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Unread 03-04-2013, 04:49 PM   #91
Jon In Tucson
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[/QUOTE=Matt1981CJ7;15077810]It's interesting that you claim to build racing engines, yet you had a shop tune your Jeep's engine.

It's equally interesting that you think a carb can cause one cylinder to detonate, considering your vast racing engine experience.

Matt[/QUOTE]



Boys, play nice... We just want to get Mike's friend's CJ up and running. It' not like we're trying to balance the budget or anything hard...
God bless.
Jon In Tucson

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Unread 03-04-2013, 05:08 PM   #92
dslywalker
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this should be the schematic for the connector
http://winaldl.joby.se/aldlcable.htm
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Unread 03-04-2013, 05:11 PM   #93
Matt1981CJ7
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Jon,

I appreciate your calm attempts at moderation.

But let's be honest. Mike has shown nothing in this thread that demonstrates he's even tuned an engine, let alone built drag racing engines. His claim that a carb caused one cylinder to detonate was the clincher, for me.

How can we give honest advice, if Mike isn't honest about his experience level?

Matt
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Unread 03-04-2013, 05:19 PM   #94
Jon In Tucson
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Quote:
Originally Posted by Matt1981CJ7 View Post
Jon,

I appreciate your calm attempts at moderation.

But let's be honest. Mike has shown nothing in this thread that demonstrates he's even tuned an engine, let alone built drag racing engines. His claim that a carb caused one cylinder to detonate was the clincher, for me.

How can we give honest advice, if Mike isn't honest about his experience level?

Matt
Point taken. God bless.
Jon In Tucson
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Unread 03-04-2013, 05:32 PM   #95
copauls863
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Quote:
Originally Posted by motormike24 View Post
you are right, carbs have been doing fine forever, i build lots of high power drag racing engines every year that run 650 and 700 cfm carbs all day long. however, this jeep has soured my faith in carbs. how it happened is after 3 different carburetor shops attempted to tune the motocraft carb on the first rebuilt engine, they all claimed they could not get it to run right. and it indeed ran like ****. less than 200 miles into the engine break in we ended up with piston from cylidner 6 having a hole melted through it from the top all the way through the piston rings and into the wristpin. even the machine shop said it was extreme detonation that caused it. no other pistons were hurt, and the guy told us it was very likely a bad carb that burned it. that carb ran exactly as bad as the original junk carter carb did. it was very hard to start, and when it did start it smoked badly and had many misfires, and in order to take off in 1st gear you'd have to rev it up beyond 2000 to 2500 rpms to keep it from stalling before it got moving. regardless of how lean or rich the mixture was set to. certain ways it would smoke badly (very rich), and other ways it would not smoke at all (very lean). but for the last 100 miles of that engine's life, it was set fairly rich, which should have had the opposite effect of detonation, as that is generally caused by an extreme lean condition. however, as of an hour ago, i have everything running perfect on this TBI setup. its base timing is set at 0, it idles around 1000 to 1100 when warm, and the injectors send fuel every time at initial cranking. the only issue now is that since i havent yet got the wiring pigtail to hook up the dual purpose speed sensor (so i can still use cable speedo and hook the computer into it as well) to the computer. so if i try to burn out in first it bogs for a moment then takes off. otherwise i can run around town all day long idling in 2nd or 3rd gear no problem. thanks again to all you guys for your help, it definately helped me understand how this primitive system works. in the near future i plan to wire in the aldl connector and check engine light circuit, as well as create/obtain an obd1 usb cable. but as i stated before, id never again run a carb on one of these engines again. definately worth the headache ive been thru.

Good to see you got it running properly. I personally think it is all just a matter of preferance(did i spell that right?) or a generation gap. As I am a younger fellow and I HATE carbs. Anywho carb/tbi/mpfi it all does the same thing, deliver fuel, just in a different way.
Each has advantages/disadvantages just as everything else in this world does. But the fact that you have a running properly now is a great thing, as it takes work and learning these systems to set them up, which you have done, so that is great.
I had to go through the same thing fighting my old carb and ignition system, then the tbi and durspark, then the tbi and hei clone. And I am sure with enough time and patience I could have got it all right, and proper, but the 4.2 was old and tired, so I retired it from service and hired a new 4.0 with MPFI to power my jeep. Like I said, I went through a TBI an all that. But after this 4.0 I will never own a jeep that doesn't have one. If by chance I get one that don't.... I'm gonna swap one in there. So like I said carb/tbi/mpfi meh all the same, all preferance(???still seems wrong?)
However my personal thought and theory is that technology was developed for a reason, therefore I will never choose a carb again, cept maybe on my quad or 4wheeler.

