• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

will not start when hot...

69redrunner

69redrunner

Well-Known Member
Local time
5:05 PM
Joined
Aug 9, 2011
Messages
614
Reaction score
196
Location
Prescott, Wi
After reading threads by others, I figured I would try the phenolic spacer route. Just finished the install, took her out for a nice warm up test drive...park her in the garage and let her sit for 10-15 minutes. ...no start. Cranks and cranks but will not fire. Backfires thru the carb occasionally. Pump the pedal, hold it to the floor, makes no difference. Will not start. Let it sit for an hour or so and it starts right up.
I'm open for suggestions. ...
 
Fuel seems to be evaporating quickly from the bowls in the carb by your description. That is not unusual with the newer blends of fuel. Could also be the fuel pressure from your tank to you carb. Is there a fuel filter in line or something else that would be slowing the amount of fuel to it. I have been dealing with a vapor lock throttle issue lately and just got it ironed out yesterday. Went with a 1/2 inch spacer and rechecked my electronic distributor setup. Had a Reluctor issue and after re doing it the car is running excellent. Oh...And what type carb are you running. That would help us out too...cr8crshr/Tuck
 
Tuck, its got the carter AFB carb. I have an inline filter under the hood, its full, with no bubbles when running. When I shut it off the fuel seems to drain from the filter pretty quickly. ?????
 
evaporation and timing issue i would say. is there any chance of running a check valve near the tank to keep more fuel in the line, also running a return line from carb or regulator back to tank. and then look at getting the heat away from your fuel lines and carb, by wrapping your lines in heat proof, re-routing them, etc. backfires is usually a timing issue i am lead to believe
 
69redrunner said:
After reading threads by others, I figured I would try the phenolic spacer route. Just finished the install, took her out for a nice warm up test drive...park her in the garage and let her sit for 10-15 minutes. ...no start. Cranks and cranks but will not fire. Backfires thru the carb occasionally. Pump the pedal, hold it to the floor, makes no difference. Will not start. Let it sit for an hour or so and it starts right up.
I'm open for suggestions. ...
Click to expand...

Man, summer is the season for fuel problems. You will find lots of info if you use forum search, also the 'similar thread' section at the bottom of your post. The hemi thread from 2012 is a good one to read through.

Everybody has a different setup so its hard to have a prescription for each situation. Backfire might indicate lean condition or timing issue, so if you have timed your motor from cold start you probably have vapor lock or fuel flow issue from the pump, or some sort of fuel delivery problem.

It's interesting that you say the fuel drains back quick? If you are running deadheaded (no return) with a mechanical pump the fuel should be pressurized even after shutdown because the pumps have an inlet check valve that prevents fuel from flowing back to the tank. Back when I ran line straight from pump to carb, if I opened the line up even at 5psi I would get sprayed, this is well after key off. The bowls would have to be full with carb inlet shut for it to remain pressurized. I would take a closer look at the pump. If you are getting proper flow, those bowls should be full if you are just idling.
 
Good advice here. Is it the1/2 inch spacer? Mine was a combination that helped. The spacer, coated headers to reduce overall underhood temps, and rerouting and wrapping the fuel lines. Shroud. What was the ambient?
 
Keeping todays fuel cooler is a high priority on these cars, Like Dennis said wrap your fuel line keep as much heat away from the carb as possible. Remember today's gas is for electronic fuel injection systems not carbs.

You can buy this 6000° tubing stuff off ebay to slip over your lines or find something from jegs etc. Nitrate or phenolic spacer under carb wrap headers if you have to. upgrade radiator / fan size etc. make sure tank vents are clear and only venting not drawing in hot air.
 
Blocking the heat crossovers will help quite a bit as well. Not preferred for cold weather operation, but I'm guessing you're not out Christmas caroling in it come December in Wisconsin. FelPro makes a valley pan for a B or RB block with the crossovers blocked already.

http://www.jegs.com/i/Fel-Pro/375/1214/10002/-1

http://www.jegs.com/i/Fel-Pro/375/1215/10002/-1

As far as the spacers, IMO the wood ones from edelbrock always work well. Like the other guys mentioned, wrap your lines in thermal tape or use some thermal sleeving. Those will also help quite a bit. My roadrunner, I also wrapped the lower portion of the pass. header, where it comes in close proximity of the fuel lines. Good luck.
 
