FORD

Hey all, so i have been battling a problem with my truck ever since iv had it. Been about a year now. When my truck is warming up, it seems to flood all the time. smells like gas, but this happens mainly in the cold winters. And if i punch the throttle, the engine cuts out for about a second then picks back up. i have to slowly ease on the gas. this happens from 1st to 5th or neutral. It gets alot better when warm but the problem is still there. i have replaced dist cap, rotor, plugs and wires, o2 sensor, fuel filter. and no cel lights. any help appreciated!

mattches

No CEL, have you checked for stored codes? You can have stored codes with no CEL. Sounds like your cold start injector is going crazy. This can be because of a bad temperature sensor (the one for fuel injection & computer) or the injector is bad. Try unplugging it, see if it still floods. What kind of mileage do you get?

scope103

I'm with mattches; I'd look at the cold start injector (CSI) system. http://www.ncttora.com/fsm/1990-1995...yste/colds.pdf If unplugging the electrical connector to the injector changes things, you'd need to look at ECT (Engine Coolant Temp sensor) and the cold start injector timer.

You might also have a leaky CSI, but that would be less likely to clear up when the truck gets warm.

FORD

thanks for the reply guys, would I have to take it to a yota dealer to check stored codes? I ran a test on the CSI and it sprayed once like it is supposed too. did not leak. I replaced the time switch yesterday and no difference. I have a spare CTS I can swap in. I will try that too. I almost seems like there is too much fuel pressure, or just running rich

BMcEL

These engines do run a little rich and don't take kindly to hot rodding when cold. Almost sounds normal to me.

And you can check for codes by inserting a jumper wire or paper clip between terminals E1 & TE1 in the diagnostics connector by the battery.

FORD

it couldnt be the injectors because it clears up mostly when warm correct? if it were it would run like crap all the time. What about a timing issue? even when it is warmed up, if i stomp on the pedal or take my foot off fast even at highway speeds the truck will jerk. I am not sure about other yotas but my pedal is pretty stiff also

FORD

bMcEL,

i have owned a 95 4runner before this pickup and it never did anything like that. People that drive my truck just stall it every time because it cuts out so bad. I am 100% sure this isnt normal. I have checked for codes doing that aswell, got nothing. but that was awhile ago, will check again

TNRabbit

Could also be a fuel pump or fuel pressure regulator issue. Agree you need to check for codes.

mattches

Check for codes.

What is your fuel mileage like?

Try disconnecting the wire to the CSI, is it still "flooding" and smelling like gas?

Always keep in mind that EFI motors don't "flood" like a carb can, it relies on a complex mix of sensors to determine how fast the motor is going, the temp of the motor, the temp of the incoming air, the amount of incoming air, the actual position of the throttle, the position of the crank, the effect of ignition (detonation/ pre-ignition), spark timing, and about 50 other things- all within a split second- and continues this as you drive, it doesn't just blindly shoot gas in and expects it to lite. If you are having a gas smell and it is stalling on you, this is NOT NORMAL...... it has to be a sensor somewhere or a malfunctioning piece of hardware that is controlled or affected by a sensor.

If the csi does not solve the issue then it still can be the temp sensor- that damn sensor is responsible for telling the computer when your engine is up to temp- one of the most critical elements for proper ignition, as the computer will then modify the fuel mixture curve, if the sensor is malfunctioning or broken then it has a direct impact on all the other sensors as they expecting something (running rich symptoms) that they are not sensing correctly. If you continue to let this go, you will end up with a DEAD MOTOR, detonation and excess fuel in the chambers can cause serious damage, like warping rings that will snap at a moments notice seizing your engine- trust me on this, I have seen it first hand!

It also could be combined with the throttle position sensor, which is very touchy to calibrate correctly. And can have impacts on the amount of fuel coming in as compared to the load and speed of the engine- this can cause the hesitant throttle response.

But start simple, check your codes, look for vacuum leaks, loose wires, etc...

Update us on what you find out

FORD

my fuel mileage is not good at all, I don't know exactly how to do it, but a full tank will get me about dead on 300k, highway kilometers that is.

I will put in the coolent temp sensor tonight. does anyone know a trick for that? I broke the time switch last time those are difficult to get out in one piece.

I also forgot to mention my temp gauge works intermittently, it will either stay at the bottom or go up to half which is normal. I don't think this related because the temp gauge is run from different senders. am I correct on that?

mattches

We can only be so much help without specific info.

Your mileage (km/l) is not quite up to par, and could be better. I get about 210 per tank, maybe 250 if I push it, just daily driving. You are getting about 185 miles.

As far as the sensors, the only real way to get to them is to remove the plenum and carefully remove them with an open end wrench, not a socket. Since you have everything open, then take the throttle body off and calibrate the throttle sensor while you have it easily accessible.

Yes, the ECU temp sensor is different than the gauge sensor, and the time vacuum switch as well, but the are all on the same manifold riser at the back of the engine. Plus some bypass hoses, the heater connection, all on a 2x6" piece of metal. The coolant connection to this crosses from the front of the engine under the intake, and returns just underneath it to the block for the return heater hose. A real PITA to get to, and easy to FU if you don't put it back together in the right order and be sure to use a new plenum gasket each time it is opened.


It really sounds like you are just starting to throw money at this. I am simply trying to let you know that there are many, many things that could be causing your issues.some of which are VERY EASY TO FIX- like a loose connection or vacuum leak. But we cannot help, other than guessing, to resolve your issue if you can't provide codes or basic troubleshooting before start tearing the entire top end apart which can cause undue stress on connectors, break seals, and apparently breaking sensors while you are at it.

Hopefully you can get us some codes before you have decided to open up the top and disconnected the battery and cleared the ECU memory.

Team420

Agreed!! Except the part about using a wrench instead of a socket, and pulling the plenum, they can be changed CAREFULLY with a o2 sensor socket and ratchet w/o removing the plenum

I would start with the easy stuff first! Check for codes, Do a compression test... This will give you an idea of your motors health, if u have low compression on any cyl, it will certainly contribute to this issue, then move on to vacuum system, then electrical components

If u just start tossing parts at it, theres a pretty good chance ur gonna end up having the same problem, and a much lighter wallet.

FORD

so I checked for codes, I got nothing. the check engine light was just blinking. that tells me it could be something pretty minor since it won't register. do you guys think it could be a timing issue? the guy I bought it from said it was timed for higher octane fuel, what do you think?