Kevin Michael

Tampa that skip or miss looks to be very random and sporadic. I can't think of anything it could be though. I got to get me one of them thar thangs. Looks pretty cool.
Kevin

Tampa 928s

Just send my Maf for a check out and/or repair, I'll keep you posted.

Giovanni

My SC is doing exactly what your is. if I am driving around town at a constant speed it will surge for a second or so. If I give a little gas it will surge again (for a split second) and then starts pulling very strong. it usually does this when commuting around 45-55 mph. Last time I had it on the track that thing loved high rpm, it just hates slow driving I guess.

I can't find any receipt showing when the oxygen sensor was last changed so that is the next thing on the list. It drove pretty good when we sharktuned it with the new O2 and then gradually started acting up with the stock o2.

Tampa 928s

Humm mine is an 86
Your the third one to bring up the surge issue is there a common link such as year, type of S/C etc.
My ox is brand new along with about everything else.

Tampa 928s

Look at this it shows what is going on when it skips.

Kevin Michael

Tampa, do you wnt me to send you a maf to try or do you have it covered?

Tampa 928s

Kevin,

I already sent it out, after 22 years and 93K it would not hurt to spruce it up at least I will know what it isn't

Thanks for the offer.

Kevin Michael

my pleasure.

Tim Murphy

Hi Kevin,
It's been a while since you installed your kit so I cannot remember what you have changed since you purchased the stage one kit. Are you still running stage one with the stock injectors? There is something wrong if the car is running rich all the time, and it's not because of the sc unless you are blowing out metered air through a manifold leak

hacker-pschorr

Sure, drag my car into this......

Leak fixed, life has been good for a couple of years now. Just a bad embarrassing memory that was 100% my fault.

AO

Tampa...

Weren't you having similar issues before you boosted the car? Just wondering is there is any relationship here. Let me see if I can find the threads...

Got 'em:

https://rennlist.com/forums/928-forum/351135-inj-and-maf-wiring-testing.html

https://rennlist.com/forums/928-forum/357581-86-no-start.html

Kevin Michael

Hey Tim! Yeah it's been awhile since we have talked. The only modifications I have done is 30lb. injectors and a smaller pulley (3.25") . Also I have added a Greddy rs BOV. at the stock location. It solved my idle surge and drop outs after much experimenting. I suspect the FMU for the over-rich when I open the throttle for no other reason than everything that could cause it has been replaced and tested. I know the Murf kit is working well ,as it is a very sound system and precisely why I chose it. As far as intake plenum leaks go I did the r&r and followed it to the letter and am confident there are no leaks. To clarify, I clamped a section of innertube (w/stem) over the MAF and introduced 5psi. of pressure. I think I just need a sharktune.
Kevin

hacker-pschorr

Only modification?? How did I miss that you installed larger injectors???

Damn it Kevin.

Tim Murphy

Well that was certainly an interesting read and adds some other possibilities of a pre-existing condition.

Looks like he found the problem with some bad injector wires but that would not explain the no power to half the fuse panel, including the LH. I see where the wire feeding the fuse panel from the battery was replaced so maybe there was two problems at one time.... One kept the car from running and the other (injector wires) was the intermittent part of the problem.

I think in this case there still might be two problems.... one intermittent and one ongoing.

The MAF is very suspect here and I think a new one will fix the ongoing problem. The intermittent cutting out problem I believe is another issue.

Kevin Michael

You didn't ask! What are your thoughts?