unhappy typhoon

[sickatea]

couple of weekends ago per my wifes request, i finally got around to recharging the air conditioning on the truck. Since then my typhoon has been sputtering at all rpms. Any insight would be great. So far I have checked the following:
new ngk plugs(.035 gap)
new plug wires
new cap and rotor
new fuel filter
unplugged o2 sensor to make sure i was getting enough fuel
fuel pressure at rail at idle is 40-42
map sensor with no vacuum line 2.35vdc
map sensor at idle with vacuum line .7vdc
tps sensor at idle .535vdc
all vacuum lines are intact with no leaks
all check valves in vacuum lines appear to be working correctly

any help would be great. thanks again

rich

 

[nonova0074]

Re: unhappy typhoon

I have the same thing with the a/c. I am going to toss a new set of plugs in and change the oil tomm. The best thing that I ever did for my ty was install a turbotweak chip it now run like a raped ape

 

[syclone809]

Re: unhappy typhoon

If you overfill the system with too much refrigerant and oil, it puts more load on the compressor which makes the motor strain. Did you recharge the system or take it somewhere?

 

[teamvortec]

Re: unhappy typhoon

Does it sputter all the time or just when the compressor is running? If it only does it when the compressor is on it could be over charged like stated above or it could also be the compressor is trying to lock up.

 

[nonova0074]

Re: unhappy typhoon

hummm maybe mine is over filled mine only does it when the as is on

 

[sickatea]

Re: unhappy typhoon

it does it all the time. i had it recharged at a shop since i wanted the system vacuumed out first. earlier today i turned the truck on and it was idling perfect in the garage. decided to take it for a ride, and it felt great for about 2 football fields then started running poorly again. go figure. the truck did sit for sometime(4 years)( and yes i am pitiful) and i have ran the gas tank out and refilled since sitting. now i am wondering the condition of the fuel in the tank. the current gas is only about 3 weeks old, but im wondering if any gunk in the bottom of the tank is finally catching up to me. i did replace the fuel filter, but i am thinking of seafoaming the gas tank. fun times

 

[Don W.]

Re: unhappy typhoon

it does it all the time. i had it recharged at a shop since i wanted the system vacuumed out first. earlier today i turned the truck on and it was idling perfect in the garage. decided to take it for a ride, and it felt great for about 2 football fields then started running poorly again. go figure. the truck did sit for sometime(4 years)( and yes i am pitiful) and i have ran the gas tank out and refilled since sitting. now i am wondering the condition of the fuel in the tank. the current gas is only about 3 weeks old, but im wondering if any gunk in the bottom of the tank is finally catching up to me. i did replace the fuel filter, but i am thinking of seafoaming the gas tank. fun times

First, IMHO, over filling the AC shouldn't make the engine "sputter." Even if the compressor totally locked up you'd just fry the belt. Disconnect the AC compressor (at the clutch) and see if I'm wrong. (Although it IS listed as a potential problem in the manual.) I suspect the problem is elsewhere. You said "all the time" but how is the idle? Does it rev good in neutral? If so then, to me, that points to ignition. You didn't mention timing, have you checked that? What's the fuel pressure doing when it sputters. Plugged fuel vent after these years? Can you post the DM file? Restricted intake somehow? By no means complete but other items mentioned are: Check o2 for contamination (you checked that by disconnect but they say to actually look at it), EGR for correct operation. A leak here would be a issue.

HTH a bit

 

[Jimmy]

Re: unhappy typhoon

I'm with Don,ignition related. Maybe the ignition module? I can't see the ac causing it unless the compressor is locking up.

 

[whooped]

Re: unhappy typhoon

N/A 4.3 did this to me... check the harmonic balancer. cracks in the rubber indicate that it's time for a new one.

 

[Syclone22]

Re: unhappy typhoon

it does it all the time. i had it recharged at a shop since i wanted the system vacuumed out first. earlier today i turned the truck on and it was idling perfect in the garage. decided to take it for a ride, and it felt great for about 2 football fields then started running poorly again. go figure. the truck did sit for sometime(4 years)( and yes i am pitiful) and i have ran the gas tank out and refilled since sitting. now i am wondering the condition of the fuel in the tank. the current gas is only about 3 weeks old, but im wondering if any gunk in the bottom of the tank is finally catching up to me. i did replace the fuel filter, but i am thinking of seafoaming the gas tank. fun times

Do you have a in cabin fuel pressure gauge to check if
pressure does increase with boost you can just hook up a
fuel hose with clamps and run the gauge outside the hood
for a test also check your fuel filter it maybe clogged up !!!

 

[sickatea]

Re: unhappy typhoon

even with the belt off the ac,truck still sputters. idle seems to be good until the truck is put in gear or ac running. revs great in neutral. fuel pressure appears to work correctly driving down the street according to other posts. i did not take out the o2 sensor, i thought that unhooking this sensor would cause the truck to run really rich. i did check timing and it is set to 0 degrees with the wire unplugged under the dash. i made a egr blank off plate to see if that may have been the issue, and it runs the same. someone mentioned a plugged vent. when i took the truck out earlier, i did take off the gas cap and put it back on prior to driving it. it drove great for a bit then stopped. where is the vent for the fuel system.
sorry if vague, wife and kids are gone, so i cracked open my first beer(or two)

 

[Syclone22]

