Refusing to go over 65mph - Page 3 - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > Refusing to go over 65mph

FS: Jeep Fog Light LED Bulbs! Several Brightness Options! Clayton Off Road JK Short Arm Suspension Kits~Artec JK 1 TON SWAP~

Reply
Unread 07-29-2013, 12:33 PM   #31
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 4,663
Are you sure?
I just did a search for the part at two parts places and quadratec and none had a knock sensor for a 4.2.
I'll check my shop manual when I get home. But I highly doubt that the 89 or 90 computer was sophisticated enough to retard the spark because of knock.

vadslram is offline   Reply With Quote
Unread 07-29-2013, 01:28 PM   #32
dancytron
Registered User
1990 YJ Wrangler 
 
Join Date: Jun 2008
Location: st. louis
Posts: 1,273
http://home.sprynet.com/~dale02/knock.htm

That's one of the big changes when you do the Nutter. Stock with the computer, the timing is set really high and it relies on the knock sensor to tell the computer to retard the timing when it knocks.
dancytron is offline   Reply With Quote
Unread 07-29-2013, 03:33 PM   #33
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 4,663
Well I stand corrected. It is pin out #51. I guess I just assumed it was a temp sensor...I guess I need to get a pipe plug because that's one more thing coming out from under my hood.

Best thing my PO did was give me the shop manuals!!
yj-wiring.jpg  
vadslram is offline   Reply With Quote
Unread 07-30-2013, 08:54 PM   #34
whiskeywiz
Heineken?
1989 YJ Wrangler 
 
Join Date: Mar 2012
Location: Buffalo, ny
Posts: 1,047
that's not a Haynes manual. Looks nice. What is it?

Well I got a carb rebuild kit for a 77 Plymouth Volare which is what came with a Holley 2280, (which is as I said what somehow made itself onto my rig). Got home with the kit got to the first gasket and realized I had the wrong kit. Took it back to Autozone, got refund. Called Napa. After cross referencing a couple shop manuals, the guy said that the kit is obsolete. Well isn't that just wonderful.

So while putting my antique carb back together I noticed a stopper thingy next to a spring loaded plunger thingy. The stopper was in a stuck position. I freed it up with some carb cleaner and compressed air. Put er back together and its running like a raped ape again. Now if you recall, (I think it was this thread) it ran like that after I shot some carb cleaner down the barrel, but then after a day it went back to falling on its face when I gave it too much gas. As if I knocked some crud loose and it got re-stuck.

Did freeing up the stopper thingy solve my issue for good? (for a while anyway, until I get rid of that carb?)...
whiskeywiz is offline   Reply With Quote
Unread 07-31-2013, 06:29 AM   #35
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 4,663
It isn't a Haynes. It's the DC Jeep Shop manual,a 2 volume set one for engine and body the other is all electrical.

The stopper thingy sounds like the power valve. The plunger thingy is most definitely the accelerater pump.

You can google "holley power valve how it works" but here is a quick clip on it's operation

Quote:
A Power Valve is little more than a vacuum operated on/off switch for fuel. It operates using a vacuum diaghram and a spring, which determines when the valve opens. I believe this is best explained using an example. Let's use an engine that makes 13" manifold vacuum at idle, a typical lightly modified performer. Knowing that value, we know that a 6.5" rated power valve would be used (typical power valve selection is 1/2 the amount of vacuum at idle, in our case 13/2=6.5). So, during idle and light cruising (above 6.5" vacuum) the power valve will be in the closed position ("off"), but during moderate to full throttle operation the vacuum will drop to below 6.5" and will cause the valve to be open ("on"). The power valve itself doesn't control the amount of fuel delivered, that's the PVCR's job.
vadslram is offline   Reply With Quote
Unread 07-31-2013, 07:14 AM   #36
whiskeywiz
Heineken?
1989 YJ Wrangler 
 
Join Date: Mar 2012
Location: Buffalo, ny
Posts: 1,047
The part i am speaking of is number 25 in the diagram in the link below. Cannot find one with explanation yet, (on my phone at work).

http://www.carburetorfactory.com/images/expvw16.jpg
whiskeywiz is offline   Reply With Quote
Unread 07-31-2013, 11:12 AM   #37
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 4,663
Well #30 is the accelerator pump and from what I could find #25 is the power enrichment valve.
I came across a couple of 2280 rebuild videos on youtube, but youtube is blocked where I am now so I couldn't look.
vadslram is offline   Reply With Quote
Unread 07-31-2013, 11:38 AM   #38
vadslram
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2006
Location: VA Beach
Posts: 4,663
Here is a link showing how to adjust that power valve
http://www.autozone.com/autozone/rep...00c1528007fc69
vadslram is offline   Reply With Quote
Unread 07-31-2013, 09:01 PM   #39
vcallen7
Registered User
1989 YJ Wrangler 
 
Join Date: Jul 2013
Location: Grant, Alabama
Posts: 23
I can get my YJ to sometimes do 70... downhill with a tail wind. I thought that was just the way it was. Guess I was wrong.
vcallen7 is offline   Reply With Quote
Unread 07-31-2013, 09:19 PM   #40
whiskeywiz
Heineken?
1989 YJ Wrangler 
 
Join Date: Mar 2012
Location: Buffalo, ny
Posts: 1,047
got er to cruise on the highway good. No bucking at 65mph. Spidey senses tingly though. Stopper thingy could bust loose at any moment. Just get me and the wife to the Hip show and back on Fri...
whiskeywiz is offline   Reply With Quote
Unread 07-31-2013, 09:23 PM   #41
whiskeywiz
Heineken?
1989 YJ Wrangler 
 
Join Date: Mar 2012
Location: Buffalo, ny
Posts: 1,047
putting that carb on antiques roadshow after replacement arrives
whiskeywiz is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.