3.4 swap into 1985 Jeep Cherokee questions?

[cardana24]

I don't... I went to the local Shucks and tried to get my code read (free), but I didn't have the VIN# to put in the device.

what kind of code reader requires a VIN? I thought the codes found from the ALDL port are pretty much universial codes.

Anyway, does anyone have suggestions of what I need to do or check? What would cause the crappy running and pulsing in the exhaust?

[geoffinbc]

You don't need the whole VIN just the Vin Code of the engine. Or you can select based on year make model. Well at least on the good scanners you can. As long as you select a vehicle with the same engine/injection it will work

For example if you have a 1991 2.8L Trooper and plug in a scanner and tell it you have a 1988 2.8L S10 it will still work the same.

[Canyonero]

what kind of code reader requires a VIN? I thought the codes found from the ALDL port are pretty much universial codes.

Anyway, does anyone have suggestions of what I need to do or check? What would cause the crappy running and pulsing in the exhaust?

I KNOW I've mentioned fuel injectors before. I had problems with the ones that came in my salvage yard engine, one was stuck wide open. So I swapped in another set I had and the engine wouldn't start at all, they were all clogged. I bought a brand new set (Accel 17-lb) and my engine has been purring ever since.

[cardana24]

I KNOW I've mentioned fuel injectors before. I had problems with the ones that came in my salvage yard engine, one was stuck wide open. So I swapped in another set I had and the engine wouldn't start at all, they were all clogged. I bought a brand new set (Accel 17-lb) and my engine has been purring ever since.

How was your engine running with the clogged/ wide open injectors? You don't have a video do you?

[Canyonero]

I'm sure the engine can run any number of ways depending on the type and severity of the clogs. You could have some injectors clogged completely, and/or some that are spraying poorly.

My truck was drivable with the open injector but raw gas was literally coming out the exhaust and I got several quarts of gas in my oil. I'm surprised my crankcase didn't explode. I had no fire at all with the other set. Just cranked and cranked...

I bet your CEL is something painfully obvious and unhelpful, like "engine misfire" or something.

You can mail your injectors here to get tested/cleaned/flowmatched: http://www.witchhunter.com/

Or you can just buy new ones:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SMP-FJ95&N=700+4294924760+4294908216+4294908198+4294925239+4294839074+4294840048+4294870762+4294870747+115&autoview=sku

http://store.summitracing.com/partdetail.asp?autofilter=1&part=ACC-150617&N=700+4294924760+4294908216+4294908198+4294925239+4294839074+4294840048+4294870762+4294870747+115&autoview=sku

[cardana24]

I'm sure the engine can run any number of ways depending on the type and severity of the clogs. You could have some injectors clogged completely, and/or some that are spraying poorly.

My truck was drivable with the open injector but raw gas was literally coming out the exhaust and I got several quarts of gas in my oil. I'm surprised my crankcase didn't explode. I had no fire at all with the other set. Just cranked and cranked...

I bet your CEL is something painfully obvious and unhelpful, like "engine misfire" or something.

You can mail your injectors here to get tested/cleaned/flowmatched: http://www.witchhunter.com/

Or you can just buy new ones:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SMP-FJ95&N=700+4294924760+4294908216+4294908198+4294925239+4294839074+4294840048+4294870762+4294870747+115&autoview=sku

http://store.summitracing.com/partde...5&autoview=sku

Yeah, injectors are not the cheapest thing, so if they are the problem I would like to pin point it first before I just start throwing money at it.

Does any one know how to read codes off of this ECM with out an expensive code reader?

[Canyonero]

Yeah, injectors are not the cheapest thing, so if they are the problem I would like to pin point it first before I just start throwing money at it.

Does any one know how to read codes off of this ECM with out an expensive code reader?

So test them. You keep asking for help, and I suggested that you check your injectors a long time ago. They are very possibly bad.

[cardana24]

So test them. You keep asking for help, and I suggested that you check your injectors a long time ago. They are very possibly bad.

noid lights? Is that the best way? Will that actually tell if they are firing or if they are just getting an electrial pulse telling them to fire? I'm willing to test them I just don't know exactly how but I do have a set of noid light now that I have never used.

