My 87 TA had an all stock carbed 305. The carb started to mess up and eventually the misture control solenoid went out. I figured while i was working at it I would just rebuild the whole top end. Rebuilt heads, street dominator intake, street avenger carb, mallory 85 series dist w/ accel super coil. I made sure the engine was at TDC before putting the heads back on, fuel is reaching the carb just fine. when I started the rotor on the the dist was between the 1 and 8 plug wires...but it just wouldn't start. I hooked up the timing light and while turning the key it seems to be firing evenly....but it won't fire...by-the-way, plugs are new. It just cranks...and eventually it backfires out of the carb....I did away with the ECM, but have everything wired right. and I double checked that the dist was getting power...any ideas what is going on? I'm stumped...

 

Assuming that you mean "#1 TDC":

You will no doubt recall from your most basic engine knowledge, that there are 2 instances of #1 TDC during one complete engine cycle: #1 firing, and the one you put the distributor in at, which is #1 exhaust closing & intake opening and #6 firing.

Bump the motor over with the starter until the rotor points to #1, and the piston is just reaching #1 TCD. Take the distributor out (lift it up) just far enough to clear the cam gear; and drop it back in such that it points straight toward the pass side of the car. Drop it back in; after it rotates on its way down, it will be pointing at the #6 cap terminal. If it doesn't go in all the way, push it down GENTLY while someone bumps the starter over. Put the cap back on, the wires back where they belong, etc. Reach in the window and start the car.

 

that didn't work...still just cranking.

 

What do the spark plugs look like?

Is it backfiring out the carb any more?

What does your timing light say? Is the spark occurring somewhere reasonable?

 

the spark plugs are new, so they're not the problem. it's not backfiring out of the carb anymore...well, it did once but it was because I got too much fuel in it I think. it's cranking smoothly, and the timing light is flashing steadily...I'm baffled...I just got done doing a chevy conversion in my girlfriends olds and rebuilt the engine for it and I didn't have a single snag....

 

But of course, they all were at one time...

But how are they NOW? Are they new since this has been going on? If not, then they're not "new" any more; replace them.

When the timing light flashes, does it show the timing mark at some reasonable point? I.e., is the spark coming at about the right time and going to the right cylinder?

 

they were new since last night when I bought them and put them in after the rebuild. I double checked the gap too just because I can't figure anything else out. the timing light shows the mark at about 4 or 6 degrees BTDC...that's while someone is cranking the engine with the starter.

 

Are the grounds on the back of the heads tight? And the engine to body ground.

 

Well that timing should be close enough to start...

Remember, it only takes 3 ingredients for an engine to run: compression, spark at the right time, air/fuel in reasonable proportion. All you've got to do, is figure out which one is missing.

You haven't done anything that would alter the compression, with the possible exception of valve adjustment. If that's been disturbed it wouldn't hurt to check it. Otherwise, don't touch it!!! it was fine before, it should be fine now.

If you open the throttle wide open and let it clear whatever fuel it got flooded with, you should eventually get back to a reasonable air/fuel ratio. If on the other hand no fuel squirts from the accelerator pump, try pouring some gas into the intake.

You have spark at the right time. But you don't know if it's actually "spark", or if the spark is being diverted straight to ground by a bunch of soot on the plugs. Hmmmm......

What do the plugs look like? Got another set, just to try? Good used ones even?

Bad grounds won't cause a no-start in a carbed non-computerized car. Especially not when you can see flashes from the timing light. I wouldn't waste time on that detour.

 

havn't done anything to alter the compression...I disconnected the fuel from the carb to make sure I had the bowls cleared, then poured a little in to get it going. the plugs are getting a little black from all the backfiring, I'll toss ina nother set to check.

 

I agree with most of what you say but I do disagree with the bad or more specifically no ground causing no start. My first engine rebuild was a carbed 76 olds cutlass, I forgot to reconnect the ground strap from the head to the body and could not get it to run, reconnected the ground strap started first try. Every electrical system needs a complete circuit including the spark plugs. The engine to body ground is the primary ground path for the plugs through the heads and block, without it there can be a high resistence in the ground path if it has to find a ground through the wiring system. That is the primary reason for the ground ckt between engine to body then body to battery. Even though the timing light may flash it is only seeing a current flow through the wires by reading the EMI produced it does NOT give an accurate representation of the amount of electrical power actually getting to the plugs, just because there is enough power to light an inductive pickup there may not be enough to jump the plug gap with enough power to fire the fuel. Been bit in the A** to many times for that.

 

okay easy enought to test a plug for "actual spark" get your handy dandy screw driver or the prefered safer method the plug tester

 

I did double check the ground strap...no luck

 

okay you believe you have spark, fuel and hopefully compression. you have dumped fuel into the engine? did it start for a couple of secounds? or backfire?

 

it backfired. so far I couldn't even get it to fire up for a split second.

 

well if it is backfiring out of the carb you have a ignition problem your wires are out of order or your dist isnt installed correctly... you could try moving all of your plug wires one post clockwise... make sure the you have the firing order going around the plug in the correct direction... which way is it going now?

 

my firing order is 1-8-4-3-6-5-7-2, clockwise around the dist. and all the wires are running to the correct plugs...

 

good to have that sorted out now your dist is installed incorrectly OR... your cam is

 

well, I didn't touch the cam or the timing set. that leaves us with the dist...which I've tried everything I can think of...now my battery is dead from cranking it all day. lol. I'm taking it to autozone to have it charged in the morning since my charger has come up missing and my spare bettery is bad.

