hey guys. I'm not sure if I have a problem or not. Off of idle, as soon as I hit the gas the truck will "die".. but it doesn't. It's like it's not getting enough gas. It's been like this forever, but lately it's been getting more noticable. I'm a little concerned - I don't think this is normal. Does the idle just need turned up? If so, how do I do this?

Also I've noticed (I tried to do a search here) I seem to have lost a little power. The ttruck is running good but seems doggy. I know the air filter is clean, just changed the fuel filter, and I change the oil regularly. Other than a belt that needs replaced right now I can't think of what could be wrong - if anything.



EDIT: Also I should probably note that my truck idles fine. It's just when I first hit the gas she acts like she's not getting any gasoline. Weird?

 

Is this injector on that engine? My guess it must be dirty have you try sea foam or Lucas?

I would try go to store get that sea foam then pour though vacuum hose to injector or dump in gas tank.

what last time you change spark plug.

Worse thing it could be fuel pump go bad soon?

Is fuel pressure good? 40 to 60 psi?

 

Is this EFI or carb? If carb, what model?

 

1994, EFI.


Checked the spark plugs not too long ago, they were good.

I don't know how to check my fuel pressure. I know my oil preasure is outstanding though.

Also, what is seafoam? How do I run it through? Just put it in my gas tang? What will this do?

 

sea foam is very good you would notice power.

For me I dump in carb but your truck don't have carb but I am sure some members here show you how use vacumm hose suck from sea foam.

But dump in gas tank is ok but it get long time to change because sea foam become weak when mix gas but put sea foam in engine like I pour though carb acutal powerful job plus ton white smoke because it clean carbon off in engine.

But you need ask members if they know where vacuum hose that would suck sea foam.

 

here link to sea foam http://www.seafoamsales.com/motorTuneUpTechGas.htm


forgot to add info. Did you know if your gas have water in it? We have bus with diesel that have water it run so weak but run better at idle but when drive it would get long time to get speed plus tons of blue and white smoke.

 

Replace TPS, check/replace MAP

 

Thanks bud. I'll look into it.

I don't know what those things are.

 

buy urself a repair manual (perferably the old haynes style off ebay) and read. after u read what they are check the EGR, TPS and MAP.

EGR - Exhaust Gas Recirculation...routes a small amount of exhaust into the intake to reduce emmisions

TPS - Throttle Position Sensor...tells the computer what position the throttle body is open for desired fuel amount

MAP - Manifold Air Pressure - tells what kind of load the engine is under pending on the load

 

Alright, me and my dad worked on my truck today. Changed the spark plugs and replaced the belt, and checked out my pumpkin. I think two of the spark plugs weren't even firing. I got dad to check out the hesitation problem. He thinks he knows where it's coming from. It's no big deal as it isn't enough to actually kill the motor.

Also, can somebody please tell me exactly how spark plugs work?? My truck feels really strong now (I"m ready to race you, Iceman ) It's been running like a dog lately and now it's running much much better now. Is this because we changed the spark plugs? Or is my truck going crazy?

And thanks to everyone who's been posting.

 

The purpose of the spark plug is to house an electrical arc that will ignite the compressed air\fuel mixture. Between each firing, the coil builds up a magnetic field, which induces a very large voltage on the secondary windings of the coil. When the distributor is ready to fire the coil, it breaks the ground to the coil, and the high voltage on the secondary windings looks for the best possible ground it can find, which is the engine block through the spark plug gap. The spark plug threads into the cylinder head, which is bolted to the block, which is grounded with the battery. The electrode in the center of the spark plug makes a connection to the plug wire, and the spark plug tip is extended from the plug threads, as you can easily see. The spark plug tip is essentially grounded once the plug is installed.

Electricity can arc across air if the voltage is big enough. So for a given voltage, there is a specific range of air gap that the spark can travel across. This is why spark plug gap is important. If the gap is too wide, the spark won't jump. If it's too narrow, the spark will most likely jump, but the electrodes will get burnt, and after a while the spark won't jump. Furthermore, a common misconception is that you can take an otherwise stock setup and increase the plug gap for "performance" because the spark will "be bigger." That is garbage. For a given firing voltage, there is a specific width that the plug gap has to be for the arc to jump. No more, no less; plain and simple.

 

That's a lot to take in, but clearly wrote. Thanks for the information! I never heard of messing with spark plugs to gain preformance.

 

Bill did you solve your hesistation problem? I'm having the same trouble with my 87 300 with manual OD ( Mine will stall sometimes )except it also has an uneven idle, but runs strong under load. Did you get it fixed? ( Puter says my message is too short to submit. apparently brevity is not a virtue on this site.)

ylBill]Alright, me and my dad worked on my truck today. Changed the spark plugs and replaced the belt, and checked out my pumpkin. I think two of the spark plugs weren't even firing. I got dad to check out the hesitation problem. He thinks he knows where it's coming from. It's no big deal as it isn't enough to actually kill the motor.

Also, can somebody please tell me exactly how spark plugs work?? My truck feels really strong now (I"m ready to race you, Iceman ) It's been running like a dog lately and now it's running much much better now. Is this because we changed the spark plugs? Or is my truck going crazy?

And thanks to everyone who's been posting.[/QUOTE]

 

Once I find out for sure what the problem is, I'll let you know. Do the same for me. The truck is running good, but now her idle is getting worse (even after I put a better grade of gasoline in it.)

So far I'm still trying to save a little bit of money. My job is killing me I think. Ha ha..

 

The most common source of the dreaded 4.9 EFI hesitation is the throttle body gasket sucked in. If you look in the TB with the throttle blocked wide open you can often see where the gasket is sucked in.