Chevy & GMC Vans

All,
I've had problems w/ my van for a while now, but lately it's been getting a lot worse.
It used to shift poorly, so I thought I had a tranny problem, but now it looks more engine related.
When accelerating, particularly under light throttle, the engine misses badly and has a hard time shifting. I've noticed recently that it seems to be worse in the wet. Last week when it was -5 and super dry, it ran perfect. Now it's 30 and freezing fog and it runs like shit.
I did a tune-up a while back, and I think I'll start there again after reading the board.
I read the thread on caps, and I used a NAPA/Echlin one last time. I don't think I changed the wires due to $$. Plugs were AC Delco. Gotta say, the 2" lift really makes plug changes a breeze!
Before I drop a coupla' bills on a tune-up, any recommends on Cap/Wires/Plugs?

Anything else I should look at?

2months ago, I towed one of my SAABs from Boise, to Seattle and it ran perfect. Then we headed over to the Olympic Nat. Park. As soon as we got over to the coast it started to miss a bit. I blamed it on the local gas.

Any and all help appreciated!

john

How long ago on the cap change? I've heard tale that the napa caps are not as good as stock. Jim

Welcome to the site, John. Most of the guys here recommend using the stock AC Delco parts. And I agree to some extent. I've used Standard Motor Products Ignition parts for thirty some years and have never had a failure. That kind of quality speaks for itself. Any high end spark plug wires will work. Another problem area is the coil. An easy check is to remove the engine cover at night and watch for electrical components arcing.

Only 6K miles since plugs, cap and rotor. It's been foggy the last few nights so I'll take the cover off tomorrow and try it tomorrow night. This problem is driving me crazy! I was starting to think it could be the FI as well.
I'll start shopping for new wires tomorrow.
I've had good luck with Standard in the past, but some cars are more finicky about ignition parts than others...


john

Great A'Tuin wrote:I've had good luck with Standard in the past, but some cars are more finicky about ignition parts than others...

These vans are finicky, I strongly believe in using AC Delco ignition parts, and also fuel pumps. 96 and up vans have bad design for a distributor cap makes it very easy to have cross arcing. The older vans don't seem to mind as much what cap you put on. I have used Standard many times on alot of vehicles and have not had a problem. I'm not bashing them. When I can buy AC Delco parts for the same price or less why wouldn't I. I work at a dealer get them at cost...

Great A'Tuin wrote:Anything else I should look at?

before you go dropping anymore coin grab some q-tips and sensor safe tb cleaner (something that doesn't leave a residue)

remove and take apart your MAF and clean it up .. specifically the 3 small wires that are hair thin. they get very dirty on the side that you can't see without taking it apart.

only takes 20 min or so start to finish ....

for more details... check my thread viewtopic.php?f=4&t=5013

Well, near as I can tell, it was the plug wires.
I replaced the cap, rotor and wires and cleaned the AMM.
The AMM was already pretty tidy, but what could it hurt?
The cap pins were heavily corroded and carboned. There was evident arcing on the inside. At only 8K miles.
The rotor was OK.
The WIRES! Holy crap. Near as I can tell, they were the originals. The #6 plug connector came apart as I tugged it. Another was loose and arcing. Nasty.

The van now runs almost perfect and shifts great. I drove it around all morning and not a single hiccup.



john