NO start - Timming 351w

[hetrickw]

I had a previous thread on rough running 351w. I pulled the cap off the distributor and moved crank around to tdc and noticed the rotor was pointing to 12 o clock position not 1 o clock. I had symptoms of rough running to a point where it would shut off, now no start w/backfire. I've got gas & spark. I'm guessing the engine's timing chain jumped a tooth or is too slack. when I see how much the rotor moves from stop(when I reverse direction on crank) from tdc its im guessing 6-8 degrees. but i'm almost blind and can only guess at those numbers. Any suggestions before I pull the TIMING CHAIN? Thanks all! Bill

 

[jbojo]

I had a previous thread on rough running 351w. I pulled the cap off the distributor and moved crank around to tdc and noticed the rotor was pointing to 12 o clock position not 1 o clock. I had symptoms of rough running to a point where it would shut off, now no start w/backfire. I've got gas & spark. I'm guessing the engine's timing chain jumped a tooth or is too slack. when I see how much the rotor moves from stop(when I reverse direction on crank) from tdc its im guessing 6-8 degrees. but i'm almost blind and can only guess at those numbers. Any suggestions before I pull the TIMING CHAIN? Thanks all! Bill

First of all the position or the rotor does not matter as long as its pointing to the post on the cap that goes to the #1 cylinder At TDC. Couple of questions:

* How did you determine that you were on TDC of Cylinder #1 on the compression stroke?

* did you ensure that you have the firing order correct?

From the backfire its indicating an incorrect firing order or you have the timing way off.

This is what I would do:

* Find about 7* BTDC on the compression stroke on the balancer.

* Rotate the distributor so that the rotor is pointing to the post on the cap to the wire going to cyl #1 or if its too far off take all the wires off and place #1 wire on the post where the rotor is pointing. Then attach the remaining wires in the firing order listed below.

* The rotor turns CCW so ensure the firing order is 1 - 3 - 7 - 2 - 6 - 5 - 4 - 8 on the cap for the wires going to those plugs.

* Start motor and then time to get the factory spec using a timing light.

This is the cylinder numbering below.

firewall





4 - 8

3 - 7

2 - 6

1 - 5

front

Sorry if this is too basic but I didn't know your experience level.

 

[hetrickw]

I had a previous thread on rough running 351w. I pulled the cap off the distributor and moved crank around to tdc and noticed the rotor was pointing to 12 o clock position not 1 o clock. I had symptoms of rough running to a point where it would shut off, now no start w/backfire. I've got gas & spark. I'm guessing the engine's timing chain jumped a tooth or is too slack. when I see how much the rotor moves from stop(when I reverse direction on crank) from tdc its im guessing 6-8 degrees. but i'm almost blind and can only guess at those numbers. Any suggestions before I pull the TIMING CHAIN? Thanks all! Bill

First of all the position or the rotor does not matter as long as its pointing to the post on the cap that goes to the #1 cylinder At TDC. Couple of questions:

* How did you determine that you were on TDC of Cylinder #1 on the compression stroke?

* did you ensure that you have the firing order correct?

From the backfire its indicating an incorrect firing order or you have the timing way off.

This is what I would do:

* Find about 7* BTDC on the compression stroke on the balancer.

* Rotate the distributor so that the rotor is pointing to the post on the cap to the wire going to cyl #1 or if its too far off take all the wires off and place #1 wire on the post where the rotor is pointing. Then attach the remaining wires in the firing order listed below.

* The rotor turns CCW so ensure the firing order is 1 - 3 - 7 - 2 - 6 - 5 - 4 - 8 on the cap for the wires going to those plugs.

* Start motor and then time to get the factory spec using a timing light.

This is the cylinder numbering below.

firewall





4 - 8

3 - 7

2 - 6

1 - 5

front

Sorry if this is too basic but I didn't know your experience level.

it's actually has 302 cam in it so it's firing order is a 302. I determined tdc when I moved crank around until my previous mark on tdc harmonic balancer hit TDC on the mark alighnemnt. I've always had it align with the 1 oclock position (#1 cylinder) on the rotor. I know it can me 180 out but it isnt. IF I"m sure its TDC (crank and piston) and now just recently the rotor is in the 12 oclock position, IF IM SURE ITS tdc and the rotor is not on #1 (distributor), it should be timing chain ...... wont start to far out of time, I don't mind any assistance, im for sure jjust a weekender...

 

[jbojo]

Yeah I tend to agree with you. Sounds like you have checked everything. Hopefully someone else has an idea.

 

[hetrickw]

Yeah I tend to agree with you. Sounds like you have checked everything. Hopefully someone else has an idea.

Thanks jbojo.....appreciate the input! if it's not the timing chain , atleat itlll give me an excuse to get in the garage away from the wife for a weekend! LOL

 

[kcmash]

I suggest you pull the distributor and check the gear on the bottom. In the 351W it is held in place by a roll pin. I have seen a few failures on the 351 W where that roll pin shears and the timing goes out.

Worth a check!

 

[jbojo]

I suggest you pull the distributor and check the gear on the bottom. In the 351W it is held in place by a roll pin. I have seen a few failures on the 351 W where that roll pin shears and the timing goes out.

Worth a check!

+1

Yeah I heard to use a case hardened pin. Doesn't take much of a twist to change the timing a few degrees. Good call kcmash.

