defdes wrote:Okay so one more thing. On start up it was rough running again, I held it at 3K and put in the clutch, it smoothed out. I am pretty sure that one (or all) of the bearings in the gear box are shot as when I sit at a red light in neutral, I get that box of rocks grumbling from the trans and when the clutch goes in it goes away. Do you think the two are related?
It seems kinda odd that it's putting enough load on the engine to make it run rough at 3k! It seems if there is that big of a load because of a bad tranny if the hood was popped you would see the engine flex when releasing the clutch in neural. Did you every try pulling plug wires while it was running bad just to see? If the problem is only sometimes I can't really imagine it being a bad tranny, it seems like the load would always be there. But then again it's odd that when the clutch is depressed the engine runs better. Is your clutch switch hooked up? Maybe something is back feeding.... I'm a wiring guy.... It's always got to be the wires
"People don't like it when shit doesn't match their rule of thumb." Sam
Clutch switch is the other sender behind the reverse light sender? Then no it's not, what is it, and what does it do, and do I need it?
I didn't pull a plug wire while running, only because it cured itself when depressing the clutch.
defdes wrote:Clutch switch is the other sender behind the reverse light sender? Then no it's not, what is it, and what does it do, and do I need it?
I didn't pull a plug wire while running, only because it cured itself when depressing the clutch.
No I was thinking of the one under the dash on the actual clutch pedal assembly. Just out of curiosity how did you wiring in your crank fire ignition?
Does it feel like there is a lot of load on the engine when the clutch is released?
"People don't like it when shit doesn't match their rule of thumb." Sam
Yes - I agree with Ice house: if it is a tranny issue - I would think you would have symptoms most of the time. The only other thought is a throw out bearing that is not releasing or on the carrier properly. If it were bouncing around on the shaft, and the gets centered when the clutch is depressed and the bearing is on the clutch - alleviating the noise. I don't really know if this is possible, but it is the only bearing in the tranny that should be reacting differently with the clutch pedal depressed.
Something in the circuit with a switch on the clutch also would make sense. Does the situation improve with the engine warm? I would throw it in neutral and pull the plugs as suggested by icehouse as well - just so you can eliminate that as a problem.
Curious stuff - but I'm sure you will figure it out and it will make sense - hope its easy and cheap to fix!
icehouse wrote:
No I was thinking of the one under the dash on the actual clutch pedal assembly. Just out of curiosity how did you wiring in your crank fire ignition?
Does it feel like there is a lot of load on the engine when the clutch is released?
Crank fire is wired per spec...this is a problem that has just come on over the last couple months.
And a big no to your other question. The gear box needs to be gone thru at some point given the loud rumblings, but I'll keep plucking away at it to see if I can isolate it more. Thanks for the suggestions.
Yeah, pretty sure it's the main input shaft bearings, pilot bushing and/or the TO bearing. The whole box needs a rebuild, and I am all in on my race car right now and don't have the time or money to get into it. I am still dd'ing it but gingerly.
Got the box back from the rebuild, new bearings and collars (?)...something that 3rd 4th and 5th had that needed replacing? Can't remember. $300 with a new paint job. When I pulled it, I was missing the trans to motor bolt by the header which I am sure added to the problem i was having mentioned above. I'll have to pull the clutch to replace the input shaft bearing as it looks pretty well chowed.
While I had it out, I took the headers for jet coating. My project is not the best engineered. I have to remove the engine mounts and push it over to get the headers out. They were resting against the steering box, so I heated them up and tapped in a little clearance. You can see where it was pushed against the steering box to the right when it was last bolted to an L16. Also, when I pulled the header out I heard a rattle coming form inside and I had left one of the aluminum splicing collars inside the #1 tube when I was fitting everything up. I cut out a 3" section to remove it. Gonna get everything back in tomorrow in time for the "Nick's" meet on Sunday.
Until yesterday, I have been running my "temporary" exhaust set up.
In order to fit up my headers, I made a 18" slip fit that I fit over my header end and into a slip fit end on my exhaust by the tranny. It leaked pretty miserably resulting in lots of backfire popping on deceleration. Yesterday I had a new slip fit made at an exhaust shop, and had it welded into my system. Wow, what a difference in throttle response and acceleration. At idle, I can still feel/hear a little leak at the slip fit on the header, as well as subsequent popping on decel. I didn't want a flange welded onto the header because I was worried about the flange hanging down and dragging on an already low car. Should I try one of those stepped band clamps on the joint between the two?
Anyone else have this issue, or how did you handle the transition between header and exhaust?
On my SR20 I used the Greddy turbo elbow and cut the 3 bolt flange off, welded a v-band connection there, then a turn under the pan to the flex pipe to another v-band clamp, then thru the rear cross to the muffler. I still get the backfire on decel, but I don't think the design on my exhaust has anything to do with that....it's more the blow-off valve/intake system configuration.....or the fact the ECU has no speed signal input to adjust the air/fuel at certain speeds....other than that....I have no idea....but i don't have any leaks that I can hear.....or see.
