Jeep Strokers

Thanks Silver XJ. I'm going to try the old coil tomorrow, but what are your thought on my plugs? what else should I try?

Will

W_A_Watson_II wrote:After installing the NGK BKR7E-11 (Gaped at 0.044”) I took the Jeep out for a spin. A/F Ratio seems even more stable. However it started missing even before it warmed up. Might have just been new plugs, but nope. A few miles down the road I got on it. Missed at high RPM, at 4,000+ RPM, A/F ratio in 10-11.5 range (rich)
Will

I would close the gap to 0.035" and try again. Maybe even 0.032".

Tried the stock Champion Plugs with out and with the old coil, and the miss is still there. The 2nd gear 5K miss in the one video where it doesn't shift to third is the rev limiter, but I do still get misses under hard acceleration once the miss appears.

With the stock plugs fresh I started it and a miss was quickly there, then as the engine warmed up it was gone. several miles and good runs and all seemed well. That is until I ran for a short distance in 2nd at 3,500 RPM and 55 MPH, as soon as I put it up into 3rd, the miss was there and very prominent.

Once back at the shop I let it idle and checked for misses and any leaks, none. I rev it up to about 4,200 RPM and the miss is there, drop back to idle and it's gone. I've shut it off at 2,000 RPM, and will pull the plugs for one last check before I start looking else where for the issue.

Frustrated,
Will

In going back over my notes and research, and I think the plug recommendation I got from the Strocker community is off. They recommended the NGK BKR6E-11, but it's tip did not protrude as much as the stock plugs. In doing some part number cross referencing and deciphering I thought I needed the NGK BPR6ES-11 as it's a Projected Insulator Type plug like the stock Champions. However it wasn't. So I went back with a set of stock Champion RC12LYC Plugs. The miss started again cold, but it cleared up. was it because of just being new plugs? Well no, the miss did eventually come back just as before. I tried the old coil and the miss was still there. I pulled the plugs, again with a hot engine and running 2,250 RPM. the looked OK to me, except for a small imperfection on plug #3's insulator, a defect/crack? It's getting replaced.



The fuel pressure gauge test kit was out on load at the Auto Parts store, so I decided to go ahead and install the fuel pump anyway. The pump looked to be the original 1993 Bosch pump, and I found some debris in side the strainer, so it might be having problems. Well, the new "I call generic" pumps the auto parts store had in stock fit like crap, the pump was loose and would surly rattle. So I'm waiting on a new Bosch which I should have tomorrow. I spoke with the machine shop that did my block/head work, and the guys at the parts stores, and they suspect I might have an intermittent air leak. guess as soon as I get the pump back in and re-install the stock plugs, I'll see what I can track down next.



Will

Holy mother of god batman, this may save me a mountain of hassle.
Is there a window to get to the fuel tank goodies? What vehicle is this in?
Back on topic. I just found this: http://zelscope.com/
I don't know if it's any good or not, but the price is right.
My diagnostic tool of choice would be an o'scope with the problems you describe.
Another thought, have you used a timing light at the miss RPM to see if anything is arwry?
I guessing it's not plugs.
I would lean towards electrical first.

I don't think its the plugs either. While the stock plugs aren't optimal they shouldn't cause this problem. I don't believe to be the AFR either. It would take a lot to make it miss. Right before this happens do you see black smoke out the rear?

Since you have two coils I don't think that is the cause either.

We need to narrow it down to spark or fuel.

As said, get on to checking the fuel pressure under this condition. At idle and reving won't cut it you will need to drive it and see what it is doing, testing the volume.

This miss, is it like hitting a brick wall or rev limiter?

As for spark, I would double check the wires, ohm them out. Check the distributor cam and rotor for wear and carbon traces. If that checks out I would think about the CPS. Maybe its sending a weak signal and has problems as the engine revs higher and the sensor gets hotter.

JBXX - I cut that opening in the tub while I was doing my body repair as a just in case I need to get to the fuel pump. Glad I did.

