Vapor Locking Bronco

[Custom_300]

So my trusty 82 Bronco is giving me fits. ( she may just be jealous of the Heep I mean Jeep I have been working on. )

Symptom 1: It will drive on high way does fine, Get off high way and she will do ok for a bit then start to sputter and stall. If I put my foot in it I can usually get past this and she will be fine. It has been hot here in Denver 85-105 for the past few weeks.

Symptom 2: Sitting at a light today she died all together No warning or anything. Also no highway driving. Acted like it has no fuel but gauge read 1/4 tank. (witch usually is right on the money)

After seeking some advice through a mechanic friend of mine he and the local parts store recommended relocating the fuel lines away from the block.

So my questions are:

1 has anyone done this and what was the outcome?

2 is vapor lock common with the stock 82 Bronco 302 manual pump, 2bbl motorcraft carb? (See specs below)

3 if I dont relocate the lines what are my other options?

 

[Bully Bob]

Hmmm.., what's the temp. gage reading...?

This could also be an issue with the electronic ignition. (coil, module, pick-up inside the dizzy, or some dirty/weak connections)

 

[Custom_300]

Hmmm.., what's the temp. gage reading...?

This could also be an issue with the electronic ignition. (coil, module, pick-up inside the dizzy, or some dirty/weak connections)

The temp gauge always reads hot but it has never been a real issue.

The truck usually runs fine when its cool ie.. 85deg and under.

 

[Krafty]

being as the mechanical fuel pump it right on the block you're not going top be able to move them far. you can try using some heat tape/wrap but my first move would be to rebuild that carb, replace fuel filter and check the fuel flow.

ill bet in 1982 they had 85+ degree heat and it didnt act up, otherwise who would buy a vehicle that wont run right from the factory.

 

[miesk5]

yo,

fuel can boil in the carb if there are improper or missing gaskets or spacers between the carb & manifold. A heat riser stuck in the closed position will also cause boiling and flooding.

Some excerpts from

http://www.recarbco.com/technical/newtrouble.html#Hesitation

Hesitation, stalling, stumbling, flatspot, or deadspot during acceleration: Backfiring or spitback up through carb.

1) Vacuum leak. 1) Check for vacuum leak & fix it.

2) Ignition timing ******** too far. 2) Reset timing.

3) Accelerator pump nozzle has dirt in it. 3) Clean out the nozzle tip.

4) Accelerator pump cup swollen up from contact with bad gas or chemicals. 4) Replace the pump cup.

5) Economizer jet too small or partly blocked. 5) Clean out economizer jet & check the size.

6) Choke pull-off open too far. 6) Adjust the pull-off tighter.

7) Secondary throttle plates not closing all the way. 7) Fix it.

8) Vacuum hoses hooked up wrong. 8) Connect up right. Be especially careful of the EGR & Dist. connections: sometimes the pipe locations are reversed on Rochesters.

9) Idle jet partly blocked with dirt. 9) Clean out the jet & any other dirt that is in there.

10) Distributor timing not advancing properly. (worn breaker plate, worn shaft, pin hole in diaphram, crack in hose, etc.) 10) Check distributor and all related systems carefully. Replace defective parts.

---

see Vacuum Leak Test @ http://broncozone.com/topic/22770-low-idle/

; On an idling engine check for vacuum leaks using a mechanic's stethoscope with the probe removed, or a ~3' garden hose section. BEWARE of fab, belts, pulleys and hot engine/hoses.

On COLD ENGINE only, use propane torch w/rubber hose attached, UNLIT (have fire ext @ hand for all tests)

or spray carb cleaner, when it gets to the the leak the RPMs will rise.

Also check: vacuum hoses; intake manifold gasket & throttle body;

 

[Bully Bob]

"The temp gauge always reads hot but it has never been a real issue."

This would be your first clue. :-" :-B

The least exp. route would be to test your temp gage & sender.., then serv. your cooling system. Waterpump is ok, then on to T-stat, hoses OK.., clean & proper amount of anti-freeze, Insp./test/clean radiator. Flush the whole system if dirty.

If carb. has been altered...research as M5 says.., & that heat riser must be working.

Small $$$$ well spent.

If prob. still exists.., then clean, insp. test ignition.