[Canyonero]

Noid lights will tell you if the injectors are getting a trigger pulse. They probably are, although there are two injector banks and it's possible you could have a problem with only one bank and the engine is running on three cyl (only one bank getting the trigger pulse). Possible, but I doubt it. I did accidentally short a wire and blew one injector bank fuse once. If you have noid lights, by all means use them. Just adds one more bit of information you can use in troubleshooting.

I've never done this method to test injectors, but I've seen it mentioned here.
Pull the fuel rail with attached injectors out of the engine with wiring and fuel lines still attached. Have someone crank the engine, while you watch which injectors spray and observe the spray pattern.

[cardana24]

Okay, I tested my injectors with noid lights and they are all getting the trigger pulse. One thing that I thought was noteable is that while un plugged the egine still ran about the same as it was currently with the #3 and #6 injector un plugged. It ran rough with each of those un plugged but it did crank right up. When most of the others were un plugged the jeep really did not want to start unless you turned it over for a really long time.

Should I send the injectors off to get cleaned? Anything else this could point towards?

[Canyonero]

That tells you that you have some problem on those cylinders. Air, Fuel, Ignition or Compression. My vote is still on fuel.

You can get them cleaned. Or you can just get two new ones. Or you can salvage yard more and hope you get two better working ones, then run seafoam in the gas to hopefully clean the injectors.

I suppose if I were you, I would pull all my injectors and ship them off to witchhunter. Best case, they can clean them all and restore them to proper working order. Worst case, you will have a couple they can't clean but the rest will be freshened up and you can buy two new ones.

[cardana24]

That tells you that you have some problem on those cylinders. Air, Fuel, Ignition or Compression. My vote is still on fuel.

You can get them cleaned. Or you can just get two new ones. Or you can salvage yard more and hope you get two better working ones, then run seafoam in the gas to hopefully clean the injectors.

I suppose if I were you, I would pull all my injectors and ship them off to witchhunter. Best case, they can clean them all and restore them to proper working order. Worst case, you will have a couple they can't clean but the rest will be freshened up and you can buy two new ones.

right on. I have a compression tester and I will try to get that tested tonight. If that checks out then I will send the injectors off. Because I have changed my plugs several times, and I also changed all of my coils last night and the jeep is still running the same way.

[cardana24]

Compression numbers are in and not looking good.
1-190
3-190
5-0
2-30
4-190
6-10

What would cause this? Unless the dude I bought it from lied, I have a video of the engine running well before he pulled it. What could I have done to cause that and more importantly how can I fix it?

The method I used was taking all of the plugs out and and then disconnecting the fuel pump, then doing each cylinder at a time. The ones that had poor readings (5,2,6) I checked them 3 times each to make sure I was getting the right readings. Looks like I found my problem....how can I fix it? I know when I was using the valve hold fitting with compressed air all of them were holding when I put everything back together. The only thing I have taken back off while the engine has been put back together is the intake manifold and that does not affect compression does it? I could really use some help guys. Thanks.

[Canyonero]

Oh, weak. Sorry man.

I have less experience with the innards, I've done most of my fighting with the wiring.

Possibly got the cam timing wrong? Incorrect valve lash (too much preload on the spring)? Those are the only suggestions I have. I recall you doing using the valve-hold fitting, so I just assumed your compression would be ok.

Suppose next I'd pop the valve covers off and back the rocker bolt back to zero-lash and see if that makes a difference.

[cardana24]

Oh, weak. Sorry man.

I have less experience with the innards, I've done most of my fighting with the wiring.

Possibly got the cam timing wrong? Incorrect valve lash (too much preload on the spring)? Those are the only suggestions I have. I recall you doing using the valve-hold fitting, so I just assumed your compression would be ok.

Suppose next I'd pop the valve covers off and back the rocker bolt back to zero-lash and see if that makes a difference.

Also with the vave hold fitting that was set ~100 psi and they all held.


I guess I don't understand compleatly but could the lash be set so tight on some of the cylinders that I am not getting compression?