DemonicPupil

So, I took my 87 out to NJ again. I had posted here round about Xmas that I had trouble with sputtering on my way there. I was getting a nasty fuel cut. After 2 weeks of messing with things, replacing parts, and adding grounds, the car ran GREAT and has up until today.

So we get into Jersey and the damn thing starts acting up again like it used to. Go over some nasty bumps and all of a sudden I'm getting HORRIBLE sputtering and at one point, the car cut out completely.

Pop the hood and goof off a bit, and it still doesn't wanna run. I slapped the AFM and car seemed to run good. Get it going again and it gives me hell after hitting another NASTY set of bumps on 130. Sputter it's *** to my fiance's mom's house and park it for a while. Came out later and it didn't want to start. So I go into the engine bay and slap the AFM against the fender and try to situate it on the fender.

Car fires up and I had a 100% smooth ride all the way home.

Question is, should the AFM be grounded against somehting in the engine bay? This is rediculous and erie that going to Jersey is making my car go nuts. Anyone have any ideas on this? I regrounded the injectors/harness and the coils. What other things can I check?

AcidAngel7477

iTrader: (16)

damn that sucks....my 87 has a grounding problem too for some reason when i run it and then shut it off i hear clicking everywere that also drains the batt. witch suck the big one so im going to try to see if its a grounding problem....good luck with the problem, im sure that ill figure it out.....

:AA:

iceblue

maybe the plug was getting bad connection. The door sticking from oil from the PCV. The fuel pump switch in the AFM is out of shape.

iceblue

corroded connections loose connections associated with the starter.

misterstyx69

iTrader: (142)

off chance..when you hit a bump that you are shorting your battery up against your hood?/..Check your hood above the battery for Arc marks ..that would explain the cut out over rough terrain..also check the connections to the engine for the starter.and the battery connections..and the alternator area(especially behind the alternator)..AFM connector too..

DemonicPupil

The fuel pump is turned on by something in the AFM? I thought the s4 pump just ran?

When I bought the car, it had a cone filter with this AFM on it. Think installing the factory AFM would be a better option?


Battery and hood are clean. The hesitation starts AFTER the nasty bumps and continues for quite some time till I get out and slap the AFM around a lil bit.

The only thing being affected by this electrical issue is the fuel. And the vehicle has brand new fuel pump, strainer, and filter.

I recently installed an S-AFC and A/F guage. It begins to run REALLY lean when the stuttering starts to happen. The idle also gets really bad.



Thanks for the replies.

Sideways7

iTrader: (7)

Maybe theres a short in the afm thats causeing the signal to be interrupted.

DemonicPupil

seems that that shaking also made my speedo cable come undone?

Went to go to work today and my speedo is going INSANE. Then just drops to zero and pretty much stays there.

I looked under the car and it looks like my tranny is draining gear oil all over the CAT and it's sprayed all over the underside of the car.

I'm at work now, just want to make sure... All I have to do is get under there and screw this puppy back in right?? Assuming it only came unscrewed... Tranny fluid can leak from this spot right? Or do I have a bigger problem?

For a second I thought I had another electrical problem, but the car ran very smooth except for that damn speedo problem today.

I needed to do an oil change on the tranny anyways, guess this just gives me a good reason to do one tonite in the frigid cold.

iceblue

wash all that fluid off it can catch on fire! Yes oil will come out if the spedo cable comes out. Yes it is keyd but it does just plug in and scew.

Yes the S4 AFM has a switch in it to turn the fuel pump on. You can also jumper the fuel pump test connector on the strut tower to bypas this circuit. Some AFMs also had some tin tabs onto each sender wire "e2" of the AFM and if the rod that slide on the carbon pickup hits these it will go heywire and sputter. Just cut the silicone off the cap of the AFM and inspect the internals.

Tournapart

iTrader: (4)

^^lol yeah just screw it back in, make sure they're still a needle on the end of the speedocable, when mine fell off the needle broke off, it will still screw back on to the trany but you will need a new speedo cable.

Try getting another S4 AFM, like from a friend of go to the junkyard or something, after so many years they do go bad just like in any car

DemonicPupil

iceblue... thanks alot, did you do up those images yourself?

didn't think about that oil catching on fire, but guess it didn't, no1 came yelling about a car on fire. Thankfully, my cat is hollow (sort of)... I hammered a 2" pipe into it for a midpipe effect, rather than having all that air gathering up inside a hollow cat. So hopefully the cat wasn't as hot as it may normally get.

iceblue

Those images have previously been posted from HAILERS. Took me forever to find them I was about to go out to my shop and take pics lol. Bu HAILERS are much bettor anyways.

DemonicPupil

Thanks for finding them and thanks to HAILERS for drawing them up. I'll replace the AFM tonite while I'm doing the tranny. Just so happens the idiot had enough brains to keep the stock AFM and threw it in with the car when I bought it. Too damn cold to be doin all this work tonite though. Gonna have to shove some handwarmers down my pants

DemonicPupil

I installed a new AFM and the car is running smoother for sure. Feels a lil less powerful though, but I didn't get a good chance to goof off. It started snowing and in less than 3 minutes after leaving my house, the roads went from clear to covered. Twas odd.

Anyways, with the AFM and stock box installed, the car is running even richer than it was. Gonna bring it down with the AFC, but I was quite suprised with the difference. So I guess that other AFM was shot.