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Engine miss above 2000 RPM

OK, so what is the best technique for waterboarding a jeep?
 
I never had procedure, just held the throttle open and dribbled water from a cup. If the engine died it was either not enough throttle, or to much water. ;)

So, maybe I'll learn something here...
 
Well lets see what the Jeep Collective knows.

http://www.naxja.org/forum/showthread.php?p=246508749#post246508749

I never had procedure, just held the throttle open and dribbled water from a cup. If the engine died it was either not enough throttle, or to much water. ;)

So, maybe I'll learn something here...

I used distilled water then Gumout spray, back and forth twice last night, used a plastic trigger sprayer that had 409 in it once. Spray or stream did not seem to matter. Ran the engine at about 2500 rpm, good and hot. Sprayed it on the throttle body throat onto the butterfly plate

The STFT is now very close to normal, going from 135 to 115, at idle, and acting OK at higher rpms (running about 80-90 at the lowest) and got better as I did the cleaning, and the LTFT dropped just a little, first time it ever moved off of 128. I did cycle the engine on and off 4-5 times, and that seemed to help too with the relearn cycle. The Renix computers do in fact have KAM Keep Alive Memory and they learn and store data on what worked better in closed loop at various operating conditions. I could see it learning live on the Snap-on MT-2500 as the numbers converged to better numbers as the engine smoothed out. Shutting it down and restarting it seemed to speed the relearn process up by erasing older (oldest) data....

It still has a shake at idle, but is now back up from 600 to 750 rpm with out me doing anything but alternately waterboarding it and using Gumout spray, and while the idle still has a shake it is smoother, and the rough acceleration stops at 1200 rpm now, not 1500 rpm. So it is making progress.

Still afraid to cross a busy intersection or drive it yet as it may back fire out the intake still on any heavy gas application from idle. But it is 65% better, at least when hot at idle. Have not tried it cold yet today. Still working perfectly from 1200 rpm (now) to 4500 rpm. At idle when I give it gas the exhaust sounds like a tuned muffler, till it changes at over 1200 rpm, it goes pop pop pop, then over 1200 rpm it sounds normal.

Oh and the exhaust now feels like my diesel, massive pressure and flow coming out the exhaust at idle like I have never seen before in 13 years on this jeep. Maybe on any of my renix jeeps? It was very obvious!!!

There was a +/- 2 psi vibration (needle) in fuel pressure when I started. At first I though it might be the vacuum vibrating and causing the FPR fuel pressure to oscillate, but the vacuum gauge needle did not vibrate (no leaking intake valve?). The vibration stopped after a while, after I had done 2-3 cleaning cycles. I will watch it closely today on cold start, etc. It was steady at 34 psi in the last 20 minutes of running. The Fuel pressure was steady at higher rpms the entire time. So I am watching that very closely.

Seems I need gas now :( :mad:
 
CPS is 2.20 volts at idle AC, gets up over 6.0 volts at about 3000 rpm or so. Solid signal at all speeds.

CPS is .61 volts AC cranking with fuel pump relay pulled to test CPS.

Cold idle is rough still. Fuel pressure was 34-35, vibrating between the two cold start up at idle. Stops vibrating at speeds of about 1500 rpm cold. When hot the shakes are smaller and stop at 1200 rpm and higher. It goes closed loop very fast, the shakes are not an O2 sensor, or fuel trim issue.

Next on the agenda is Seafoam in the intake and more waterboarding, new plug wires just rule them out (they all passed inspection and resistance tests. Just added gas to the tank. Last tank of gas had a can of injector cleaner in it (Gumout or B12 cleaner I forget which).
 
Time to close the story here.

Main hard to find problem the shear pin on the helical gear on the Dizzy was going bad. It finally broke. While tracking it down I found a bad section of vac line to the MAP that was on its last legs, but fixing that did not solve the problems. But it did need fixing!!! Other issues that would soon be causing problems were fixed.

Replaced the distributor. That got it running again. But not like before. Indexing the distributor using the Cruiser54 guide helped, but did not solve the shake at idle.

So I solved the last problem. Seems even a Jedi Jeep mechanic can make a rookie mistake and cross two spark plug wires, LMAO. Gotta love these fixes that do not require pulling the timing chain cover, or a head job, or waterboarding the jeep :)

Had the #3 and #4 plug wires criss-crossed (probably when I index the dizzy and swapped caps twice in the process, they got crossed). And it still ran like a beast above idle even with the 2 SPwires crisscrossed. These engines are beasts!!!!

Runs like a new engine for the first time in 13 years now, only 290,000 miles on it. The 87 Wagoneer XJ.
 
Ah, spark plug wires , the phantom menace ;)

I made a mistake like that trying to show my nephew how to do a tune up, I kept warning him not to screw up , I am the one who didn't push the contact deep enough to hear the click and we had a misfire code


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"the phantom menace" INDEED!!!

I was telling my Daughter, now in the Colorado Chapter area, long distance how to check and replace, if needed the Cap and rotor and plug wires on her new 1989 XJ (she finally has a 4x4), the day I forked mine up, and I was warning her and telling her how to avoid making the rookie mistake of crossing wires.

No doubt my phone rang, it started raining (That actually did happen all week while under the hood working on the beast) or something interrupted me in the process, and I flipped wires 3 and 4. Always smart to recheck our recent work first, 3-4 times, LOL.

Glad I did before resorting to plan Z and pulling the head, LMAO.

My son had a Ford we did the heads on twice, and it had a bad miss the last time we did it, and OBD-II showed a miss fire code on Cyl 3 in the V-6. Turned out we were looking at cyl 6 for the problem thinking it was #3 while the impossible to reach plug wire had come loose on the real cyl 3 between the firewall and the block that took little midget hands to reach and install while blindfolded. Sometimes we get lucky and its simple basic stuff.

Ah, spark plug wires , the phantom menace ;)

I made a mistake like that trying to show my nephew how to do a tune up, I kept warning him not to screw up , I am the one who didn't push the contact deep enough to hear the click and we had a misfire code


Sent from my iPhone using Tapatalk
 
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