| Go back to previous topic | | Forum name | Performance/Engine | | Topic subject | Fuel Starvation? (Long) | | Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=10700 |
10700, Fuel Starvation? (Long) Posted by daved, Dec-23-01 08:33 PM
Alright everybody I think I am having some sort of fuel starvation problem. Just had a new engine put in a couple months ago I have about 2500 miles on it right now so I have started to give it a little bit more gas. But lately the car seemed to have trouble under low rpm loads, such as it being jerkey during acceleration. At first I thought it was a plug not firing but I am 99% sure that is not the problem after what I found out today. Here is why I don't think it's a plug, under normal acceleration my Air/Fuel Ration gauge wasn't picking up on the problem. When I decided to give it full throttle today the led lights on the gauge went all the way over to rich and then the car started having a hard time accelerating, jerkey and shit again as soon as that happened the A/F Ratio gauge jumped all the way over into the lean red led lights. I mean all the way down only 3 red led lights where on. After about 2 seconds the A/F Ratio gauge jumps back to rich and the car takes off again, kinda throws you into the back of you seat. So from what I know about cars I am having some sort of fuel starvation some where in the fuel system, a plug not firing wont give me a lean condition I beleive correct me if I am wrong.
So lets say I am having a fuel starvation problem, what ever or where ever it is occuring it only occurs during certain rpm ranges and certain gears. First gear between 1000 to about 3000 fine after 3000 the cars goes into lean and I bog down then it jumps back up. Same thing happens in second gear, not the same rpm's though. Third seems to be fine haven't taken it over that yet, damn I wish I had the EGT gauge now to make sure I am not running the engine too hot. IMO that sound like some kind of computer problem right? What are your thoughts? I have been thinking about this all day and I have been workin on it all day can't figure it out, Iam getting ready to go to Satan soon and I dont have the money for that. Also I do have a CEL on but I have a 99 and I can't do the key dance shit so dont anybody go and tell me to do that shit. Is it ok to drive the car if I keep it under the points its leaning out? I dont want to fuck this new engine up.
Also forgot to add up top the car is ideling just fine, not rough at all, just another reason to prove that it's not a plug or plug wire.
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10701, RE: Fuel Starvation? (Long) Posted by MuRiX, Dec-23-01 10:07 PM
Try unplugging the ecu if you can for an easy first test. It might be something stupid like that. I had a few funky problems with my car stuttering and it seems I unplug the ECU for a little bit and it goes away. It is a start at least.
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10702, RE: Fuel Starvation? (Long) Posted by daved, Dec-24-01 10:05 AM
Its a little cooler out tonight and the car is running a little better, but not perfect yet. It leans out for allot less time and the car feels much stronger. Earlier in the day it was still hot and it was still having problems. Outside air temperature seems to have an affect on the problem. I am leaning towards some sort of sensor sending the wrong signal to the ECU and the ECU doesn't know what to do so it cuts fuel off, just guess though I am not sure. Going down to Satan on Wednesday. After this explanation does anybody have any idea of whats going on? I want to have some sort of idea so Satan doesn't try to fuck me giving me parts I don't need, I already caught them doing that once. I guess they didn't know that I know my car pretty well.
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10703, RE: Fuel Starvation? (Long) Posted by daved, Dec-25-01 12:15 PM
Anybody?
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10704, RE: Fuel Starvation? (Long) Posted by DarkOne, Dec-25-01 01:42 PM
Could be your MAP sensor.. or your fuel pump going out.
Got any gauges? What do they do? (besides the aforementioned AF gauge .. they're pretty useless for diagnostics..
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10705, RE: Fuel Starvation? (Long) Posted by daved, Dec-25-01 06:19 PM
The only gauges I have are Oil Pressure, A/F Ratio, and a Tach. Been thinking about getting the S-AFC but money has been really tight the last couple of months. I know, I know that A/F gauge is not the best for diagnostics but it is without a doubt reading lean when the car starts to jerk. Oil pressure remains constant, no drop just holds still around 50 psi during normal driving. The tach just shows that the car is struggling, normally it goes fast all they up till when the power curve drops off when the car starts to jerk the needle drops about 100 rpm's and goes back and then repeats that process untill the engine stops leaning out and the A/F gauges reads rich once again. My idle rpm's are around 1000 is that a little high? Idle oil pressure is 25 psi which is normal, about 50 psi during light driving, and under WOT 75 psi so it looks like I am not having any problems with oil pressure. I spun the tires tonight and scared the shit out of me I wasn't ready for it, I was under WOT just testin shit out and it was struggling then after it got past about 3500 rpm's the car hooked up again and spun all the way up till when I shifted.
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10706, RE: Fuel Starvation? (Long) Posted by daved, Dec-26-01 02:57 AM
Well just got back from Satan and it turned out to be plug wires. The ECU was leaning out because it was reading a miss fire and stoped dumping fuel into the cylinders. Just picked up a set of MSD 8.5 wires and the car runs perfect now.
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10707, RE: Fuel Starvation? (Long) Posted by Fast420A, Dec-26-01 03:23 PM
Damn thats what I was about to say, plug wires. Sorry I didn't check the board sooner.
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10708, RE: Fuel Starvation? (Long) Posted by daved, Dec-26-01 04:48 PM
No problem Fast420A I am kinda glad it was my plug wires gave me a reason to get some nice aftermarket ones. And yes Satan wanted to fuck me today, they wanted $275 for new stock plug wires, stock spark plugs, and labor. I told them to fuck off went to Automotive Engineering (I am sure you know where that is for those that live in the Tampa area) got a nice set of aftermarket MSD 8.5 mm wires for $51 and got new plugs for $8 so I spent a total of $59 and I got better shit than stock! Fuck Satan, this is why I do all my own work on my car they always try to rape you.
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