can someone please help???

[wickeds.h.o.]

hi guys, i have a 02 i got about three weeks ago. i have changed plugs and got 150 miles on 50 dollars of gas and then hit a deer. filled the tank up and got 150 miles on that tank mostly highway. kept getting 5 & 7 missfire so checked all COP and all have spark . i swapped them around and got 1&5 missfire. i swapped around fuel injectors and haven't got no codes so far but used 1/4 tank of gas in 18 miles highway. also i have noticed that from 45-70 it will drop about 500 rpm and shake real bad. the only way to stop it is to play with the gas. i am lost and have no clue where to look now.
i have checked fuel pressure and its 30 psi KOER and 0 KOEO ANY IDEAS OF WHERE I SHOULD START NOW? thanks for any help

 

[FordandPolaris]

Holy moly, 18 miles on a 1/4 tank...? Check vacuum lines, O2 sensors, MAF sensor, all of these could cause drops in fuel economy. Although with that low of fuel economy, I would be looking for a leak in the tank honestly. Start the truck and see if you can find leaks underneath.

Also, if you moved the COP's around and got misfires on different cylinders, those COP's need to be replaced. Regardless if they spark at idle, they may be failing under load.

 

[wickeds.h.o.]

i have replaced 3 vac lines and cleaned maf and it ran allot better but only got 229 miles on full tank highway. i have also checked for gas leaks but it is all dry and no signs of gas leaks. it is running really rich when it gets warm.

 

[FordandPolaris]

Then I would look at doing O2 sensors, but start with the two bad COP's

 

[stamp11127]

Get it scanned for codes, especially the historic codes. Autozone reads for free down here. A good reader will also graph the signals from the O2 sensors which you can use to determine if they are at fault.
Don't play around to long, if raw gas is going into the cats they will be history very quickly.

 

[wickeds.h.o.]

i will have it scanned tomarrow. can autozone test coils with the obdII or is it just the dealer that can test them? i think the converters may be bad because i dont know how long he drove it like this. seems like it only had half the power it should and hardly has any take off

 

[stamp11127]

Your fuel pressure is at the minimum acceptable limit, it should also retain pressure when turned off. How long does it take to hit "0" once the engine is turned off? What was the condition of the old plugs? All have black electrodes?

Listen to the injectors with a stethoscope if you have one. You can hear a difference in one that is giving trouble.

Concerning your fuel range, make sure it is going into overdrive on the highway. These get very thirsty when they don't.

Post more info on the vehicle: mileage, mods etc.

When your diagnosing a problem, make one change at a time. If there isn't any difference return it to what it was originally. Then make a second change, note any difference and so on.

 

[wickeds.h.o.]

i will also check fuel pressure tomorrow and let you know what i get. plugs that i took out looked bad and there was 4 different brands of plugs. 2 ngk plugs had a gap over 70. no mods and it has almost 170,000. i had to take off the throttle body because there was 1/8 inch layer of carbon build up. the overdrive seems to work but the neutral safety switch is bad. i have to start in neutral to be able to shift into any gear.could that have an affect on it.still haven't had check engine light come on since i swapped around and cleaned the injectors (around 150-200 miles)

also what should fuel pressure be with it on and off? i keep getting different answers

 

[1997SCEBFEX]

I think all the major identifiers/problems have been referenced above!
I suspect it's a multitude of problems. & add:
- fuel filter
- air filter
- thermostat
- egr
- DPFE sensor
- throttle position sensor.
- etc...

PanHandler.

 

[stamp11127]

wickeds.h.o. please don't take this wrong, sounds like you have a redneck special. Any time I run into mismatched parts it throws up a red flag. It may seem like more work but it is usually faster to return the engine to the factory base than to jump from one problem to the next trying to find your cause. I do a few basic tests to determine where I'm at...

Since your TB was caked with carbon you may have problems with the egr system and / or low compression.
First up would be to pull codes and make sure your check engine bulb is working. The cluster does a self test when you first turn the key to run position illuminating the bulbs. The redneck method of turning off the check engine light is to remove the bulb.

Check the harness to all the sensors looking for a redneck repair or not being connected.

Is there a round fuel pressure regulator on the driver side fuel rail, or is it the returnless fuel system?

Next up would be a compression check on all cylinders unless you find a low one during the test. My seat of the pants low limit is 100-110 psi. There are numerous videos on youtube that show the process if you've never done this.
It can be a pain at times, you may want to check the egr prior to this test.

If all cylinders are healthy (165+) then I'd pull the egr valve and check / clean the passages & check egr operation with a vac pump.

The compression #'s are my guidelines. Others will have their ranges that they work with, the lower the number the less power is produced. You are looking for more or less equal numbers on all cylinders. If one is way out or reads 0 then you have a problem with that cylinder.

I've had lawn mowers run at 85psi - not well but they did run, smoked the mosquitos also. A true oil burner.

 

[wickeds.h.o.]

well light came back on missfire 5&7 so i got compression tester and getting ready to do that now.

 

[stamp11127]

Have you performed a compression test before?
If not:
1) pull the fuse to the fuel pump
2) If it has a coil pack disconnect it from the harness to kill the spark - no chance of getting zapped this way
3) Test with wide open throttle
4) If a cylinder reads low, squirt a little clean oil in and retest
5) Turn over engine long enough to get the highest reading - 5-10 secs is good

 

[wickeds.h.o.]

well did the test and all were around 165 except for cyl 5 it was 190 the first try and 180 after that.

 

[Jason_CPAPS]

When I got my expy I had the same isssues. Replace the coils. I got from summit. They work just fine, my cats were completly melted now they are gutted, dedd feed back pressure, egr valvr and some sensor near egr, cleaned maf, replaced 2 vac lines and the line amd elbow that runs to back side of engine. Start with coils and look at egr components