Bad spark plug wire???

[maxfax]

Well, not quite, but that's what it feels like.. I feel it when cruising at a constant speed usually from about 45mph to 65mph.. More noticeable when hitting a slight incline..  I don;t want to say it bucks or jerks, not smooth enough to be what I would refer to as a surge, just kinda like a slight misfire when the wires are shot on that Chebby Tree Fiddy.. 

I posted about this years ago, got some good ideas (air leaks, fuel filter, fuel quality, injectors, timing, compression, cv's etc), But never really got to the bottom of it in the last almost 200K miles.. Injectors have been replaced/rebuilt twice, pump was resealed and gov mod done..  Clutch, CV's, and trans have been changed in this time..  At one point the shut off solenoid started leaking fuel around the stud so it got replaced.

The kicker is, it comes and goes..  Weather makes no difference.. Fuel makes no difference..  It can go a month and be fine, or it may to it every other day, or every day for weeks..  I think the issue was slightly worse and more consistent when the shut off was leaking.. But I can't say that for 100% sure..

I've been thinking pump issue for the longest time..  This is on the "crack" engine..  I wasn't going to bother investing anything more into this engine (I think I said that a few $$$ ago though) as it's not intolerable..  But since I blew the budget on a building another friggen 1.6 NA (I think I coulda bought an AAZ for what I have in that wreck) I was considering reusing this pump for now..

Thoughts, ideas, recommendations, donations?

[mystery3]

But since I blew the budget on a building another friggen 1.6 NA (I think I coulda bought an AAZ for what I have in that wreck)

I know the feeling exactly.

As to your issue I would think it's probably pump related but perhaps you're getting intermittent air in a fuel line?

[truckinwagen]

As to your issue I would think it's probably pump related but perhaps you're getting intermittent air in a fuel line?

I think this would be it too, I have been noticing it in my car too, seems to go away with the lift pump.

do you have a lift pump on it?

-Owen

[maxfax]

I've run with and without a lift pump..  Doesn't seem to make a difference..   Tank has been removed and cleaned, new lines (both rubber and steel) front to back on inlet and return.. Tried another filter housing for the heck of it..  I wish I could rig a couple gallon jug under the hood and drive it say 100 miles off that..  But then again that could be one of it's well behaved 100 miles..

When I had the pump apart for the reseal there didn't seem to be any obvious issues with the lift pump and governor..  I have no ideas about the mileage on this thing, could be that the head is just getting worn.. But I'd think it would be not so intermittent..  

First time I replaced injectors I bought new ones from a less than reputable seller.. The engine did run smoother/better overall other than the plug wire thing..    Second trip I had the originals rebuilt and even watched them being tested.. Those injectors didn't act much different, so I guess that says something for the China injectors, at least that batch...

Overall I've never had a problem with starting, economy, or power..  I know I'm not crazy, well totally crazy, as I've had a few other people take it a spin with no knowledge of what they were looking for..

[rs899]

I had a similar issue with the Jetta that I reconstructed.  I decided to rebuild an older IP I had lying around and when I swapped that in, the problem went away.  I haven't dissected the "problem" pump, so I can't say what was wrong, but the car had been sitting for several years.

[maxfax]

The pump is the only thing left in the equation I suppose..  I have some others that I may try resealing and see what happens.. At worst this pump is at the least useable...

Thinking about it, this pump has over a half million miles, and has only ever had seals and a bushing.. And, when I bought this car it did sit about 2 years till I did something with it...

[Smokey Eddy]

i ve had a similar thing happen and it was from the wire going to the fuel shut off being frayed/burnt/corroded inside the plastic sheathing.
replace that power wire to the pimp as close to the dash as you can get. AT LEAST change where the wire moves any amount.

[maxfax]

Ed, has anyone told you that you are BRILLIANT lately???  

I read your post before I left for home last night, took one of my jumper wires with..  Sure enough it was misbehaving, so I pulled off and hooked that bugger right to the battery.. It was fine the rest of the way home, and back to here..

And now things are making a whole lot of sense..  No so long after I started running this car the wire to the IP rubbed, shorted, smoked, and got cussed at... I replaced the worst part of the wire, but never the whole thing as I planned to get around to it later...    And I'd say that pretty much when this started..

I'm wondering if it may also be wise to replace the ignition switch while I'm at it.. I dunno if it's ever been changed, but this chassis is probably pushing 600K - 700K miles..

Thanks again Ed!!  Something so simple I never gave it a thought!

[the caveman]

I was going to suggest looking at the rotor and distributor cap.....maybe even the spark plugs.....................................

[maxfax]

I was going to suggest looking at the rotor and distributor cap.....maybe even the spark plugs.....................................

I was suspecting the points and condenser myself.....

[macka]

I was going to suggest looking at the rotor and distributor cap.....maybe even the spark plugs.....................................

I was suspecting the points and condenser myself.....

points are set at .020" FYI

[truckinwagen]

I like that idea!

I may go and replace as much of the shutoff wire on mine too, someone put one of those "quick splices" in that wire to switch some stuff under the hood, probably not doing it any good...

-Owen

[maxfax]

Couldn't hurt..   I sure as heck never even gave it a thought.. I have about 3 crimp connections where I doctored the wire "temporarily"  ..  No clue what it looks like under the dash... IT probably isn;t good after the short...

  I was thinking about putting a relay on it while I'm at it..  I suppose it isn't that high of a load, but I like relays.. I have a new ignition switch on the way too...  Can't hurt I guess..

[rs899]

I had a similar issue with the Jetta that I reconstructed.  I decided to rebuild an older IP I had lying around and when I swapped that in, the problem went away.  I haven't dissected the "problem" pump, so I can't say what was wrong, but the car had been sitting for several years.

Come to think of it, when I rebuilt the pump, I crimped on a new lug on the shutoff.  I wonder if that's all it was....oh well, good experience anyway rebuilding the IP....

[R.O.R-2.0]

this problem has happened to me so many times i didnt even think to say something about it..