Jordan Double

Ok I am new to the forum and hope this gets seen but I just preformed a motor swap on my 89 Cherokee and it seems to run amazing...... when it does run. It seems to be flooding itself when off, almost as if the computer is saying u need more fuel and that it’s full throttle but when u turn it off. I have a bunch of new stuff in it, new cps, fuel pump, fuel filter, 4hole injectors, and have made sure the line to my map is good I even cleans the ground on the dip stick, but I might hit it with a wire wheel again later today. When I say dumping fuel I mean dumping fuel like there is fuel dripping out of the flange from my header to the rest of my exhaust and compressing my gas into my oil. Any ideas would be great on a tight budget but open to anything at this point. I might even try swapping the fuel pressure regulator with the one from my spare fuel rail later today after school. Thanks again

fb97xj1

Here is the link. http://cruiser54.com/

Dave51

What motor is in there now? Are all the components (especially the intake manifold) from the new motor or the 89?

Jordan Double

The intake and core sensors are all from the 89 but I used the nicer better flowing exhaust manifold form a ho I believe, the motor I pulled for a buddy’s parts 88 Cherokee but it had already been swapped so the motor is for a 98 wrangler I believe. We’ve had a couple issues that have come from that like the pilot bearing we had to machine ne a custom one to work with the wrangler crank and the BA10-5

Dave51

That thing has an ECU right? Can you get the ECU from the other XJ?

Got this? (Don't know if it will help now, but certainly a good thing to have):

http://cruiser54.com/wp-content/uplo...ion_manual.pdf

Dave51

Oxygen sensor good?

Consider oscilloscope-ing the fuel injectors.

Dave51

Entry level PC based oscilloscope will run about 100 bucks, but something to keep in mind.

You can measure all the electricity as well as what the injector is doing throughout a cycle:

Dave51

And how about the flexplate? You got the right one?

Jordan Double

I used the original flex plate from the 89 so It should be the right one, and the o2 sensor should be good but even if it wasn’t wouldn’t it just run Fitch not flood the engine when not running

Jordan Double

Man rn would be a good time for one of those Renix engine monitors that one guy makes, I don’t have any money to try much rn but I’ll try more if what I’m doing rn doesn’t fix it after I get paid, let’s hope this spare fuel pressure regulator fixes it 🤞🏻

Dave51

I don't think that's it-- can you get the free noid light at AZ? And the fuel pressure gauge?

Jordan Double

Idk yet I’ll look into it me and some buddy’s are starting to tear into it now I’ll let u know how it goes, thanks for the help sofar tho

Jordan Double

Well today we ruled out fpr and the fuel relay thing in the engine bay, I forget what it’s called. I think tomorrow we are goin to try and swap the ecm with one from my buddy’s parts 88. We did figure out that it’s definitely the injectors being told to just stay wide open because after you cut off the key all the way they audibly stay on full blast for about 30 seconds. If this ecm doesn’t fix it the only other thing really is the distributor grounding all the time so idk we’ll see hopefully the ecm fixes it

Noah911

You could also try disconnecting the PCM. Then, jump the fuel pump on.. If the fuel injectors also spray when you jumper the fuel pump on. It means the control circuit is shorted to ground. Or, ALL of the injectors are stuck open (which would not be a likely thing to have happen on all of them).

If they do not spray then the PCM is most likely no-good.

Dave51

Is the distributor from the 89 or 95?

That the injectors are firing with the KO is certainly a baffler. I think you should get the noid light and fuel pressure tester (or at least a multimeter) to see if the injectors fire for 30 seconds and stop or if they're hot all the time and it's only because you run out of fuel and the noise stops.

Changing the distributor (or at least the sync generator) is a good idea if you can do it for free (that would seem to explain why it's batch firing) but IMO you have at least 2 issues.

See if the Latch Relay is still good.

Cruiser probably has the answer, but don't give it away just yet!