SilverRocket

Alright boys. I'm in need of some urgent help...

I'm home only for 3 days, and if I can't fix this problem my car may have to be parked for the winter. **** I don't want to drive my stupid *** honda civic again...

In advance, I'm sorry this post is so long!

Here's the problem that developed today (I drove 8 hours today on a long trip):

1) Symptoms:

This problem only manifests itself under wide open throttle (WOT)

Under WOT, everything is normal for 3-4 seconds. Then the power just cuts - it will hold at a given rpm but will not rev up any further. This is accompanied by an audible "rattling" noise. The noise sounds like it's coming from underneath the car. I don't believe it's coming from the engine.

This doesn't seem rpm-specific. It just happens after a few seconds of WOT - whether at 7000 rpm in third geat or 5000 rpm in fourth gear, it doesn't matter. It only happens only in 3rd gear and up. However, 1st and 2nd are over so fast it wouldn't have time to happen anyways.

The motor will rev up freely in neutral, no problems there. I can also hold at any given rpm on the road and it's fine. Like I said, only after WOT.

I kinda feel as if the motor is running a little "off". I don't believe that it would be noticeable if you didn't know the car like I do... It just feels a little different than usual. Power 'may' be down overall a small bit, but not a lot. It is intermittenly idling a a little low, but that's nothing too out of the ordinary.

2) What I did so far (and found something weird)

So I decided to change my fuel filter, first things first. When I pulled the lines off the old filter, fuel started gushing out like crazy!!! Usually a few drops come out, but approximately 1 liter came out while I changed the filter. Is it possible there is some valve or something stuck open???

BTW changing the fuel filter did not solve the problem.

I'm tired and it's dark so any real work will have to wait until tommorow.

I talked briefly with RXcetera on the phone earlier, he suggested perhaps the car might be misfiring or detonating. My timing has been set at the Paul Yaw settings of 24L 16T @ 4000 rpm for the whole summer, with no problems. RXcetera thought maybe this was a little on the advanced side of things.

I really godamn hope this 'rattling' sound I'm hearing is not detonation... I have never heard detonation before, and never want to. I hear that the motor would shake noticeably if this happened though - it definitely is not shaking, just holding at rpm and not reving any more. Like I said, it doesn't really sound like it's the engine that is making the noise.

So what's the deal?? Is it my fuel pump? Ibell told me about another problem area last weekend - some kind of "sender" in the gas tank? From what I have seem I think this is a fuel problem. But then what the hell is the rattling sound?

How about my driveshaft, maybe u-joints loose? I really hope this isn't somehow my tranny. I think my ignition system is alright, or at least was up to this point.

Thanks so much for your help in advance, you guys are awesome. If I don't figure this out in the next 3 days, I'm fucked

clean

Hey, I really don't think this is your problem, but I'll throw it out there anyway, I had a problem kinda like this on an old mustang, it was a four speed, and it only did this in 4th gear. It turned out it was the gasket between my carb and the block, it was shot. When I got up to the high speeds, I guess I ended up getting air leaking through underneath.. as I said before, I don't think this is your problem, but take a look at your carb, see if it seems a little loose, or if you can see any peices of gasket material. If this isn't your problem, you won't waste any more than a minute or two figuring it out.. I hope..

SilverRocket

Thanks for the suggestion Clean, I'll check it out tommorow.

Anyone else have any ideas?

bennett

Not that I have the end all in experience, but a friend of mine had left a fuel filter in for way too long and started having some spontaneous power cutoffs. He replaced the filter, but still had some of the problems that you're talking about. We concluded that the fuel pump was getting overworked all those years and that caused some damage to the pumps effectiveness at high-flow.

However, there were so many problems in that 82' that we could never really isolate the problem as the pump issue or bad carb.

I don't know if putting a psi or volume gauge on that pump can help you diagnose it, but it might be worth a try.

I don't know about the rattling -- unless it's your fuel pump dangleing under the car.

Viperx7

iTrader: (4)

Kinda sounds like the fuel pump. How old is it?

Denny

That was the name I gave to my old 544 Volvo Turtleback (Looked like a minature '40 Ford), 'Ol Rattler....

You still runnin' cats, Son?....Bet yuh are, aren't yuh?
Without being there, I'd hazard a guess that you've got a clogged, or broken cat converter. I'd say you giving us those indicators...Sounds like the honeycomb inside is broken, and that's whats rattlin'. After a long trip, hot cat, go over a bump, or some railroad tracks, or even on it's own accord, honeycomb can break, clog up the passage, and rattle around. Check it out, Pardner...

