Hot Rods SBF running crappy

Can not get the car to run very well and backfiring thru the exhaust.
I have played with the carbs and now looking at the timing.
Engine is a early 90`s 5.0 with a E303 cam.
With the timing light pickup on #1 very erratic to the point of rarely seeing the numbers on the balancer. On a whim, switched to #5 wire and all is well, numbers are there and no variation. Where am I going wrong?
Firing order is for a 5.0, 13726548.

 

What dizzy are you running?

 

Don't be insulted by this,but you do know that Ford numbers their cylinders completely different from Chevy,right?

The Ford order is:

Passenger side from front to back:1,2,3,4
Driver's side from front to back: 5,6,7,8

A lot of Chevy guys get it wrong on a Ford (just like I effed it all up on a BBC I built once).

Scott


Posted using two Dixie cups and a medium length piece of string.

 

This I know and it is correct.

 

It is a mallory unilite.

 

Is this a hi out put with a roller cam? if so it uses a 351 w firing order.

 

Did you just replace the cam? I am running a 306 with E303 and shaved heads. I had the same problem with stock distrib. chamged over to MSD with a 6al box and problem solved.

 

Tedly you beat me to it. That was my next question.

 

Edelbrock aluminium heads, Malory Unilite and a MSD 6A box as well.

 

Ran fairly well with a 650 DP but seemed to always be running rich.
Now have 3 Holley 94`s that the Dickster has helped me dial in.
I don`t think the carbs are causing it and suspect it may be timing.
Had the dizzy in and out several times, swapped wires forward and back . Everything is back to the way it was last year now.

 

Yes it is the HO. Isn`t the order 13726548?

 

Did you degree the cam in final build? How old is timing chain?

 

Timing chain was installed new.
No I did not degree the cam, just installed per manual, marks on gears.

 

No the ho is early timing.

 

Everything I am reading is saying the HO with a roller cam uses the 137... order and the same as the 351.

 

Just a bit of advice (I learned the hard way) ALWAYS degree an after market cam. Some times things get mislabeled. I have had late model cam in an early model box.

 

Have you checked for vacuum leak on vac. advance

 

Vacuum disconnected to set timing as per manual.
That is something I need to check in the morning. Thanks

 

I would hope that Ford would have gotten it right.
I have the card somewhere I think.

 

Is the distributor a used unit?We pulled one out of a Ranger with a 2.3 with lots of miles on it.
The distributor looked pretty clean,and appeared sound from just a visual inspection,but after checking everything else we could think of,the backfiring and crappy performance persisted,so the distributor was pulled....and literally fell apart when removed from the motor.
Rebuilt distributor cleared up all the power and driveability issues.

If your distributor is in good shape and can be ruled out,what have you got for a timing chain and gears?Those old stock ford aluminum camshaft gears with the nylon teeth are a major problem....they spit out teeth like a preppy kid at a gang BBQ in the hood.

Or maybe the distributor just decided to mess your life up by sliding in one tooth off...?

If it runs good otherwise,and only backfires when you chop the throttle shut,it may just be a vacuum leak or a carb that is waaaay lean?

I probably shouldn't have thrown out eleventeen dozen things at once there,but I figured I would just give you everything I could think of right outta the gate,and give you some possibilities.Hope I could be some help to you.

That should be one good running little motor once you get the bugs worked out.Please keep us posted with your progress.I would like to know what the problem turns out to be.

Scott


Posted using two Dixie cups and a medium length piece of string.

 

I just did a E303 in a 5.0 with out having the cam timed and the timing is all wacky now. I get the feeling that the cam may be a ways off as it is reading 37 degrees initial advance where it runs best. I have the cam card for it if makes a difference.

 

Thanks For your input Scott.
New everything.
Steel gears, double chain.
Tri power and idle circuits in primary only with progressive linkage.
What has me scratching my head is that the light shows nothing with pickup on #1 but works fine on #5. This I can`t figure out.

 

5.0L HO motor is definitely NOT early 289/302 firing order,its 351W firing order as the OP stated.

Scott



Posted using two Dixie cups and a medium length piece of string.

 

I'm running an X303 cam, they use the 351 firing order just as does the E303. You have your wires in the wrong sequence.

Don

 

Crank timing should be between 10* and 14*. Also check plug wires for cracks or spark jump (short) and check for resistance

 

Sorry I ment 351 timing not early. Its been a long day.

 

Is cylinder #1 missfiring?
Try setting the timing with a vaccuum guage.
Connect guage to manifold (not port) vaccuum.
Adjust timing to obtain the highest vaccuum reading. Then back off the timing by about 2 degrees.
Readjust carb idle speed. Recheck timing/vaccuum reading.
Road test. Listen for pinging.
Timing marks/outer hub may have slipped on the balancer.?

 

I figured that's what you meant,as you have obviously worked on plenty of Fords,judging from your responses about this stuff.
You obviously have your shit together Brother

I just wanted to prevent any confusion.Sorry if I came off sounding like a bit of a knob...

Scott


Posted using the Full Custom H.A.M.B. App!

 

Did you change drive gear on the distrid. before install. It needs the bronze gear.

 

No Scott I'm glad you cought it or he could have had worse problems. Thanks