FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#1
|
|||
|
|||
New engine won t start
I ve got a rebuilt 455 that won t start. Got fuel and spark. Lifters adjusted with intake off, so valves should be right. Installed dizzy with engine on comp. Stroke. Put balancer on zero. Rotor pointing towards #1 plug wire on cap. Firing order confirmed. Counterclockwise.. it doesn t even cough or spit !. What have i missed ? One ? Where should vac advance be pointing since that affects rotor to base orientation. Tks
|
#2
|
||||
|
||||
Not being critical, you need to back up and reevaluate. If you have fuel and spark, and the valves are right, you'll get a bang. Maybe at the wrong time (distributor off), but you'll get something. One of the things you've crossed off the list isn't right yet.
__________________
'65 Tempest 467 3650# 11.30@120.31 |
#3
|
||||
|
||||
Agree with that. Getting fuel into the cylinder? Perhaps it needs a richer mix to start?
George
__________________
"...out to my ol'55, I pulled away slowly, feeling so holy, god knows i was feeling alive"....written by Tom Wait from the Eagles' Live From The Forum |
#4
|
|||
|
|||
Compression test with all plugs out?
|
#5
|
|||
|
|||
It would be a good idea to check this. Most of the new no-starts I run into are an issue with valves not closing all the way. You didn't mention if you have an adjustable valvetrain or the stock-non-adjustable stuff the engine came with. During a typical rebuild, reusing the old valves, cutting and grinding the seats, gets the stem height all messed-up. You end up with valves with a too long effective length. Tightening the rockers up to the 20 ft. lb. stock setting for the bottle neck studs results with some or all the valves held open just a little bit. No-start is the result. Try to evaluate and fix the situation, whatever it is as quickly as possible. It's very bad for the rings, and hard on the camshaft to crank a long time without starting that first time for break-in. Good luck with it.
|
#6
|
||||
|
||||
Quote:
...Verify Fuel,and Spark to the plug, not coil wire (if equipped) I’d work on #1 cylinder, verify everything, including dizzy install. Vacuum advance can location will change where #1 is on the cap relative to diagrams, but #1 is where the rotor points, just past TDC ...on compression stroke. |
#7
|
||||
|
||||
Just verifying you're on the compression stroke for the distributor drop in by the finger over the hole method may help provide clues... No blow, start over on the valve train adjustment.
__________________
'65 Tempest 467 3650# 11.30@120.31 |
#8
|
|||
|
|||
35 yrs ago I had no start,timing on no. 1 Exhaust valve. I learned.
|
#9
|
||||
|
||||
your timing is way retarded. confirm with a timing light, or just start moving the dist. clockwise.
|
#10
|
|||
|
|||
Adjustable valve train by the way. I think u guys are on to something with valve adjustment issue. It s the only thing i haven't dbl ckecked. Mainly cuzz i adjusted them with intake off, looking right at the cam lobes for low spot. I still could've got it wrong i guess. I'LL READJUST and let you know. I'd bet ya'll r correct though, because it doesn't really sound right when it's spinning over , now that i think about it. Tks.
|
#11
|
||||
|
||||
Are you sure it’s number 1 and not number 2. Just saying .....asking for a friend?
__________________
Jim Moshier 1971 Grand Prix 462ci SD Performance 6x heads 1962 Catalina 389 1968 Firebird 400-455 I haven't decided "If we ever forget that we're one nation under GOD, then we will be a nation gone under." - Ronald Reagan |
#12
|
|||
|
|||
Quote:
WHAT DISTRIBUTOR DO YOU HAVE? There may be more wrong than just this. |
#13
|
|||
|
|||
No points. Pertronix III modual in stock style dist. I have fire at plug
|
#14
|
|||
|
|||
Quote:
Point being, you'd want to put the damper at something like 10 degrees BTDC COMPRESSION STROKE for #1 cylinder. Get the rotor in the general direction of #1 spark plug terminal on the distributor cap. Then rotate the distributor body to the point where the module would trigger a spark. Easy with HEI or with points, but I don't know Pertronix. |
#15
|
||||
|
||||
Petronix is having some issues currently so don't rule out something going on in that area.
