Truck has a jolting symptom while driving?

[Hiroler]

I'm following this thread.  I had only a shudder or two before a hose fell off my fuel pump (1988).  Now with a new fuel pump/filter etc it's gotten worse.

 

Any chance you're near me (20904) in MD and we can go through the pain together?  I am leaning towards an electrical issue on mine.

[cruiser54]

I'm following this thread.  I had only a shudder or two before a hose fell off my fuel pump (1988).  Now with a new fuel pump/filter etc it's gotten worse.

 

Any chance you're near me (20904) in MD and we can go through the pain together?  I am leaning towards an electrical issue on mine.

Of my Tips, how many have you completed? 

[omega_rugal]

wait, the MAP sensor must be connected to the throttle body vacuum? i have it directly to the manifold...

[cruiser54]

wait, the MAP sensor must be connected to the throttle body vacuum? i have it directly to the manifold...

That's fine.

 

Is the hole in the throttle body where it used to go plugged? 

 

 

Also, see post 27........

[Hiroler]

I'm waiting to borrow a fuel gauge but I expect there to be an injector issue since wiggling the #2 injector wire bogs the engine down.  I checked all the easy things like MAP which previously gave me issues until I made a vacuum line T into the manifold.  IAC is clean and CPS is new. I am a bit curious about that camstaft sensor in the distributor, since it runs like it has a heavy cam. 

 

Truck has 312k miles and one foot in the grave.  It's got vacuum leaks and a broken exhaust manifold bolt but besides high idle the truck has run great for 3.5 years.  My issue seems directly related to the fuel pump incident and I will say that the new fuel pump is loud too.

[Hippie66]

Very possibly plugged injector. If you still have stock ones, good excuse to upgrade.

[FLETCH14519]

I can wiggle this piece on top the manifold. Should this have any movement or be completely sealed and no movement

 

[Hippie66]

That's the valve cover, not manifold. It will move.

[FLETCH14519]

That's the valve cover, not manifold. It will move.

Valve cover, my mistake. Thanks...just throwing questions out there as I go through cruisers tips

[omega_rugal]

That's fine.

 

Is the hole in the throttle body where it used to go plugged? 

 

Also, see post 27........

 

 

it is...

[rocketwheels]

I had the jolting issue, too. Mine turned out to be the distributor, the hold down ear was cracked, letting the dizzy rotate slightly ... mine would idle fine and also hammer down just fine....my bucking was intermittant and only happened while trying to hold a constant speed on the highway...eventually got so bad truck was undrivable, found the broke ear while changing the injectors and plugs, caps and wires.

 

Just another place to look.

[Hippie66]

Just for grins, with the engine idling, try moving the wiring to the ecu. The weight of the harness can pull down and crack the circuit board over time, can cause cutting out. As it gets worse, a no start condition can occur.

[cruiser54]

I had the jolting issue, too. Mine turned out to be the distributor, the hold down ear was cracked, letting the dizzy rotate slightly ... mine would idle fine and also hammer down just fine....my bucking was intermittant and only happened while trying to hold a constant speed on the highway...eventually got so bad truck was undrivable, found the broke ear while changing the injectors and plugs, caps and wires.

 

Just another place to look.

Yep. Always a good idea to index the distributor. 

 

http://cruiser54.com/?p=68

[FLETCH14519]

Off the wall question,is it possible the jolting could be a torque converter? The jolting seems to go away when I apply the breaks a little while going about 70-75mph. Just throwing it out there

[HOrnbrod]

Nice to know you have an auto. Yes, "jolting" can be caused by a bad AW4 solenoid #3 (torque converter lockup) that can cause the TC to engage/disengage under certain conditions like coasting. It can also be caused by a maladjusted throttle valve (TV) cable. Try adjusting it:

 

http://www.allpar.com/SUVs/jeep/cherokee-transmission.html

[FLETCH14519]

I happened to find this today, this went to the EGR valve that has the plug in the line.@Cruiser54

 

[cruiser54]

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Shouldn't really cause an issue. I'd be looking at dizzy indexing.