Ok quick details on what happened. Several cars went on a run. Myself and Fire451's car were out in the lead. He developed an electrical problem; car would completely shut down like he had pulled the keys out and turned the ignition off. It was around 11pm on a very cold heavy raining night. The decision was made that when his car came alive he was going to book it hard for my house. We were pushing 90-100 mph in a heavy downpour of rain. (Ya I know it was dangerous and stupid but there was mild traffic and I am veteran of 11 years driving this Fiero we both have good tires and suspension) We sustained 90mph for a great deal of time. When we got off the freeway I noticed my car sounded like it was detonating.

Is it possible that I had sucked in enough water and was still drawing in enough water that it was causing the compression ratio to be artificially high due to the fact that water won't compress like air does. That is my only possible guess. I know that people running boosted engines use water injection systems, but that is in a controlled system. I was probably sucking in a lot of rain. We were at about 1/4-1/2 throttle 3-4000 rpms.

Any suggestions on this.

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85GT 4spd MSD Everything, Big Cam and Nitrous. www.captfiero.com

I can't see how that would work cap... Even at high speed, the scoop wouldn't be sucking in too much water, as it is horizontal. Even if it did suck in the water, there's a pretty big slope for the water to have to travel up... and the high rpm you had wouldn't allow any signifigant amount of water into *each* piston's cycle.

Just my thoughts, anyway. Anyone else got any ideas?

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That's where you guys went the other night. I was looking for a drive somewhere. But probably a lot later than you. I went out about 11:00pm.

Anyways...back to your problem. Sounds like you were hoping you got "water injection" in your system.
It is unlikely as the previous poster noted. First water has to be sucked into the airbox, through a filter (is yours a K&N....which actually doesn't mind a bit of moisture?) which, if it makes it there, would be vaporized when passing through the filter. Then Up a pipe tha bends a bit and into the plenum. The engine heat should evaporate any moisture before it actually makes it into any cylinder.

I'm thinking moist air, heat and high voltage electricity in your distributor could cause some condensation and arching in your distributor at high speed. As there is a sensor in the throttle body that reads the fuel air ratio, I would think the problem isn't with fuel going into the engine. So my first thoughts would normally be electrical as most old cars are prone to develop electrical glitches when they get old.

Just a theory.

I think I stated that wrong. I don't want water injection. I was just looking for a reason for that to have happened. I know on other instances, after driving in a heavy rain, I have pulled into a gas station and just for hte heck of it pulled the air filter out and it was soaking wet, with a puddle of water in the air box.

I know I sucked in a fair bit of water, I just wanted to know if water in the motor could have caused what sounded like detonation.

I just installed the same side scoop (Fiero store, but I think they're the same) and haven't had any odd problems yet since the rainy season started here in CA, and I've made an 85+ Mph run or two myself in the rain (wide tires, stiff springs, and no brains). Then again, my water separator is intact, so that may be a big difference, though I find it hard to believe that the water wouldn't be sucked right in with the scoop at the speed I was going. I would tend to think that a little water would give you improved knock retard... but if you had a major amount of water in the engine, enough to artificially decrease chamber area enough to give you knock, that your air/fuel mixture would be so screwed up that other problems would show up first? I've also experimented with spraying varying amounts of water into the throttle body with the intake hose off. A little bit of water didn't seem to do anything, it ran and idled fine. When I'd pour a greater amount of water in, the engine would begin to stutter some (and there'd be alot of steam coming out the exhaust). Not enough to hydro-lock it (!!!), but enough that the engine would begin to choke. I never heard the slightest ping of detonation - but this was at idle. I couldn't spray enough water with the pressurized sprayer I had at 4 or 5 grand to make any difference whatsoever, and though I put the sprayer in my trunk and drove around with a mist spraying into the intake hose, I never injected enough water under load to simulate your condition. Let me know if you find out what was going on, I'd be interested to know. Good luck with that.

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Chris

Blue 1987 GT Getrag 5 speed, 1" lowering springs, 225 50R16 rims and tires, Fiero Store 9 3/4" HD clutch
SIlver 1986 2m4 THM 125c automatic
Black 1985 2m4 SE Isuzu 5 speed (no paperwork)

I doubt water would cause any type of detonation. Like was mentioned, the water has to get past the filter, etc. Even is any water vapor did make it to the combustion chamber, that would tend to cool combustion temps and would be more likely to cause a misfire than detonation.

I've got the Fiero Store's Holley-style scoop on my car with no water separator. I'm running a flex pipe from the scoop straight into the OEM air cleaner and I've never had any problems. I have had the filter get wet, but never any sign of moisture past the filter. I've also had the filter get soaked just sitting in the rain with the engine off - probably running in around the bolt on the lid, so I doubt the scoop's the cause there, either.

