Ok.. since getting my car Ive managed to put a hundred and change miles on it, closing in on 200 and little problems are starting to pop up here and there.

This is an odd question and a very generalized one as well, which I normally try to avoid, but simply want to ask, for piece of mind, or lack there-of. The car simply isnt running very strongly and I want to know if its lack of power can be attributed to the issues I know it has. Now, it runs well.. Doesnt stumble or hesitate exactly, accelerates smoothly and the gas mileage seems to be about on par with what I was expecting (17-20 or so on the highway) but it simply doesnt have the ***** a 275/330 big-*** american V8 should have.

For starters.. just spinning in 1st gear requires a little more effort than it should and it wont just roast the tires. Going from practically red-line to second gear with my foot to the floor causes a little chirp and thats about it. My SHO was more violent into second than this car is. I rebuild 5.0's on the side for a little extra cash so I have driven in many stock Fox's and a bone stock fox is considerably more stout than my Trans-Am is right now, and there really isnt any excuse for that, given that this car is, stock for stock, noticeably faster. I understand that my *** dyno isnt all that reliable, but Im trying to describe this as best as I'm able. Flat out, I dont feel very much faster than my 15.2 SHO.

My car currently has four issues that I know of, could one of these, or a combination of them cause this amount of power loss? That car feels like a slug.

Ok, issue one, unrelated to power.. I simply list so as to be thorough. Cooling fan does not work. At idle or low speed driving I have to turn my heat on to get that fan running to cool the car, otherwise temps will gradually climb.

Issue two, throwing a rear o2 code. I'm inclined to believe the cat itself may be at fault. Could a clogged or poorly functioning cat cause this amount of power loss? I'm leaning toward this as being the most possible single cause. Ive hit it with a hammer and poked around and I cant hear anything rattling around, but that doesnt always mean its functioning as it should. The o2 code is basicly Catalyst Below Efficiency, Bank 1. I'm sorry but I dont remember the exact code. I have it written down but dont have my little notebook with me at the moment. For the sake of argument, lets assume the cat is infact toast.

Issue three, throwing an EGR code. I'll have to dig up my notebook for the exact code but its a general one. I havent had the time to test the EGR and poke around just yet.

Issue four, Elbow is crap. It must be ripped in 4 different places and its ripped very badly in one. I ordered a Trick Flow elbow earlier today, for the time being I have good old electrical tape on the worst tear to try and mitigate the amount of air it sucks in.

Thats all I know of as being wrong. I replaced the ECT sensor already. It wasnt reading as bad but I was running down possible causes for my fans and just went ahead and bought one anyway. No other codes are being thrown. Ive checked the coolant and oil for cross contamination and checked to see if the car puffed any blue or white smoke on start-up, under heavy throttle or any condition and its all fine.

At idle the car has a tiny amount of shake and sits at 900rpm or so. The car runs very rich on cold starts and until the engine warms up will stumble a little, the exhaust reeks of gasoline and I'll get little pops and backfires under heavy throttle.

I'm going to run the TPS through its diagnostics tomorrow and pull the plugs and replace them at some point this weekend (virgin.. so it should be fun, no wait.. not fun.. hell.). It had a tune up shortly before I bought it, but with it running so rich on cold starts I wonder if the plugs arent a little fouled. It goes in tomarrow to have my new (to me) tires put on my 007's and I'm going to see about talking my bud at the dealership in to putting it on his lift for a few hours and see about dropping the exhaust and gutting the cats. I'll just buy o2 sims to kill the SES light or live with it until I get it tuned and just have them delete the codes out, or whatever that can do.. MAF was removed and cleaned with MAf cleaner.

Sorry this was so lengthy, just trying to explain in as solid a detail as possible.. thoughts, opinion?

Oh, '97 Trans-Am. Stock except a flowbastard cat-back and K&N.

 

If your plugs and wires are messed up, that will kill your power. I was amazed at how much mine was affected by the plugs and wires when I replaced all of them. It sounded about like your's and then it went to smoking the tires at will from anywhere under 50 or so.

 

2nd the plugs and wires, but scan your car to see if other codes are thrown. From the 4 things you listed, I would lean towards the torn elbow. The elbow is after the MAF, so you're adding air that the system is not anticipating.

 

Thanks folks. Picking up some plugs tomarrow and I'll start in on changing them (pray for me..). I'll pop the wires off one by one and ohm check them as I go to see if any are problematic or damaged.

What reading should I be looking for as acceptable?

Thanks folks.

Oh, I ran the codes last night shortly after posting. Same two I've had, EGR and o2 related, nothing new. Still gonna run the MAP through its tests as per my Haynes manual and check the TPS, just for kicks. No codes being thrown but it doesnt take long to test either and atleast it acts to eliminate problems.

Sounds like plugs and possibly wires are my best bet for now.. Bunch of guys hitting the drag strip this sunday and I hope its running like its supposed to by then, I'd hate to miss a chance to run it, but I'll be damnded if I'm gonna drop an entry fee and waste my time and pull a best of like 14.9, lol.

