when it rains it pours

[mike reeh]

needing to vent and maybe get some suggestions.....

weekend before last I tuned up my 77 K25 and had it running SO good for the desert trip that weekend (glamis)... first tune up since I had broken in the motor, (sbc400) and it was running great, I tell ya. smoothest idle you ever felt, timing was dead on and it was unstoppable. It was great... took it to glamis 3 hrs away, and was playing in the dunes.. I think I over revved it. it started missing on a cylinder or two, and just being shakey if I got on it.. I knew something was up. Hoping there was the smallest possibility that it was a bogus cap & rotor (been there done that) I went to the closest autozone and bought a new one, didnt help it.. well my truck was out for the rest of the weekend. luckily I had my banshee .... anyways it made the 3hr trip home just fine.. limped but was stable the whole way.. a few days later I needed a 4WD to get to the jobsite so I drove it to work about 150miles round trip. Same thing, stable but something needed fixin.

so last weekend or so I start to track down the problem... first thing I think is maybe its running lean.. It was, carb cleaner on the intake mating surface would bring the idle up enough to make me wonder... When I installed the intake my engine builder said use no silicone on the intake ports.. I disagreed but did as he said anyway. so that was my first suspicion.. So I yanked the intake and re-did the gaskets, this time with form-a-gasket.. put it all back together and as im doing this, notice that my tranny modulator line was disconnected (at the tranny side).. so I hooked that back up. that would have made a pretty large vacuum leak so I was pretty confident that one of those would have fixed it.. got it all back together the next day or so and took her for a test drive. Fired right up no problem.... but was still a little shakey.. it seemed better but somewhat different. hmm I thought. Maybe I need to tune it up. On the test drive it was acting funny.. one run it had NO power, and on a few others it was just acting funny. I dunno. I only set the timing by "eye" and who knows what else needed fixin'......

well at some point i bust out the timing light.. I had the timing set pretty far advanced, checked it, then revved the motor once to watch the advance kick in.. well the timing line disappeared and never came back.. the timing just moved a BUNCH just from revving the motor. Damn accel distributor (im 100% anti-Accel now, more on that later)... so today I take the distributor out.. check it out.. just for grins, I replace the module with a GM, and the coil with a GM... and cap & rotor with napa.. and I check the vacuum canister, its working good. greased and checked the mechanical advance weights with lithium grease. everything is great. the only thing in that distributor I didnt mess with was the pickup coil. Too much trouble and it was a longshot. So in other words I dropped in a whole different distributor.. was real anal about getting the rotor where I wanted it (instead of just close enough like usual)... and got it perrrfect. (after about 3 or 4 tries of moving the oil pump driveshaft)........ anyways I get her in.. hook up the plug wires.. they're new... new spark plugs (about 300miles actually but all look real good from the lean drive home)

intake is fresh, I did a compression check on the motor the day before I removed the intake... good results there.

get her all hooked up, new fuel filter since it was right there anyways, everything is ready to roar.. for some god forsaken reason my battery is now 100% dead. Yeah the new optima. WTF is draining the battery? I still dont know. This is the second time its happened, seems to happen when it rains. Get out the portable jump starter thing and hook up the remote starter switch... cranks and will only sputter for a few seconds. Wont stay running.. arghhhhhhhhhhhhh. Spray a little ether in the carb and she'll run on that *seemingly* fine.... for some reason it will not idle at all.. if I twist the throttle a few times to squirt some gas thru the accel pump, it will run off that but it wont run off the carb. at this point im irritated. pull the carb and check and double check everything. End up tearing down the carb completely and blowing out passages, and checking everything. Everything checks out O.K.... this carb has not so much as hiccup'd in the last 1 or 2 years since I rebuilt it. But it doesnt make sense. Its definately getting fuel and spark (I have a clear fuel filter right before the carb connection)....

Now im thinking back to the motor thing

now, I can get it to sputter on 6 or 7 cylinders for a few seconds then BAM it backfires thru the carb and dies... and will do what looks like dieseling sometimes for a second or two.. I have checked and double checked every !@#$ing thing.. The motor and everything on it is new or fresh.

