Topic: Hesitation at 45mph

[dwtaylorpdx]

I've dropped the tank on my YJ several times, its like a 20 to 30 minute job... Not that big of a deal really.
Unless you have to do it with the tank FULL 

4 bolts for the skid plate,
lower slightly with floor jack,
Remove filler and vent hose, 2 hose clamps.
Lower more unhook hoses for breathers for vapor cap system.
Unhook fuel lines and wiring harness, its on the ground.

Dave

[bluebomber]

From what I've read and also in my Haynes manual there is no external filter.  Some engineer decided that Chrysler could make more money by forcing people to go to the dealership to get a filter change.  It's the same thing on my '97 Grande Cherokee.  Luckily I was able to find a friend with a lift that changed the filter on the cherokee for nothing, I've heard horror stories about paying upwards of $500.00 to do this.

I pulled the Bosch plugs last night but I have no idea of how to set the gap on them.  I also noticed that sometimes there are two separate gap designations for plugs.  One would be dealer recommended and the other would be manufacturer recommended.  Some food for though when you gap your plugs to make sure you are using the correct one for the plug you are using.

I'm going to contact the dealership to find out what dealership cost would be on a new set of plugs/wires/cap/and rotor.  I might just bite the bullet and go with that to eliminate any possibilities.  I can then save the aftermarket parts for the next tune-up if this doesn't solve it.  I plan on keeping this Jeep as a toy for the next 10 to 20 years.

I believe you need to relieve the fuel pressure using the schraeder valve to change the pump.  Does anyone know if you need to do this just to change the filter/regulator?

[sharpxmen]

I believe you need to relieve the fuel pressure using the schraeder valve to change the pump.  Does anyone know if you need to do this just to change the filter/regulator?

yes. i dunno if you have one though, in case you dont remove the fuel pump relay and start it like that, crank it a few times after it stops also - that should clear the pressure enough. Just so you don't get fuel in your eyes i would also remove the fuel line at the rail with a rag around it to make sure there is no remaining pressure in the rail.

[dwtaylorpdx]

I have used the Echlin NAPA cap and rotor for years on my YJ, Brass instead of AL and they have never let me down.

I tried Bosche Platinum plugs and went back to Autolite. The jeep does not idle worth a hoot for me with the Bosche.

I have also found that if I buy off teh shelf wires, I get about 1 to 1.5 years at best out of them. Usually the #1 plug
wire is shot by then, or I've torn it up changing spark plugs.

Dave

[Jeffy]

so you need to drop the tank for that then? unless there's another way to do it that's a pretty stupid setup, i like the YJ fuel system better - not to mention the no schraeder valve on the fuel rail either. I wonder why they didn't put a access cover in the tub i that case.

Nope, to check fuel line pressure you need a tool.  It's just two connectors with some hose then a block with a schraeder valve on it.  All the Jeeps after the YJ have the combination Fuel Pressure Regulator/Filter.  It's supposed to be a no maintenance item. You have two choices, drop the tank or cut a hole in the floor.

[sharpxmen]

Nope, to check fuel line pressure you need a tool.  It's just two connectors with some hose then a block with a schraeder valve on it.  All the Jeeps after the YJ have the combination Fuel Pressure Regulator/Filter.  It's supposed to be a no maintenance item. You have two choices, drop the tank or cut a hole in the floor.

i was asking if you need to drop the tank to change the filter - i think i can figure out you can check the fuel pressure w/o dropping the tank 

[bluebomber]

Hey jeffy, that's not a bad write-up.  "How to install a fuel pump hatch on TJ Wrangler."  I like it, if I get the chance this summer and decide to modify I'll take pictures.  I know there are other vehicles out there that use some type of hatch.  My '49 Chevy had a homebrew hatch in the drivers side floor to get to the old style master cylinder reservoir.  That's when they put the reservoir down on the frame rail.  I think the major consideration would be sealing the hatch to make it air tight.  This way you wouldn't get exhaust fumes or fuel vapors inside the Jeep.

anybody know where I can get a Schraeder valve to make a pressure gauge with a 6 foot hose?  I think my brother said that they have them on the AC recharge kit hoses.