 

Man,it,s amazing the poor thing even runs at all!First ;your mileage on the highway is poor,it should be at least23-25,so car definitely needs plugs and a tuneup.Second is the code29 for egr; not having it working is causing misfire a low engine speeds and you are getting KR as well, probably 10-12 degrees and this kills power!Third is the fan(s) not working; this means car runs too hot and again causes KR .Even a couple small tears in the rubber elbow can cause vacumn leaks,again causing car to run horribly, so i would fix the small things first and optimize your present combo before even going near a dragstrip b/c a track reallyshows the weakness,es.BTW the flowmaster c/b and k/n are better than you are giving them creditfor so this is a real sign that you car is,nt anywhere near where it should be.

 

also after fixing what you know is wrong you can disconnect exhaust to see if that is causing problems o2 code could be false due to bad o2 sensor but with it sucking too much air it could be dumping too much fuel for sensors and cat to work properly/and replace temp sensor for fans

 

I'll have to find the codes.. Why the hell I cant remember them is anyone's guess. Seems I have my notebook or my laptop, never both at the same time.

I'm really gonna try to set aside tomarrow to wrench on it and I may take Monday off of school to fight with her as well and try to get everything done. My elbow isnt scheduled to arrive 'till Tuesday though, so thats just gonna have to wait. Its ripped so badly all attempts at an actual repair have failed.

Thanks for the info guys, very appreciated. Whatever the problem(s) is its getting worse as its driven, the idle is rougher and its got even less go than it did.. Its parked for now. I tell ya what, pulling 80 hour weeks between school and work is just tiresome and doesnt leave a lot of time for my car.

I picked up some TR55s today as they seem well recommended. Hopefully tomarrow will see the MAF checked and diagnosed and atleast half the plugs in, ha.

Oh, the actual cause of my fans not working is STILL eluding me. I have a post about it. Ive put them through every test I know of and they simply wont kick on. I can run my defroster to kick the A/C fan on to keep the car cooled down in low speed and idle driving though. Im starting to get frustrated with this fan situation. I'm just gonna start replacing crap *****-nilly soon.

 

on the fans if they come on with the defroster you know fans themselves are fine and it is electrical,radiator temp sensor/relay.unfortunately fixing some problems take time and with your limited amount just remember to relax and take your time and you will get right

 

Ok, little update right quick,

I got nothing done today.. I went outside to test some sensors then get to work on the EGR code and try to figure out exactly what the issue is. Well, I had noticed a couple flat spots in the throttle around 2-3k RPM's and figured a two minute test would allay any worry regarding that, so i figured I'd knock that out right quick... Well, let me run my results by you all real quick and see what you think, then I'll get to the really fun part of my day, you may get a laugh. I didnt, but its pretty funny regardless.

Ok, using a pair of sewing needles to probe the wires these are my results-

5v ref is fine, tests at right at 5v.
The output signal is bizarre though.. Tested with key on and key off, idling and non.. it reads 15v (huh? lol) at all times and doesnt change. Now, with the engine running, probing the output signal wire with my volt meter and grounding the volt meter out causes the engine to stumble and almost die.. What? I'm not the brightest bulb in the box but I know how to use a volt meter, its pretty damn simple, so I cant attribute this to operator error, as odd as it sounds. I made sure when I peirced the wire with the sewing needle i didnt go through it and in to another wire or anything. The car is NOT throwing any code in relation to the TPS though.. *shrug* I'm inclined to replace it just to see what will happen. thoughts? opinions? donations of liquor?

Ok, on to the funny part. So, the TPS tests out weirdly and doesnt seem to be operating.. So I unplug it. Its my understanding that when its dead or unplugged the ECU will use some default values to take the place of the TPS's readouts so the vehicle is still driveable. I figured I'd unplug it and go for a quick test drive just to see what happened.. Maybe my *** dyno is confused or just looking for some hope, but the car felt a little peppier than it has and while it was still way too slow, it felt better than it has and seemed a little more eager. Yay right? Well, I'm rolling down the street and slow way down to do a 1-2 WOT pull and take off.. Again, the car felt better than it had, I was a little happy thinking maybe I found SOMETHING that will help out, well, I shift hard. I ht the pedal hard.. and apparently my Trans-Am just isnt capable of handling that. My Lumina was. My Paseo was. My SHO was. My F150 was. Everything I have ever owned has put up with the way I shift and drive without issue.. but my trans-am? Nope. The throttle cable SNAPPED and I idled to a stop wondering what the hell just happened.

Thank god it has torque.. I was about a mile from home and had to very carefully let the clutch out and idle it all the way, flashers on, waving poeple around me the whole way, no throttle what so over. It was pretty funny. I wasnt smiling at the time and since i dont know how much another cable is gonna set me back, Im still not smiling much, but it was humerous. I took off work tomarrow night so I can dig in and try to get this BS worked out. The cable looks like its a clean break at the little.. I dunno what to call it, retainer I guess that hooks it to the TB linkage.. So repairing it doesnt look possible. My welder is flux-core and I seriously doubt its gentle enough to weld the cable back on. If theres a little pigtail left on the broken end I may be able to use some kind of wire clamp to join em back together. Likely as not I;ll be calling junk yards for a new cable.

