4-cylinder engines: upgrades through the years

[Mr_Random]

The front yoke on a 231 bolts right up to the 207. The 231 rear shaft is shorter then the 207 IIRC so if it is going in a lifted xj the 207 shaft may be perfect.

Yes, it's lifted, I probably lost a good 3/4" on the yoke from it, but the rear sits a half inch lower than the front and I was thinking some shims would both even it out and fix the yoke play. MJ shackles could do the same thing...

But anyways, what about a 231 with SYE? There's one for sale here I think for cheaper than I may be able to get a stock one from a junkyard (the JY's here are all overpriced, they aren't u-pull-it's). Then there's the speedo gear... ah... too much thinking makes me go :wierd:

 

[xj92]

I got the new flywheel on, and the old clutch back on (I'm leaving the small 4-speed in for now). Any reason I can't crank it to see if it will run even though the tranny isn't in yet? I can't think of any problems it would create, but I've never tried it before.

Edit: Except maybe that there are only two mounts holding it in place without the tranny mount & connection. Is that an issue? I'm just anxious to hear it run .

 

[Mr_Random]

I got the new flywheel on, and the old clutch back on (I'm leaving the small 4-speed in for now). Any reason I can't crank it to see if it will run even though the tranny isn't in yet? I can't think of any problems it would create, but I've never tried it before.

Edit: Except maybe that there are only two mounts holding it in place without the tranny mount & connection. Is that an issue? I'm just anxious to hear it run .

just try it! it's a tiny four cylinder! do it now and tell me how it goes!!!

Oh yeah, and mine lost most oil pressure today, the same day that I sent money for my final two parts for the conversion! Looks like I'll start gathering engine rebuild parts now...

 

[xj92]

My tranny is back in, tried it, still won't run. Doesn't even try to start now, just cranks & cranks. I'll have to wait until I can spend more time just checking over all the connections again & stuff. If anybody has other ideas, let me know. This conversion isn't worth it and I'd never do it again. Should have just swapped in a whole different engine. Too late now.

 

[Mr_Random]

I actually agree, should have invested the money in buying a better jeep... I passed up too many deals on the way, and even contemplated giving up for a little while. I feel bad, but have to finish it anyways...

I'm going to do an engine rebuild now, too... I'm concerned about my sanity...

Well, I'll be shelving the parts for now, I believe I have everything needed... I'll do the rebuild soon, no compression in #2 cylinder, burning oil like no other, general unhappiness... but yeah, it'll be my first rebuild, so I think it'll be fun...

oh yeah, and forgot to say that I'm $800 in or so...

 

[wolfpackjeeper]

ground strap, check it, then install a new one

 

[Ghost]

My tranny is back in, tried it, still won't run. Doesn't even try to start now, just cranks & cranks. I'll have to wait until I can spend more time just checking over all the connections again & stuff. If anybody has other ideas, let me know. This conversion isn't worth it and I'd never do it again. Should have just swapped in a whole different engine. Too late now.

If you have a spark tester then check for spark. If it has spark then you jsut need to make sure it is timed right. If its a no spark issue then you need to check the coil and the cps and the nss.

 

[Mr_Random]

If you have a spark tester then check for spark. If it has spark then you jsut need to make sure it is timed right. If its a no spark issue then you need to check the coil and the cps and the nss.

Shouldn't have a NSS if it's a five speed.

After all that, check injectors, fuel pump, FPR, fuel filter, make sure fuel lines aren't swapped.

Make sure throttle cable is adjusted correctly... still, if nothing, check TPS and IAC, then MAP.

Oh, and make sure your computer is plugged in! haha.

 

[xj92]

• Fuel lines are correct, fuel pressure is within spec (low to mid 30's).
• I am getting spark at each cylinder (checked by pulling the plug out while still attached to the wire, grounding it, then watching it spark while cranking it).
• Checked the camshaft position sensor in the distributor housing to see if there was more than one way to put it in there. There is only one way, so it is in correctly.
• Went through the whole procedure of checking for top dead center of piston #1 by removing the #1 spark plug, plugging the hole with my finger, and feeling the pressure so I knew when it was on the compression stroke and lining up the mark on the crank pulley with the 0 mark on the timing whatchamacallit, then making sure the rotor was pointing to where it will send spark to the #1 plug. In the past I did swap in a '93 crank pulley in place of the stock '88 one, but it was keyed if I remember correctly so it has to be on right.
• I tried pouring gas down the throttle body before I knew that it had sufficient fuel pressure but that didn't change anything.
• I need to borrow my dad's electrical tester and read up on how to test the Crank Position Sensor, Cam Position Sensor, Fuel Injectors, and all the others. I have the FSM with all the procedures, I just have to learn how to use the electrical tester and read the manual again.
• Grounding strap is attached from back of engine to firewall and visual inspection doesn't show any problems with it.

 

[Mr_Random]

Looks like that would be the Crank position sensor, the jeep should be able to at least idle with most of the other sensors disco'd, but the CPS sends info regarding TDC for each piston and which injector needs to be fired when. I honestly can't say whether the flywheel needs to be aligned a specific way, but really hope it doesn't, that would suck!

 

[xj92]

The bolts on the flywheel only allow it to go on one way, so it has to be on correctly.
Theoretically, if the '93 crank pulley was marked different than the '88 crank pulley it replaced, that could cause problems, but when checking cylinder #1 for top dead center it all seemed to match up with the pulley mark hitting the 0 spot, so I believe that part is right.
I picked up the Crank Pos Sensor that I previously tried (new autozone one from '93 2.5L xj when I had the old flywheel on) so that I can rule that out as the cause again.