 

You said you rebuilt the heads, did you set the lash when you put them back on? I would take out #1 plug hook up the wire, set it on your intake put your finger over the hole and have someone bump it over, see if your sparking when your finger gets blown off the hole. Was that carb on the car before? you might wana set the mixture screws back to 1 1/2 turns out.

 

The heads are rebuilt, but not by me. a local shop did them. I did set the lash. the carb wasn't on this car before. but, the heads, intake, dist, and carb all came from the same car. I took it all off my 84 TA, which is also a 305. I just got home from work and am about to go and put the engine back at TDC on the #1 piston and without the dist in and start everything all over. hopfully with everything you guys have helped me with I can get a better result.

 

you need to make sure that you are actually on the combustion stroke on #1 and not that other instance of tdc

 

I talked to an old friend from school today(we were in auto together) and he helped me over the phone...but I can't test it out just yet because I can't get the dist to sit flush on the intake. I figure the cam gearisn't lining up with the oil pump...

 

where is you trusty long flat head?

 

lol. yeah, I headed outside and dug out the rarly used tool...I set the #1 piston at TDC on the compression stroke, and set the rotor on the dist to the number 1 wire...flame shot out of my carb....

 

okay how are you finding TDC? you have a valve cover off and are watching the rockers and aligning the marks on the balancer right?


this might sound rude and probably unwarranted as you know the firing order but which cylinder is #1

 

I'm using a compression guage to find the compression stroke and a screw driver in the plug hole to tell when the piston is all the way up...and the #1 piston is the front driver side piston...

 

so you are turning the engine over with the starter until you get a reading on the gauge then what? seeing if you can touch the piston with a screw driver?
use the compression gauge to find the comp stroke if you like
if you have the timing tabs line up the mark on the balancer with the TDC mark on the tab as the crank has quite a bit of rotation while the piston is at or nearing dtc which wont be noticable with the pick axe you are using to measure

 

I'm using to the guage to find the compression stroke. then I put a screw driver in the plug hole so I can feel once the piston gets to the top. the timing tab is lined up, I just like that extra bit there telling me it's right...

 

I always had problems with forgetting to mark the distributor when i yank them out. If you mark your cap and base, line up 0 on your pointer, drop it in a little to the right so when it sets down it points at # 1 cylinder. Re assemble, crank it over, if it backfires, pop the cap off, spin the crank till the tab lines up and the rotor is facing away from #1. Pull it out and drop it back in facing # 1.

 

well if your getting flames out the carb then it isnt right... but if you believe that you are getting the dist installed absolutly correct then the only other explination is that the cam isnt installed correctly....

 

A step I usually use is to spray "quickstart" (Either) into the open carb while someone cranks. Keep your face away, if it backfires, you might loose some eyebrows if you have your face stuffed into the carb.

If it has compression and doesn't start with that, it's electrical, not fuel or compression.

Are you getting good spark? Good healthy spark? Put the either away and pull out a plug, attach to the wire, and ground it against the engine. Have someone crank the engine, and you should see healthy spark even in a well lit room.

Good spark? Then it's not at the right time, timing problem. Could be cam timing, but you said you didn't move the cam.

Sometimes a coil will act funky and make the car fart, if you have a spare, try a different coil.

Otherwise, you seem to have found compression TDC, you could have a bad distributor module, so swap that out as well. These are all good items to pick up the next time you see a car like yours at the boneyard, total investment will be about $25 for all kinds of spares that you can use at times like these.

Good luck

 

got the car started. My dist must've just been really touchy...ran kinda rough, worked out a few kinks in the backyard then took it for a spin...everything seemed fine so I took it to the gas station and filled it up....got down the road from my house...and smoke started billowing out of the nostrils on the hood and then it stalled....yeah, you know what's going on already....the engine had burst into flames. as the people across the street laughed I put out the flames and got some friends to help push it home....that was about 30 minutes ago. still havn't checked to see what happened....

EDIT: just went out and looked around. didnt try and find the source of the blaze yet, but there was no structural damage at all thank god. the insulation under the hood is still intact.

 

oh sheet. thats not good.

 

Pull those plugs out and check them, after all those timing issues i bet they are in rough shape. Sounds like you timing is still off some, mabey air/fuel ratio also. Stay close to the house or fire dept on your next test drive .

 

If you are using rubber fuel lines check them and make shure they arent leaking.

 

well, the fuel lines are good. looks like the fire was only on the driver side...I remember the opening the hood and specifically seeing the spark plug wires burning...when I went out and checked it out it even looked like they were burnt up. reached down and rubbed em....they're fine. lol. they were covered in soot...along with everything else on that side but I guess I got to it in time because so far nothing major looks damaged. some wiring is fryed, like all the wires to the windshield wiper motor and a few relays. but nothing I can redo...I think I luked out on this one. lol. I'm gonna go out and see what I can do for it tomarrow...I've got a freshly built 350 sitting on the back porch ready for intalation too...too bad I already said I'd put it in my girls olds....damn

 

ok guys, went outside this morning and got in the car...it fired right up, no problems. Pulled it around back and parked it and started to look around for the source of the fire. I'm not positive that that this was the cause, but it seems posible, and it's the only thing I can even see out of place...the driver side exhaust manifoldbroke loose from the y-pipe. the manifold and y-pipe are all black where they connect and the fire was in that area...anyone ever here of such a thing and why it coulld've caught fire? I'm going to assume it was as simple as the heat from the exhaust and the fuel fumes in the engine bay...