engine falters at 2100 rpm - help!

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My brother degreased, rinsed, and blew off ( w/ compressed air) his motor on his 94 LC...he said at first it wouldn't catch, but when it did it idled fine...when he accelerates and it gets to 2100 rpm, the engine falters and the rpms go down, even though his foot is in the same position on the accelerator (while in PARK). I'm thinking something electrical got wet and recommended that he leave it alone to dry out for a day. Any ideas what could've gotten wet so I could go over there and see if I can get it cleaned/dried out? I believe he was primarly working around the valve cover (very oily - bolts loose).

Thanks,
Chris
'75 FJ40
 
Most likely dist. cap and or wires. Some of these caps are vented so you might want to pull the cap and make sure it's nice and dry.
 
I did that once.

plug wires -- check those too. you might've gotten some water in there (on the plug end).
 
Small and often hard-to-see cracks in the plastic intake hose can also cause these symptoms, IIRC.
 
Thanks for all of your suggestions. I spoke to my brother today (his LC) and he had replaced the air intake flexible tube because the original broke when changing the air filter. Now when it revs up, it'll falter and the rpms will go down @2600 rpms. If he keeps his foot on the accelator (steady pressure), the revs go up and as soon as they hit 2600 rpm, the engine revs go way down and will die if you let it. By the way, the revs go down, then up, then down, then up, then...ya know...

Chris
 
Just throwing out guesses here...but it sounds like a fuel delivery problem (FP, FP regulator, relay, filter...). I'd also check the TPS and associated vaccum lines.
 
Did he replace the intake tube at the same time that he washed the engine down? Did he reconnect the harness to the A/F meter? This will give this symptom also.
 
If it doesn't work itself out by this weekend (hey, I can wish can't I!?) I'll be looking at it then. The air flow meter harness doesn't need to be disconnected to replace the tube...so I assume he didn't touch it. I'll call him and ask though.............!!!

Thanks, I'm open to any other suggestions before I go look at it if anyone else has experienced this...Chris
 
figured it out!!!

Replaced the spark plugs, one had a little water in it....checked the dist cap, it was dry....ran it and the problem was still there, intermittent though. Started checking wiring and plugs.......then HEY! is that plug supposed to have water in it??? The problem was with one of the three wiring plugs that are right on the intake, it was the one that has black connecters, positioned at an angle, but still upright. What does this control? It was connected to something that is bolted directly to the intake...man!!! this was starting to stress us out!

Thanks for all of your help,

Chris
 
Not sure where to begin...

"\
The problem was with one of the three wiring plugs that are right on the intake, it was the one that has black connecters, positioned at an angle, but still upright."

This is a pretty vague description, but I suspect you're referring to the MAF connector? Otherwise it would be the IAC or TPS connector. BTW...they're all black--I don't have a non-black connector on my truck.]]

Bolted to the intake? Do you mean the air intake hose after the air cleaner (then MAF) or intake manifold (?), or TB intake (IAC or TPS)?
 
it's on the intake manifold...the other 2 plugs in the area are grey on his LC...oh well, it's fixed now...when I get a chance I'll see if I can take a look at it to describe it better...
 

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