greg1990964

Hey all. Yep, another post from me..Ok, So I have been having this intermitten power loss issue for a couple of weeks now. I checked the ground terminals and the one on the strarter looked a little loose. On the terminal that has the two cables going to it, (left side) it appears that terminal stud is loose. I replaced the starter with a reman Bosch a couple of months ago. I never noticed that that terminal is loose to the solanoid housing. It came with two nuts so last night I tightned the first nut all the way down to tha base and it is not loose anymore. then put on both cables and tightened that nut. Seems to be good. My first question is that terminal/post supposed to be loose out of the box like that? I would assume you dont have to put the nut all the way down to tighten it before you put cables on it. Also, my power loss and slight hesitation when I blip the trottle I am thinking could be caused by something else. Not sure what. I have installed new isv, newer MAF, plugs, coils. I bought new coils but the old ones worked better then the new brazilian ones, so left them in. new caps and rotors, new dme relay. I am at a loss here. we hooked it up and didnt throw any codes (thanks Rocket Rob)
Could be faulty starter solenoid post? it is suppoesed to be able to spin the post in the starter? Moving it up and down a 1/4 inch before tightning bottom nut?
I suppose I will clean my newer isv, and check MAF connections. MAF does not seem to sit perfect into the other black hose/box, 3/4 is all I could manage to get it connected. Arbox stopping it. Need to get more patience and check that.
Any suggestions are great. Thanks.

dkcaims

Ran across this post on the PCA canada archives...worth a check perhaps.


Alex
04-24-2012, 02:59 PM
Hi to all!

I just thought that I would pass this on to all older (pre 964) 911 owners.....I learned a valuable lesson for sure!

For some 4-5 years now, I have been having ongoing issues with my '80 SC 3.0L. Above 3500RPM I would get a lot of hesitation and then bucking if I would try to drive the car "hard". I was never able to get her anywhere near redline. I was also getting a fair amount of exhaust backfire. My now former mechanic couldn't figure it out either!

I found out that the problem was that above 3500RPM, my AFR would drop like a stone....into the low 9.0's for sure. So, after doing much research (PelicanParts forums, etc.) I thought that it must be fuel supply/injection or ignition related....I then started "digging"...replacing some components, falsely adjusting others.... all to no avail!....I was getting more and more PO'd in the meantime!....I was just about ready to "launch her off a cliff somewhere"! I decided to post one more plea for help on the PelicanParts 911 technical forum...this time in CAPITAL LETTERS!

A "pelican" by the name of Lonewolf responded and after I had explained, in detail, what was going on he told me that it was probably my battery. I thought how could it possibly be the battery, as the car starts up fine and when the vehicle is in storage I've always got it on a trickle charger? The battery was only (duh!) about 4-5 years old. So I did some tests on it as he recommended and, sure enough, it wasn't able to keep a descent enough charge! So, essentially, I was getting a weak spark, which, inturn caused a low AFR reading as I was getting incomplete combustion. This would also explain the exhaust backfire, as there would be unburnt fuel in the exhaust.

I installed a new battery and BANG, what a difference! The old girl is back! I'll also be doing some tests on the alternator as well, just to rule that out. Lonewolf seems to think that trickle chargers, over time, reduce the amperage output of a battery, however there is no real way of checking that. So, imagine that! After all my trials, tribulations, mechanic consults, and, of course, $$$... it was all due to a....stooooooopid battery....$165.00!!!

So if any of you are having intermittent, what appear to be, "ignition" issues....check your battery first!!!

From now on, my $0.02 worth on to you!

Alex

sml

have you tried a spare DME unit yet? (ie not the DME relay but the DME unit thingy).

greg1990964

Not tried another DME. A good idea though. It could take a week as it loses power sometimes not for a few days or more. I put in the new coils tonight I thought were bad, and seems to be fine so far. I tested them tonight by installing them one at a time along with one old coil and unplugged one ignition unit and it ran fine off of only one coil. then went for nice spirted ride into Boston and back. Perfect night for top down driving and it didn't slightly lose power as it always has when hot..Fingers crossed!. I am sure I just jinxed it. I am always thinking it is running better to only be disaponted. I did have a young blonde come out of a bar where I was stopped and gush about the car. Thats always fun!