[sharpxmen]

anybody know where I can get a Schraeder valve to make a pressure gauge with a 6 foot hose?  I think my brother said that they have them on the AC recharge kit hoses.

you need an adapter that goes on the fuel line on the rail - i think it's a specialized tool or dealer item. you can make something yourself but i'll stay away from making suggestions on ghetto solutions - have a look at it, you can figure it out what you can do there but unless you will buy the propper fittings it will involve a permanent change. You don't need a schraeder valve if you make your own since once you're done measuring you can remove the gauge with the fitting and all.

[dwtaylorpdx]

I'd likely get rid of the tank filter, and put the prior model YJ filter along the frame rail...
The first time I had to do it...

Dave

[bluebomber]

And the test results are...    ....drum roll please...   .... the fuel pressure was approx. 48 to 49 psi.  We checked it at idle and then I put my foot on the brake, put her in drive, and ran it up to 3k on the rpms and no change.  We lost maybe, and I say maybe because the gauge was in increments of 2, one pound after 5 minutes from shutting of the engine.  I would consider that pretty good.  I also put my spark tester on each plug wire and watched the strobe.  I noticed an erratic spark on plugs 2 and 4.  I shut all the lights off in the garage at night and started the engine.  I noticed a very small amount of spark grounding coming from the coil wire and #4.  I put new wires on the coil and #'s 4 and 3, that's all I had time for, and we took it for a spin.  It had plenty of power for a 4 cylinder, no missing, but I'm still having issues with the lockup solenoid when the transmission goes from drive to lockup.  It bucks a little bit until I can get past 45 mph.  I'm going to throw new wires on #2 and #1 cylinder this weekend and cover all the wires with some looming material for protection.  I'm also going to call a tranny shop to see if the lockup solenoid can be  tested and replaced without dropping the tranny.  I'll drive it for a couple weeks to see if the lockup solenoid issue gets any worse.  If it does and I can't easily fix it I'm going to either throw a switch in to keep the solenoid from locking up unless I'm on the highway or I'll just disconnect it all together.  What do you guys think about these ideas?

[sharpxmen]

And the test results are...    ....drum roll please...   .... the fuel pressure was approx. 48 to 49 psi.  We checked it at idle and then I put my foot on the brake, put her in drive, and ran it up to 3k on the rpms and no change.  We lost maybe, and I say maybe because the gauge was in increments of 2, one pound after 5 minutes from shutting of the engine.  I would consider that pretty good.  I also put my spark tester on each plug wire and watched the strobe.  I noticed an erratic spark on plugs 2 and 4.  I shut all the lights off in the garage at night and started the engine.  I noticed a very small amount of spark grounding coming from the coil wire and #4.  I put new wires on the coil and #'s 4 and 3, that's all I had time for, and we took it for a spin.  It had plenty of power for a 4 cylinder, no missing, but I'm still having issues with the lockup solenoid when the transmission goes from drive to lockup.  It bucks a little bit until I can get past 45 mph.  I'm going to throw new wires on #2 and #1 cylinder this weekend and cover all the wires with some looming material for protection.  I'm also going to call a tranny shop to see if the lockup solenoid can be  tested and replaced without dropping the tranny.  I'll drive it for a couple weeks to see if the lockup solenoid issue gets any worse.  If it does and I can't easily fix it I'm going to either throw a switch in to keep the solenoid from locking up unless I'm on the highway or I'll just disconnect it all together.  What do you guys think about these ideas?

how did you end up hooking the pressure gauge?

so the shop that measured it the first time must've had a faulty gauge i guess.

[bluebomber]

The gauge my brother had was designed for Schrader valves.  We hooked it diredtly to the fuel rail.  We de-pressurized the fuel line and hooked the gauge up.  We only had about 1 foot of hose to work with so we couldn't actually drive the vehicle and check the pressure under load.  That's why I put the vehicle in drive with my foot on the break and ran it up to 3k on the rpms.  He watched the gauge as I was working the gas pedal.  No change in fuel pressure.  I think that the hesitation I was getting was from the pinhole grounding of the wires on the coil and #4 cylinder.  I can't understand why the lockup solenoid decided to start acting up after the motor change.  I was tempted to use some of the Lucas brand additive in the transmission but I've heard good and bad stories so I'm hesitant to try it.  I don't even know if it's compatible with the Dexron 4 used in the tranny.