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Questions (TBI & Flooding)

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Miller75

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Well I went out and tried to start my truck today and the result was the same (no start).
This time I was under the hood bumping the starter watching the injectors. There was an excessive amount of fuel coming from the injectors in my opinion. So I pulled all the plugs (Verified they were fouled dripped wet) disconnected the injectors and spun the motor a few times to blow out the excess fuel which there was a ridicules amount being blown out of cyl#8.

Here comes my questions before I replace the plugs what pieces should I pull off and have tested?

Has any one run across this before?
 
Simple question. If you disconnect power to the injectors, do they still spray? If so, one or both is stuck open.

Otherwise, most likely problem, is pressure regulator, dirty injectors, or, if you don't know the history, wrong injectors, unlikely though.
 
I had one injector at one time, as soon as i hit the key, it would spray and pool up in the throttle bore. :doah:replaced it, all was fine :D
 
Simple question. If you disconnect power to the injectors, do they still spray? If so, one or both is stuck open.

Otherwise, most likely problem, is pressure regulator, dirty injectors, or, if you don't know the history, wrong injectors, unlikely though.
Click to expand...

no spray when the power is disconnected...I think the first piece i should do is a tbi rebuild kit

I had one injector at one time, as soon as i hit the key, it would spray and pool up in the throttle bore. :doah:replaced it, all was fine :D
Click to expand...

I'm not sure what you changed the injectors?
 
well so far it sounds like from the responses I have received a bad regulator allowing to much pressure through
 
The fuel spray should resemble a very nicely defined "cone" shape coming out of the injectors. If it is just pouring out, there is a problem... Did this problem just start? We need a bit more info to help. There are a couple different TBI rebuild kits, the one I bought cost about $50. It wasn't as hard as it looked, it was just a box of gaskets and O-rings, but I opted for a kit that included a new diaphragm for the fuel pressure regulator. Took me about 2 to 3 hours from start to finish and several cans of throttle body cleaner. If you can, give us a little bit more history of the truck, the more info the better.
 
I always try and check fuel pressure first.
The reg diaphragm could be torn.

If you have access to a scanner check inj. Pulse, map volts, and tps position. For some basic checks. A Dvom can be used also.
 
As mentioned, if the fuel is pouring out you have a problem - it's most likely a bad o-ring. Otherwise it is probably the FPR. There are two o-rings for each injector - a small one at the bottom which is missing/mis-seated/broken will allow a ton of fuel past, causing flooding. I actually hydrolocked my engine with gasoline because of this... and then caught it on fire when I removed the plugs and cranked the engine over. Literally cups and cups of gasoline came out and a spark went off somewhere ... BOOM. Only a tiny amount of damage occurred, luckily, because I had a fire extinguisher nearby (albeit not near enough!) Hint, hint! :doah::haha:

New injectors were $75/each at Advance Auto, and the rebuild kit was cheap as I recall. It has all the gaskets and o-rings you need.

When you take it apart, pay special attention to the fact that there are THREE o-rings on each side - the rubber one at the top, then a tiny sliver of a metal one underneath it. Don't lose that one! Then there is the one on the bottom. The injectors only go in one way and have a little pin to help you align them. Remove them by using two screwdrivers - a largo one as a leverage point across the housing, and another to stick under the lip of the top of the injector and pop it out. Putting them in is easy - make sure the o-rings are all in place, slide it in, put on the cover, and tighten down the torx screws.

Follow the directions for the fuel pressure regulator. I put my spring in backwards which caused problems, so PAY ATTENTION when you take it out.

That should take care of it ... at least it did for me!
 
Well here is some background information.

I purchased the truck during the winter of 09 parked till spring of 10 found the truck had a oil leak that would compete with BP. During this time I experiance these symptoms sparatic loss of idle (had to feather the gas to keep running), hard starts both cold and warm conditions (typically when warm), This summer I swaped out the block had a few minor hiccups but all was well at first. I took the truck out for a test drive and noticed it was backfiring, sputtering under load and weak power I figured the timing was off so made some adjustments which was a mistake not realizing that tbi is completly different than a carb w/HEI. Timed the truck back to 0tdc w/est bypassed and I was off and running the truck ran great. But while working on removing the nerf bars I noticed a pin hole oil leak in the oil pan so I started up the truck. this time is was a hard start wouldnt hold its idle backed it down the drive way about 70ft then crawled/stumbled the truck into the garage. Pulled the oil pan put the new one on went to start it at the end of the job and nothing. The engine was flooded, plugs fouled and gas was visibly running out of the headers. So I watched the injector spray to see if it looked normal which I belived to to be.

