5.7 TBI runs like crap in the rain.

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sntrym

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Oka I'll give that a try and see what happens hopefully that'll solve it.

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You might find that one of the connectors has a bad seal. Sometimes you can fix that with some bearing grease, other times you have to replace the pigtail. I would also keep an eye on the cap/rotor combo. I've had to replace them due to corrosion from sitting around during wet weather.
 

Justin S

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I second trying a squirt bottle of water while its dry and running. Soak each plug wire one at a time and see if it causes it to stumble or if you see any arcing. If not, try the distributor. If not that, try some random connectors to see if it causes any changes
 

dsunrise

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My 1992 Chev Silverado K1500 with 5.7 tbi rebuilt motor with only 600 miles on the rebuilt. RPM's would fluctuate and it would run rough and I changed every sensor in that thing and the fuel pump. Still had problem and it came down to the fuel injection pressure regulator. Inside the regulator there is a spring that breaks and allows the gas to keep flowing. When I tried to find it for my year truck it didn't show the actual part I needed so I ordered for the 1994 GMC 5.7 that my son has and it is exactly what I needed. Replaced and now my truck is running great and getting good mileage again. See the picture of what I ordered to fix my truck.

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CRF450R

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Thanks for the responses when I get some time and my leg allows me to I'm going to get back under the hood tinker some more. I had a spray bottle and sprayed the cap area the other day with water and it seemed to screw around again but that acdelco cap is less a year old. I broke my leg in a dirtbike accident in June so somewhat limited to what I can do but I'm getting there shop rate around here is $145 -$160 /Hour. Broken leg or not I'm still not paying a shop that much to work on it.

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I had a similar issue on a 95' Suburban 5.7tbi. It would run great during normal weather, run great during rain, but if I drove threw somewhat deep standing water or drive threw a big puddle it would start to buck and stall. I tried hoseing everything down and it would run great. Just for the f of it I changed the O2 since it's the lowest sensor. It had the original AC branded sensor at 150K. A little rusty, not to bad replaced it with a denso and now it doesn't get fazed in water anymore.
 
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