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Need help...350 tbi stumbles after hosing engine

nutt7

nutt7

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So there was 1 inch of dirt and rocks (yes, 1/2 inch rocks) between my valve covers and tb from the PO. I always noticed it but never bothered with it...anyway I chiseled the cake and took a hose to it. I let it sit for a few hours. Now my engine stumbles a little and occasionally misses while cruising. I put about 10 miles on it like this. It is worse with the A/C on.

What got wet that shouldn't have? Dizzy? some random module? Did I maybe blow off a vacuum line? I focused the blast to that specific area and nowhere else really.
 
tomtom said:
Sounds to me like you got some water in something. Dizzy, plug wires, coil etc.
Click to expand...

That's where I put my money as well. Its hard to say if a good long drive will cook all the water out, I'd pull em all and check.

But just to ask, the engine wasn't hot when you sprayed it was it? I cracked a spark plug that way once. Didn't know wtf happened until I saw the short at night. Pretty cool looking the spark traveling outside of the plug and grounding on the head :D
 
Engine was cold and off. It kept bucking in OD on the freeway last night and has a rumbliness when accelerating. I drove about 30 miles last night...still the same so I don't think it will dry up. My egr throws code 32 on the freeway but always runs fine, I wonder if I pushed it over the edge with the water.
 
Just pop your dist cap off and dry it out. That is the #1 thing that happens when you hose it down.

If that's not it THEN you can start checking other things. Start with the simple stuff! (Although removing the dist cap isn't always easy ... :D )
 
WD-40 on a clean rag and wipe out the inside of the dist. cap works great.

The WD in WD-40 stands for water displacement, 40 is the 40th formula they tried before getting it right.
 
under the cap looks clean and dry...a little black dust on top of rotor...no evidence of water inside (at least no spots, and very little dust around ig module) The outside of the cap has water marks in the ignition module area. The other sensors have clean/dry connections and the egr at least moves by hand with clean vac lines. I am thinking ignition module. Sound feasible? What else should I check?
 
So for fun I added a little more heat compound to the ig module, WD40 in the cap, and started the truck and it was rumbly. I removed the tps and started it and it still ran the same but I got an SES light. I started it without the IAC connected and it idled high, but rumbly. Then I started it without the connectors on the 45 degree angled thing with the solenoid on it (I think I left the actual solenoid connected) and it ran a little rougher; when I plugged it in it smoothed out to rumbly again. Also, when I disconnect the EGR vac hose, nothing happened, but when I press the diaphragm it wants to stall.

Does this reveal anything?

It still seems like a spark thing...is something not getting advanced/retarded?
 
Possible tbody or intake manifold leak?

If there was a bunch of stuff all built up around the mating surfaces it could hide the gasket air leak.
 
I test drove it with the air cleaner off and I could easily replicate the missing and bucking when I have low RPM and I press the gas about half way. Also without the cleaner, it would pop or backfire (sounds under the hood). I am guessing its audible since the cleaner is off.

Any guesses?
 
nutt7 said:
I test drove it with the air cleaner off and I could easily replicate the missing and bucking when I have low RPM and I press the gas about half way. Also without the cleaner, it would pop or backfire (sounds under the hood). I am guessing its audible since the cleaner is off.

Any guesses?
Click to expand...

I would definitely check your timing. Then check for manifold leaks.
 
metalneverdies said:
I would definitely check your timing. Then check for manifold leaks.
Click to expand...

I sprayed starting fluid around the manifold but couldn't hear a change in idle...hell, I don't even know if that works. Timing shouldn't have changed...the problem is somewhere else. I checked it anyway with the brown wire disconnected, and it was maybe a degree or two btdc. I am not too good at reading the marks...how many degrees are between each tooth by the balancer? I don't know how the timing should look with the wire connected but it was an inch or so to the left of the last tooth.
 
nutt7 said:
I sprayed starting fluid around the manifold but couldn't hear a change in idle...hell, I don't even know if that works. Timing shouldn't have changed...the problem is somewhere else. I checked it anyway with the brown wire disconnected, and it was maybe a degree or two btdc. I am not too good at reading the marks...how many degrees are between each tooth by the balancer? I don't know how the timing should look with the wire connected but it was an inch or so to the left of the last tooth.
Click to expand...

I timed my 87 tbi with the mark being as close to dead center of the bigger timing V notch. I too a grease pencil and marked the timing line on the balancer so it is easier to see.

You must use the timing light with the brown wire (think it has a black stripe) disconnected.

It has to be a pretty bad leak for noticeable idle change. With out a live data plot on a scan tool it's hard to tell.

Other than that I don't know of what else to check.
 
What do think about the ignition module? Couldn't that cause timing issues that might result in pops and backfires like I described?
 
nutt7 said:
I test drove it with the air cleaner off and I could easily replicate the missing and bucking when I have low RPM and I press the gas about half way. Also without the cleaner, it would pop or backfire (sounds under the hood). I am guessing its audible since the cleaner is off.

Any guesses?
Click to expand...

Backfiring out the carb/tb usually is caused by the timing being off or bad wires allowing spark to jump between them. Maybe also try this spray on all your ignition parts and sensors that may have gotten wet like tps, map, etc.
http://www.amazon.com/PERMATEX-81082-IGNITION-DRYER-SPRAY/dp/B004QD002U
 
nutt7 said:
What do think about the ignition module? Couldn't that cause timing issues that might result in pops and backfires like I described?
Click to expand...

As long as all the wires and terminals pass inspection I don't see why It would. If it only got wet and isn't fried I don't see how it could have changed anything.
 
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