Jeep 5.2L V8 problems

[getlost4x4]

I just bought my 1994 GC 5.2 V8 about 2 months ago. It has 132K on it.

It was running great up until last week.

I bought it for around $600. I knew it had some issues.

So far I have replaced:

Radiator and all the cooling hose
Recharged the AC
New plugs
New air and fuel filter
New thermostat
New valve cover gaskets
New battery
New oil and filter
New battery terminals
New rebuilt tranny 4000 miles ago

It suddenly started running really rough. I just pulled the catalytic converter and muffler last night because the cat.was broken and the muffler was rusted out from the inside.

The engine is still screwed up. It back firing. The only way I can get it to run is by pressing the gas pedal to the floor.

What should be my next step? I'm thinking about new wires and cap and rotor.

Do you think it could be a fuel pump or ECM?

Thanks
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[Maximus Ram]

HAve you tried the MIL check.
turn the key to on...go on off on off onoff on.
count the number of times the lights go on and off. the test ends when you see the lights blink 5-5 .
I just got a check engine light on my 5.2 in the Dodge. It came up with a 43, being the ignition coil. After reading what the code meant, it was misfiring apaerently. This could lead to it ruining the cat. Weel , I just had to replace my cat back in July. I just put in an MSD coil.
Try that and see what happens.

Good luck

 

[JeepN95YJ]

The throttle position sensor also caused that type of problem. Run the codes.

 

[eagle1]

you might also want to try using some throttlebody cleaner spray,and some fuel injector cleaner. also check the wires for damage

 

[StumpXJ]

Coil could be cracked, Throttle position sensor, MAF, CPS, etc. etc.

~ James

 

[Warhead]

there are literally a million things it could be, with that mileage I would also check the timing chain.

PS has it ran OK since you changed the plugs? maybe the plug wires are on incorrectly?

 

[PGW]

When I replaced my thermostat on my 5.2 ZJ I accidentally pulled loose the coolant temp sensor on the intake. It started running like crap and would stall out if I put it in gear, the check engine light was also on. I managed to track it down, plug it in, and all was well.

 

[whowey]

I had the same issue on my 94 5.2... turned out my cheap distributor cap had cracked from the engine bay heat. Another known issue on these motors is the intake gasket, it can split and cause a leak.

 

[getlost4x4]

alright. i spent some time looking under the hood.

the only thing i can see so far is the PVC hose is split. i'll replace that and the PCV.

all the other connections are hooked up. non of the vacuum lines are damaged.

i'll pick up a basic ignition tune up on Monday, including new wires, cap and rotor.

 

[Amauri]

Did you do the key trick to get codes?

 

[getlost4x4]

tell me the key trick.

i have OBDI on this jeep. wish it was OBD2

 

[getlost4x4]

i just the key thing to get the codes.

i got a 55

i looked in my manual and it doesn't have any info for a 1994 GC 5.2L

 

[Maximus Ram]

55 is end code.
It means that there was no code thrown...hmmm, interesting...

 

[getlost4x4]

alright. that sucker was dirty.

i removed the throttle body and cleaned everything except the MAF sensor with B12 chemtool. put on a new gasket and replaced a few rubber vacuum lines. it fired right up. i also found one of my spark plug wires was not fully seated on a spark plug (reason for the miss).

it fired right up

 

[Amauri]

Woot.