'81 Tune-up question

Reply Subscribe

Thread Tools

Search this Thread

Apr 30, 2002 | 08:57 AM

rmadlem

Thread Starter

Burning Brakes

Joined: Jun 2001

Posts: 1,166

Likes: 0

From: Beautiful Grand Rapids MI

'81 Tune-up question

Just got it out of storage and she seems to be running a little rich. Are there any good articles out there that will walk an average wannabe mechanic through the steps of timing adjustment and fuel mixture adjustments?
'81 stock with a Rochester carb.

Thanks for any help !! :confused:

Apr 30, 2002 | 11:07 AM

81VETTOM

Pro

Joined: Dec 2001

Posts: 582

Likes: 72

From: Near Raleigh NC

Re: '81 Tune-up question (rmadlem)

I'd suggest you get a shop manual, saw one in parts for sale other day. Also, if you're using stock plugs, I converted to Rapid-Fires and added a K&N air filter. Runs a lot better. If your running rich there are a number of things that it can be. I'd suggest driving it some, (get a shop manual) to get back in shape and them start :smash:
:cheers:

[Modified by 81VETTOM, 10:08 AM 4/30/2002]

Apr 30, 2002 | 11:35 AM

stickboy

Safety Car

Joined: Jul 2001

Posts: 3,921

Likes: 2

From: York PA

Re: '81 Tune-up question (rmadlem)

If it was running fine before you put it away then it probably just need a rebuild. Do a search about rebuilding the electronic carb in the '81 vette (rochester E4ME) there have been a few topics in the last month. Make sure that the choke opens fully in about 3.5 minutes and make sure that the check engine light comes on with the ignition on but the engine stopped. :cheers:

Apr 30, 2002 | 11:53 AM

Gator81

Melting Slicks

Joined: Jan 2000

Posts: 2,386

Likes: 3

From: far, far away

Re: '81 Tune-up question (rmadlem)

Pick up Doug Roe's book, "Rochester Carburetors", at your local auto parts store. Got mine at Pep Boys. There's all you need to know about tuning that carb on your car, including a section specific to the electronic Q-jet, the E4ME.
Good luck! :seeya

Apr 30, 2002 | 01:30 PM

Dalannex

Safety Car

Joined: Mar 2000

Posts: 4,077

Likes: 27

From: Northeast South Dakota

Re: '81 Tune-up question (Gator81)

I would say to first look into it a little deeper to see what has changed that made it run rich all of a sudden. I agree that you should probably take it out and drive it a good bit to see if that helps. A lot of times cars don't like storage.

Apr 30, 2002 | 01:44 PM

UKPaul

Safety Car

Joined: May 2001

Posts: 3,758

Likes: 3

From: Surrey

Re: '81 Tune-up question (Gator81)

This might (will) sound a bit obvious, but try changing the air filter. I know so many people (me included) that have been caught out by a dirty filter & consequently tore into the carb/engine/wallet. This very thing happened 2 weeks ago, in that an engine that had been layed up for the winter was running rich. As the guy had been driving around all last summer with the filter getting slowly clogged, he didn't notice the drop off in performance b4 putting it away for the winter.
Another simple thing to check for is varnish/crud in the carb from the fuel drying up. Sometimes just running a couple of tankfuls of gas will cure that.
Another simple thing to check is the fuel - are you using the old fuel that was in the tank. Modern gas goes "off" (been told that the shelf life of UK unleaded petrol is 6 weeks - don't know how true that is, but it definately goes bad over the winter & makes engines hard to start & run with poor performance).
Try the simple stuff 1st b4 suspecting something more serious (I've even had a new spark plug die in my daily driver within 1000 miles!).
:cheers:

Apr 30, 2002 | 05:32 PM

Gator81

Melting Slicks

Joined: Jan 2000

Posts: 2,386

Likes: 3

From: far, far away

Re: '81 Tune-up question (UKPaul)

Oh, yeah, that reminds me of a question you asked me awhile back, Paul. I put that fuel preservative, "StaBil", in my full fuel tank last fall before I put the little 'glass darling under her blanket for a winter's nap. You wanted to know how well it worked. Well, over the winter I went out and fired her up every 3 or 4 weeks, and let it run until full warm, about 30 minutes or so. Always started easy, no changes over the winter. And when I brought her out in the sun back around the first of April, she ran just the same as before her nap, so I would say it worked just fine. So I think I'll be using "StaBil" from now on. :)

Apr 30, 2002 | 09:05 PM

rmadlem

Thread Starter

Burning Brakes

Joined: Jun 2001

Posts: 1,166

Likes: 0

From: Beautiful Grand Rapids MI

Re: '81 Tune-up question (rmadlem)

Thanks for the tips everyone. I did put fuel stabilizer in it when I stored it last October; and it has a K&N air filter which I need to check for cleaning. I think I'll give it awhile and "blow some crud" out of it before I get too worried or tear into anything that I could just make worse !! :smash: But hey, I did change the radiator last year with success !! :cheers:
I think I will pick up the Rochester Carb book though, if nothing else just to read about what I have !!
Thanks again guys.
Rick :seeya