Could it be that my optima is so far gone that the alternator cant keep up with charging it AND providing 12v to the distributor? These optima batterys have done some wierd things. Thats one theory im going to toy with before I get into it too deep.

Explain this: the day I did the compression check... I start with the passenger side bank, hot motor..

160, 160, 160, 160... bam, quick and easy as that..... heres where it gets weird: in the time that it took for me to unhook the last cylinder on that side and hook up to the 1st cylinder on the drivers side, something happened to where Im only getting 140psi.. the 1st one I was like shoot... only 140?? then I goto the next one.. same. next one, same.. and same, 140psi for all 4 cylinders on that bank. what the?? so just for grins again, I go back to the other side, 140 over there now too!!.. i dismiss it as luck of the draw, and figure all my cylinders have good compression.

so here I am. truck will not run at all now. It ran "fine" when I pulled it into the garage to fine tune it after messing with the intake.... Im 100% sure about the intake & vacuum lines, 100% about the distributor and ignition, and 75% about the carb. I do have an olddddd carb at my friends house that Ill have to pick up and see what happens.

While I had the intake off, I cranked the motor over and watched all the valvetrain, it all looked xlnt. Definately no obviously weak cam lobes or anything.

I dont really expect any help but if you're still with me, god help you Im very irritated right now. I need to get a leakdown tester to get a better idea of whats going on in the cylinders.. and I need to charge that battery.. until then Im seriously contemplating driving the truck off a cliff.

good day!

mike

[CHaingKaiShek]

Just a thought on the compression changing when you checked it.

As you crank the engine over, fuel washes the oil from the cylinder walls resulting in lower compression. Normally by the time I test one side (getting about 165lbs) I will test the other side and be 20-30lbs lower. So using a spoon I put a bit of oil down the plug holes and it helps out with the compression .

Maybe not the problem in your case, but just a suggestion.

Because your truck runs on starting fluid, I would suspect maybe the fuel pressure is too low? Buying a cheap fuel pressure testing unit will help diagnose that problem.

Stupid question here.. sure there is gas in the tank?

I only ask because when helping a friend of mine out, he was having a similar problem. Well his fuel gauge reported 1/4 tank remaining, but it was dry.

Jeff

[79BIG10]

Damn Mike that does suck. On the carb issue sounds like the timing is off a tooth. Mine did the same thing with a tooth off. Took a bit to start then sputtered when you shut it off. Also if you can get it running take a vacuum gauge to it to check for leaks. Sounds like a chance of a leak as well. Good luck!!!

[PHOENIX]

TDC the engine and set the rotor. Does sound like the problem I had after I re-installed the distr. Check to see if you are getting 12v at the distr. if possible check amps and how much draw at the distr. when you try to crank it and when you can keep it running. I could get it to run with carb cleaner sprayed inside the carb, but then when I took away the life support (carb cleaner) she would die and sputter as described. After getting the rotor just right, she was running again!

I would also check fuel pressure.

Another thing is the ignition module. They cant act very very f*cked up! I know I had two of them play some tricks on me, some really really weird tricks
I ended up changing the module and everything was ok, but still something wrong internal with the distr. I ended up replacing the entire setup (distr. wise) and solved my problem. Is it affected by temperature are all? Mine would only start in the afternoon but you couldnt start it for the life of you in the morning (and it wasnt even cold). It was something in the distr. that would only react when the temp. was just a hair bit hotter then in the morning, its the only conclusion I could come to. Damn it still bothers me, now that I think about it. I should have taken that distr. out to the desert and gave it a dirt knap!

[mike reeh]

CHaingKaiShek: good point on the washing of the cylinder walls. I didnt consider that. I do think that was probably the case!

as for the fuel pressure, it has xlnt pressure and flow, I made sure of it. As for gas in the tank, another good point, one I didnt overlook though... I cranked the motor once or twice when the fuel filter was unhooked and almost lost an eye from the stream that shot out of the gas line.

big10: I definately made sure I had the distributor in correctly. Like I said, the distributor was one of the things I was 100% about.

