94 xsport engine HELP!!

[smores85]

Here's the deal, my engine is a 4.0 v6 w/ 154,000+ miles, we replaced the sparkplugs and MAF. The check engine light is sporadic under certain conditions. In town it runs fine and check engine light is usually on unless it is real windy in town. Out on the highway the truck starts chugging/hesitating around 45 to 50 mph. It levels out when I romp on it and get it upto 55 to 65. Sometimes the cel is on and sometimes it will just go off. It seems to like real windy weather, it runs better.
I tried to check the codes with an auto x-ray but it couldn't pick anything up. Kept getting an error. There is no autozone near here. Any ideas?
Thanks in advance.

 

[Blee1099]

Originally posted by smores85
Here's the deal, my engine is a 4.0 v6 w/ 154,000+ miles, we replaced the sparkplugs and MAF. The check engine light is sporadic under certain conditions. In town it runs fine and check engine light is usually on unless it is real windy in town. Out on the highway the truck starts chugging/hesitating around 45 to 50 mph. It levels out when I romp on it and get it upto 55 to 65. Sometimes the cel is on and sometimes it will just go off. It seems to like real windy weather, it runs better.
I tried to check the codes with an auto x-ray but it couldn't pick anything up. Kept getting an error. There is no autozone near here. Any ideas?
Thanks in advance.

It could be a number of things causing your check engine to come on. Before trying to replace any other parts, try getting the codes scanned somewhere else, they should stay in memory. Once you find out what the codes are, post them on here and I'm sure someone would be more than willing to help you with your problem.

 

[88vert]

How is your gas mileage?

 

[MrShorty]

On a '94 you only need a paper clip to access the EEC-IV diagnostic tests. The trouble codes are output as flashes of the CEL. Follow the instructions at www.dalidesign.com/hbook/eectest.html or in any good repair manual. Remember that trouble codes represent circuits, not sensors alone, so pulling codes is just one step in the overall diagnostic scheme. Always resolve the codes in order of KOEO hard faults --> KOER faults --> KOEO continuous memeory.

 

[smores85]

88Vert:

My gas mileage stinks, I have 31x10.5's on. It does pretty good on highway even at 60mph. Could a bad cat converter cause some of this? I have a glasspak on it cause I put two holes in the muffler. Can't afford Flowmasters just yet, It also makes a weird chuff chuff sound underneath.

oops oh yeah, the highway chugging is kind of like a flat idle spot with major vibration. Under 45 it doesn't do it and 55+ it doesn't do it.

 

[410Fortune]

Sounds like a fuel system problem

Could be a leaking intake manifold too

Could also be bad 02 sensors or a clogged cat.

But it doesnt do you any good to throw $$$ at it, without first reading the codes.

You might try some simple stuff like cleaning the MAS, resetting the battery, and replacing the fuel filter.

If you have the means check the fuel pressure at the fuel rail.


Step 1 is to pull the codes.
If the CEL comes on there is a code or two......

 

[88vert]

Might want to check your Fuel pressure regulator also

 

[smores85]

The fuel filter has been replaced, less than 5m old. Well try to get codes and then I'll post them. I'm figuring possible IAC, Fuel Reg, and bad cat. It has been running rich. We've been putting reg. in it instead of Plus. The Plus makes it worse and we can smell it more often.
Thanks for the help. As soon as I can get codes I'll know more about what's going on..I hope!

 

[410Fortune]

A rich condition is either
bad fuel pressure regulator
bad 02 sensors
or leaking injectors/lack of spark

Rich condition will also clog the cat very quickly.

Forget the IAC, it is not the problem.
Have you cleaned the MAS?

Again, pull the codes.

 

[88vert]

Originally posted by 410Fortune
A rich condition is either
bad fuel pressure regulator
bad 02 sensors
or leaking injectors/lack of spark

Rich condition will also clog the cat very quickly.

Forget the IAC, it is not the problem.
Have you cleaned the MAS?

Again, pull the codes.

Also a bad regulator will mess up your 02 sensors too

 

[410Fortune]

Yes, for whatewver the reason, if it is running rich, raw gas getting through into the exhaust will kill 02 sensors and also clog the cat converter quick

 

[smores85]

oh Gadzucks!!!!
Okay, I realize without getting codes it's hard to tell what is going on, but in theory if it's the fuel reg leading to bad 02's and a clogged cat, about what price range am I looking at and would it be better to take it to Ford or an indep. mech? We can take apart an old engine but these electronic suckers are a pain in the arse.

Oh and no haven't cleaned the MAS, well do that. Do you need to disconnect the battery and have it relearn after the cleaning?

 

[88vert]

Dont take it to a mechanic you can do this yourself its not that hard