Anyways I kept you too long here. Great job man glad to hear you put work in and made thise jeep better.

and GOD BLESS
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Unread 03-04-2013, 05:44 PM   #96
Matt1981CJ7
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Let me see if i have this right.

The engine is idling at a abnormally high 1000-1100 RPM, and it bogs when you get on it in 1st, and this is because of what?

Matt
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Unread 03-04-2013, 11:47 PM   #97
motormike24
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matt, its ok, keep talking sh*t. anyone whos ever built an engine knows that the only way to melt through a piston short of having a NOS issue, is detonation. which is a lean condition. its funny that you say the carb cant do that, yet it did. the original carter carb melted a piston in cylinder 2. then the motorcraft carb melted piston 6 in the reman engine in under 200 miles. yet, i rebuilt that one with new pistons and bearings and all, and swapped to tbi, and its got over 4000 miles on it with perfect compression all across the board. and yes, you may call me an idiot cuz i couldnt tune a ford junk carburetor. and im so stupid that 2 or 3 other shops couldnt either, yet it was brand new out of the box. and im sorry im not an electronics expert. i BUILD ENGINES, not electrical circuits. ppl bring me their engines, i tear em down, get em machined, build em up, and give em back. and they perform great. i dont do any computer mods, or wiring schematics, or any of that. i take what the car came with and build the **** out of it. and yes, the big V8's i usually build run great with carbs. THESE ARE NOT I6's. if you notice, the front and rear cylinders of the I6 are farther from the carb/tbi unit than any of the other cylinders. thus can cause tuning issues. v8's are all equally spaced. much easier to tune. and im master certified and have been building performance engines since i was 14. so before you spout off tryin to run me down because i dove into a crazy electrical nightmare ive ADMITTEDLY never even attempted before just as a favor for a close friend of mine, how bout you learn something yourself? dont post on my topic anymore please. everyone else here, like jon, has been VERY helpful despite the many things of this project that i admitted i did not know. this is not a pissing match. the whole idea here is supposed to be to help folks like myself that are just in a bit over their heads. and thanks to these good people we now have an amazing machine that we have dubbed "the spaceship". thanks again you guys!
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Unread 03-05-2013, 01:47 AM   #98
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Quote:
Originally Posted by motormike24 View Post
matt, its ok, keep talking sh*t. anyone whos ever built an engine knows that the only way to melt through a piston short of having a NOS issue, is detonation. which is a lean condition.
Gee, and I thought detonation could also be caused by improper ignition timing, lugging an engine excessively, low fuel octane, or too much compression...just to name a few. I'd still like to know how a carb can cause detonation in only one cylinder.

Be honest, Mike, you don't really build racing engines, do you?

Regardless, I'm glad you got the TBI working, and it only took you 3 weeks, with some of the best help on this forum.

Matt
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Unread 03-05-2013, 04:46 AM   #99
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If their is a bad seal at the intake manifold to head surface that cylinder can go lean while all the others are ok. If you didn't remove the intake manifold and replace the gasket the problem could still be their.

All TBI is is a glorified carb. And with a O2 sensor checking for lean conditions, if one cylinder is lean it will richen up the entire engine untill its happy.

My neighbors a ASE certified mechanic. It doesn't mean much to me. He knows Zero about carbs, needed my help fixing his crossfire camero, and couldn't get the points set on his dads T-Bird.

I'm not trying to be judgmental but leave your certifications out. It does nothing for you or any of the other members that mentioned it while asking for help.
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Unread 03-05-2013, 05:02 AM   #100
Matt1981CJ7
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Originally Posted by 86cj74.2L View Post
If their is a bad seal at the intake manifold to head surface that cylinder can go lean while all the others are ok. If you didn't remove the intake manifold and replace the gasket the problem could still be their.

All TBI is is a glorified carb.
Exactly, 86. And both are nothing more than a glorified squirt bottle on top of the manifold.

That's been my point all along. If a carb is running lean, it runs lean for all cylinders, not just one. I think Mike is blaming the carb for a different problem.

Perhaps, as you said, the problem will still exist with TBI. Do you think Mike would ever tell us, if that were the case? Doubtful.

Mornin', 86

Matt
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Unread 03-05-2013, 05:15 AM   #101
86cj74.2L
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There are a lot of threads that have no ending.

The learning curve for FI setup is steep but once you get your head wrapped around it its not that hard to work on. Granted you need some sort of way to look into the black box.

After stabbing the flyweights and having the timing at 0 initial ( he may have already done this) I'd drive it a while and then check the plugs. His should look clean. (Cleaner then yours and mine) If their dark its either not going into "closed loop" or running fat for various other reasons.

And Morning. On my off stretch waiting for the big snow. Figures I go back to work just in time for it to get nice out again. Oh well, I chose this job-path.........