SilverXJ - I've come to agree it's not plugs as well. No smoke that I've noticed. Yes, the one miss I had at 5,000 RPM when it would not shift out of 2nd was the Rev Limiter, but I have a miss other than that as well. I've re-adjusted the kick down linkage and need to check to make sure it's correct now for proper shifts. No play in the distributor (New but I did check) Rotor and cap new, and I've checked for carbon traces, and there isn't any. I installed a new CPS, but guess it could be bad. Speeking of the sensor getting hot, read today's activities that follow:


FROM TODAY - Before I go on my rant about Aftermarket Parts Engineers and Bean Counters (My degree is in Engineering so I can rant), I think I might have to concede and say I'm running Lean. Fist I want to know who the (Expletive removed) Engineer was/is and the (Expletive removed) Bean counter who probably forced the Engineers had to make a (Expletive removed) generic fuel pump and sell it as an exact fit that in no way fits the vehicle! Even the Bosch replacement unit (The 3rd one I tried to make fit) fit's kind of crappy! It's in and at least it's snug and fits good enough that it isn't loose in the sending/pump bracket. Not the easiest to install, but it's in and working, quietly.

I also changed the fuel filter, but first a warning. If you own a Bone Creeper, and are in a low humidity area, or like me keep the shop humidity low, be very carful of electrostatic electricity. Every time I get on the creeper, and go under a vehicle, as soon as I touch the vehicle, ZAP! I got hit so hard the other day, my finger still hurts. I had to be sure to not let a spark fly while changing the filter, as fuel always runs out of the line and starts evaporating.



I re-installed the Champion Plugs, and a new one to replace the defect in #3.

Well, after this, it was still raining and wet out, so I backed the Jeep up to the door and opened it enough to vent the exhaust and shop. I started the Jeep and let it idle for a long time, and a few off misses, but all was well. A/F Ration was 14.6-15. After everything was good, I revved it up and held it at 2K, 3.5K and back to 2K RPM a couple of time.

On the third time, I got the miss I'd had before. So I held the throttle between 3 & 3,500 and started checking for air leaks or any other issues. None found. Then I saw something, and got worried, the exhaust header was glowing red, and bright. I let off the rpm, let her cool down and shut her off. Oil is still right on the mark, and as clean as brand new oil, no issues seen anywhere. I know with no air flow over the engine, they can sometime glow, but I suspect I must indeed be running lean. The A/F Ration gauge was showing 14.7-15 at these RPM's.



So I will order the Adjustable Fuel Pressure Regulator. Do you guys recommend the HESSO or the Leigh Performance unit?

I'll also order/build the MAP Sensor Adjustable Voltage Adjuster.

Now what should I set these at to start off with?

Thanks,
Will

W_A_Watson_II wrote:I also changed the fuel filter, but first a warning. If you own a Bone Creeper, and are in a low humidity area, or like me keep the shop humidity low, be very carful of electrostatic electricity.

I never experienced that on a creeper, but that happens to me with any vehicles with cloths seats.

Well, after this, it was still raining and wet out, so I backed the Jeep up to the door and opened it enough to vent the exhaust and shop. I started the Jeep and let it idle for a long time, and a few off misses, but all was well. A/F Ration was 14.6-15. After everything was good, I revved it up and held it at 2K, 3.5K and back to 2K RPM a couple of time.

How long did you hold at each RPM?

On the third time, I got the miss I'd had before. So I held the throttle between 3 & 3,500 and started checking for air leaks or any other issues. None found. Then I saw something, and got worried, the exhaust header was glowing red, and bright.

I've had the header glow during a cam break in but no where near that extent. Usually just at where the pipes make their first bend. What was your AFR at this time? It shouldn't be much off from 14.7:1 as it is a no load condition.

Do you guys recommend the HESSO or the Leigh Performance unit?

Leigh performance. Bump the fuel pressure up to around 43.5 just to bring the injectors to 24 lbs at first. However, I think you should still see a lean condition on the wideband prior to the miss, but you said that it was actually rich?

Late timing can also cause the headers to glow

SilverXJ wrote:I never experienced that on a creeper, but that happens to me with any vehicles with cloths seats.

I contacted them, and they confirm in dry conditions it's a known issue.

SilverXJ wrote: How long did you hold at each RPM?

A few minuets. Say 3 at the most.

SilverXJ wrote: I've had the header glow during a cam break in but no where near that extent. Usually just at where the pipes make their first bend. What was your AFR at this time? It shouldn't be much off from 14.7:1 as it is a no load condition.

The A/F Ration was bouncing between 14.7 and 15.0

SilverXJ wrote:Leigh performance. Bump the fuel pressure up to around 43.5 just to bring the injectors to 24 lbs at first. However, I think you should still see a lean condition on the wideband prior to the miss, but you said that it was actually rich?

