SO, at this point, idk, I am leaning towards tearing my injectors out again, but don't really want to and am hoping maybe someone might have some insight on my issue/issues lol!
1992 305 tpi 5 speed
Things that have been done:
bosch 3 19lb injectors (REMAN)
New plugs
wires, coil, cap, rotor, icm, ecm, map/maf(I always forget), cleaned the iac
adjusted TPS,
cts, FPR...............................
Idk what to do at this point!
I have a very slight misfire, and of course I'm running really rich, I miss her how she was when I got her, driving home from phoenix to Tucson thinking my gas gauge was broken because it didn't even budge!
I have not changed my o2 sensor, nor do I have any check engines lights or stored codes. My egr is still good also! Please help!

 

If the O2 is orginal, I would change it.

Also, driving habits can have a tremendous impact on gas milage. My car is close to 450 HP, carbed, kinda high revving motor. Everything that should make it horendous on gas mileage. But yet if I drive it easy, I can get almost 15 MPG in the city. If I'm flooring it, it will flat out drink gas.

I would find out what is causing the misfire. Is a plug fouled from running too rich? If you have a missfire than the engine is not running efficiently. This will waste gas.

 

The o2 looks to be new, and also I drive like a grandma, first of all, and my car is completely stock, even my Hummer flooring it gets better MPG. Thanks for your help!

 

I would check for a vacuum leak... The TPI is very prone to getting a vacuum leak. You can do a quick check with a can of carb spray by spraying it around the runners, intake manifold, plenum and TB. If the engine starts to die then picks up with a slightly higher RPM, you found your leak... Have fun...

 

Ya sry but no vacuum leaks at all, been chasing problem after problem on her since I bought her back in Aug 2010

 

Is the fuel pressure regulator good? Is any fuel coming out of the vacuum line while running?

Sorry just saw you changed that..

Have you done a compression test? Check engine light on?
Maybe a plugged cat?
How does it run?

 

Compression is 140-160 on all cylinders, fpr was just replaced when I did the injectors the first time, found it running fuel through the vacuum line, but at that time gas mileage was awesome. Not sure about the cat, I asked a muffler shop and the said that my cat seems fine ( one of my original thoughts) No engine light nor do I have stored codes. Car has power but seems sluggish at times, and kind of bucks during acceleration like around 2500-300 rpms. I'm so lost at this point.

 

Seems like you've covered everything. Did anything get wet in the ecm? Like a windshield leak. My buddy's Grand National did something similar, and turned out the Eprom was fried. We put a good known chip in it and the car ran better.
The only other thing I can think of is maybe the distributor is going bad, maybe a bad pick up plate.

I'm sure you checked grounds too right?

 

I just thought of one more thing. Check to see if the wire going to the knock sensor is grounding on the engine or the exhaust. Check to see if the plug broke and is grounding on the block.

 

Just be happy it's not $3.94 like it is here.

 

Definitely take a good look at the distributor. Then use a timing light to verify ignition advance. Get access to a scan tool and read data. What are your fuel trims doing? they must be way off on the rich side. If not, replace your O2 sensor. Just because it looks good doesn't mean it is. I've seen a few be bad out of the box. Use the scan tool to compare reported timing advance to actual advance as read with the timing light. What is knock retard doing? Block learn below 128 means the system is trying to compensate for a rich condition and you should suspect your injectors or high fuel pressure or some part of the engine management system. Datastream, if you have educated yourself on what the PIDs are and what they mean, will reveal problems in this area. If Block learn is normal or high and plugs are black, suspect the O2 sensor or ECM/PROM.

 

or about $8.50 like here and I drive mine every day and it doesn't even get 18 mpg

 

We are all lucky. I believe Scotland/Ireland gas is 15-20 dollars per gallon in USD. Bicycle anyone?

 

The Netherlands, where I live has the highest gas prices in the world, has been the world leader for years, 70% is taxes

 

Ouch!!!

 

Break it down for us, what does it cost? If you don't want to do the mat I will do it for you, just post the cost and uom and I will figure it out.

 

If you want to check the ECM let me know... I have a spair that I could loan you. I moved from Tucson back in 2004 and I'll love to go back. The only thing I don't miss is the emission test, it took me hours to set my cars up just to pass the darn test only to re-adjust after they passed. I would also check the distributor, my '88 vette started off missing then it would not start when it was hot and it turned out the pick-up coil was bad... Enjoy

 

Turkey's had you beat for years now.

 

No leaks, I changed the ecm, but just swapped out the eprom with the same one, I'm kinda wondering if maybe my prom is tuned or something.....
Haven't thought about the distributor and I think the pick up coil was just replaced, if I remember correctly, will look into that though! Thanks!

 

http://pre.cloudfront.goodinc.com/po...72GasChart.jpg

you have to look at the 95 stuff and multiply the turkish prices by 0.46 to get euros but the prices vary a lot in turkey, in remote areas it's a lot more expensive and that runs up the average.

