HELP! - Engine Dies When Revved

[froggyrocket]

Anyone -

I've got a 1988 Festiva L that for some reason almost always runs GREAT but every now and then the engine boggs down/starts to die when you rev the engine up above idle. To clarify: it runs fine in idle but when you step on the gas pedal to get ready to release the clutch, it starts to die. (yes, even with the clutch fully engaged) At the desired higher RPMs, unless you constantly goose/rev the gas pedal it will bog down and die. If it dies you can immediately start it up and it will run just fine in idle. Try to rev the engine above idle and it starts to die again. My guess would be that for some reason the fuel flow requirements above idle (stepping on the gas) cannot be met, as in, something must be restricting the fuel flow when above idle??? The car sat for almost a year while I was overseas but that ended about 9-12 months ago. When I worked on getting it running again the problem then was it would die in idle. The following repairs solved the idle problem:

- 88 Festiva L
- 167,300 miles
- no engine mods
- overhauled/rebuilt carberator
- new spark plugs
- new spark plug wires
- new distributor cap
- new fuel filter
- new air filter
- tightening a loose wire inside the distribtor (after the engine was warm the wire would start to arc and cause the engine to run rough/die in idle)

Even after 4 or so tanks of gas, could it just be water in the tank?

BTW, the fix seems to be to just let it sit. Several hours later or the next day it runs just fine. It started acting up today at 11:15 AM and when I ran it tonight at 7PM it did the same thing. However, I ran it just now at 9:40PM and it runs JUST FINE.

ANY IDEAS???????

[perucho]

Does the distributor have a vacuum advance? Is it working properly? Is you accelerator pump working well? Go over your whole vacuum system and make sure you don't have any leaks.

[FestYboy]

i would suspect your accel pump first given the description you have. and is the issue temp dependant?

[froggyrocket]

OK, claiming ignorance here....what's an accelator pump? Where is it? What would cause it to act sporadically? How would it "fix itself"? (Just waiting seems to fix it).

No, the issue doesn't seem to be (so far) temperature dependent. Before today, it happened about 5-6 weeks ago and temp was fairly warm. Today temps were about 80 degrees. It does seem to happen within a minute or so of starting the car for the first time of the day. Ran it tonight right after my post and it ran great.

[FestYboy]

your Accel pump is a small plunger that forces raw fuel into the throat of the carb durring throttle stabs (one burst per stab). it's located at the lower right rear corner of the carb (passenger side). if the diaphram is punctured/torn in any way, it can bleed down and the plunger resevoir will go dry untill more fuel from the bowl can fill it back up.

if your bowl bleeds down overnight, this can also affect your accel pump (why it happens in the morning and not later in the day).

also take a look at your choke plate in the morning (cold engine), it shoule be completely closed, if not you could have a lean bog condition. (i don't subscribe to this idea too strongly though).

[2ndmouse]

One of ours did that too once, it was the pressure regulator on the fuel rail. It ran fine till you pushed the rpms up or put a load on it.

If yours is FI, that could be it.

[TominMO]

One of ours did that too once, it was the pressure regulator on the fuel rail. It ran fine till you pushed the rpms up or put a load on it.

If yours is FI, that could be it.

- 88 Festiva L
- 167,300 miles
- no engine mods
- overhauled/rebuilt carberator

[johnmt]

I just went through that on my 88 - idled fine but it would stall with any throttle, even no-load. When it acted up once, I noticed that the accelerator pump was not working. Even though you just rebuilt your carb, you may want to check the inlet check valve to the accelerator pump. The passage is right at the floor of the float bowl in a narrow slot. If you pull the acc. pump (4 screws) and Acc. pump diaphragm off, there is a little brass piece at the bottom. I couldn't remove it (pressed in?) so I just made sure it was clear of crud on both sides. It seems to have fixed the problem on mine. Good luck, John

[MAVRICK513]

My carb'd '89 was doing the same thing. I rebuilt the carb too. All vacuum lines were on correctly & I put on a new fuel filter. It still wanted to shut off when I tried to pull out. I never could narrow down to what it was. I changed the plugs, plug wires, dist cap & rotor, coil, reset the ignition timing, installed an extra distributor I had laying around & suddenly it was fixed. I'm still not sure what fixed it. Good luck!

[froggyrocket]

(froggyrocket's dad) Guys -

Thanks for all your ideas, particularly the specifics from "FestYboy", "johnmt" and "MAVRICK513". I printed out all the posts and will take them to a mechanic to look at. I saw that at least 2 of you have had the same problem so at least I know I'm not smoking crack or am simply cursed.

I am curious though as to why this happens only every now and then. It's been running pretty danged good since I posted in late September. Any ideas on that?

[Mike McKown]

(froggyrocket's dad) Guys -

Thanks for all your ideas, particularly the specifics from "FestYboy", "johnmt" and "MAVRICK513". I printed out all the posts and will take them to a mechanic to look at. I saw that at least 2 of you have had the same problem so at least I know I'm not smoking crack or am simply cursed.

I am curious though as to why this happens only every now and then. It's been running pretty danged good since I posted in late September. Any ideas on that?

I'd pull the drain plug in the gas tank and let it drain into a clean container, let it sit for awhile and see what settles out. You may see water or you may see a very heavy haze mixture of gasoline and ethanol floating toward the bottom of the container.

[drddan]

There's a drain plug on the gas tank?! I'm gonna go look! That would be so cool. Never seen a drain plug on a gas tank. Also the accelerator pump DIAPHRAM on carbs do that a lot when stepping on the gas. Used to have to change the diaphram on my old 80 Bronco every 2 years or so. They have a tendancy to get small holes in them and then bog when accelerating. I think gas with ethanol alcohol in it speeds up the detereration of the rubber diaphram as alcohol and rubber dont like each other.

[Mike McKown]

Left side of the tank. About 14-15 mm hex head plug. It's probably covered with undercoat and could be hard to see.

[sanjeet]

Simple check, look in the window on the carb and check the fuel is at the right level (it should be in the middle of the sight glass) if its not you will need to check the float etc

[hermit]

id open it up, take the fuel sending unit out and check the gas tank for rust, had the same problem as you and changing the tank out fixed it. my tank was extremely rusty though


could be rust clogging up the sock in the fuel sending unit when you step on the gas.