If you were getting detonation, it was more likely caused by hot engine temps due to the high speed run. If you've got any carbon buildup in the engine, when you run the engine hard, they can create hot spots in the combustion chamber, which can lead to detonation. Also, an exhaust leak, lean condition, or bad timing can also cause it.

[This message has been edited by Formula88 (edited 11-07-2004).]

Hmm engine only has about 15,000 miles on it, timming is set to 12' with a timing retard comming in at 4000 to bring it back 2' I have 19# injectors and a custom fuel curve. There is almost no chance of carbon build up in this motor due to the way I drive it.

I think I will just blow this off as a fluke.

I will just keep driving it and see what happens.

Oh P.S. when it made this noise the temp guage was only about 1/4 on the gauge as the outside air temp was around 44F and the rain was comming down so hard you could barley see the tail lights of the car in front of you at points.

i would suspect misfiring rather than detonation

I also vote against detonation, and what you got was misfires, due to water/steam in the cap. yes, you may have been sucking humidity, but not water.

I know this is a little out of left field, but with that much water is it possible you just had a wet engine?

If the ignition gets soaked all sorts of strange stuff can happen.

BTW, how about a Fiero speed boat? Hydroplane? Airfoil? Submarine?

I kinda doubt the wet ignition system idea. I have a new cap and rotor, with MSD Coil and an MSD 6AL Box with MSD Superconductor Wires. The 6AL box is mounted in the truck.

I doubt that enough water made it up into the cap area. I doubt even more that any moisture at all made it into the dist cap. I drove this car though a flooded road once, when I got about 1/2 into the road I quickly realized that it was flooded a lot more that I had first thought. When all 4 rotors became submerged in water and the exhaust note changed becuase the entire exhaust system was under water and I had steam billowing out my hood vent becuase 3/4 of the rad was under water I realized that I could be in for a hell of a fight. I kicker her into 1st gear and managed to plow my way thought it. I was terified that it was going to suck water in the scoop and hydro lock the motor but I managed to just push through the water.

The idea that there was enough water in the intake air stream to make the plugs damp and harder to fire suggestion is probably more the likley reason.

That heavy a rain will suck a LOT of water onto the engine bay. Plugs and plug wires plus the top of the cap will be soaked. Just the nature of the way cool air flows into the engine bay will soak it down like your spraying a water hose on it. Like already said, water coming thru the intake will tend to deter detonation, but will cause misfiring.

[This message has been edited by rogergarrison (edited 01-28-2005).]

You got some water some where, and some people clean out the tar in the buss box behind the battery and that tar is used to
keep the water out. Needs some type of sealer . May be your problem, then agin may not be. Check the connections to the coil and
make sure the foam gaskets in the connections. Make sure the other connection have there rubber seals also.

Battery is in da trunk, mounted inside a marine battery box.

Coil and all spark plug wires are thick MSD boots with 8.5mm wires.

The battery cables have been replaced with heavy gauge welding cable and all open terminals are wrapped in black tape and then coverd with split wire loom and then covered again with either a single loop of black tape or zip ties.

I had a nasty charging and starting problem a while back, and replaced every cable in the system and went overboard with the weather packing and ways to keep moisture out.

Ah...David..one more thing. What kind of gas are you running? I think you're using midgrade or premium?
My car hesitates a bit at high rpm and a can of fuel injector cleaner usually does the trick (assuming the gas filter's in good shape). Not sure how that leads into my next idea.....

On the news about 3 weeks ago, I heard a story that said in BC, the oil companies didn't sell as much gasoline as expected in the summer so they have a glut of "summer" fuel. The additives change to meet the needs of the different season. They need to sell off the gasoline so they can bring in the winter additives. Hence for the next month or so, Vancouver BC area gasoline prices are going to be a few cents per litre lower than expected based on world market prices. Hence we're able to get regular gasoline at about 68 cents a litre right now (71.5 less the 3.5 cents hidden rebate).

It could be the fuel in your car mixed with the moisture in the air.

If the air filter is wet, and there's puddles in the cleaner housing, then you're not flowing enough air. not enough oxygen will cause it to quit.

Yep, water injection actually helps control/reduce detonation. If you got enough liquid water into the cylinder to affect detonation the engine would have died outright, maybe even hydrolocked.

JazzMan

im new to the fiero world, and this water thing is a huge concern with me., i have a 87 plymouth voyager, race van, yes race van, but i have a cold air intake that takes in air right through the grill into a cone filter, if it rains, even light rain, the motor will sputter and makes all kinds of noises, if you floor it, it takes off like its pulling a 5 story building, goes nowhere!, and ive noticed on my fiero , the vent for air right on the side there, leads up into a filter, up somere right into the TB, i just replaced my air filter and the old one was rusted like an old ford!, im killing pontiac if my motor fails due to hydrolock!!!, is there some kind of water detour system in the ducting??? and how much for one of thoes cool little scoops?..ya i know the scoop would increse water intake...but there just so cool! lol

[This message has been edited by 88 forumla (edited 01-26-2005).]

