dixie wrecked

iTrader: (6)

My tpi has been giving me issues lately. Quite frustrating.
305 tpi, who knows how many miles, mostly stock save for de-catted and flowmastered, and the air box replaced with tubing and a cone filter, plus De smogged.
Its been on and off with code 34 and 44, running fine at everything but idle.
Idle, it'll start hunting between 700 and 200, at times dying.
If I two foot it and keep her above 800, all is good.
My mass air looks good, went through a can or three of Maf cleaner, cleaned my IAC, and re calibrated my tps.
Can't find any immediate vacuum leaks, tho I honestly didn't look too hard if I'm honest.
It just suddenly started doing this. I replaced the maf relay,
Pn mr82, slight change/better, no codes. Most of the time there's no codes.
I looked and sealed up the tubing between the maf and throttle body ad best I could, namely with duct tape and silicon caulking. Viva la *******!
Any tips? Was gonna replace the burn off relay, but of course no one on my side of town has it.
Also getting like 15 mpg/180-90 miles a tank, not sure if that's normal or not.

dixie wrecked

iTrader: (6)

Scratch that, I'm an idiot. Put the new maf relay on the burn off circuit by accident.

Better question that I need advice on, is why I'm getting a staggering 15mpg.

Its an 87 bird, 305 tpi, auto, a mystery amount of miles (ticker says 240k, oil pressure and p.o. says substantially less.
273 posi rear. Only mods are no emissions or cat, air box removed and replaced with tubing, (possibly, based on the sticker on the dash) a hypertech "performance" chip,
And its lifted 3" in the rear, 1.5 in front with 32" mudders and I don't remember what size a/t's up front.
I drive like a soccer mom, minus the occasional offroading and mud bogs, yet here I am, 180-190 miles later at a gas station.
No check engine lights, everything seems good to go.

Yet, my 97 Mercedes, which weighs even more, similar rear end, 4.2FI V8„ auto and driven like its on Top Gear, and it belts out 400 miles avg on a 20 gallon tank

MoJoe

iTrader: (5)

Those 32" tall tires are 23% larger than the factory 26". That and your 2.73:1 gears would be equivalent to stock tires and a 2.21:1 rear gear. Does the trans ever shift into OD and lockup? That 7004r/2.73/32" combo calculates 1500rpm to go 75mph.

What are codes 34 and 44? That should point to your problem.

dixie wrecked

iTrader: (6)

Yes, it goes to OD just fine. I'm in lockup at 60 @ 1400 rpm.
34 and 44 are MAF issues. Can't remember 44 exactly, but 34 is MAF high voltage low flow.
It was just the relay, swapped that and its gone. The codes were intermittent, usually not there

8Mike9

You're lugging it, plus pushing big tires. Probably no where in a decent tq curve when driving..especially taking off.

Edit, what kind of vehicle is this?

alex722607

iTrader: (3)

I have a 350 that is pulling the same crap as yours, except mine is a swap car (previously 305)

I get codes 34 and 36, and have replaced the relays, ecm, checked, double checked, and triple checked the wiring. My evap system is screwy, and I average 160-170 before I need to go get fuel.

I also burn oil.

All of the above is why I gave up on TPI and my lovely gen I SBC

tunatrky

I REALLY want to see this. Please post pictures! Unfortunately I'm not sure about the codes you're throwing. 15MPG doesn't seem unreasonable for such an old 305. My '91 Pathfinder was getting 10MPG with 150K on it and 31" tires, but it was also over 4300 pounds. Can't remember the weight.

dixie wrecked

iTrader: (6)

Is yours speed density or MAF? sounds like you've eliminated most everything but the maf itself, or a vacuum leak/air leak between the Maf and TB. I'm pretty new to TPI as well, coming from a carb'd, point type basic as it gets 355. Nothing like a holley..

I don't have current pics of the 87, I'll post a pic of my 85 tho.

They're identical, tho I didn't have a lift kit put on in this pic.
Plus its carb'd, my 87 is tpi so no hood cowl and no stacks (yet, just got this car)
My 87 has the lift, jaws, same wheels..etc.

I've gotten rid of the codes, it was just a relay that I switched around mistakenly, I figured that would be why I was sucking gas. P.o. said motor was replaced a few years back, guessing it had around 50k on it. 26 psi oil at idle, 55 at 60mph/1400 rpm.
Odo says 240xxx miles, no way in hell I'd get that kind of pressure after 240k, so p.o. sounds accurate for once.
If others are getting that ballpark mpg as well, then that answers my question and all is well

dixie wrecked

iTrader: (6)

Its an 87 trans am, 305 tpi with performance suspension package. Not a GTA or formula from what I can tell

darbysan

Have you checked your speedometer for accuracy. Bigger tires can throw off your speed and mileage in a big way. Might need a different speedo gear in the trans to match up to your tires.

tunatrky

Ha, it's crude and I love it! Also, i've got an alleged 170K+ 305 [dont know, speedo broke], and my oil pressure never dips below 30PSI. Usually around 50PSI when cold.. Wonder how accurate that gauge is.

At any rate, if you ever get around to it, please post the lifted one Your vehicles are just rad

dixie wrecked

iTrader: (6)

Its 8mph slow, with or without the mud tires. I bought it with much, much smaller (aka, the right size) 15s on, and it was still slow by 6ish mph. I'm guessing the vss/whole tranny isn't original to the car. Ever since I made the MAF happy, mpg already seemed upped. I'm at just under half a tank now, showing 145 miles on the trip meter

dixie wrecked

iTrader: (6)

As of two hours ago, lifted and all!
Thank you, good sir or madam! When its all said and done, looking at about 8 inches of lift, still a unibody/not bolted to a full frame, all suspension. May go with a Dana 60 and a long travel front, just because why not. Definitely want that Dana tho..
she's getting PIAAs pretty soon, as well as headers and the side pipe exhaust from the 85