Oh, and you should be "gushin' gas" when you change that filter. One of the lines is an open one straight to the tank. I always plug it when I change fuel filters, but I still get some running down my arm....Stings in the 'ol armpit, don't it?

Best to yuh!
Denny, from the 'ol corncrib....

REVHED

Since it's only happening after running at WOT regardless of gear or rpm I'd say it's gotta be fuel related. The rattling sound could very well be your engine detonating due to running lean. Not very healthy. Might be a good time to get rid of that stock pump and put in something decent. Take it easy.

vaporhead

since it only happens at wot it might be float drop related. unless you hammer it pretty hard, pretty often the secondary float doesn't get much exercise. and that could also make a lean condition under WOT.

SilverRocket

Ok guys, thanks for the informative replies.

I'm worried that the rattling sound is in fact detonation. I just hope I haven't damaged my motor all ready.

Denny, I don't have any cats (full RB exhaust), so unfortunately that isn't the problem. I wish!

I think the fuel pump is a definite possibility, I don't have a pressure guage but I can easily do the volume test to see if it's the culprit.

What's the best fuel pump to get if I do need one? I see 'Carter 7psi' all over the place... I assume that's the hot one? And a pressure regulator I guess to go along with it? Does this pump bolt in the stock location easily, or is it a 'custom' intall?

I wondered about the carb too, is there an easy way to determine if the secondary float is not doing it's job?

RXcetera is coming over thie afternoon to help me figure this out. I'll post up results later today.

Thanks for the help guys!!

REVHED

What do you mean by secondary float? There's no such thing. There are two float bowls, one for each rotor. The primary and secondary fuel jets for each rotor feed out of the same float bowl.

And SilverRocket, the Carter won't bolt in the stock location but it mounts very nicely on the left sub-frame rail. There's a little flat spot just where it begins to curve up over the diff housing. But you should probably check your float drop first though. The only way to do this is to pull the top off the carb to gain access to the floats. The difficulty of this varies depending on how much **** you still have bolted to the carbie. Mine takes about 2 mins.

vaporhead

sorry; bad gouge on my part. standing humbly corrected.

rotorhead

my vote is on the fuel pump. had a similar problem myself not too long ago. what was happening is that my carb bowls were full, then hit WOT and they emptied out faster than the pump could supply new fuel. usually you can get around 8 to 10 secs WOT off a full carb bowl, after that, you're relying on the pump to keep the fuel coming. sure hope it helps!

MyRxBad

Any luck yet figuring it out? R U here or R U in Ottawa?
I've never pressure tested a pump before, but I have swapped new ones in and out of the 'ol 12a and stuff. So if ya need pointers and it ends up being your pump, lemme know, or give me a call. You still have my number?

Jeff20B

iTrader: (13)

I'd say it's a fuel pump and filter.

I cuurently only have enough fuel for around 10 secs of WOT in 3rd up a hill (it's good to give it a real load ).

If you get a carter and a pressure reg, be sure to "dead head" your pump. I love that term! Dead head means to block the return line.

I'm doing it to mine and I'll see if it makes a difference. Mine is a facet RB Holley 6PSI pump and a purolator press reg set to 5PSI for a 13B carb.

You'll need like 3-4PSI or somthing. The purolator diaphram style press regs are less accurate than the Holley style that Paul Yaw recommends.

SilverRocket

Hey all, thanks for the great suggestions!!

Anyways, believe it or not, the culprit was a broken trailing sparkplug. The porcelain around the electrode was broken off and wedged in between the 4 points, so that the plug could not fire.

The reason I thought it was giving out under WOT is that it was only misfiring in 4th and 5th gears, under high load. Little did I know that I was spinnin around on only 3 plugs.

RXcetera is the man; he came over and helped me fix my car for countless hours this week.

I was going nuts trying to figure this out. RXcetera and I checked the whole fuel system, timing, swapped in another distributor, new coils, cap and rotor, and I can't even remember what else. Checking my "brand new" plugs (bought last month) was an afterthought.

Anyways, yet another example of why to check the simple things first, even when you think you know they're fine.

MyRxBad

Same sorta thing happened to me.

Brought a brand new starter, 3 weeks later, car doesn't start. Change the battery, change the cables, and voila! the stupid brand new starter is the culprit. Arrggh..

Back up and running, great to hear!

JIMMY54

iTrader: (2)

i had that same stuff happen to me before