Late timing can also cause the headers to glow

Yes, in previous drives with the miss it was rich.

Thanks,
Will

W_A_Watson_II wrote:A few minuets. Say 3 at the most.

It shouldn't be glowing in that short of a time.

The A/F Ration was bouncing between 14.7 and 15.0

What cam are you running?

Unburnt fuel cam make the exhaust glow as well, but not show a very rich condition.

Are you 100% sure the distributor is indexed correctly?

SilverXJ wrote:What cam are you running?

Unburnt fuel cam make the exhaust glow as well, but not show a very rich condition.

Are you 100% sure the distributor is indexed correctly?

The cam is the: COMP Cams SK68-232-4 - Xtreme 4x4 Cam and Lifter Kit

I believe so, the distributor is installed with the forked portion around the hold down bolt under the hold down clamp.

Will

W_A_Watson_II wrote:I believe so, the distributor is installed with the forked portion around the hold down bolt under the hold down clamp.

On a stock engine that may be correct. On a stroker you may have to break those ears. 80% of problems come from the distributor indexing. http://www.angelfire.com/my/fan/dist_index.html check it again.

Thanks, I'll check and adjust.

I've done some research and learned that the distributor pick up coil (or what ever you want to call it) doesn't affect spark timing, it's used for injector timing. http://www.wranglerforum.com/f5/how-whe ... ost1855380

So I Indexed the Distributor. As you will see in the below pictures, the distributor would have been sending the injection pulse just a little late. I opened up the slot on the "ears" (http://www.angelfire.com/my/fan/dist_index.html) and re-installed the distributor properly indexed.



Took the Jeep out for a leisurely drive, no high RPM's or hard accelerations. It sis miss some after I started it and drove it out of the shop, but shrugged that off to the computer learning the slightly new curve. And again, after everything got well warmed and up to operating temperature it started missing again. When it did this I pulled off the road to a safe place, and opened the hood. at idle all was fine, revved it up and the miss started. Held it there for a little bit, and could see the header starting to glow red. So I headed back home.

Thinking through it if it's spark timing related, perhaps the new CPS sensor was bad. Could it be getting hat and causing the problem? So I grabbed the old one and pulled the new one out. In the picture blow you will see that it looks like the flywheel has rubbed across the face of the new CPS, and a small sliver torn loose. The new one has no slot of adjsutment, just a hole, unlike the old one that has a slot. So I've installed the old one and will give it a try.



Jeff at Leigh Performance is out of the FPR and MAP Adjustors, so I'll have to pick them up else where.

Will

SilverXJ wrote:As for spark, I would double check the wires, ohm them out. Check the distributor cam and rotor for wear and carbon traces. If that checks out I would think about the CPS. Maybe its sending a weak signal and has problems as the engine revs higher and the sensor gets hotter.

Well, the prize goes to SilverXJ for his post yesterday! After this mornings test with the re-indexed distributor, it looks and seems to me that the fuel was still getting into the exhaust manifold and burning there. This to me it was still a spark/timing issue. So since I'd been through everything else except the computer and CPS that is as you see above where I went.

I just completed a 26 mile trip in the Jeep, and for the first 3/4's of it I just cruised, no hard accelerations or high RPM's. No misses like I had this morning, so I did the 3,500 RPM at 55 MPH for a while and then shifted to 3rd, and unlike before, still no misses. Next I did a couple of hard accelerations, and even at 5,000 RPM and an 80 MPH (it still didn't shift to 3rd until I let up a little), still mo misses. I'll have to adjust the cable a little more to see if it correct the shift issue, if not I'll let the transmission guy address it. So after the 26 miles and no miss, it looks like, and Lord please let it be, the CPS was indeed was the problem.

The A/F Ratio seems to average out about 14.4/14.5 at cruse and idle. On hard accelerations, it doesn't go as rich as before, and seems to hit 11.0 at 5,000 RPM.

Guess I'll stay on my old factory CPS until it fails. Guess that's what I get for replacing parts that were still good. The 1" body lift sure made it easy to change it though.

I want to thank everyone here who has helped, not just Silver XJ. This is a great community and I've sure learned a lot and I'm sure there is more to learn.

Again Thanks!
Will
http://www.jeepforum.com/forum/f12/star ... st14094522
http://jeep.wawii.com/93YJ_TrannyJob.htm