 

[cudak888]

Also pull the rotor itself and inspect the tab inside it. This happened to me on a 400: http://www.7173mustangs.com/thread-obscure-fix-intermittent-rough-idle-tied-to-sheared-distributor-rotor

-Kurt

 

[hetrickw]

Great info. I certainly will check the distributor carefully. I"ll post a f/u when I get the issue cleared up. Thanks all....Bill

 

[Mikes73]

Take the distributor cap off and verify the rotor is actually turning while cranking the engine. If the roll pin is sheared on the dizzy gear this will keep it from starting and running. I'm not sure if you checked that out or not but I have seen this problem a couple of times usually from some debris locking up the oil pump and shearing the roll pin preventing the rotor from turning.

 

[mustang7173]

hetrickw,

I agree with jbojo, Kcmash, cudak888, and Mikes73. How many miles are logged on the 351W engine? Do you know if the timing chain is the original? If is an original chain, then definitely look into replacing it. The originals had the plastic teeth gears that were really not for any performance application, except to reduce noise.

I would recommend a Top Dead Center Indicator like this one from Walmart.

http://www.walmart.com/ip/19664747?wmlspartner=wlpa&adid=22222222227017141191&wl0=&wl1=g&wl2=c&wl3=52332326775&wl4=&wl5=pla&wl6=79430357415&veh=sem

I have a similar one that really helps with locating TDC.

COMP Cams Magnum Double Roller Timing Sets 2138

http://www.summitracing.com/parts/cca-2138/overview/make/ford

mustang7173

 

[hetrickw]

Awesome advice. Last night i ordered a TDC tool off ebay. i want to check (for sure) its TDC first, then move on from there. Maybe harmonic balancer bad also, i'll check it. The engine (best guess is from 1975) and was rebuilt in 1985. So, since 85 i probably have less than a 1000 miles on it. Its been garaged the entire time. I do not know (but doubt) they replaced the timing chain. Plastic ?? ...... i did check turning crank how much slack seemed to be in the chain by watching distributor rotor from reversing crank and i crank pretty far before the rotor moves when i reverse direction from a stop.......so i'm fairly sure t hat's it. great advise...... i guess i need to pull the numbers off the block to see what year this thing is......it's been a mystery for 30 years to me.

hetrickw,

I agree with jbojo, Kcmash, cudak888, and Mikes73. How many miles are logged on the 351W engine? Do you know if the timing chain is the original? If is an original chain, then definitely look into replacing it. The originals had the plastic teeth gears that were really not for any performance application, except to reduce noise.

I would recommend a Top Dead Center Indicator like this one from Walmart.

http://www.walmart.com/ip/19664747?wmlspartner=wlpa&adid=22222222227017141191&wl0=&wl1=g&wl2=c&wl3=52332326775&wl4=&wl5=pla&wl6=79430357415&veh=sem

I have a similar one that really helps with locating TDC.

COMP Cams Magnum Double Roller Timing Sets 2138

http://www.summitracing.com/parts/cca-2138/overview/make/ford

mustang7173

 

[mustang7173]

Hello hetrickw,

The forum members have provided some great information to help with process of elimination. Hopefully, the P.O. did replace the timing set assembly. I would then pull all of the spark plugs, so the engine will turn easy by hand, find TDC, and see where the rotor is pointing to the relation of the #1 pole on the cap. then pull the distributor. In my years of messing with the distributors, it is one of the toughest things to get back right. But, once you get it right, you can tell the difference in the way it starts up.

mustang7173

 

[hetrickw]

good deal thanks!

 

[hetrickw]

Here's the pics of what I observed. The chain has about 1/2" play (right side) left is pretty tight. The dampner looks pretty bad (rubber) one side other looks good. THe tdc marks on gears look right to me (exactly). Its' at TDC when I took pic of the rotor in the 12oclock position. I'ts not close to 1 oclock (#1 piston), I didtn pull rotor but it the teeth/pin down inside BLOCH look ok., no broken rotor. Im far enough out for it not to run, but why didn't the timing set gears jump a tooth? I think harmonic balancer is in rough shape. but nothing explains the jump from 1 oclock to noon straight up. WHAT AM I MISSING? I've got the TDC TOOL coming int he mail. Not exactly SURE its at TDC didn't pull #1 plug yet. Thanks all ! BILL

I had a previous thread on rough running 351w. I pulled the cap off the distributor and moved crank around to tdc and noticed the rotor was pointing to 12 o clock position not 1 o clock. I had symptoms of rough running to a point where it would shut off, now no start w/backfire. I've got gas & spark. I'm guessing the engine's timing chain jumped a tooth or is too slack. when I see how much the rotor moves from stop(when I reverse direction on crank) from tdc its im guessing 6-8 degrees. but i'm almost blind and can only guess at those numbers. Any suggestions before I pull the TIMING CHAIN? Thanks all! Bill

 

[jbojo]

Do you have a picture of the gear on the crank without the bolt on it?

 

[hetrickw]

here are two w/out crank bolt, but taking off the bolt moved the marks.....

Do you have a picture of the gear on the crank without the bolt on it?

 

[jbojo]

I can't remember but maybe someone else can confirm. When the two gear marks are aligned you should be at TDC. Where is the rotor at and where is the timing mark at on the damper. I would think TDC if everything is aligned correctly.

 

[hetrickw]

thats' mu concern. when the timing marks are aligned on the crank gear and cam gear the rotor is at noon position, and the #1 culider corresponding dist cap wire plug is at 1 oclock. so, how if I have tdc with timing crank/cam marks did it slip out to 1oclock on the distributor rotor? I'm missing something simple here. the distributor is fully enganged in the mesh gears and seems fine. even iff the harmonic balancer was out, the gears and rotor should be true, just timing BTDC/ATDC would be innacurate. thanks all

quote=jbojo;219461]

I can't remember but maybe someone else can confirm. When the two gear marks are aligned you should be at TDC. Where is the rotor at and where is the timing mark at on the damper. I would think TDC if everything is aligned correctly.