Which leads to my earlier post. I'm tempted to yank out the tbi/ecm and swap in a carb and HEI dist for simplicity sake.
 
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Don't yank the tbi for a carb, while intimidating at first, they are actually very simple once you work with it a little. Then factor in the reliability, better fuel economy, ability to run on a steep incline versus a carb, etc... Plus, there are so many guys that pull all that stuff off, only to have just as many problems trying to get the carb setup working properly, only to complain about the loss of performance and fuel economy. I'm positive you will be happier with the TBI setup in the end, so let's start over...
Is the check engine or service engine soon light working? Is it throwing any codes? Remember also, that everytime you disconnect the battery for I think 30 seconds or so, you erase the trouble codes, but the the computer also has to relearn how to run properly ( takes about 20 or so minutes of driving I believe). So, it's important that everything is hooked up properly, no vacuum leaks, timed correctly, etc... 2 main issues I see, the truck sat for a while, and you swapped motors. Time to take a step back and go over everything again. Make sure all the sensors are hooked up, and no broken wires etc...
 
Yeah, TBI is ridiculously simple compared to a carb. Don't swap it all out, I can't even imagine going back to a carb on a car any more, they were such a PITA compared to FI vehicles.

Do this - remove the air filter, remove the intake throat surround, and turn on the ignition key without starting it. Go look at the injectors. Is any gas flowing? (No is the correct answer!)

Then start the truck, if you can. Look at the injectors. Is it spraying in a nice cone shape? (Yes should be the answer).

Come back and let us know what it's doing.
 
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I thought so, but I'm not 100% sure, everytime I've watched my injectors at startup and idle, both were firing... No dripping or pouring, nicely defined cone shaped spray patterns.
 
Do you know if anyone removed them? The injectors are connected via those different wire harnesses. Orange and green goes on the throttle lever side, and pink and brown wires go to the TPS side. Do you have them correct?

Are you also sure these are the correct injectors for the truck? Other injectors will fit in there but have different flow rates.

How is your PCV valve? That can cause problems too.

TIP: If the engine on the TBI is flooded, fully push down the gas pedal when starting it. This tells the computer to go into "Flooded engine" mode and only cycles the injectors 20:1 until the engine starts and/or the gas pedal goes under 80% open.
 
Jessie James said:
Gas should be flowing from one injector only at idle - the drivers side.
.
Click to expand...

UMMM,, NO???

the injectors pulse back and forth from what i understood, you will ALWAYS see fuel coming out of both, even at idle.

And only feeding the one side, would only feed one side of the engine, these aren't single plane manifolds.
 
The other thing is that the coolant temp sensor also helps control the fuel delivery rate. If it's bad, replace it.

And here is an easy test - disconnect the injector wire terminals and then have someone turn on the ignition while you are watching the injectors. If there is spray from either injector they are defective or the o-ring(s) seal is bad.
 
4xcrazy said:
UMMM,, NO???

the injectors pulse back and forth from what i understood, you will ALWAYS see fuel coming out of both, even at idle.
Click to expand...
You are 100% right. I just read the troubleshooting steps in the manual and it says BOTH injectors should be spraying. And I was going to edit my post but you beat me to it! :D
 
ok here is what I know so far.

not sure what the PO did to the truck.

I believe everything to be correct for the truck due to a few months I drove it with no issues.

the check engine light is non-functioning so pulling codes is virtually impossible.

Both injectors spray fuel while cranking with the wires connected. (There not a fine mist more of a heavy cone shaped spray)
With the wires disconnected no fuel is released from the injectors during turn over.

Pulled the plugs and they where fouled visibly wet with gas.

Spun the engine to clear the cylinders of any excess gas which cyl#8 was spewing a decent amount. Also, gas visually trickled from the passenger side header

The PCV, IAC, EGR, MAP and TPS are all operational. I believe all the vacuum lines are connected correctly (have not found a way to verify the exact routing).

My first point to look at is rebuild the TBI and verify the injectors are functioning correctly (I have a spare set that came off the donor motor i can use if needed)
 
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