It's 1.75 Euros per liter here as of today for 95 RON, the "good" (ahum) stuff, 98 RON is 1.81 Euros

You also have to factor in that they hardly pay any other taxes over their cars. Here new cars are taxed around 50% upon base price + an added 19% sales tax and there's also a road tax here, for a 3rd gen it's right around 210 euros for 3 months. It significantly runs up the tab. Everything is crazy expensive here

 

Need to get an aldl cable in order to do the scan, but have a program already, thanks for all of your insight, gonna look into it!

 

Thanks that's too awesome of you, but I changed my ecm because my hubby was convinced that was the problem, only nothing changed after $90 and the swap I did however, just swap out the chip/prom that was in it, so idk. Tucson is so hot and yes I despise emissions too; I don't have to test mine until Jan 11, so I'm hoping to get this $hit fixed before then lol!

 

So to check the grounds, I would just make sure they are clean right?

 

That's the basic check. If you have doubts, you can get more invcolved and do voltage drop tests across the ground circuits. As far as grounded out sensor circuits, a close visual inspection and maybe a wiggle test will usually reveal these.

 

Great, thanks so much for your help! My lil boy and I woke up feeling shitty this am, so unfortunately, she will have to wait!

 

it could be a very very bad vacume leak, or intake leak,

 

Maybe look into the fuel pump. when they get weak the injectors dont spray as good. this happened to me in my 90 iroc i was getting 6 mpg. Changed the fpr, nothing, checked for leaks, nothing. injectors were not leaking either. Swapped the fuel pump and am getting 14mpg.

 

Idk, my fuel pressure is still at 47psi, even after being hooked up for 20 minutes, would this still be a possibility?

 

Tore it apart last night, found an injector that might be bad, hopefully this solves it, I am sending them all in to be double checked, gotta love warranties!

 

yea a bad injector will do it. my bad i thought you had said that the injectors were good. but if one is clogged or leaking it could cause your problem

 

None were clogged or leaking that I could tell, but I am sending them all in. However, I did find one that i had to put slight pressure on to get any kind of reading, even then the numbers were jumping all over the place anywhere from 8, 11, 16, 32....etc, it was odd! Going out in this mornings mail!

 

I would do like someone else suggested and verify ignition timing with a timing light

 

Sorry, not trying to ignore the timing comments, but my timing was just corrected before taking her apart. I was lost so I paid a shop to look her over and they advanced my timing and never tightened my distributor back up! Was like that for like a month and just kept getting worse, that is what I ended up finding out. The one time I take my car to a shop and this is what happens. But I will have the timing checked again when I get my injectors back, thanks!

 

I looked into the prom tuning and yeah so not happening! Anyone know of a reputable place to buy a new prom? don't need anything fancy just one for a stock 305, thanks!

 

I just got a factory one from chevy when I found that the previous owner put in a silly hypertech one. If i remember correctly it wasnt too expensive.

 

Julie from South Bay(where my injectors are from) got back to me on Sat and informed me that my injectors came back and checked out perfectly; and the puzzle continues!

 

Awesome, thanks!

Just called and was informed that the eproms are now discontinued! :/

 

Sorry to hear it wasn't the injectors. Did you scan the car yet?
The check engine light does illuminate when you turn the key to the on position correct?

Did you check the vacuum line to the MAP sensor, I saw you replaced the sensor.

 

I haven't gotten my injectors back yet so can't start it yet, thanks for you sympathy . Yes my engine light does work, I have scanned a few times already in the past to double check, and only get a code 12. checked all the vac lines and they are all fine.

 

literally just had this problem with my tpi trans am. i had to adjust minumum air and then set the throttle position. i tried doing both at once but the procedure is specific. it helped that i had mitchel on demand for referance and a tech 1 scan tool to show throttle voltage. problem was solved though, and its funny because i did everything you just said and hadnt a clue.

 

i had my minum air set too low, and my tps set to compensate, even though it was at the correct voltage, my throttle was closed too much and my iac had to compensate. and the iac being more open caused hesitation under throttle change. i had messed around with all the stuff you had done with the same problem and nothing worked but once i did the gm procedure from minumum air and tps (which was hard to set exactly with a tech one scan tool, can imagine usinga jumper and a volt meter) it ran beautifully and went from the 5 mpg i was getting (because i hotrod the crap out of my car) to 15. but had i drove it like a granny i probly wouldve gotten around 8, and i could now get 19 from it if i tried hard.

 

wow that is an amazing difference, thanks for the input, i am totally going to try that. I cleaned my iac and my tps is good but I had not adjusted the air yet! My husband and I keep telling eachother that it is prolly something so simple and we are gonna laugh about it later! Wish you would have been on here like a week ago before I tore my injectors outs to send em back! Still wasiting for them, but should be here today or tomorrow! will let you know! Btw, I drive like a grandma so that's prolly why my mileage is better than yours was lol!

 

Got my injectors back slapped em in, and adjusted the air mixture! Ding ding ding, after 5 mechanics and both of us later, you were the one who was correct! You are awesome, thanks again so much for your help, we were so lost! We are gonna have to wait and see how my mileage goes but, holy $hit does she have some ball$ now Went on a fun ride a lil bit ago lmao Anyway, you rock!

 

no problem, glad i could help