Hi Kerry, That sounds great, do you know if the old plugs were the right heat range ? Keep your eyes on the new ones and you might want to check and make sure you have a good strong spark at the plugs. Just make sure it is not running to rich and fouling out the new plugs. Congrats on the mighty troubleshooting Allan R On Wed, 20 Mar 2002 09:16:03 -0800 (PST) KerryPinkerton <pinkertonk@xxxxxxxxx> writes: > Ah well better lucky than good. > > Problem solved but it was a very unexpected solution. > > A little recap. About a year ago my 73 with a factory > rebuilt thermoquad started running crappy. She would > cough off idle and was very flat at top end. Vacuum > readings were low, in the 17 range when a few months > earlier it had been 20. > > None of the traditional vacuum leak tests show any > results including Dick B's trick of covering the > primary with cardboard and seeing if the rpm increased > before it died. I set the timing and tune over and > over and there was no significant change. > > Last week I replaced a drivers side exhaust manifold > (forearm is STILL sore from banging it on the brake > booster repeatedly). In the process of doing this I > noticed that the plugs were heavily sooted but my > spark indicator showed that all were firing strong. > Checked the firing order again and again. > > Based on the lack of vacuum leak test results, i had > about decided it was the carb and, in fact, pulled an > Edelbrock from my son's Mustang to try a different > carb. Of course the linkage was not the same and > before I messed with rigging something up I decided to > change the plugs. No rational reason for this after > all they were 'new'. The old plugs (AC) are about 2 > years old but 'new' in that they only have 3-4K miles > on them. It was just a cheap, eliminate a slight > possibility kind of thing. Autozone only had Bosch > and I got the cheap ones since I was just testing. > > BANG! What a difference! Vacuum back up to 20. Idle > is smooth, power is strong. She be back! There is a > moral to this story but I'm not quite sure what it is > yet. Reminds of my English Lit classes. Didn't > really enjoy the process and never quite came up with > the same conclusions as the professor... > > The only complaint is that in passing gear at WOT she > seems to stay in passing gear a little TOO long. I > say this because the rate of acceleration falls off > and then picks back up when she shifts into high. The > shift point from 2-3 seems to be about 70 at WOT. If > I punch it at 65 she sometimes will drop into second > for just a second and then back to high. > > That however is a completly different problem and I > will research it later. For now, I'm going to change > clothes and go for a drive in the rain. The 64 is in > the shop drying off. She has a squeek in the front > end. > > In the tlc department, the 73 also had a squeek in the > rear end and I tracked it down to the upper shock bolt > being just a tad loose. Tightened it up and no more > squeek. > > I am a MUCh happier camper. Now I just need to think > about what she was telling me and why it took me so > long to fall into the solution. Is there a way to > tell that the plugs are misfiring under load? > > Someone asked how to change plugs on a 71. On the 73 > (similar) the 1,3,5 4, plugs can be reached from the > top. The #7 plug from below and I had to put a wrench > on the end of my plug socket as there was no room for > the ratchet. #8 also is easier to come out from > below. > > Having said that, there is below and then there is > below. Being on a creeper makes for a different arm > angle than standing up with the car on a lift. > > One final trick is because some of the areas are so > tight it is difficult to start the plug back in the > hole. You can take a piece of vacuum hose or (my > preference) a piece of 1/8 id flexible water line and > put that over the end of the plug to act as an > extender. For several of the plugs this is the only > way I have found to get them started. > > happy happy.. > > Kerry > > __________________________________________________ > Do You Yahoo!? > Yahoo! Sports - live college hoops coverage > http://sports.yahoo.com/ > >