Buddy I had a similar problem with a fuel injected CHRYSLER 5.9L in an 89 yj. I got an inline regulator for efi systems. Works good so far. I have been driving it for two months as a daily driver. Hope this helps. P.S. I got mine from jegs, don't know the part number. If that doesn't work put a real engine in it. MOPAR:flipoff2:

 

Your motor should have a fuel pressure regulator on the fuel rail to keep the proper amount of fuel there. If the FPR is malfunctioning then you can get too much fuel. Have you checked your fuel pressure? That is your first step to see what is going on. Do that, then report back.

 

i planned on checking the pressure today, but havent yet.

 

By simple deduction if you have a fuel problem where you don't know how much fuel you are getting....


you check it. :flipoff2:

Newer motors are very specific about fuel pressure and volume. The E8248 pump is great and should supply enough of both for your needs. Do you know the proper method for checking fuel pressure?

 

Yes, i agree.

I finished it about 1:00 AM got up for work @ 5 and drove it for the first time on the new pump.

My assumption up until now is this: Stock pump alone = running fine but not where it should be.

Adding the E8248 is adding more pressure. These problems didnt arise until i added the new pump.

I was going to cruise over to see the greese monkey at lunch as my tools are at home and 45 mins away.

Thought maybe i was missing something obvious.

Thanks Dookey.......Do you ever miss the LT1 TJ?

 

Thanks Dookey.......Do you ever miss the LT1 TJ?

I miss goin wheelin more. I have another project that needs some serious dedication. Should be pretty pimp when I'm finished.

 

Well a quick lunchtime visit to my buddies at the offroad shop has yielded me the following conclusions.

1. My primary issue is this, NO return line from the fuel rail. It has been capped off.

2. Fuel Pressure Regulator on the rail is not working. Without a return line there is nowhere for the excessive pressure to go. (I have always know that there was no return, but never seen a reason to have it, until now)

3. As soon as I put it in drive, it smokes, tries to die, and smells rich.

4. At this point I still don’t know what pressure is at the rail……but know its too much.

Game Plan

1. Remove new pump, go back to relying on the stock TJ pump in the cell

2. in spare time, run a return line and a fuel pressure gauge.

3. Once 1 & 2 are complete than try to run bigger pump again

 

1. My primary issue is this, NO return line from the fuel rail. It has been capped off.

2. Fuel Pressure Regulator on the rail is not working. Without a return line there is nowhere for the excessive pressure to go. (I have always know that there was no return, but never seen a reason to have it, until now)

That's most likely the problem!:laughing: Run a return and fix the FPR.

 

You are going to have a screamer once it is right. I wouldn't wait long to get the return line in place. You will burn up your pump without it.

 

thanks bro.

I sure hope so, i'm still running 4.10's now........and have yet to be impressed. Fixxing the fuel system is my next project.

 

I have a 94 YJ with a 5.3 vortec, my buddy has an 89 YJ with the 6.0 vortec. We both looked through the books at the auto parts place until we found an inline pump with the correct PSI. In addition we used a corvette fuel filter with return outlet. Works great. You do need a return of some sort, this worked for us. Here is a pic of my setup before wiring in the pump(there is also a standard Fram inline filter closer to the tank that is not pictured too), and I will try and dig up some part #'s for you too if I have them.

 

i been serching the threads here and this may also help out with our next project, 88 YJ with a 1994 4.3 vortec. been wondering about the fuel issue, somebody already swapped in a built SBC. the motor is tired runs hot most of the time, and friggin carbs are a nightmare in the rocks....
if you can locate some part #'s i'd appreciate it and so would my sanity....

 

The problem with the TJ fuel systems, is the FPR is located inside the sending unit assy along side the factory fuel pump. when you added another additional fuel pump to the system, you increased fuel line pressure, causing the fuel injectors to dump additional fuel when cycling. When this is done, this causes the fuel injector to also run in a dangerous region that can cause injector failure. You actually want to run a fuel rail pressure around 42 psi at idle. Just let the injectors do thier thing. The only time when you need to add additional fuel pressure is when your running extremely large injectors(40#'s or larger) with a performance engine or performance adders(nitrous, turbo's, S.C.'s)

A stockish LQ33(5.3 GM) averages around 305 HP. So all 4 injectors are probably around 24-26#'s. There should be no need to add an additional fuel pump. Thats why it runs like crap at idle. And stock TJ fuel systems will not have a return line with a FPR at the rail like the YJ's did.

