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-   -   New Jeeper. Fuel Issue? (http://www.wranglerforum.com/f218/new-jeeper-fuel-issue-51763.html)

South23 05-28-2010 09:21 AM

New Jeeper. Fuel Issue?
 
Ok, bought a 1987 YJ, 4.2L about a month ago. Jeep looks amazing, only issue when I purchased was a sputtering/hesitation/bucking when trying to accelerate. Seemed like a cut & dry carb issue, so I upgraded to the Weber carb, rather then money on a rebuild.

Since the purchase, I have (myself) put in...
Battery,plugs,wires,dist. cap, rotor, starter,starter relay,oil change,pcv valve,ignition coil,valve cover gasket.
Then I took it to a mechanic to install the carb, and adjust it, and connect all the vacum lines correctly.

After the carb install, ran great for two days. Then, the bucking/sputtering/hesitation (and ocassionaly stalling while driving) came back. But, it only happens after about 10-15 minutes of steady driving, and only at about 35-40 mph or faster. Also, if I can fight past the bucking and keep my foot in it, 45 is top speed, no more acceleration. If I am just doing a short 5 minute trip, no problem. And if it starts happening, and I slow down to below 30, I can get home.

With all the ignition stuff I have replaced, I am thinking its a fuel issue. Could this be fuel pump? or could the brand new weber carb. be bad?
I don't want to regret this purchase.

drivebytruckerz 05-28-2010 09:25 AM

Look for a leak (even a tiny one) in your fuel pump (an all parts around and associated with the fuel). If air is getting sucked in somewhere you'll get these types of issues.

4Jeepn 05-28-2010 09:44 AM

I would re check the vacuum lines, those are usually where some issues pop up.

drivebytruckerz 05-28-2010 09:50 AM

Air, Fire, Fuel.

South23 05-28-2010 09:58 AM

thanks guys,
gonna start by looking for some fuel leaks.

Drivebytruckerz, love the name by the way....great band!!

drivebytruckerz 05-28-2010 10:08 AM

Quote:

Originally Posted by South23 (Post 636955)
thanks guys,
gonna start by looking for some fuel leaks.

Drivebytruckerz, love the name by the way....great band!!

And you would know here in the "Dirty South.." :punk:

sevenservices 05-28-2010 10:21 AM

sounds like water in the gas IMO

make sure your coil wire is secured really good to, sometimes I've seen 'em pop off a little on the nipple. It will run fine until you rev up the RPMs a bit.

kik 05-28-2010 11:01 AM

With my 89 4.2 I had the same thing happen. Replaced everything and still happened. An old mechanic told me to replace the "spark box" (Ignition Control Module). I did and it has never run better. Good luck.

South23 05-28-2010 01:35 PM

Woah, looked up a "spark box", couple hundred bucks! Gonna go to that as last resort. Its got a full tank of fresh gas, 93, from a different gas station then I filled it up from the last time, because I thought that might be it too (I have had a similar problem in my boat). But in my inspection, I see there is a moist spot on the blcok where the fuel pump bolts on! could this be a very slight leak, allowing gas out and air in? could this be the culprit? I am going to try and track down a gas pump to put on tonight, see if that helps.

Garyk 05-28-2010 01:47 PM

I did not see where you changed the fuel filter..

South23 05-28-2010 02:02 PM

Quote:

Originally Posted by Garyk (Post 637179)
I did not see where you changed the fuel filter..

Oh, sorry. Yea, brand new fuel filter and lines from the mechanic when he did the carb.

kik 05-28-2010 03:49 PM

Quote:

Originally Posted by South23 (Post 637160)
Woah, looked up a "spark box", couple hundred bucks! Gonna go to that as last resort. Its got a full tank of fresh gas, 93, from a different gas station then I filled it up from the last time, because I thought that might be it too (I have had a similar problem in my boat). But in my inspection, I see there is a moist spot on the blcok where the fuel pump bolts on! could this be a very slight leak, allowing gas out and air in? could this be the culprit? I am going to try and track down a gas pump to put on tonight, see if that helps.

Not the one for 200.00. You can get an OEM replacement for less than 100.00. That's the one I have and there are no problems. At this point I don't think replacing it should be your last resort. I bet this is your problem.

South23 05-30-2010 05:40 PM

kik,
thanks for the input. I was unable to get a fuel pump anyways. I have to order it, soooo, I am going to inquire about an Ignition control module.

South23 06-01-2010 09:21 AM

Quote:

Originally Posted by kik (Post 637279)
Not the one for 200.00. You can get an OEM replacement for less than 100.00. That's the one I have and there are no problems. At this point I don't think replacing it should be your last resort. I bet this is your problem.

kik,
found a store that has the ignition control module in stock, going to pick it up this afternoon, and put it on tonight. I will let you know if it does the trick!

South23 06-01-2010 09:50 PM

Quote:

Originally Posted by kik (Post 637279)
Not the one for 200.00. You can get an OEM replacement for less than 100.00. That's the one I have and there are no problems. At this point I don't think replacing it should be your last resort. I bet this is your problem.

kik,
thanks for the input, but I replaced the ignition control module, and its still doing the same thing. Didn't even get around the neighborhood (less than 1 mile) before it jerked, sputtered, and lost power. I downshifted, saved it, than it died.

I did notice, while its doing its impression of a bucking bull, if I step on the gas, I can hear the carb "hissing", so if the gas is going through, does that mean its a spark problem.

If anyone knows what else I could replace, please let me know. Few more attempts, and this POS is up on autotrader.

So far, I have done...
Carb
fuel lines and filter
ignition control module
ignition coil
spark plugs and wires
distributer cap and rotor

what could it be???

Garyk 06-02-2010 03:21 PM

Just cause the carb is hissing does not mean there's gas going in. If the carb has a bowl drain, drain the bowl into a clear container and see if has any water in it. At this point it appears to be fuel issue.

South23 06-04-2010 09:11 AM

Quote:

Originally Posted by Garyk (Post 641921)
Just cause the carb is hissing does not mean there's gas going in. If the carb has a bowl drain, drain the bowl into a clear container and see if has any water in it. At this point it appears to be fuel issue.

It appears it may be correct, I noticed some deposits and what appeared to be fine drops of water in the fuel filter. I changed the fuel filter, added some dry gas, and topped it off with new fuel. It is still sputterig real bad, so I just let it idle for a while until it was time to shut down the garage. Going to let it run a bunch more today. Does it take a while to run all that stuff out you think?

kik 06-04-2010 04:03 PM

It does seem like you have a bad batch of fuel and/or water/contaminants in the tank. At this point, since the tank is an 87 a new fuel tank is probably a good idea and fresh gas.


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