Propwash said:
Blocking the heat crossovers will help quite a bit as well. Not preferred for cold weather operation, but I'm guessing you're not out Christmas caroling in it come December in Wisconsin. FelPro makes a valley pan for a B or RB block with the crossovers blocked already.

http://www.jegs.com/i/Fel-Pro/375/1214/10002/-1

http://www.jegs.com/i/Fel-Pro/375/1215/10002/-1
Click to expand...

X2 on blocking off the head crossover passage- it will keep things a lot cooler and even help cool down intake charge when running.
 
I had to go with a 1/4" spacer due to clearance issues with the air grabber hood.

Based on recommendations I will put a new fuel pump in just to eliminate that as a possible candidate. I will also wrap the lines.

I am not running headers, I have stock cast exhaust manifolds.


Does the intake and or heads have to come off to install the block off valley pan?

Is there a way of visually seeing if the crossover is already blocked?
 
To install a valley pan, you'll have to pull the intake. Well that and the 2 hold down straps at each end of the block. When installing a new pan put one in that has the X over ports blocked off. Fel-pro #1214 I think for B engines. #1215 for RB engines. Simple enough of a job actually. And no, there is no way I am aware of to see if the crossover has been blocked without positive visual confirmation.
 
So, if the intake has to come off to install the new valley pan (which I did buy and have plans to install) would it benefit my situation any to go with an aluminum intake instead of the stock iron intake? If aluminum would be better. .what brand?
I have a 4 speed so looking @ 0-5000 rpm
 
Heck yeah man lol Loose the weight and gain some HP I run the edelbrock performer air gap and love it. Dual plane, another great buy for my 440.



69redrunner said:
So, if the intake has to come off to install the new valley pan (which I did buy and have plans to install) would it benefit my situation any to go with an aluminum intake instead of the stock iron intake? If aluminum would be better. .what brand?
I have a 4 speed so looking @ 0-5000 rpm
Click to expand...
 
Thanks bigman. Is the eddy performer air gap manifold about the height as the stock o.e.? I need it to fit under the air grabber hood.
 
I didn't read every post.....would an electric fuel pump do the trick?? it worked for me.
 
Fuel pump shot..... is what I think... once everyone stops selling parts.... the fuel pump pleads down.... an electronic pump runs cooler... I like the one for a 78 Chevy luv pick up..... Napa sells 2for it and I get the expensive one....
 
I have a new spectra premium replacement fuel pump on it's way. Not an electric, just a like for like mechanical pump.
 
Sort of, eddy is a bit tall will work if you use single paper gasket and low profile air cleaner. I had that originally then got a 6bbl hood. If you use a drop base style 14" or so you can get a 2" filter I also used that with a kn filter top. Just fit under hood lol.
 
My stuff is to tall already. I'm running a 440 with a 1/4" phenolic spacer and still using the 383 air grabber base. When the hood is closed it pushes the rear of the hood up about 5/16".
 
Same with mine it was easy for me to switch hoods since that was the direction I wanted to go in anyway solves a lot of clearance issues. Some things you have to make to hard call on. This is one of them.
 
You must log in or register to reply here.

Similar threads

P
MOPAR PERFORMANCE 6.4 HEMI CRANKS NO START
Replies
7
Views
2K
Polara426
P
matchek
70 Charger having trouble starting in park when cold
Replies
16
Views
1K
Ron H
R
D
1972 440-4 Difficult start after not being driven for several weeks
2
Replies
34
Views
2K
Geoff 2
G
dadsbee
Any seasoned Mazda Techs on the board
4 5 6
Replies
117
Views
5K
RemCharger
RemCharger
F
318 hard start when cold
Replies
10
Views
3K
Franky318
F
Auto Transport Service
Back
Top