31 replies to this topic

[Johnny D]

Ran Sat fine, did practice fine Sun. Filled and ran full tank of gas for enduro. 1st time for full tank. Dirty gas filter/screen?

One person said it sounded like I was hunting for ducks. pow,pow,pow.
Lift off the gas on went back on full throttle sometimes would solve the problem.

Also in neutral my idle is fine, put it in gear the idle revs up and down.
Vacuum leak? Kinda separate problem but throwing it in.

Dyno will show the problem or try some things 1st and then dyno to verify?
J~

[James York]

What circumstances did this happen? Straights, coming off curves, etc. Full tank only or all way down to empty.

[Johnny D]

Seemed mid to exit curves, but happened down the straight as well. Only ran for 1/2 hour hoping it would get better but people running into me when they thought I was fine one moment and chocking at points I should be on the gas. Finally smelled gas, I was pounding the engine with it bucking and called it a day.
J~

[Jim Drago]

Seemed mid to exit curves, but happened down the straight as well. Only ran for 1/2 hour hoping it would get better but people running into me when they thought I was fine one moment and chocking at points I should be on the gas. Finally smelled gas, I was pounding the engine with it bucking and called it a day.
J~

Johnny
Do the tach/gauges blink and go crazy when it happens? (electrical problem)?
Jim

[Johnny D]

Yes the tach goes crazy.

I did find a wire in my trunk that went to nowhere and I taped so it wouldn't short.
Maybe I screwed myself and it was supposed to be grounded.

So this could be anywhere and maybe only with a full tank?
J~

[Jim Drago]

Yes the tach goes crazy.

I did find a wire in my trunk that went to nowhere and I taped so it wouldn't short.
Maybe I screwed myself and it was supposed to be grounded.

So this could be anywhere and maybe only with a full tank?
J~

check and clean all grounds

I think you have an electrical problem and full tank is a coincidence.
Check spacing on the crank trigger ( most common)

Replace cam sensor ( if you don't have a spare, you need one)

check the vacuum cannister up at the front of the motor that mounts on passenger side of engine compartment and slides into the holder ( roughly size of a coke can) make sure there is no fuel in it.

Check to make sure the battery hasn't slid where the hold down is now against the positive terminal and melting itself away, also very common.
Jim

[James York]

The reason I asked questions is that my car exhibited similar symptoms as to what you describe when I ran above 1/2 tank years ago. My issue was liquid gas overloading the vapor recovery system from the connections on the filler neck.

Do you have your roll-over check and tank check in place? I know some folks remove the tank check but I had to put mine back in to stop my problem which on the surface sounds the same as yours.

[Johnny D]

I got mine on CL with a blown engine for 1K.
Later it turned out it had a bad wiring harness. Missing wires. The shop said.
No telling how long it had been sitting.
Got a replacement from a junkyard.
Left head light still is dim.
Ran it all last year.

The little flap door on the fill, Yes it's there.

I'm hoping Deans enduro video will catch me in it and shed some light.
J~

[Johnny D]

check and clean all grounds

I think you have an electrical problem and full tank is a coincidence.
Check spacing on the crank trigger ( most common)

Replace cam sensor ( if you don't have a spare, you need one)

check the vacuum cannister up at the front of the motor that mounts on passenger side of engine compartment and slides into the holder ( roughly size of a coke can) make sure there is no fuel in it.

Check to make sure the battery hasn't slid where the hold down is now against the positive terminal and melting itself away, also very common.
Jim

Thanks Jim,
I know the battery is not sliding.
I'll have to dig into all the rest and order parts but gives me a good direction to look.

J~

[mdavis]

Thanks Jim,
I know the battery is not sliding.
I'll have to dig into all the rest and order parts but gives me a good direction to look.

J~

Had the same problem.
Did it throw a code? Had the same problem when it finally threw out a code. If I remember, the code is generic for either crank
or cam sensors. I ended up replacing both and problem solved.

[Johnny D]

Check engine lights on all the time. I didn't check for a code.
Thanks I'll replace them.

Anybody have this one...
Also in neutral my idle is fine, put it in gear the idle revs up and down.
Vacuum leak? Kinda separate problem but throwing it in.

J~

[chris haldeman]

had the same issue and found my crank sensor wires were chafed and grounding out on the lower pulley.replaced sensor added lots of zip ties and all was good.
good luck

[James York]

I got mine on CL with a blown engine for 1K.
Later it turned out it had a bad wiring harness. Missing wires. The shop said.
No telling how long it had been sitting.
Got a replacement from a junkyard.
Left head light still is dim.
Ran it all last year.

The little flap door on the fill, Yes it's there.

I'm hoping Deans enduro video will catch me in it and shed some light.
J~

Neither check about which I asked is the little flapper on the fill. But if you built this car yourself off a craigslist sale and don't know where the parts I referenced are located, then obviously you didn't take them out.

Jims and Chris' suggestions about a ground somewhere is also a likely possibility.

[Johnny D]

Neither check about which I asked is the little flapper on the fill. But if you built this car yourself off a craigslist sale and don't know where the parts I referenced are located, then obviously you didn't take them out.

Jims and Chris' suggestions about a ground somewhere is also a likely possibility.

No I didn't build it. I'm just good enough to be dangerous.
I'm a mech. designer and work in a machine shop, not a mechanic, but mechanical.
But I'm learning and working on my car more as $h#% like this happens now.
Thanks James,
J~

[Alberto]

Don't you also have an issue with the wiring to your cig lighter?

[Keith Novak]

At idle, if you jumper TEN and GND in the diagnostic box like when you're doing timing, does the RPM change significantly? I've found a couple vacuum leaks that way.

[Johnny D]

Don't you also have an issue with the wiring to your cig lighter?

I found the loose wire and the cool suit worked fine all weekend.
J~

[Johnny D]

At idle, if you jumper TEN and GND in the diagnostic box like when you're doing timing, does the RPM change significantly? I've found a couple vacuum leaks that way.

Haven't done it before, I'll have to try it. (Dyno guy did timing)
I jumper the fuel pump to drain the gas.
Thanks Keith.
Squirt soap and look for bubbles or something?

[Keith Novak]

The ones I've found, I just eyeballed my way around the intake side until I found something. The sudden drop in RPM hooking up the jumper just started me looking for what was wrong. When you mentioned possible vacuum leak it just struck me as a really easy thing to check.

[Johnny D]

All my hoses are orig and old, a couple more things to get weather I have a leak or not. Thanks again.
J~