unusual tpi response
09-03-2005, 12:38 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
HELP TPI PROBLEMS
justa while ago i did my rebuilt on my l98 tpi just that before i did the rebuild my car had this problem with something cut out or bogging. i htough i had fixed this problem but it came back after i dropped inthe engine. ive chenged the EGR IAC TPS fuel pressure regulator and ignition module. the car is runing with out the air system for the exhuast. it feels bad and when i step on it the car feels spongy!!i need help badly cant let this new engine have problems like this. the car at certain time acts dumb and goes no whereso when i let of the gas it drives normal but when i step on it nothing!! anyone experienced this problem? any help?
Last edited by TPI TERR; 09-03-2005 at 04:42 PM.
09-03-2005, 04:44 PM
#2
my car did something like that a very long time ago it could be floored and it would just slow crawl down the road and it didn't shift at the right times i took it to GM they replaced some relays under the hood and they put a new computer in it thats about all i can remember
09-03-2005, 09:43 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
Originally posted by obeymybird
my car did something like that a very long time ago it could be floored and it would just slow crawl down the road and it didn't shift at the right times i took it to GM they replaced some relays under the hood and they put a new computer in it thats about all i can remember
my car did something like that a very long time ago it could be floored and it would just slow crawl down the road and it didn't shift at the right times i took it to GM they replaced some relays under the hood and they put a new computer in it thats about all i can remember
09-04-2005, 07:32 AM
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Car: 1987 Iroc
Engine: 5.7
Transmission: 700R4
Are you sure it's not a vaccum leak? I experienced the same thing after adjusting my fuel pressure. As it turned out, I disconnected the vaccum line to the EGR while messing with the fuel pressure.
09-04-2005, 07:48 AM
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Car: Take
Engine: Your
Transmission: Pick
If the MAF sensor is bad, it will send incorrect readings to the ECM, and the ECM will use those "bad" readings to try and make fuel delivery decisions resulting in poor performance.
If you unplug the MAF, the ECM recognizes the loss of signal and goes into a "default" mode where it relies on all other sensors to make decisions. 9 times out of 10, if you can get the ECM to ignore the MAF sensor and it runs better, then the MAF was bad. (this trick doesn't work 100% of the time though).
If you unplug the MAF, the ECM recognizes the loss of signal and goes into a "default" mode where it relies on all other sensors to make decisions. 9 times out of 10, if you can get the ECM to ignore the MAF sensor and it runs better, then the MAF was bad. (this trick doesn't work 100% of the time though).
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09-04-2005, 02:28 PM
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Car: Take
Engine: Your
Transmission: Pick
So I assume you didn't have any stored trouble codes in the ECM?
Have you been able to check fuel pressure when it "acts up"?
Have you been able to check fuel pressure when it "acts up"?
09-04-2005, 08:58 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
ok so i changed one relay next to the electronic spark control near the brake booster the first one to the left. b4 i changed it that car was acting up. i put it on and was runing normal. there are 2 more relays to the right of that one are they the same as the first one? they look the same?
Last edited by TPI TERR; 03-19-2006 at 01:18 PM.
09-05-2005, 09:42 AM
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by TPI TERR
ok so i changed one relay next to the electronic spark control near the brake booster the first one to the left. b4 i changed it that car was acting up. i put it on and was runing normal. there are 2 more relays to the right of that one are they the same as the first one? they look the same?
ok so i changed one relay next to the electronic spark control near the brake booster the first one to the left. b4 i changed it that car was acting up. i put it on and was runing normal. there are 2 more relays to the right of that one are they the same as the first one? they look the same?
The fuel pump relay, and the MAF relay are interchangeable, but the fule pump relay doesn't have a resistor across the coil like the MAF, and MAF burn-off relays do.
09-05-2005, 12:31 PM
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Car: 1992 Camaro Z28
Engine: 5.7 LT1
Transmission: 4L60
Axle/Gears: 3.23's
Ive experienced the same thing. Where intermittently you get no throttle response. But I've got MAP instead of MAF. Could this be my MAP.
09-05-2005, 06:52 PM
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Car: 88' IROCZ
Engine: 388 TPI Motown 350 Race block
Transmission: 700R4
Axle/Gears: 2.77
Originally posted by cheese_kake
Ive experienced the same thing. Where intermittently you get no throttle response. But I've got MAP instead of MAF. Could this be my MAP.
Ive experienced the same thing. Where intermittently you get no throttle response. But I've got MAP instead of MAF. Could this be my MAP.
09-05-2005, 10:17 PM
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Car: 1992 Camaro Z28
Engine: 5.7 LT1
Transmission: 4L60
Axle/Gears: 3.23's
You missunderstood me. I know exactly where my MAP is. I was saying could the MAP be the cause of the problem he described?
09-07-2005, 02:42 PM
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Car: 1988 Corvette
Engine: 5.7L TPI L98
Transmission: 700R4
Axle/Gears: D36 2:59
i sure did!
does it do it on low fuel only. My vette does it when i've only gotta couple gallons in it. My fuel pump gets air pockets from being low on fuel. I'd check fuel pressure first. So now i always make sure i have about 3-4 gallons in it before WOT.
I thought my baffles in my tank where broken but apperntlly there really arent any baffles.
does it do it on low fuel only. My vette does it when i've only gotta couple gallons in it. My fuel pump gets air pockets from being low on fuel. I'd check fuel pressure first. So now i always make sure i have about 3-4 gallons in it before WOT.
I thought my baffles in my tank where broken but apperntlly there really arent any baffles.
Last edited by 8UpAFord; 09-07-2005 at 02:48 PM.
09-10-2005, 12:35 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
well my cars been runin good and i took it to get diagnosed and my 8th inector is out. are venom injectors from summit pretty good?
09-15-2005, 02:41 AM
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Car: 1989 Iroc
Engine: 5.7 350 TPI
Transmission: 700r-4
same prob
The same problem arised from my TPI engine. I took it to a mechanic and the computer read 2 errors but I cant remember what. The check engine light was coming on and off and the car shut off. Before I took it to the mechanic the car had ***** and hauled ***. The MAF sensor was messed up but he had an extra one so I wouldnt have to spend 500 dollars to get one and I have it on the car now. The only thing is that the car takes a while now to take off but the check engine light came off and doesnt shut off. Is there anyway to let the car breathe a little more and give it the same take off it had. I know for a fact that it was the MAF sensor that made the difference in the take off.
The same problem arised from my TPI engine. I took it to a mechanic and the computer read 2 errors but I cant remember what. The check engine light was coming on and off and the car shut off. Before I took it to the mechanic the car had ***** and hauled ***. The MAF sensor was messed up but he had an extra one so I wouldnt have to spend 500 dollars to get one and I have it on the car now. The only thing is that the car takes a while now to take off but the check engine light came off and doesnt shut off. Is there anyway to let the car breathe a little more and give it the same take off it had. I know for a fact that it was the MAF sensor that made the difference in the take off.
10-02-2005, 02:11 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
i changed my injector to 24 lbs the car was runign great imean better than ever but not even a month with the and its having the same symptoms
10-06-2005, 04:39 PM
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Car: 87 IROC-Z
Engine: LsX
Transmission: MN12 6speed
Axle/Gears: 3:42
changed those b4 but ill have to try the filter again the fuel pump is a granetelli not sure if they go out that fast
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