My suggestion, get rid of the additional inline fuel pump, and replace the stock TJ Fuel pump/sender assy with a unit from Hesco. Or, fab up a return system running an adjustable FPR.

 

Good info. Didnt know that about the TJ fuel system.

 

Well, finally got some time to work on it. I added the corvette filter/regulator and ran a return line to the cell.

runs good.......for about 45 sec. Than it dies and wont re-start. I think i need to evaluate my fuel line diameter. I think that i created a path of least resistance with too large of a return line.

Another day....another headach

 

UPDATE

Changed out the return line for a smaller line. After that it seemed to run fine. Took it on a test drive. Lost fuel pressure and was stranded.:shaking: I believe this was caused by cavitation.

Drug it home, bought another Dash 8 fitting and bypassed the factory pump. Took a 3/8 line from the cell to the E8248. Pulled the relay and capped off the line on the factory pump.

Seems to run fine. i will try to test drive in a few days.

FYI- Un-regulated the factory 4.0 pump was showing about 45 psi and the E8248 after regulated shows aprox 59 psi

If anybody needs the part # for the fuel pressure gauge to mount to the rail i can post them

thanks for the help:beer:

 

i aint proud
i'll take any part #'s/ manufacturers you have for your fuel system.

thanks :smokin:

 

What size fuel line are you running. I've plumbed up a 6.0 LITER WITH A 3/8feed line and 5/16 return with no problem. I'm using the same pump as you with the corvette filter regulator. Runs great,good luck with your issue.

 

Same with me on the 5.3 Liter. Works great.

 

3/8 from cell to pump and regulator

5/16 return from regulator to cell

5/16 from regulator to fuel rail

 

I am curious as I have a similar problem with no return line, runs fine for the most part but idle it runs very rich. So the explainations here seem to make sense.

Now the second problem that I have all revolves around vapor locking. The pump on the fuel rail and the two cats beside the transfer case where the lines run, under the hotest day so far this year has left me stranded for a short bit.

So two things are in the works to correct the second problem which I am curious why it was not thought of before. (Maybe it has and dismissed) Isn't the intank pump out of a V8 Grand Cherokee different than the one in a 4.0 TJ?

I know several people running that pump in the tank with no problem with the 5.3

I have a new tank that I built and modified to accept an intank pump. I know, some ppl don't like intank pumps, but they do prime better if you ever run out of gas or other problems strike and they are cooled by the fuel and out of direct heat. Also bought steel lines to run outside the frame rails to get the lines away from cats and exhaust.

The idiot that put the motor in was fired for many reasons and I have been left with getting it running and this is the last problem I think that needs to be addressed.

So from what I hear in this thread is that I need to use a FPR at the rail and set the pressure correctly. Does it have to have a return line? I know even hesco sells a block off kit for the return line but that is designed for the Mopar Injection kit he sells with his newer pump.

Getting about 5-8 MPG in town becuase it idles really rich, get it on the road up to Big Bear and I was getting 18MPG all the way from SD to Big Bear doing 80-85 the whole way.

So I know something isn't right and there is no codes being thrown. Mine is also the 5.7.

 

Part Numbers to adapt vortec fuel rail to fuel pressure gauge

Dash 4 gauge adapter - Earls 100201

Dash 4 cap - Aeroquip FCM3752

100 psi 1 1/2" Fuel Pressure Gauge - Auto Meter 2180

 

Mine is an '02 motor that has a 66PSI regulator on the motor. I pulled the internal tank pump completely and put in a hose to replace it. I use an external pump, MSD 2225, got mine from Summit (cheapest proper pressure pump I could find). It's been fine for all 5 years since the swap.

 

thanks for the info
maybe my sanity will remain intact lol

 

Well, new problem.

Starts up.....ok Takes 3 hits of the key

Idles fine, revs fine

Put it in gear and let the RPM's drop and it dies. Not even let off of the gas, just not give it as much gas, and it dies.

Any thoughts?

 

Any thoughts?

Yeah, hang a fuel pressure gauge on it and try it again. If it's not ok, keep at it. If it's ok, look for a non-fuel problem.

 

PSI is 59-60

if i go back to the stock 6cyl pump, 45 psi. The issues go away

 

Don't go by this pump or that pump. What's the spec of the motor. Pumps don't regulate, the motor's regulator does. The pump just has to be strong enough get to and keep the spec pressure at the flow rate the motor needs. You could have a bad regulator.

 

might be a bad regulator. Do you have the Vette filter/regulator or the regulator built in to the rail? I bet its the a bad regulator especiallly if you have the one on the rail.