Edit. The guys here with this setup are keeping him onto the correct path. With the jeep not at his house it may take time to find out what happens.
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Unread 03-05-2013, 09:56 AM   #102
motormike24
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just to show you non-believers, heres a couple pics from the most recent performance engines i've built. one is a 1980 corvette that is now a 358 c.i. with a 1/2 lift 3/4 race cam that does over 140 mph. the other is in a 91 chevy 1500 but its only mildly built, bored .030 over, RV cam package, 3 way valve grind on valves, port matched/polished heads/intake/exhaust, etc.

now, aside from that bs, we plan to drive the jeep around today for a good hundred miles or so so that we can do as 86cj said and check the plugs to verify proper computing. and yes, ive already locked down the flyweights and timed it at 0. drove it a few times yesterday, and as expected, it faltered quite a bit upon the first cold start since setting the timing at 0 and such, but after it nearly died and came back, over and over again for about a minute and a half, it seemed to find its happy place around 1100 rpm. i figured since its learning still, that should be fine for now. i also have not messed with the idle set screw, so that could be why as well. drove it around for maybe 10 mins after it was warmed up, and got a bite to eat. when we came out of the restaurant, it was about 110 or 120 degrees (engine temp), and it fired right up, but again faltered back and forth, but this time only for about 30 seconds. it seems every time we start it cold, the duration of it faltering is less and less, so im assuming (yes i know what that means) that its just learning the cold start thing. runs like a beast when its hot. my buddy said its an entirely new jeep, that it feels a LOT stronger than it ever was since the day he bought it. sooooo, as i said we will drive it around a bunch today and see where it leads us, and hopefully can complete the learning issue. thanks again all you awesome jeep gurus!
350-bored-cammed.jpg   358-corvette.jpg  
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Unread 03-05-2013, 10:18 AM   #103
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Who refers to cams as RV cams or 3/4 cams anymore? That nomenclature was incorrect from the day it started.

Your high idle could be from a vacuum leak. The adapter plates between the throttle body and intake are notorious for leaks.
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Unread 03-05-2013, 11:47 AM   #104
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Who refers to cams as RV cams or 3/4 cams anymore? That nomenclature was incorrect from the day it started.

Your high idle could be from a vacuum leak. The adapter plates between the throttle body and intake are notorious for leaks.
as for the RV cam, thats what comp cams and GM both calls their cam package that came factory in RV's. idk what else you would call them. and if you would like me to be more specific on the 3/4 race cam, its a 270H compcams. 1/2 lift.

anyway, i suspected that i had a vacuum leak, and when i pulled the tbi back off the intake the other day, i discovered i was right. the factory carb base gasket i was using between the adapter plate and the stock intake was less than 1/16" too short on the ends therefor not sealing. so i traced a new gasket on gasket paper and extended it to the proper size, and it helped a lot of the sputtering i had been fighting with for awhile, but it has all new intake/exhaust gaskets (and hi temp rtv on them in a small layer both intake and head sides) from when i rebuilt the "reman" enginet that detonated be4 i started this tbi project. i did the "water test" at idle poured water all over the intake ports and anywhere else it could possibly leak, no issues there. we just picked up the new pigtail for the dual purpose speed sensor we installed so now i can wire the speedo into the GM computer. that should fix the few remaining issues, hopefully anyway. if not, i will keep plugging away at it. next step is going to be making that data link cable we were talking about previously. i think the computer is learning quite well, because the inability to burn the tires i spoke of the other day is no longer a problem. it barks tires all day long now. just had to do some driving. again thanks you guys are great!
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Unread 03-05-2013, 12:21 PM   #105
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Well Mike your bullheaded if nothing else. and that is not an insult. But I think you are expecting alot out of the learning curve of this ECM. These "computers" have a whopping 32K for the prom and are measured in nanosecs for speed. In otherwords they are small and slow. The only thing it learns is the BLM and that is lost everytime the computer looses power. Also the only thing the speed sensor will do is improve MPG's at highway speeds with no load on the engine as it retards the timing. I have pretty much the same setup on my 258 and I love it. My friends cant believe that when its -5 deg here I can reach in and turn the key and it fires like a camp.
If there is one thing I don't like about it is the slight stumble I get on accel. But I've come to the conclusion that because the ECM is really for a v-6 and I have it in an I-6 the distance the fuel has to travel in the intake manifold is farther than what it is set up for. To correct this I will need to burn a new chip with new acceleration enrichment settings. But for that I would need some better software and a burner. Not the priority for that $300.00.


ps If your friend cares about it, I get 17mpg on 33's with 3.23 gears and a TF999 trans. And got 21 mpg's all highway on a trip to the U.P. Wheeling that's a different story

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