's awesome! Thanks so much for that I'll be sure to try it out and let you all know how it goes! Now on the original topic of this thread I've been running some more tests now that the trans is back in and today I pulled the return line off the fuel rail and ran the car with the fuel pump on and plenty of fuel was coming out of the return line but the car was still smoking and running really rich like it had before. I turned the pump off and sure enough fuel stopped coming out of the rail but the idle cleared right up and it started running great which I still wish I could explain. Since I've replaced the AFM, fuel injectors, fuel pressure regulator, and tried tuning the air-fuel mixture with the screw on the back of the AFM, and ruled out the possibility of a return line clog, how else can I adjust the air-fuel mixture to make it run right? Could this be a problem with my ECM? I didn't think that controlled the ratio but I could be wrong. Thanks to everyone who has replied to my posts you're all awesome I love this community!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.