Hesitating C1500 Only at Highway Speeds and Under Load

[jeff's88silverado]

symptoms still sound normal like on the vortec's. You said it wouldn't do it this morning. I have a 98 blazer in the yard right now same thing the miss would come on go as it pleased and no jump in rpms until it got really bad at the end.

And the clunk your hearing in your drive train could be from the miss since when you have a miss you make no power during that part of the rotation but as soon as the next cylinder fires its like you get another boost of power so the strain from no power on one cylinder to power on the next can cause a clunk if the miss is bad enough and especially if your u joints have some play

EDIT: Im not good at typing what im thinking so i hope that makes some since. lol

EDIT 2: Also if you dont want to pull your dist. at first then check your timing and see if its off

 

[jeff's88silverado]

Its not the best pic but i did dig it out of the trash.

Anyways if you look at the gear closey you can see the shiney part of the gear well thats the wear that causes problems in vortecs and is very well possible with any distributor

You must be registered for see images attach

 

[Gatorboy]

If I remove the distributor will I have to do the timing again?

 

[jeff's88silverado]

if you mark it and put it back exactly then no. But its so simple to check timing i'd just recheck it after i pulled the distributor

 

[Gatorboy]

How do you do the timing on these motors? I heard you don't need a light or anything.

 

[jeff's88silverado]

you do need a timing light.

Lets see if its the 95 in your signature unplug the brown wire under your glove box then set base timing with light

If its the 89 pull the black cover off the firewall left of center and the brown wire is there then crank and set base timing

 

[Gatorboy]

Alright I've got to dig out my ancient craftsman light lol

 

[jeff's88silverado]

update?

 

[Gatorboy]

I had to order a different light, mine finally broke. So I should get a chance to pull it by at least Sunday, maybe earlier. Found another old, unused, Craftsman light on ebay (I love them). Just waiting on delivery. How the heck did you reach the bolt for the retainer for the distributor? Did you use a wobble extension?

 

[jeff's88silverado]

believe it was 9/16 but a regular open end wrench is what i used


EDIT: but if you have a ratchet wrench with a pivot head would be the best