Hi!

First, let me start out by saying that other than minor maintenance issues like changing the plugs or doing oil changes I'm not a "real" mechanic. I know basic mechanics and I can twist a wrench thanks to my dad who was a master mechanic and taught all of his kids how to do the basics.

I'm currently summering in Lewes, DE (haaving trouble finding a good Jeep mechanic...if you know of one in this area, please let me know!) I bought a used Jeep for summer fun and daily driving. I thought I was getting a nice deal, but what I ended up with is a project. I have a 1988 YJ with the BBD equipped 258 (4.2L) engine, 6 cyl. 5 spd. manual trans.

ISSUE:
It has all the classic symptoms of the ECM carb (stepper motor) problems: lack of power + surging and missing at idle. I've read that changing to another carb will only complicate the situation by confusing the ECM resulting in the spark timing being off. I read an article which detailed doing an ignition bypass at http://www.4x4wire.com/jeep/tech/electrical/jn-ignition99/ but it says that it will make the Jeep street illegal in the U.S. I'm not sure I want to go down that path.

According to the article:

"Any change to a different type of carburetor, or to a TBI fuel injection system such as those offered by Holley or Howell may confuse the ECM resulting in the the spark timing being off. The addition of high performance parts or engine modification such as head modifications, headers, or intake modifications may also require that this sort of modification be done because the modified engine may operate outside of the parameters for which the ECM was designed."

It goes on to detail how to do the fix. I don't have the knowledge to do this and frankly, I want to completely get rid of the emission stuff under the hood or bypass it.
A> Is it possible to get rid of the emissions stuff?
B> Will the Jeep still run and will it run better?
C> How involved is it to do this?
D> is it very costly ($$)?

I'd also like to install an EMPI 32/36 Electric 2 BBL Carb w/Float Bowl vent:

A> If I do this, what happens to the preheater hose?
B> Do I need a different breather? Will this indeed confuse the ECM?
C> If I get rid of the emissions junk, will there be anything to confuse?
D> Can I put a new carb on the Jeep without having to re-wire the ignition system?

What do I do to get rid of the dreaded ECM carb problems?

I don't have the knowledge, $$ or the means to do perform any major modifications. If possible, I'd like to do the minimum to make the YJ run better. I'm only trying to make the YJ a dependable daily driver and fun summer ride without all the carb and ECM problems.

HELP!

Any advice or knowledge you can share is greatly appreciated.

Thanks in advance,
Barb

Well it has run for 20 years and been fairly dependable like it is!
The short answer is: The computer controls BOTH the carb and the distributor.. So BOTH must be deleted from the computers control NOT just one.
That carb you ask about is indeed a good one! However it's problem is the size of the aftermarket air cleaner that must be used with it...in my not so humble opinion.
There is a proceedure called "the nutter" that can be used after installing the new carb that disables the computer from the distributor.. It is a popular proceedure and has been used sucessfully by many Jeepers.
Changing dist types is not a good thing for novices to attempt...
My first thought is for you to look for vacuume leaks. One little vac leak can cause the problems you have described.
Big JIm <img src="/forums/images/graemlins/pfft.gif" alt="" />

A BIG thank you to Big Jim for his wise counsel!

You need to remove the aircleaner and take a look down the carb. You will see 2 small brass rods ending in a circle with a very small hole thru them. They should atomize the fuel and spray it down into the carb but because they are so small they often plug up and cause a surging idle or worse no idle at all.This has covered many times but before you go replacing a bunch of parts try using a can of compressed air sold for cleaning computer keyboards,etc and using it to blow out the tiny holes. There was a fix from the factory for this that called for opening up the holes a bit but you will have to search for it since I cannot recall the size. Big Jim has mentioned many times that you can use a small bottle of propane to locate vacuum leaks. For this you start the motor and while staying carefully away from rotating parts open the valve on the prpane a little and release the propane around the carb base, vacuum limes etc. If there is a leak the propane will cause the idle to increase and you will have found your leak. Also do not wear any loose clothing that can get caught in the fan belt, etc. Hope this helps, my friend uses the can of air on his carter bbd and it works great.