Toyota 2.7 power issue

catfishblues

catfishblues

Well-Known Member
Joined
Jul 26, 2005
Location
Pfafftown, NC
I've got a 94 T-100 with the 2.7 and a 5-speed. Great little truck with 280k on it and very little work ever having been done. It cranks great and gets killer mileage. The problem is a weird power issue. In the midrange, between half and full throttle, it will occasionally fall on its face as if it's got a carb leaning out. In each gear, you'll feel it a couple times throughout the rev range. It also feels down on power. This truck has been in my family since new, and I've been driving it off and on this whole time. I feel it, my Dad says he doesn't. What does he know, though? He revs it like it's a Cummins. Anyway, before I started digging at it, I just thought I'd put it out to the gurus to see if anybody else has dealt with this issue. Thanks!
 
I am, but I don't have a scanner to read it, I don't think. I've got one that will read pre-OBD2, but it's only got adapters for the big three, and I don't know if it supports the Toyota OBD1 protocol.
 
A knock sensor code will also contribute to lack of performance. The engine goes into protection mode. I would put some 93 and fuel treatment through it and clear the code if that’s the code thrown
 
Update: I cleaned the MAF with CRC MAF cleaner and rerouted the plug wires away from the metal intake resonater. It made it worse, and moved it down the rpm range. Now it seems to struggle more pulling hills. Plugs and wires are new, wires are Toyota style noodle wires. Pcv was replaced recently, and I think I replaced the distributior and igniter/cps within the last 8 years. Vaccum lines are old, but I couldn't detect any leaks They need replacing, but I'm not sure that's the problem.
 
Is cat still in tact?
 
Really really need to check the codes. I'll look in the service manual tomorrow & see if there is a way to read without a scanner. It's probably a drive but if you bring it by my shop in Rutherfordton, I'd be happy to help you out.
 
I can paperclip the codes. I found it online, along with the key. I'll do that when I get a chance. Considering the change in condition that happened when I attempted to clean the MAF, I'm leaning towards replacement.
 
@a_kelley As is fitting with my luck of late, the light stayed solid. Checked and double-checked the sockets I was jumping. Tried a different wire. No flash. I know it's doing something when I jump it, because I ended up cranking the truck while trying to figure it out, and the jumper affected the idle speed. I can install the jumper and it will kick the idle up a bit. Remove it and it drops a couple hundred revs.
 
Problem solved! When I did the MAF the first time, I pulled it off, housing and all, assuming it was a wire across like others I've seen. I sprayed into the little aluminum air catcher, but must not have gotten the filaments well. I pulled the actual element off the top, (which was easier than pulling the whole housing, and I should have started there,) and cleaned the filaments well. One was noticeably dirty. Put it back together, cleared the code, and it runs so much better now! The CEL came back briefly, but has since gone off. Its still no powerhouse, but it never really was. It will hold its own against the minivans once again, though! Now...what does anyone know about turboing or getting more power out of these engines? :D
 
Turbo / super and probably a split second box unless someone hacked the ecu like I'm doing for the Jeep sbec. It's allot of work to map a new ecu. Use your gogglefu and look for

Toyota 2.7 "flash/chip/tune"

Probably year specific to the obdi generation. Split second is really the easy way out, but is limited in how you can tune it because it manipulates the sensor inputs to the ecm in order to achieve desired AFR in and out of boost. SS has write ups on it. Me, I'm a glutton for a challenge and decided to under take mapping/reversing the Jeep sbec II specifically. (With help from @sev80. Which I've found interesting trivia things out, like the 4 & 6 cylinder code is the same, just changes the injector outputs!!) If I went SS route, my Jeep would already be seeing boost if it were running..
 
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