Phoenix: ignition module was known "good" and I still replaced it with a known good one.

heres the update: The only other thing I could think of was maybe this optima battery was absolutely fried (it happened once before).. so today after work I disconnected the battery all together and jumped her. VROOOOOOOOOM fired right up. My alternator is now junk too. If you all remember, I posted about this same thing happening not too long ago. My optima died 100% dead for some reason and then my alternator goes with it. My alternator is pushing 20volts at 2500rpm, and whining. 14v at idle. *sigh*...... thank god for warranties... these are not cheap products either.. the optima is brand new and the alternator is a nice Napa unit. I think Im going the high output 1-wire route pretty soon. Also considering getting a sealed delco battery. These optimas are too much trouble!

mike

[Cole's 87]

Sorry to hear about all your trouble. I do know this from experiance on a 83 T/A I used to own. A alternator is designed to keep a charged battery charged or maintained ,if the battery shorts out this will cause the alternator to run wide open which generaly burns up the regulator sticking it to full voltage. Hell I had to drive home one day with everything on and I still had almost 17.5 volts. Why the battery is shorting out is what I would be trying to fing out. Hope you find the root cause of your problems

[swervin ervin]

Mike,

I agree, sounds as though you have somthing killing the battery. This is turn burns up the alternator, thus, you have no power to run anything or fire the plugs right.

I think you need to track down the battery problems before proceeding to the next step. On the Optima's. At one time I thought I wanted one, but I'm not sure now after hearing of all the bad ones. You're not the first I've seen complaining about them. Think I'll just stick with my old fashioned type for now. I've had a Autozone Duralast Gold since August 1998. Been doing fine, except for me running it down once when I left the door open for two days.

Anyway, good luck with finding the cause of your trouble.

[CHaingKaiShek]

May sound stupid, but I had a remotely similar problem with battery death. Along with some other electrical problems listed in another post here on the board.

Does your engine have the little braided ground straps?

I believe all/most of our trucks are supposed to have them, either from the block/heads to the frame or from the block/heads to the firewall. It grounds out the truck's 12 volt circut allowing all of the voltage to return to the battery, instead of being lost along the way.

Without the grounds the battery will not properly charge, resulting in more stress upon the battery and premature failure.

Just a quick thought, I added two of those straps and now my ol' truck's electical ills are cured.

Jeff

[Troy 82]

I know how you feel. I'm having problems with my truck starting in the morning. When it does, it idles like crap. I can't figure it out either. Swervin has been a big help, but I still can't figure it out. I know how frustrating it is. Good luck!

[Txstruck]

I dont know a whole lot about gassers but i read this one time... Isnt there some kind of metal plate between the distributor and the engine. maybe you spun it or wore it out. Just my 0.02

[mike reeh]

txtruck, im not exactly sure what you're talking about but im pretty sure thats not my problem..


I got it all back together now and its running good but still has a massive vacuum leak, and it has to be internal to the carb. Its definately not a vacuum line..

this is one wierd problem. Sometimes after Im on the throttle Ill let off to where it should Idle and it will be at a real fast idle, like 1500rpm probably... noticeably fast.. the throttle is definately not sticking, and its definately not the choke fast idle cam... so I got it to do that fast idle and pulled it into my garage and had a look see. I checked everything, and nothing is leaking, nothing is hung up, etc.. Its a lean fast idle too.. Explain THIS: when I opened the secondary air valve (flap) with my hand, it idled back to normal..................... When I let go and it closed, the idle went way back up... after doing that a few times, it slowed down to almost normal but still fast... The secondary metering rods do move when you open that flap. but I dont see whats going on here. I think my carb is hella tweaked and its not something you can diagnose visually. the only thing I can think of, is that one of those little ball bearings pressed into the casting of the float bowl, came out.. they are vacuum plugs and some motors had one or two of the two or so holes pluged.. when i rebult the carb, one fell out and I pushed it back in. I forgot to check that when I had the carb apart. But thats the only thing I can think of..... *sigh* it never ends.........

more later. I gotta get a new carb. Im sooooooo tempted to charge a new edelbrock Q to my credit card but I *JUST* payed it off.. I hate the thought of rebuilding another Q but Ill probably end up doing that..... wish me luck

mike

[c10scotty]

sorry man, i know its frustrating...just hang in there. there have been many a time when ive wanted to take a baseball bat to my pos 305...like yesterday for one

itll all be worth it when you get her runnin