Visually observe #1 intake valve open then continue to rotate the engine in the normal direction till just before TDC. Wire up the distributor in the correct firing order from that point based on where you set the rotor orientation. Get the pickup as closely aligned as possible to when it would be triggering a spark. It should roar to life instantly if you are close.......
__________________
If you can read this, thank a teacher. If you can read this in English, thank a Veteran! https://cliffshighperformance.com/ 73 Ventura, SOLD 455, 3740lbs, 11.30's at 120mph, 1977 Pontiac Q-jet, HO intake, HEI, 10" converter, 3.42 gears, DOT's, 7.20's at 96mph and still WAY under the roll bar rule. Best ET to date 7.18 at 97MPH (1/8th mile), |
#16
|
||||
|
||||
You have confirmed the 3 things the motor needs to start , but there's a 4th as mentioned, that being compression.
Do this, pull some plugs and if they do,not look wet then fill up the small center section of a spray paint can cap with fuel ( yes fill it up with fuel! ) then dump in into the Carb while holding both the choke and the primary throttle plate open some. Next have someone Crank the motor over while you slowly spin the distributor clock wise to advance the timing. In doing this if you have compression then the motor should become very hard to Crank over which is good and means you have compression , if not and the motor does not back fire then you have some valves set too tight. The rotor in Pontiac distributors spins counter clockwise, so advancing will be made by spinning the dizzy clockwise.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#17
|
||||
|
||||
Are the plugs NEW?
__________________
************************************* 1968 Lemans. 37,000 original miles. GTO clone. 462ci/KRE 290 heads. UltraDyne 280/288 Solid/850 Qjet by Cliff/Performer RPM/TSP 9.5" in TH400/8.5" 3.42 gears/3950# Race weight/12.58@106 at Bandimere speedway high altitude |
#18
|
|||
|
|||
I replaced a points dist with HEI in my 68. Had spark, but still wouldn't start. Turns out I had 9 v or less to the HEI. Not enough spark for fire. Another one I thought I had everything line up but no start. Turns out timing was retarded instead of advanced.
__________________
Frank M. 75 Firebird 68 Firebird 400 RAIII 66 Chevy II 461 Pontiac in AZ |
#19
|
||||
|
||||
Quote:
Yep, I got bit by this one about 25 years ago. A buddy had his heads (350sbc) reworked, installed a new cam, and could not get it to start - so called me to come over. Distributor was throwing a nice spark. Carb appeared to be working fine. I pulled a valve cover to confirm #1 on compression, spark plug out of the hole to confirm piston at TDC. Turned out the machine shop did a REALLY sh!tty job on the valve guides. Valves moved around so much that no compression could be built, and it would not fire. We put a new set of heads on a few weeks later, and it fired right up.
__________________
'73 T/A (clone). Low budget stock headed 8.3:1 455, 222/242 116lsa .443/.435 cam. FAST Sportsman EFI, 315rwhp/385rwtq on 87 octane. 13.12 @103.2, 1.91 60'. '67 Firebird [sold], ; 11.27 @ 119.61, 7.167 @ 96.07, with UD 280/280 (108LSA/ 109 ICL)solid cam. [1.537, 7.233 @93.61, 11.46 @ 115.4 w/ old UD 288/296 108 hydraulic cam] Feb '05 HPP, home-ported "16" D-ports, dished pistons (pump gas only), 3.42 gears, 275/60 DR's, 750DP, T2, full exhaust My webpage http://lnlpd.com/home |
#20
|
||||
|
||||
Quote:
Also when working only on #1 cylinder, if all is well in your checks, but low compression...your cam timing could be off. |
Reply |
|
|