Darkness Posted May 5, 2005 Report Share Posted May 5, 2005 Hey guys. My car seems to be behaving a little strangley. My buttdyno is telling me that my car performs better at partial throttle than it does wide open throttle. It feels like when I have the pedal only most of the way down, my car flat out screams, but if I punch it to the floor, I'd swear my wife's Hyundai could kick the snot out of it. It doesn't really bog down, it just doesn't accellerate much. Any thoughts? I have a cheap cone filter on it, which may not be allowing enough air on WOT, maybe? Weak fuel pump or should I start out by replacing my fuel filter? Thoughts, opinions and suggestions welcome. Keep in mind, I have almost 250k miles on it now. Quote Link to comment Share on other sites More sharing options...
Jcrow Posted May 5, 2005 Report Share Posted May 5, 2005 I feel that way about my truck, I think its just mental Quote Link to comment Share on other sites More sharing options...
TGPilot Posted May 5, 2005 Report Share Posted May 5, 2005 Could be your TPS is not showing greater than 80% when you push it to the floor. I do not remember the OHm values for a properly working TPS...but I would find it and put a Digital OHm meter on the TPS. Another thing could be an exhaust restriction that slows the outflow when you get up in the RPMs and exhaust flow is needed the most... 8) Quote Link to comment Share on other sites More sharing options...
Darkness Posted May 5, 2005 Author Report Share Posted May 5, 2005 If the E-Check gets tossed at the end of this year here in Cinci, I'll definitely be taking care of any exhaust problems! I bet with my miles that the cat is clogged or something like that, which probably doesn't help. Quote Link to comment Share on other sites More sharing options...
Marcus18 Posted May 5, 2005 Report Share Posted May 5, 2005 check your coils. I had that problem once and one of them was weak. marcus Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted May 6, 2005 Report Share Posted May 6, 2005 I've noticed the same exact problem since I've had to start taking the expressway to the new work location. I'll be coasting at 60 with my foot off the pedal. I tap it lightly to get back up to speed as it decelerates, and I'm like "whoa!" It feels faster at that slight touch (1/4 down maybe) then my AWD feels at WOT! I put it half way down, and all I can say is "holy freaking shnikes!!!" And then I nail it, thinking "man....if it moves like THIS at only HALF throttle, I'm going to be plastered to my seat at WOT". But, much to my disappointment, it doesn't really seem to accelerate much harder when I push it the rest of the way down. Now I KNOW I have a TPS issue somewhere, and I'm suspecting wiring. I changed the TPS sensor a while back (don't know if it needed it, or not, but I'm changing ALL my sensors), and the odd idling issues got WORSE! It shot clear up to 3K RPM when I started it immediately after!! I also didn't start getting my first SES light till then, and it still goes off now. TPS voltage low. And then once, I got a MAP sensor voltage high. Interestingly enough, they share a ground at the computer, I believe. Thus, why I think it's an electrical issue. I KNOW this is effecting it, because it can go from normal idle, to 2K, then boucning all over the place all within one stop light (quite annoying). I can also feel it bog down at certain points in acceleration in city driving, then suddenly haul ass. You can always change the filter, since that needs to be done regardless. Fuel pump is another possibility, and one I've been thinking about, too (since the one on my red TGP went out, and just got replaced). FPR, injectors, etc. There's quite a bit that could contribute. And if that's still the original cat on there with 250K miles......DAMN! :shock: Quote Link to comment Share on other sites More sharing options...
no1kicker Posted May 6, 2005 Report Share Posted May 6, 2005 Yeah, could be a weak coil. Are you running rich at all? Quote Link to comment Share on other sites More sharing options...
Jeff M Posted May 6, 2005 Report Share Posted May 6, 2005 RareGMFan I would follow your thoughts on the grounding issue first, on the back of the block near the firewall, there is a bracket that bolts between the tranny snout and engine block, there next to the bolts at the block is 2 other bolts with very important ECM Ground, jack it up nice and safe and get comfy on the ground under it, then check the connections, take the time to remove and clean if they look bad, then inspect the wires going into these spade connectors, then fix as needed then reattach, now follow those wires to make sure they do not make contact with anything, yank them out of the wire loom, if no wire loom then good chance some wire insulation damage, fix everything you find but do all this just to finish up in this area and so you don't go back there later to find it was a couple of issues :shock: . If all is still good then swap the ECM with another known good one. Best course of action for now other than some more looking inot the connector and wires for the TPS and MAP, pinching and all that too. Also do a study of the other turbo car you have, a LOT OF TIMES, you can find where someone was messing with things, or something has changed or whatever, its nice to have two when doing this, and borrowing parts 8) . Let us know what you found, thanks! Jeff M Quote Link to comment Share on other sites More sharing options...
RareGMFan Posted May 6, 2005 Report Share Posted May 6, 2005 Yeah, having a "blueprint" definitely helps, lol. I did swap computers way back when this frist started. That was my first thought, and since I had a spare, I figured what the hell? This will only take a few minutes. So, I tried both computers, AND both a stock and one of your TG 160 chips with each ECM. Still the same. I may also have a faulty new TPS, so one of these days, when I get a chance, I'll have to try swapping that, too. I will definitely look into those wires. I've been meaning to for some time, but with the distance and work/hours involved in the new relocation of our store (30 minutes away, now :x ), I haven't had time to do jack. I just have a gut feeling that it's electrical. I have brand new Delco coils and ICM, Rapidfire non platinum plugs, and some generic new wires for the time being, to eliminate a few other possibilities. OH! One other thing that perhaps is a clue, or is something totally unrelated. Sometimes (especially when I first start it, but at an occassional red light, too), I'll press on the accelerator, and it won't budge! I mean rock hard. I have to put a considerable amount of force into it for it to sort of...."break through", and then it's fine again. And then the lady next to me has to give me an evil look for chirping the tires. "I didn't MEAN to, damn it!!" So what gives? Sticking throttle? I have a throttle body cleaner I like a LOT, but I've been afraid to use it on the TSTE because the bottle clearly says "Not for use on turbos and diesel engines". :shock: I hope this isn't taking away from Darknesseses thread. :oops: But I suppose since we're having similar problems, it can only help. Quote Link to comment Share on other sites More sharing options...
Darkness Posted May 6, 2005 Author Report Share Posted May 6, 2005 I will have a chance to really dig into things this weekend, so I'll let you know all the particulars. I picked up a new set of plugs and am going to grab a digital voltmeter, etc, so I can check out the electronics. Hopefully I'll have a etailed report for you on Sunday night. Quote Link to comment Share on other sites More sharing options...
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