 

[xj92]

Tried a new '93 2.5L Crank Pos. Sensor again. Didn't change anything.

Is the camshaft profile different between '87-'90 & '91-'93? How about the crank? Will the '88 block, crank, & cam work with the '93 harness, distributor, & sensors?

'90-'93 Cam Part #: 83507203
'87-'90 Cam Part #: 83500249

'90-'93 Crank Part #: 4713051
'87-'90 Crank Part #: 83504658

If that were the cause of the no start, wouldn't it blow out black smoke, backfire, whatever? It doesn't even act as if it wants to start, just sounds like the starter cranking and the engine doing nothing.

When I first checked for spark it sparked normal through the gap. Last time I checked it was sparking other places due to the plug being covered in fuel & other deposits, which must have accumulated during all my attempts to unsuccessfully start. If I clean off each plug, it then sparks normally in the gap again.

Ghost...you did this upgrade successfully, right? Or did you just swap in a whole '93-era engine?

 

[Ghost]

Tried a new '93 2.5L Crank Pos. Sensor again. Didn't change anything.

Is the camshaft profile different between '87-'90 & '91-'93? How about the crank? Will the '88 block, crank, & cam work with the '93 harness, distributor, & sensors?

'90-'93 Cam Part #: 83507203
'87-'90 Cam Part #: 83500249

'90-'93 Crank Part #: 4713051
'87-'90 Crank Part #: 83504658

If that were the cause of the no start, wouldn't it blow out black smoke, backfire, whatever? It doesn't even act as if it wants to start, just sounds like the starter cranking and the engine doing nothing.

When I first checked for spark it sparked normal through the gap. Last time I checked it was sparking other places due to the plug being covered in fuel & other deposits, which must have accumulated during all my attempts to unsuccessfully start. If I clean off each plug, it then sparks normally in the gap again.

Ghost...you did this upgrade successfully, right? Or did you just swap in a whole '93-era engine?

I swaped in a whole engine. But I have previously assisted another member on this board on this swap successfully. Is it a no spark issue? Have you determined that as the issue?

 

[xj92]

I had spark last time I checked all 4, but I've only checked plug #1 since putting the correct flywheel on. I'll check the others again as soon as I get a chance to make sure the plugs aren't fouled, but it doesn't sound like any of the cylinders are firing right now, and if at least one is firing then it is getting spark from the coil, right? When you helped someone do this swap, did you have to touch the cam or crank?

My dash inside is still off but the interior connectors are attached except some radio wires, heater controls, & others. Could those disconnected wires cause it not to run?

 

[Ghost]

As far as I rember he did nto have much issues with it. Swapped it all on and it ran IIRC. Check spark then we can go from their. What about fuel pressure? Is their fuel at the rail and do you hear the pump running when you key it on?

 

[xj92]

I do hear the pump run when I turn the key, and I bought a fuel pressure gauge to check it. It pressurizes to about 35psi and then bleeds down to about 31psi and holds there, which is in spec according to my fsm.

 

[xj92]

It runs! I threw 4 new plugs on cause I suspected they might be fouled from trying to start it so many times unsuccessfully, even though they were new plugs, and that did the trick. Now on to the long list of other stuff I still have to do to it. Thanks for all the help guys, I never would have thought of the flywheel .

 

[Mr_Random]

It runs! I threw 4 new plugs on cause I suspected they might be fouled from trying to start it so many times unsuccessfully, even though they were new plugs, and that did the trick. Now on to the long list of other stuff I still have to do to it. Thanks for all the help guys, I never would have thought of the flywheel .

wow yay you inspire confidence! Wait, in what jeep did you do this? A comanche?

Please tell how it runs and what kind of differences you are feeling!

What is this long list you have? haha...

 

[xj92]

It runs, but I can't actually drive it yet. I still need to:

• finish swapping the brake & clutch pedals
• hook up the plungers to them
• hook up the heater controls to the chassis harness
• get the a/c lines hooked up and charge it
• install the dash & gauge cluster
• bleed the clutch & brakes
• tighten up the loose re flex joints in my lca's
• wire the high speed on the electric fan
• replace the bench seat with the 2-dr xj buckets & console I got
• put some spacers in and tighten down the header panel
• build a front bumper or put another stock one back on (not likely)

That's just off the top of my head. I'm sure there's more.
I did it in an '88 Comanche. That made the interior wiring harness more difficult, but most of the other stuff was the same as a cherokee.

 

[Mr_Random]

It runs, but I can't actually drive it yet. I still need to:

• finish swapping the brake & clutch pedals
• hook up the plungers to them
• hook up the heater controls to the chassis harness
• get the a/c lines hooked up and charge it
• install the dash & gauge cluster
• bleed the clutch & brakes
• tighten up the loose re flex joints in my lca's
• wire the high speed on the electric fan
• replace the bench seat with the 2-dr xj buckets & console I got
• put some spacers in and tighten down the header panel
• build a front bumper or put another stock one back on (not likely)

That's just off the top of my head. I'm sure there's more.
I did it in an '88 Comanche. That made the interior wiring harness more difficult, but most of the other stuff was the same as a cherokee.

What do you mean about the spacers?

See, but now all that work will be fun work, because you know it's all gonna be road worthy afterwords!

Well, the only real problem with the interior harness was interior and tail lights I presume? You did have one less pair of doors to worry about, right?

Ah I want a comanche so bad...