Water in intake
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Intermediate
Joined: Jul 2005
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Water in intake
Today as I left work in the hard rain, I ran into a deeper-than-expected puddle in the corner of the lot. The car bogged and stalled. I removed the spark plugs and turned it over and reinstalled them. I then went straight to the auto store and replaced the air filter (I had remove the soaked one) got oil, filter and new plugs. The plugs I got were r44th acdelco, which was suggested as an upgrade from r45th for my performance coil and wires. When I got home and changed the oil and plugs (gap is .035), the car still ran rough and doesn't like to idle very well. Are there any sensors that could be bad or vacume lines possiably plugged? The oil looked fine but I'll still change it within a week to make sure there's no water in the bottom end. Maybe the plugs are too cold of a heat range? It likes to backfire a little when I let off the gas from high rpms, but I have a gutted cat and no mufflers. What's the restoration procedure for a wet engine? Thanks
Le Mans Master
Joined: Dec 2004
Posts: 5,789
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From: Myrtle Beach SC
St. Jude Donor '05-'06
Always helps to mention the year car and mods.If it is a LT1 water on the Opti will cause this but it should cause mere issues than what your seeing(it might yet).Sounds like you might be running a little rich if it is just backfiring when the throttle is released.What did it run like before you submarined it?
Thread Starter
Intermediate
Joined: Jul 2005
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sorry, it's an '85 L98 with a CUT AIR LID 
. Water just barely reached the middle of the air filter but didn't get above the bottom of the exhaust manifolds. It ran just a little rough before, but was tough to stall out after I replaced the air intake tempature sensor (last week). I think it just needs a new timeing chain. The car smoked a little bit and the old spark plugs had a small admount of carbon on the wire, so I think it's running rich. Can I adjust the gap to comp.? what else can I do? thanks
edit: Took the car out just now, seem to idle ok after hot, but feels like i'm running on 4 cylinders at start up untill I get up to speed, then picks up really well.
. Water just barely reached the middle of the air filter but didn't get above the bottom of the exhaust manifolds. It ran just a little rough before, but was tough to stall out after I replaced the air intake tempature sensor (last week). I think it just needs a new timeing chain. The car smoked a little bit and the old spark plugs had a small admount of carbon on the wire, so I think it's running rich. Can I adjust the gap to comp.? what else can I do? thanksedit: Took the car out just now, seem to idle ok after hot, but feels like i'm running on 4 cylinders at start up untill I get up to speed, then picks up really well.
Last edited by skyler_lloyd; Oct 1, 2005 at 11:46 PM.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Did you clean and dry the plug wires and area around the plugs??
If you got water that far up you might pull the IAC, clean it, set base idle and TPS base idle voltage.
If you have an high energy (voltage) ignition you could open up the gap. I have the HyperTech setup with performance wires, cut-back stock A/C Delco plugs and run a .045"-.047" gap with good success.
Also, use the ECM's Field Test mode, described on my site, to see if the ECM is going into closed loop mode.
If you got water that far up you might pull the IAC, clean it, set base idle and TPS base idle voltage.
If you have an high energy (voltage) ignition you could open up the gap. I have the HyperTech setup with performance wires, cut-back stock A/C Delco plugs and run a .045"-.047" gap with good success.
Also, use the ECM's Field Test mode, described on my site, to see if the ECM is going into closed loop mode.
Thread Starter
Intermediate
Joined: Jul 2005
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Thanks for the advice. I set the idle-throttle opening screw, reset tps (dead on), cleaned the iac and reassured the spark plug boots were dry. Later today, I think I'll open the spark plug gaps to .045 to see if this better fits the coils and wires. It doesn't "jump to life" like it did when I start it up, but I think this is an backpressure issue I've been working on for the last month. thanks again!
Pro
Joined: Sep 2005
Posts: 747
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From: Calgary '85 Z51 coupe
I gapped the plugs in my '85 at .045 but noticed later the factory spec was changed to .035. Mine is running fine at .045, but isn't a wider gap harder to fire? Not sure why you would change yours if you are having trouble.
Thread Starter
Intermediate
Joined: Jul 2005
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I don't know. I've got r44th plugs, a mallory hi-voltage coil and mallory 8mm sidewinder wires, so I thought a .045 gap would help. I'm going to change them right now. I had the 45 degree spark plug wire connector break earlier and after cutting the wire, stripping the inuslation off and placing another connector on it, it slipped off earlier in town. I'll try it and post the results
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