Thaddeus

I replaced my MAF tonight in my 86.

When I first started the car, it ran like CRAP. It has been sitting idle for a week, though, and it has been very very damp around here. I thought I'd messed something up, although I've had the MAF off a couple of times before for matters unrelated to replacement.

Then the engine settled down.

I went and started it up again 2 hours later, after it had cooled almost to cold. It started immediately and purred.

The idle seems smoother than before the replacement. I used to have a slight lope. Now it's rock steady at 800 rpms by the tach. And the exhaust does not smell of gasoline, at all. Before, it did, faintly.

Does this accord with how other people's experiences have been? Could my computer have "learned" settings to compensate for a marginal MAF, and then "learned" new setttings for the new one? Would the learning cycle account for the initial misbehavior?

I'll let y'all know how it drives tomorrow. Too wet to throw it around right now.

cheers

Thaddeus

Schocki

Did you disconnect the battery when you replaced the MAF? If not, it was still in Limp-home mode and probably had to learn again that your MAF is alive again.

But John Speake can probably tell you more about it....

hlj821

I just replaced the MAFon my 86, one thing that I noticed is the itle was a lot smoother at first, but after about 3 weeks of hard driving, the car really came alive, very rev happy and plenty of power.

Garth S

We had a similar experience with Jeffs '89: Surging idle, randomly jumping up to 1500rpm - tough in an auto ... .
We swapped MAF units, and his car purred - my '88 wouldn't run ... Eventually, we got a 'new' MAF in his car, and it fired right up; however, there was a period of learning, maybe an hour: after that, everything was smooooth....

Alan

Thaddeus,
Just changed my MAF yesterday for a rebuilt/reconditioned unit from John Speake - it was an easy change (except the FWM says MAF lifts out with Airbox bottom - yeah right... TUG TUG!)

Anyway nice improvement after the battery discoonnect - started up fine - no issues. Previously my idle was always fast (900) - more so (1.1K!) when hot, also harder to restart when hot. Car would run lean under heavy acceleration (V. Bad) and stumbled sometime at low rpm taking off. Car is now rock steady idle @ approx 650 and steady when hot too. No more pre-ignition and fells generaly smoother. I did not really have any power issues so can't say I improved performance (except of course I don't have to back off under hard acceleration anymore).

Nice, fairly quick/easy ~inexpensive fix to a long term nagging issue

Alan

John Speake

Hi Thaddeus,
Yes, the O2 loop wouild have adapted to some extent for the aged MAF. This would explain what you experienced on start up.

You should have done a battery reset, as Schocki said, then you would start again to the default settings which would then match the new MAF.

Regards

Thaddeus

I took that bad boy out today and drove it SILLY.

Smooth as buttah! Smoother idle, power seems more linear. It was running really well before... Now it feels GREAT. The engine now has the 'Thaddeus Stamp of Approval"... a hard stamp to garner because I am a compulsive freak.

Of my huge list of To-Do's I compiled when I bought the car one year and one week ago, only these items remain:

(1) Change transmission fluid
(2) Replace leaky steering rack
(3) replace motor mounts
(4) Align car
(5) Cosmetic interior crap.

(In best Napoleon Dynamite voice): "Lucky!"

UKKid35

Over three years on and I still have the five items on your list to do.

the flyin' scotsman

Thaddeus..........good to hear your results on the new MAF, I'm in the process of doing same with a John Speake refurbed unit.

Re. your list of To-Do's leave the steering rack and MM's 'till winter after which do the alignment. Interior can be cleaned on a rainy day so change the tranny oil and have a great driving summer.

Thaddeus

The only time the PS rack leaks is when the steering is at full lock and the wheels are way up or down. So I 'sect I can leave it for awhile...

As far as MM go, I have the speed mount in there, so it's not critical (yet).

But I may get it all done in the next few weeks just so I can clear the boards before the inevitable growth of the To-do list... LOL