19 a gallon... and a p0340 code

[Destroyer000]

so my 96 splash gets 19mpg a gallon! gets this if i baby the truck or if iam hard on it.. highway it gets 24.. its a stepside reg cab 5spd.. my buddies 97 excab fleetside gets 26-28... why would a "smaller" truck a little lighter get worse mileage? hell my 95 4.0 spd lifted gets 19 any ideas?


also the check engine light has come on for a cam position sensor malfunction... i replaced the sensor a while back when the code first came on drove the truck 800 miles was fine.. then it came back on again for the same code... erased the code with my scanner an its fine.. dont understand what would cause this... just does it every once in a while... worn timing belt cause this ?

 

[mrcarcrazy]

Same len here. Ever figure it out?

 

[mrcarcrazy]

Bump for assistance

Well guys I'll put in a bit more info about my truck. its a 95 2.3L with ~140k on the clock... apparently the CEL is burnt out. I ran the codes due to poor mileage...

got the P0340

I've replaced plugs/wires/fuel filter and did the seafoam via vacuum line to try to resolve mileage of ~19mpg mixed driving (majority hwy).


no luck thus far. I know for sure the fuel tank is leaking after fillups (I've read and have come to the conclusion that is due to a leaking filler neck...which I guess I'll order this week.

I hope the tank itself is okay. if its leaking that'll explain the mileage...but present new issues.


Anywho based on my searches no one knows how to fix this CEL code...please prove me wrong.

 

[mrcarcrazy]

BUMP. finally bought a code reader I'm getting P0340, and P0300

I can't feel any misfires..so I'm not sure what that's all about.

any ideas for all my woes?
-poor mileage
-P0340
-P0300

 

[mrcarcrazy]

BUMP with Update - I replaced the leaky fuel filler neck. Both codes still there, and my mileage was a horrific 18.4mpg. ...I'm slightly perplexed... I guess I'll buy that cam pos. sensor just to see if it fixes the problem....then if not I'll chase wires I guess.

Any thoughts?

off another thread....but worthwhile for anyone in my position later.
how to test your Cam sensor and wiring can be found here
http://arrc.epnet.com/autoasp/framerq.asp
username and PW are auto.

 

[bluebombersfan]

same mileage for me

I got a 96 2.3, 19-23mpg is all I ever get, I've done everthing my skills have allowed me to do. plugs, wires, cleaned K&N+maf sensor, gas filter, seafoam through booster line, even put in a fresh new upstream 02 sensor, proper tire pressure. And no codes to pull.
I guess the good news for you is you have some codes to work with that could be the source of the problem althought it sounds like it might be hard to diagnose.

 

[mrcarcrazy]

Okay, I tested the Voltage variance per the website I posted above...according to that test, the sensor is fine. (this was tested via the wires going to the sensor)

http://picasaweb.google.com/lh/photo/BPqFArn2PV8lgepZau0TvQ?feat=directlink

that's a screen capture of the instructions I followed (except I don't have a break out box) so I just stuck the probes into the wires and held them there while my lovely assistant started the engine, and altered the rev's.

So yeah according to that test my sensor is fine...however my ECU doesn't agree....I think its time for a 5.0 swap.

 

[mrcarcrazy]

I went ahead and replaced the cam sensor for shits-n-giggles. as well as cleaned the MAF, replaced the upstream o2 sensor, battery (it decided to die today), and main drivebelt (it was cracked).

P0300 is gone, P0340 is back.

I'm about 99% ready to trade the truck in on a Jeep Wrangler...

 

[ecp's_beat_98]

I'll throw in my 2 cents and ask for some help here- Go ahead with the 5.0 swap or sell the truck well you still can. About three weeks ago, after getting lousy mileage for a while, and the auto tranny hitting hard into gears, my CEL came on and threw a Cam Pos Sensor code, about 30 seconds later, the truck shut off. I have since replaced the cam pos sensor, tranny speed sensor, fuel pump and fuel filter. Truck still won't stay running for more than 30 minutes, still sending a CPS code, and I'm chasing wires everywhere looking for a problem. Truck is a 98', 2wd, 2.5l with about 160k on it. Any ideas?

 

[Earl43P]

Perhaps the timing belt is so worn, you jumped time?

That would affect the CPS.

 

[ecp's_beat_98]

timing belt seems alright. could it run for 20 minutes before cutting out if that were the case?

 

[Macgiobuin]

I had the same problem with my '00 Merc mountaineer. P0340 kept coming up, even after replacing the cam sensor, wiring to the PCM, 2dry ign cables, sp plugs, head gaskets, swapped coils, geez... still came up every time I cleared it- it would run for the first trip, with no CEL turned on, then as soon as I started it, CEL is on and it is the P0340, again. Finally, I thought that the problem may be the alternator. I just put a new one in about a month before the problems all started. How to diagnose: Charge up the battery. Clear out the codes. Run it until the P0340 shows. Bring it back home. Clear out the codes. Disconnect the alternator. Yes disconnect the alternator. Isolate the battery terminal at the alternator from any short circuits by wrapping it in elec tape. Take the car on the same trip. If the code does not set on, you found the problem. The voltage regulator is transmitting stray AC voltage that is being picked up by the cam sensor or the PCM and throwing the whole system off. Do the test in daylight with no loads on--no radio, no headlights, no blower. I didn't believe it was possible, but now I am a believer. -Mac