UIM Replaced... Now low on power?

[DieselMechanic]

Well after my engine swap (viewtopic.php?f=19&t=30576), everything seemed great til the UIM took a crap.
Got it back home, replaced it with a new one, and everything seemed fine. I've put a few hundred miles on it, and it runs perfect with the exception of one problem..
If I floor it, it feels more like it is at half throttle. Not only that but I can floor it, say doing around 25-30mph in 2nd gear, and it won't downshift to 1st... Or if I'm doing 50-60 and floor it where it should downshift to 2nd, it only goes to third. I've tried manually downshifting and it will go to 2nd, but there is still no power... It's as if I've got it at half throttle.
Now from a dig I can floor it and it will wind (very sloowly) up to redline then shift to 2nd.

I replaced the TPS with the one from the donor motor, and even tried a junkyard one... No luck. No SES lights. The only other thing I can think of is today I noticed right after I started it and began to back out of a parking space a couple of times, it would cough and sputter until I jabbed the throttle, then cleared up. Other than trying to romp on it at WOT, it drives perfectly normal.

I'm kinda stumped..
I'm betting (and hoping) it's something stupid simple that I overlooked.

[primetime2]

clean the MAF sensor mine spit and sputtered bad too

[DieselMechanic]

I thought about the MAF... But would that have those effects on it? I've had trouble with em before on other vehicles... Seemed they just kinda ran rough all the time. This runs perfect. Just seems like it doesn't know that I'm flooring it.

Once STUPID thing I forgot to mention.. I had a few cans of cleaner sitting next to me, picked up the wrong thing, and I sprayed brake cleaner all in the throttle body by accident. I did the same thing with my MAF on the Z and ruined it. The only thing I have to eliminate in the throttle body is the MAF sensor now. I simply unplugged it on my truck and it ran fine (but with SES light). Can I do the same thing to diagnose it on this?

[MattStrike]

First thing that comes to mind is that the fuel injectors may be wired differently between the two engines (this was different between the '93 SE and '93 SSEi).

If it didn't do this after the swap, forget that, then make a list of everything you had to touch to change the UIM. The first thing I do when I have a problem is look at what I've just messed with. 99% of the time the problem is something I touched while fixing something. I know it's not much to go by, but it's a start. Is it misfiring (shaking or pulsing the whole car or the steering wheel)? If you can post a video of the condition it may help.


...reading your latest post as I preview mine... Yes, unplug the MAS and see if it runs differently.

[DieselMechanic]

Thanks, Matt.

Nah, it ran fine after the swap. I'm gonna try unplugging the MAF in the morning before I head off to work. If that isn't it, I guess I'll just go over everything again, and again. Gotta be something simple that I overlooked!

[DieselMechanic]

:facepalm:

I found my problem...
Well, the heat shield that goes around the EGR valve has one 10mm nut that holds it down right next to the throttle body. When I cranked it down, it slid the head shield over just enough to BARELY touch the linkage, and just enough to prevent it from going enough to downshift.
I am an idiot.

[Bing]

Well, I think that if you were an idiot you wouldn't have found it even if it slapped you in the face. Glad to hear you stuck it out and found the problem and that all is well.