Is this vapor lock?

I recently acquired my very first ford....it's a 1988 eddie bauer bronco II. It has been brutally hot where i live for the last 10 days. On 2 occasions during this heat wave, after driving for a little while (15 - 30 minutes) with the temp hovering around 100 degrees, after a short stop - the stop was 5 to 15 minutes - the vehicle wouldn't start. After short blast of starting fluid it would run for 3 to 7 seconds and die. 1/2 dozen attempts gave the same results. So, i leave the car where it is for 20 minutes, retry the starting fluid thing and the same thing happens....it runs for 5 seconds. after abandoning the car for several hours the first time and overnight the 2nd time it will start right up...no problem.

I'm kind of liking the vehicle but i can't go on with this issue. Advice? Comments? Commands? Help me and you can be my hero for the day. &lt

Welcome Steve,

That could be vapor lock....or a mal-adjusted carb. The choke could be adjusted wrong. The float bowl coud be leaking,or other minor problems that could result in the engine actually getting flooded. Flooding could have the same systems as vapor lock , or an empty fuel bowl.

Try this: when the engine won't start, look in the venturies, and pump the throttle. Look to see if the accelerator pump is squirting fuel in the throttle bore. If there is none or very little, the fuel bowl is empty or indeed has vapor lock.

Take a good look at the fuel line. Places where it has a bend in the line and is close to the manifold is prime for contacting heat and causing problems. Look under the vehicle, I have seen a hole in the exhaust pipe blowing on the fuel line, and causing the problems you describe.

Good Luck, and let us know what you find.

yo Steve;

What engine is in it?

Any maintenance records or receipts showing the fuel filter has been replaced recently?

same for air filter and oil (not related to this issue, but I would inspect/ replace as necessary all filters; and fluids in no records are available)

Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19

http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.

Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to:

KOEO

& if you can get er running long enough to get eng @ norm op temp;

KOER

Is battery charged and all cables (+ ans -) & their connectors tight and clean?

Is there gas in the tank?

fuel injected,

fuel pump inside the fuel tank, & another between the tank and the engine. The power for pumps comes through a relay, and poewer to the relay is supplied through a fuse. If you don't have fuel pressure in the engine compartment, check those first.

miesk5 said:

yo Steve;

What engine is in it?

Any maintenance records or receipts showing the fuel filter has been replaced recently?

same for air filter and oil (not related to this issue, but I would inspect/ replace as necessary all filters; and fluids in no records are available)

Try a Self Test for Diagnostic Trouble Codes (DTC)s by my pal, BroncoJoe19

http://broncozone.com/topic/14269-code-reader/page__pid__74587__mode__threaded

The engine temperature must be greater than 50° F for the Key On Engine Off (KOEO) Self-Test and greater than 180° F for the Key On Engine Running (KOER) Self-Test.

Run it around to heat the engine up and shift thru all gears incl Reverse. Then turn off all accessories/lights, etc.

Make sure A/C is off and transmission is in Park (automatic) or in Neutral for a Manual & release clutch.

Do Key On Engine Off (KOEO) portion first.

Look Codes up in my broncolinks.com site using the new Search function.

And Post em here according to:

KOEO

& if you can get er running long enough to get eng @ norm op temp;

KOER

Is battery charged and all cables (+ ans -) & their connectors tight and clean?

Is there gas in the tank?

fuel injected,

fuel pump inside the fuel tank, & another between the tank and the engine. The power for pumps comes through a relay, and poewer to the relay is supplied through a fuse. If you don't have fuel pressure in the engine compartment, check those first.

Click to expand...

Let me start by saying that I am a computer programmer and am in NO WAY am i even slightly a mechanic. saying things to me like "look in the venturies" is like taunting a starving man with cupcakes.....I'd love to do it but have no idea how to go about it. I do know from listening to years of "Car Talk" on NPR, that there are 3 main components that must be present...spark, fuel, and air. When this problem comes up, i supply fuel with the can of starting fuel and the beast will run for a few seconds - until the starting fluid is consumed. To me (and perhaps erroneously) that means that fuel is my issue. This problem has occurred when the fuel level in the tanks has been at or below 3 gallons - and that is an estimate as the fuel gauge does not work. I've been told by folks who have earned no credibility that if i had more fuel in the tank, this issue may not occur - vapor lock or not. something about the fuel pump being in the fuel tank, negative pressure, fuel delivery in this vehicle being possessed by demons, etc. The beast has EFI, and these same folks with no (demonstrated) credibility say that vapor lock is rare in EFI cars...but that fuel lines too close to the manifold or other similar issues may be at fault. The check engine idiot light does not come on - does that mean that trying to do code reads would be fruitless? Although i may be a computer nerd, i live in the mountains and 4 wheel drive is not a luxury. I had a Pathfinder for a quarter million miles that needed no TLC - have i bitten more that i should have by getting this Bronco?

yo STEVE

I hear ya. I was lucky to learn a bit @ 5 yo when dad was a Marine and him and my uncle Pete would go to junk yards on weekends to swap engines and many parts. I was the official "crawler" and gas/brake pedal tech.

