It runs Just not that good.
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
It runs Just not that good. (124k on the motor ) Okay. So I changed the plug wires and Plugs recently. If you look under the car the waterpump was replaced. (so no doubt the opti/coil/Icm are older). I dont drive this car that much. It was running real smooth after the tune up. Im leaving work I make it 4 miles. I notice the car has a shake, So there is a rough idle and a constant missfire. Its ever so slow getting worse (and i mean slowly). The car starts up fine, The car still has some power, It has yet to die. But you can rev it in Nuteral its ok. Anything under 2.5k under a load(in gear) its noticeable its not ok. (Sometimes in 6th gear going 65ish you can hear it backfire like into the intake style with giving it gas) I have experianced maybe like 4 times that after sitting for 10 mins to have it run ok for maybe a minuet then to go back to sounding like a motor cycle.
I have read people say opti or icm when the car dosnt run, but what if it still runs?
It wont throw any codes either.
I have read people say opti or icm when the car dosnt run, but what if it still runs?
It wont throw any codes either.
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
Im not sure how important this is . But when i received the new plug wires i noticed the prong for the coil wire ( on the coil) Had corrosion on it in inspection, and the connector in the boot had some rust. i cleaned this off and it ran fine till my previous post indicates.
(Reprogrammed pcm,headers, K&n cold air, new plugs, new wires, fuel filter is on the list next)
(Reprogrammed pcm,headers, K&n cold air, new plugs, new wires, fuel filter is on the list next)
Could be so many things...
I would test your coil. I would also do this test:
http://shbox.com/1/4th_gen_tech2.html#opti_test
The backfiring is a good indicator that your problem is your ignition system.
plugs
wires
coil
opti
ICM
and wiring anywhere in between
Test/replace parts in that order.
I would test your coil. I would also do this test:
http://shbox.com/1/4th_gen_tech2.html#opti_test
The backfiring is a good indicator that your problem is your ignition system.
plugs
wires
coil
opti
ICM
and wiring anywhere in between
Test/replace parts in that order.
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
Okay so tonight it did some tests.
-I tested the ICM like in that link. There was the power to the A and D, And cranking power to the B.
-I recleaned the coil prong, put on a new coil wire. ( do to the fatigue of the coil prong and its age i think i might replace it anyways)
-Checked the wiring for the maf,coil,icm down a ways.
-Check the plugs/wires, Those checked out ok.
-I did do a fuel presser test. It went up to about 35-37psi. then bled off when i turned off the car. But my cheap tester was leaking so at this time i cant confirm it was the cars fault.
-Replaced the intake boot elbow. old one was torn.
Start it up. Runs better, after a min it starts missing again. It had a little more power/ less lag so it did feel like a step in the right direction.
If i hold the Rpms say at 1500 You can watch them jump (maybe 100-200rpms) up for a breif second as if it fired correctly that breif period.
-I tested the ICM like in that link. There was the power to the A and D, And cranking power to the B.
-I recleaned the coil prong, put on a new coil wire. ( do to the fatigue of the coil prong and its age i think i might replace it anyways)
-Checked the wiring for the maf,coil,icm down a ways.
-Check the plugs/wires, Those checked out ok.
-I did do a fuel presser test. It went up to about 35-37psi. then bled off when i turned off the car. But my cheap tester was leaking so at this time i cant confirm it was the cars fault.
-Replaced the intake boot elbow. old one was torn.
Start it up. Runs better, after a min it starts missing again. It had a little more power/ less lag so it did feel like a step in the right direction.
If i hold the Rpms say at 1500 You can watch them jump (maybe 100-200rpms) up for a breif second as if it fired correctly that breif period.
Last edited by busdude; Mar 7, 2009 at 01:14 AM.
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Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
Another guy mentioned about the same ( Car mods and running problem ) as me in another thread someone was thinking TPS. Mine will time from time after acceleration Rest at 1500rpm then fall to idle under 1k.
https://ls1tech.com/forums/lt1-lt4-m...ms-2500-a.html
https://ls1tech.com/forums/lt1-lt4-m...ms-2500-a.html
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Staging Lane
Joined: Feb 2009
Posts: 95
Likes: 0
From: Homestead, Fl
yea my t/a has never run right since i got it......doesnt miss just a rough idle...i've tried everything and nothin works the only thing i have yet to try is a comp. test cause it just seems too much of a pain to do it. i do have a loud lifter noise so i am wondering if there is some comp loss. but the power seems fine
Staging Lane
Joined: Feb 2009
Posts: 95
Likes: 0
From: Homestead, Fl
o yea i also have a 32 EGR code it sometimes throws but it doesnt stay on when it does come on. but when u turn it on if u feel the egr valve its not hot so i know its not stuck open....i dunno i love the car but just too much of a pain and it doesnt hold up to punishment too well....
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
I put in the new TPS sensor today. I must say that helped the car. It dosnt randomly cut out anymore and i am ablue to drive it now. but it still has the power loss under 3k Rpms. Still back fires in 6th on the freeway.
Thread Starter
Staging Lane
Joined: Nov 2008
Posts: 63
Likes: 0
From: Fresno ca
Another update I replaced the coolant temp sensor. I had a chance to check out the data stream and it was showing that bank2 was leaning out once it warmed up. so i went ahead and replaced the 02 sensor on the lean side. same effect ran a little bit better but still not right.