Re: unhappy typhoon

even with the belt off the ac,truck still sputters. idle seems to be good until the truck is put in gear or ac running. revs great in neutral. fuel pressure appears to work correctly driving down the street according to other posts. i did not take out the o2 sensor, i thought that unhooking this sensor would cause the truck to run really rich. i did check timing and it is set to 0 degrees with the wire unplugged under the dash. i made a egr blank off plate to see if that may have been the issue, and it runs the same. someone mentioned a plugged vent. when i took the truck out earlier, i did take off the gas cap and put it back on prior to driving it. it drove great for a bit then stopped. where is the vent for the fuel system.
sorry if vague, wife and kids are gone, so i cracked open my first beer(or two)

If you cannot see any real time fuel rail pressure when vehicle is
driving in gear this does not mean that your pressure is correct
i had this issue before in neutral engine revs o.k with no
sputter ( no engine load ) but in gear with engine load my fuel pressure
drop to 35 psi causing the engine to lean out so unplugging the 02 sensor
will not help if fuel pressure is not correct it should be in boost above 55 psi
minimum so you have good pressure to feed the injectors !!!

P/S do you have a wideband meter installed ???

 

[sickatea]

Re: unhappy typhoon

no on the wideband o2 sensor

in neutral when i brought up the rpms, i believe and will recheck but i think my fuel pressure did go to 35. i thought that was okay, but apparently im wrong. that would be great if that was it. i need to put a real fuel pump into the truck anyway.

thanks again everyone for your input

 

[Don W.]

Re: unhappy typhoon

, i did take off the gas cap and put it back on prior to driving it. it drove great for a bit then stopped. where is the vent for the fuel system. (or two)

What? See my earlier post. Leave the cap off and see how it goes. (Pun intended.) Somebody help me here. Does it vent through the canister? Does seem weird this would happen. I've seen it before but not with a canister. Maybe that line is bad or kinked. Canister is under the air filter. Two hoses one to the intake and one to the tank. There is a filter on the bottom check that it isn't plugged (rare). The manual shows a restriction in the vent line at the tank but the diagram is a schematic not an actual diagram so I don't know its actual location.

 

[sickatea]

Re: unhappy typhoon

took off the gas cap and took the truck around the block. same issue. i did have a little more time and checked all my grounds then i checked the voltage at the fuel pump connector at the back of the truck. with engine running, only getting 7.5vdc. i was unable to put my gauges on and check fuel pressure while taking a ride. the wife had duties for me(did i mention she is pregnant and not a happy camper). tomorrow i will check fuel pressure while under load..
happy fathers day to all the dads
rich

 

[Syclone22]

Re: unhappy typhoon

took off the gas cap and took the truck around the block. same issue. i did have a little more time and checked all my grounds then i checked the voltage at the fuel pump connector at the back of the truck. with engine running, only getting 7.5vdc. i was unable to put my gauges on and check fuel pressure while taking a ride. the wife had duties for me(did i mention she is pregnant and not a happy camper). tomorrow i will check fuel pressure while under load..
happy fathers day to all the dads
rich

Good idea also if possible check the intank fuel
pump filter strainer this can be dirty or stuck up
if your fuel pressure drops to 35 psi at idle when revving the
engine this is caused by the vacuum the engine has so
it opens the fuel press regulator to return pressure back to
the tank just unplug vacuum hose and check again
greetings to your wife !!!!!!!!!

 

[sickatea]

Re: unhappy typhoon

put a gauge on my fuel rail this morning. here are my findings
*key on acc truck off 38-40psi
after 15 minutes still holding above 36psi
*key on truck on at idle 32psi
*key on truck in drive at 1500rpm 37-40psi jumping as the truck seems to miss
*key on truck at idle with vacuum line off regulator fuel pressure back to 38-40psi
*fuel pump still only getting 7.5volts at connector before wiring enters gas tank

 

[Brassmonkey]

Re: unhappy typhoon

If you are only getting 7.5 volts to your fuel pump, you have some electrical problems. What is the voltage coming out of the alternator and battery? You might not be getting enough voltage to the coil.

 

[Syclone22]

Re: unhappy typhoon

If your fuel pump power feed wire is only getting 7.5 volts
you found the problem already check your relay it can also
be an issues you can install a bypass 40 amp 5 pin relay and
feed 14.3 volts to the fuel pump this will just hook up to your
existing feed wire to the intank fuel pump !!!

 

[sickatea]

Re: unhappy typhoon

Well had my blonde moment of the day. Don't measure the grey wire and the purple wire, the purple wire appears to be the sending unit for the gas gauge. With the grey wire to ground I have 12-13.3vdc. I hung my fuel gauge out of my hood and took the truck for a ride. Towels strategically placed not to scratch the new paint and my neighbors laughing at my redneck self. I also used my fuel gauge from my tbird sc since I know it's accurate. 34-35psi at Idle, once in gear it came up to around 40 but jumped from 37-40 when it stumbled. Took it for a ride and fuel pressure came up while my rpms came up. Still the truck kept stumbling and the gauge would go down 3psi then come back up. The miss is pretty strong so I came back to the house quick not to make other issues. I really don't feel the issue is fuel related, I just wanted to eliminate it.

Now I did unplug one wire from my cap and rotor at a time today to see how the truck reacted. I never did see a huge difference In the way the truck ran. Every sign to me points to an ignition issue now and the only thing i have not looked into is the ICM. I am throwing straws at this point.
It's really a shame because it is a perfect day in Maryland, I would love to go for ride. Always next weekend!!!