There is no easy answer to the issue you have such as replace fuse #z..

so, The simplest DIY tests you can attempt are;

Try the Self Test for Diagnostic Codes; you can use this test

A few possible codes that WILL CAUSE your issue are;

87 (KOEO) Fuel pump circuit fault (check inertia switch under pass side dash, next to transmission ****



READ THIS by Craig Evers

; "... pushed the RESET button on top of it, and the motor cranked right up ..."

) - Power / Fuel Pump Circuits

or intermittent in fuel pump primary circuit

91 (KOER) System running lean

95 (KOEO) Fuel pump: open, bad ground

or

Possible bad fuel pump ground or open between fuel pump and pin 8 at PCM (Fuel Pump Monitor signal)

96 (KOEO) Fuel pump monitor circuit shows no power

-----------

Again, Any maintenance records or receipts showing the fuel filter has been replaced recently?

same for air filter - check it and replace if the filter elements are not white.

and oil (not related to this issue, but I would inspect/ replace as necessary all filters; and fluids in no records are available)

==========

you or a helper can feel any pump vibration or listen for Noise to determine if the in tank pump and frame rail mounted pump runs when ign key is turned to start position. Let us know.

Your 1988 Bronco II has 2 fuel pumps. It has a pump in the gas tank and a pump on the on the drivers side frame rail

The round cannister near the fuel tank is probably empty with no filter, so don't touch that.

In-line Fuel Filter Replacement

Sorry to be so techy Steve,

I didn't know your ride was EFI=(Electronic Fuel Injection. ) so everything I posted is unusable info....sorry.

It is true that is is extreemly rare for a FI vehicle to have vapor lock. The fuel is in a high preasure loop, and doesn't get the time to sit and soak heat like a carb motor.

As M5 said check for codes. even though the CE light is not on or didn't flash on, there can be codes stored. This you would understand better than me, it's some computer decision , priority, thing, as to turn on the light or not.

Another thought is the fuel relay or collision impact (inertia) switch may be at fault. I have found a relay that got hot and would fail until it cooled off.

Or it can be a matter of some passages in the throtle body being too dirty. ( a problem exactly like yours popped up on my 500SL...it was the throttle body dirty from sitting too long.)

Check for codes and let's go from there

Rons beast said:

Sorry to be so techy Steve,

I didn't know your ride was EFI=(Electronic Fuel Injection. ) so everything I posted is unusable info....sorry.

It is true that is is extreemly rare for a FI vehicle to have vapor lock. The fuel is in a high preasure loop, and doesn't get the time to sit and soak heat like a carb motor.

As M5 said check for codes. even though the CE light is not on or didn't flash on, there can be codes stored. This you would understand better than me, it's some computer decision , priority, thing, as to turn on the light or not.

Another thought is the fuel relay or collision impact (inertia) switch may be at fault. I have found a relay that got hot and would fail until it cooled off.

Or it can be a matter of some passages in the throtle body being too dirty. ( a problem exactly like yours popped up on my 500SL...it was the throttle body dirty from sitting too long.)

Check for codes and let's go from there

Click to expand...

This was all GOOD information and dummied down to computer geek DOD (degree of difficulty). of course, i have to wait for the issue to present itself again to do some of these things....however, i will say that fuel filter will be changed anyway....air filter is good (i know this as i removed the air filter cover to spray in the starting fluid). I bought the vehicle from a friend who says the oil if pretty fresh = it was rehab project for him and he's a computer geek too....but he never drove it in the summer and never had the problem. that also lends creedence to the temperature being a factor. I've been in the flatlands all summer and the heat is WAY above anything we ever see in the mountains. I am keeping the tank closer to full too, hoping that might help banish the problem. A cousin who has a little ford wagon swears that a close to empty tank is a big no no in the ford scheme of things......

Thanks for the help and i'll post any new developments.

if it does it again try removing your gas cap, if the gas cap is not venting properly it an cause your gas tank to pressurize and thus allow the vapors into the fuel lines. vice versa if your cap is not allowing enough air in to compensate for the flow of fuel then it will starve the pump and also cause a no fuel pressure problem.

Krafty said:

if it does it again try removing your gas cap, if the gas cap is not venting properly it an cause your gas tank to pressurize and thus allow the vapors into the fuel lines. vice versa if your cap is not allowing enough air in to compensate for the flow of fuel then it will starve the pump and also cause a no fuel pressure problem.

Click to expand...

More good info! thanks - it hasn't happened again but the weather has cooled some.

Good thing I came back..

I had the same exact issue. 89 full size with EFI.

Come to find out, it was the ECT sensor (Engine Coolant Temp). I had a day like that in CO. So hot out, I ran the A/C. Was at a stop light, and when I hit the gas, it bogged and bucked like none other. Pulled off onto a side street and it died. About 30-45min later it started up, like nothing ever happened. Of course I tried to start it after it stalled but it wouldn't kick over.

Kicked and bucked again and I turned it off a few miles down the road. I was close enough to leave it and walk home. Came back that night (about 95 that day, down to 60 that night) and started up, no issue. I forget how I found the answer, but somehow I was directed tot he ECT sensor.

Some times I could drive around on a hotter day and go into subway or liquor store and come out to a truck that won't start. New ECT, never had the issue again. And I've been in TX now for the last 1.5yr where it's MUCH hotter than Colorado. 85* at night, and 105* in the day time.

Good luck!