Anyone got one for sale? ha.

Sigh.

 

Good luck, oddly enough I just got mine and have logged the same amount of miles and am tracking down slightly similar problems.

I also have a nie exhaust manifold leak to contend with soon and tomorrow I'm going to rip off the throttle body and give it a good cleaning.

I think the poor thing has been more than a little neglected and is desperately calling to me for help. But, I got the car to work on it as well as drive so I'm gonna have fun. Hopefully my problem or yours won't turn into one of those 50 page threads and after $2000 later no one figured it out.

Regards

Chris

 

I would return those tr55 plugs and get NGK G power plat. instead.They were comparable to the Delco platinuim and considering what a pita it is to do these ,will last longer.As for the egr just buy a new one ,problem fixed!

 

He has a 97, and he has a code for an after cat O2 sensor, hence he's running OBD-II. So.... we know he doesn't have DTC 29, since that's an OBD-I code. Actually, we don't know which of the EGR codes he has, since he hasn't told us, and there are two different codes.... P0400 for no sign of flow at the MAP sensor when the PCM cycles the EGR valve, and P0403 for a faulty vacuum solenoid circuit. And, why does lack of EGR flow cause misfires at low speeds?

MusPuppis:

What EGR code do you have?

What temperature is the engine running at? The stock programming does not turn the fans on low speed until the coolant reaches 226*F and the high speed at 235*F. Turning the heat on will NOT cause the fans to come on. Turning the HVAC selector to a position that also turns on the AC (e.g. - DEFROST) will turn the fans on.

Two possibilities.... cat is dead, or the sensor is faulty. Swap the two after-cat sensors side to side. If the problem stays on the same side, its the cat, if the problem follows the sensor, its the sensor. Again, knowing the EXACT code would help, since there are codes for things other than cat efficiency.

As far as your test on the TPS sensor, all you need to do is measure the volts at closed throttle (anything from 0.20-0.90V is acceptable to the PCM), and at WOT (should be about 4.0V higher than the closed throttle voltage, and not over 4.9V). Then rotate the blades slowly and look for the voltage to move smoothly between the closed throttle and WOT voltages, with no flat spot or spikes. If the voltage is outside the closed throttle limits I posted, or above 4.9V at any time, it will set a PCM code.

Hard to understand how a sensor being fed a regulated 5.0V reference through the PCM could produce a 15V signal. Where in the harness were you testing the TPS voltage?

Finally, this is definitely LT1 engine related, so I'll move the thread over to that forum.

 

MAF code is p0403.

The engine will simply continue to heat up and the fans will not kick on for any reason at any temp. Normal driving I ride around 180 or so (based on the stock gauge.. ) but when I idle they wont cool down. Ive got it around 230-240 but no hotter before I kicked the heat on. Also, when I say heat, Ive been meaning the defrost, sorry.

I'll see what i can do about the o2's.

I know exactly what you mean about the TPS sensor, it doesnt make any sense to me at all. For the ref voltage test I just popped the plug off the TPS and test there. For the output signal I spiked the wire about half an inch from where it comes out of the plug for the TPS.. Again, whenever testing this I get 15v and when I test it with the car running and ground the mulitmeter, the car will stumble and try to die.... My multi meter works just fine on everything else, so its not the meter being faulty.

Too late on the plugs, haha. I went ahead and changed em yesterday afternoon after failing to effect a reasonable repair on my throttle cable. I have to say I was disappointed. Ive been working myself up over doing the plugs as its supposed to be complete hell but, well, it wasnt all that bad. Dont get me wrong, its not something I 'enjoyed' exactly but I was all done in 2 1/2 hours and a full hour of it came from the plug under the alternator.. That one was a bastard. I got the first three on the driver side from the top without any fuss, and the last on the driver side from the bottom without any fuss.. I could have done it from the top as well but it was easier and a little quicker to just jack the car up. Two rear-most on the pass. side were gotten to by unbolting the starter and just sliding it out of the way. Didnt even unhook the wiring. 3rd was gotten to from the top somewhat easily and the 4th and real PITA was from the top after some healthy cussing.. I had to take off the alternator and move the AIR pipe thing to the side quite a bit. To be totally honest though I had a friend helping me and while hes not the best wrencher on the plan he has long fingers and very small hands, making it alot easier to get things done. haha.

I cant drive the car because of the throttle cable, but starting and idling it was smoother. It revved smoother and seemed more responsive. The old plugs were AC Delco's with little platinum caps on the electrode and 6 of the 8 had the caps missing haha. That couldnt have been helping.. On the plus side though, combustion looks good.

 

i have this exzact same issuse ... but instead i did a tune up and about 2 days after doing it on got on it really ahrd and since my car has sucked bog time .. i have to drop the clutch at 5 grand jsut to spin them and theres no power above 3 grand either .. my freinds all say it runs great but i know there a diffrence . i was going to replace all my O2's the MAF the cat and the TPS and how this helped .. otherwaise i have no idea what it is .. so i would like to see this post pan out to see what you find

 

Get some MAF cleaner and clean your MAF as well. My car was off 2-3 mph at the track and I cleaned out the maf and it really helped.