As for the misfire question...

On the 89 bonnevilleI used to have, it would run like crap in rain or cold. Solution: New plug wires. Remember on a 3800 DIS one bad wire can kill two cylnders!

Ok I have spoke a few people outside of the forum about water comming in. There were several possiblities.

1. enough water that it slowed the burn time of the fuel.
2. enough water that it made the plugs wet from the incomming air charge
3. enough water that it dissplaced enough of the air that it caused a slight compression knock.
4. who the heck knows it could have been anything. But the car runs fine now.

As for where to get the side scoupe. The Fiero Store sells a reproduction of it. You can not get the one that I have any more. It was a limited run of Holley Scoops for the Fiero that are no longer made.

Oh and yes there is a factory water seperator behind the grill. However most people myself included have removed them, becuase all but the most extreme situations they are not needed. (yes I know if I had mine in I would probably not have needed to start this thread) However this is the first time I have ever had a problem after 11 years of driving the car on the Wet Coast.

does the seperater restrict air flow?, im sure you would jump to say it does, (i mean hell i removed my radiator on my van just to get direct air into the TB), but i read somewhere (mabey here??) that a guy took a 88 gt fiero v6 auto, and ran the 1/4 with all of the air intake intact, then he made a pass with open TB nothing at all on it, and the times were exactly the same., i did that with my van and yeah the times were exactly the same (execpt mine was from a custom intake to no intake, insteed of stock intake to no intake.)

so what are the scoops running$$ us curency.

no intake at all is very bad, as the TB sits right above the exhaust Y-Pipe and be sucking in pure hot air. Stock intake to a custom tube intake that still pulls air from either the fender well, or stock vent panel, is the best to have.

I don't know if it's ever been dyno-tested, but IIRC the water seperator makes NO difference unless your engine is seriously modified.

(like if you have a turbo or a bigger engine or something)

A largely stock V6 or Duke won't notice that the water seperator is even there.

Ed

I doubt the excess water would cause detonation. In the era of large piston aircraft engines, water injection systems were used to reduce detonation by lowering cylinder head temps. Of course this was a controlled amount of water for a limited time, high power settings during takeoff primarily. ADI (anti detonation injection) was the term used. How about wet ignition system components causing a miss?

NO.
if you sucked enough water to cause running problems, and it would be VERY unlikely, they would be BAD running problems - as in blown head gasket.

if its running fine now, you just got wet ignition - and a steam cleaned motor. steam gets into the dist cap easily - its not a sealed system, it needs to breath

if its still running bad, you blew a head gasket, due to steam not comrpessing very easily & the high RPMs, tho I'd be amazed if water made it that far thru the intake system & thru the air filter/air filter can.

BTW - sounds like a fun night!

I have a turboed engine in mine, took out the baffle to run a straight tube from the Ferrari side scoop. In a very hard rain driving fast, it will sometimes cut out and missfire, even quit completely. When it did quit a few times, just waiting a few minutes, it would restart and run fine. Only has happened 3 or 4 times in 7 years though. In town driving never affected it. I run a K&N filter so water dont hurt it, it dries back out. If you run a OEM paper filter, it may get so clogged and swollen with water it wont restart at all.

It is 90% impossible that it was wet ignition.

Like I have stated, everything is weather packed. High grade MSD SuperConductor boots. I even recently replaced the boots on the coil wire because they were getting grungy.

My Ignition Box is mounted in the truck. Yes 6AL ignition box to give me more juice and ensure a good spark under the worst conditions.

I dont think this topic is worth talking about anymore.

quote Originally posted by Capt Fiero: It is 90% impossible that it was wet ignition. Like I have stated, everything is weather packed. High grade MSD SuperConductor boots. I even recently replaced the boots on the coil wire because they were getting grungy. My Ignition Box is mounted in the truck. Yes 6AL ignition box to give me more juice and ensure a good spark under the worst conditions. I dont think this topic is worth talking about anymore.

the distributer cap is NOT waterproof/air tight.
anyways, if its fine now, its fine now.

everyone's focusing on detonation, but if it were me, i'd suspect an ingition module that is starting to go bad.. just my 2 cents. thats what my car did when the module started to go bad..i drove around with that modile for about two more months.. and once in a while, maybe once a week, it would sputter and/or stall out on the highway at 80 or 90 MPH, and eventaully it just died.

also to note.. i had a bad fuel pump one time that caused the same symptoms..