tech questions: 93 wrangler, 93 gr cher

MudPuppy76 did pass the time by typing:

Probably needs an oil change. The I6 isn't the worlds most quiet engine when it's older. :) It could be your getting a teeny crack in the exhaust pipe, that will sound like a tick till the metal heats up and seals it off. Eventually it will sound like a diesel and you will have to replace it. (they all crack) linky:

Either fuel pump check valve or fuel rail pressure regulator has failed. Get a fuel pressure gauge and check the rail. 32 psi at idle, take the hose off the regulator and it should jump 3-4psi, turn the engine off and the pressure should stay level for more than an hour. To check which one is leaking you have to use a special hose that can be clamped. Clamping the OEM hoses isn't a good idea. At two days I wouldn't be worrying. Just tell here to turn the key on, then off, wait a sec, then on again, then start. You might need to replace the fuel filter.

MudPuppy76 proclaimed:

Quick diagnostic on the ZJ would be to turn the key on, wait a coupla seconds. If it starts right away then, the fuel system is losing pressure somewhere. On the 93 don't know if there is also a fuel rail check valve.

Put a gauge on it and monitor bleeddown pressure overnight. If it is your pump checkball, then I would think you would want to replace the pump - esp. if it is a high mileage unit, rather than insert a homemade timer into the FP circuit. The pump should run Key On anyway. Its the operation of the injectors during cranking that bleed the fuel line of air when you have a fuel drainback problem, not fuel pressure alone.

And incase this is just coincidence that the engine only has trouble on extended sits --- the 4.0 of that era had problems with its crank sensor. Not sure if it was still a problem part by 1993 though. Their output level would weaken at cranking speeds and cause either a no start or a long crank. Just something to think about,

Toyota MDT in MO

will check the fuel pressure when i get back to the shop on monday. maybe put a scope on the crank sensor just to see.

Ditto. That is why you get the parts from somewhere and do the job yourself.

not OEM? here is an article about autozone fuel pumps you might want to read first, I have it archived so don't have the message number: \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ Your fuel pump is more than likely on it's way out, and it would be wise to replace it now than to wait and be stranded (don't ask me how I know this). I remember reading somewhere that these fuel pumps would get contaminated with the left over solder from when the fuel tanks were put together and get louder and fail. The same thing happened to me, and mine went all of a sudden. How I missed that noise that night... Also, spend the extra money and get a >OEM< fuel pump. As a tech, I have replaced many pumps 2 and 3 times because the aftermarket ones failed after a couple of months. I too bought a Master fuel pump from Autozone, and after 2 months the noise was back, so I returned it and got a Ford one, and haven't had trouble since. Since this is a very aggravating job and the pumps seem to always go right AFTER you fill up, do yourself a favor and get a good one the first time. \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ EDITED: >OEM< was originally "Ford" in original message.

Now do you _still_ want to go through all that HELL of replacing a fuel pump with autozone part, only to have to do it again in 2 months?

Lg

What a pile of crap that post is!

'Solder' from making the tank contaminating the fuel pumps. ROTFLMAO!

I have never heard anything so foolish.

Mike

Lawrence Glickman wrote:

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Leaking up top can just mean a worn rubber seal or a loose hose clamp on one of the 3 lines hooked to the pump/sender unit or a cracked line or a rusted/leaky filter if external on the frame rail or just a leaky fill tube. It is very unlikely you need a pump to fix a leak and it is 'very' likely the leak is causing it to air lock when it sits causing slow starts when cold.

If any air can seep into the system when it sits, the gas will all go back to the tank or on the ground depending on the orientation of the leak.

Mike

"MudPuppy76

The only thing close would be that Methanol will dissolve the Tern coating inside a steel tank, contaminating the entire fuel system.

Well......

The owners manuals for both of my Jeeps specifically warn 'not' to use any type of gas contaminated with 'gasohol' or ethanol or methanol. It states you 'can' use up to 5% or less with anti corrosion stuff but it might not run well and to 'never' use any that is higher than 5% contaminated under any circumstances....

Mike

Here in Connecticut ethanol has replaced MTBE as an anti-knock agent. I forget exactly what the pump stickers say but I think it says "up to 15% ethanol."

-- "I defer to your plainly more vivid memories of topless women with whips....r" R. H. Draney recalls AFU in the Good Old Days.

Some of our stations are like that and my CJ7 will 'not' run on their fuel mix. It refuses to idle and pings out over 65 mph with the gas mileage dropping by 100 miles per tank. 'Petro Canada' gas is the worst for some reason.

I even tried dropping the timing back 5 deg or so to see if it would run on the crap and it is a 'bit' better on idle (it will stay above a stall) but top end power and gas mileage still suck big time.

Mike

////////////////////////////////////////////////////////////////////////////////////////////////////////////////// well, I dunno, I just read this *stuff* and take it at face value. I have no way of knowing if it is crap or not, but here is your reference as I was unable to locate the message headers.

So, who knows? Where this rumor got started, and why? Maybe it was true at one time.

Lg