87 Wrangler dies

[cdlongjr]

When I drove the Wrangler down 495 from Chester, Pa. a couple of weeks ago, she died 3 times before I got to the 12th street bridge. After the bridge, she ran fine. Tonight, she would die everytime I got over 50 mph, (about 52 mph @ 2000 rpms). Engine died, but would come back @ 40 mph, go up past 50 mph & die again. I had the same scenario all the way home. I made a right turn onto Red Mill Rd & she died completely. Started right back up & made it home. I have the 4.2 L & the Nutter by pass has been done, B&M auto trans, new Dura spark ignition module, new coil pick up, new coil, new fuel pump, new fuel filter, rebuilt MC 2100 from an Auto parts store,(121 venturies), new K&N air filter assembly. Oil levels are ok & just filled her with regular gas.
Any ideas what the problem might be?
Thanks

 

[CJ]

Hey CD, this sucks! You have had nothing but problems from this damn YJ...

Does it just stop running immediately? Does it fade out? Does it sputter and die?

The reason I ask is that if it dies suddenly, that is usually a symptom of an electrical problem. If it just looses power, your usually looking at a fuel problem...

Either way - it stinks...

Let us know my friend!

 

[IOPort51]

when it is not moving, does it die above 2000RPM's??

 

[cdlongjr]

When you're riding down the highway, you feel the engine die, no spittin, sputterun' or coughing. No boggin' down, she just dies. I'll run her in the driveway this morning to see if she does it while stationary.
Yeah, this YJ is gettin' on my nerves. If I can ever get her runnin' good enough to sell, she'll be goin' for a 7. After sellin' the 5, I've been brow bwt but Momma & my butt is sore from all the sell inflicked kickin'!!!!

She runs fine in the driveway. 3K no problem. I haver fiberglass frnders. The ignition module had a ground wire from one of the mounting bolts to the power steering pump mounting bracket. I ran a 2nd ground wire from the ignition module to the ground wire from the battery to the firewall.

 

[IOPort51]

The first time I read the title to this thread I thought it was from "I'm not spam".:laugh:

 

[cdlongjr]

Drove her last night with a 12v light tied into the coil. When she died, light stayed on, so I'm pretty sure it's not the ignition system. She will run at 3,000 rpms in park with no problem. I'm leaning toward the MC 2100 with 121 ventris. Mainly because the engine completety dies when making hard turns & has to be restarted. Last night when I shut her off she dieseled. Running Shell regular gas & the engine has been power timed.

 

[cdlongjr]

I put the vacuum gauge on the intake manifold last night before the drive. Vacuum was @ 16", but the pointer was swinging rapidly between 18" & 14". I shut the engine off, screwed the idle screws in & backed them out 2 turns. Started & had to adjust them out 1/4 turn to obtain highest vacuum, 20". Pointer is still swinging rapidly. I drove her & now have a bogging/stalling when I nail it. She wound out to 3k in 1st, (very slow acceleration, about 1/2 as fast as the 5 was), & at 40 mph in 2nd, died. I can pump the accelerator or hold it to the floor & nothing happened until she dropped to 20 mph, then the engine came back in. No dieselling problem when I shut her off.

 

[gert]

I would like to go ahead and reccomend fuel injection swap before you kill that Jeep

 

[cdlongjr]

No funds for EFI. I'm leaning toward fuel system problem. I'm going to run a fuel line from a 5 gal gas can to the fuel pump & see waht happens. With a multimeter hooked between the coil, voltage remained about 11.5, even when she died.

 

[cdlongjr]

Had a member of another forum suggest I put a clear fuel filter before the fuel pump. Last night I installed one. Very little fuel coming to the pump. Tonight I'll turn the air compresor pressure down & blow the fuel line from front to rear & blow out the fuel pump, then install a new factory fuel filter & see what happens.

 

[cdlongjr]

Checked all the fuel system with a blow gun @ 10 psi. No obstructions or debris. Hooked everything back up & still no start. Removed the fuel line into the factory fuel filter & placed it into a liter bottle. Good fuel flow. Hooked it back up, no start. Removed the fuel line from the carb & placed it into the bottle. Damn thing started. Hooked the fuel line back up to the carb & she wouldn't start. Removed the line again & she started again. Hooked it back up & no start. Removed the return fuel line & put a rubber cap over the nipple on the fuel filter. She started & idled better than she ever has. Usually cold, I had to pump the gas pedal to keep her running. Not this time. What's the problem with the return line? Do I just cap the steel return line so she'll pass inspection? (They pressure test the fuel tank).

 

[cdlongjr]

I wonder if the canister plumbing may be causing my problems:
CTO (As you are facing the driver's side of the engine)
I have 2 ports on the left & 3 ports on the right
Right side
1st port closest to the engine has no hose to it
2nd port has a line from the vacuum line to the brake booster (has a tee in it)
3rd port goes to number 4 on the canister
Left side
port closest to the engine goes to the modulator valve on the tranny
other port has a line fom the brake booster

Canister (from firewall to the radiator
#1 to air cleaner base
#2 vapor from fuel tank
#3 tee with PCV valve
#4 to CTO, 3rd port on the right

NO vacuum to EGR valve

 

[BrockGrimes]

When I read the beginning I was thinking You had the same issue I had with my old YJ. Drove me bonkers trying to figure it out. Turned out to be a leak around the fuel hose, that and it would try to collapse at high RPM's. The rubber line would collapse and then suck air and the damn thing would shut off.

Had an old timer point it out to me and sure enough that is what it was.
Replaced all my rubber lines and never had a problem after that.

Only thing I can figure with the return line capped is that it's putting enough back pressure in the system to keep it supplied with fuel.

Next time it shuts off see if the line to the carb is collapsed, then move the linkage and see if it squirts fuel.

 

[cdlongjr]

I swapped the carb with the carb off my 74 J-10 with the 360 CI engine. I was able to correctly plumb all the lines from the canister except the line closest to the firewall. It is supposed to go to the vent on the fuel bowl. My carb doesn't have that vent. I ran the line to the tube on the left rear of the carb, which goes into the air cleaner.

 

[cdlongjr]

SHE"S ALIVE!!! Drove her 70 mph today. Combo of wrong carb & canister plumbing.

 

[CJ]

Finally! It feels great to get it worked out, doesn't it?

I have to say, I really admire your persistence!

 

[cdlongjr]

Thank you sir! Yeah, I enjoyed the ride. I want to restore this one as I really screwed up sellin' the 5. I have sooo much time & money in her now I might as well finish her. The root problem was I had the plumbing for the canister wrong & was building vacuum in the gas tank. Since the return line had the least resistance, the vacuum pulled the fuel back to the tank. Plus the fact that I didn't have the return line @ 12 O'clock.
You'll be seeing more posts as she still has issues, starting in all p,r,d,2 & 1 is the next problem to solve.

 

[IOPort51]

It's kind of like hitting yourself in the head with a hammer, it feels really good when you stop.

Thank you sir! Yeah, I enjoyed the ride. I want to restore this one as I really screwed up sellin' the 5. I have sooo much time & money in her now I might as well finish her. The root problem was I had the plumbing for the canister wrong & was building vacuum in the gas tank. Since the return line had the least resistance, the vacuum pulled the fuel back to the tank. Plus the fact that I didn't have the return line @ 12 O'clock.
You'll be seeing more posts as she still has issues, starting in all p,r,d,2 & 1 is the next problem to solve.