bucks and kicks, rpm and speedo needles go haywire
08-18-2007, 05:42 PM
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bucks and kicks, rpm and speedo needles go haywire I got a problem and i can't figure it out! I just put in a new msd opti and it is installed correctly but a little advanced right now. My car is still bucking and kicking though. The needles on the rpm and speedo go nuts and the ses light comes on every time is cuts. I don't know what is goin on i could really use some help. it is a 93 z28. My coil is good, my opti is brand new, new wires, new plugs. The thing is it is doin this randomly sometimes it runs good and then i have to keep it alive by feeding it more gas. Also i noticed when i stop it will idle around 500rpm and slowly work it's way back up to around 1000rpm. Please help me I would really appreciate it!!!
08-19-2007, 10:07 PM
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well just incase some one else has the same problem. I hooked up a fuel pressure gauge today and it only read about 10 psi with the ignition on so i guess it's the fuel pump cause it should be 41-47 psi. Next weekend i will put in a new walbro and post my results.
08-25-2007, 02:02 AM
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haven't done it yet cause i am workin out of town so i can only work on it on the weekends. Tried tps, opti, map, coil, plugs. It isn't throwing any codes. when i turn the ignition on the fuel pressure goes up to about 15 psi slowly. Then if i turn the engine on it jumps to 43.5 psi then slowly drops down again to like 20 ish i think it was at idle. Then i turn the car off and after a couple seconds the fuel pressure is at 0 already so i am not sure if it is my regulator or fuel pump. Or possible wiring to the fuel pump but the pump does kick in normally for about 2 seconds to pressurize the system then shuts off. So i am thinking it is my regulator. I am gonna try making a shutoff valve before the regulator. So if it does pressurize with the valve closed it is my regulator if not then it is my pump. Has anyone ever tried this before? Any info or advice would be appreciated! Thanx
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08-25-2007, 05:33 PM
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ok so my car is holding about 40 psi now with the new regulator. But it drops right away after i turn the car off. Should it not hold about half the pressure for a while? I also want to upgrade to a better fuel system this winter. Here is a picture of what i basically want to do but it is different on my 93 camaro. http://www.gmhightechperformance.com.../photo_09.html So does anyone know if i can fit 94+ camaro fuel rails on my 93? I think so but not sure Has anyone done this?
08-25-2007, 05:44 PM
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My 01 Camaro did the exact same thing, all the dash lights/guages would go crazy, the engine power would cut out and sometimes it would just die with full ellectrical power loss.
My problem was the main hot that went to the fuse/relay block behind the LH head light. The nut was not completely tight and was siezed from the heat/resistance/arcing but the hot wire was slightly loose. After replacing the nut and making sure it was tight I never had another problem.
I talked to a friend about it afterward and he said he has seen that same issue a few times at the dealership service dept. he works in.
My problem was the main hot that went to the fuse/relay block behind the LH head light. The nut was not completely tight and was siezed from the heat/resistance/arcing but the hot wire was slightly loose. After replacing the nut and making sure it was tight I never had another problem.
I talked to a friend about it afterward and he said he has seen that same issue a few times at the dealership service dept. he works in.
08-25-2007, 05:46 PM
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Originally Posted by Jeremiah
My 01 Camaro did the exact same thing, all the dash lights/guages would go crazy, the engine power would cut out and sometimes it would just die with full ellectrical power loss.
My problem was the main hot that went to the fuse/relay block behind the LH head light. The nut was not completely tight and was siezed from the heat/resistance/arcing but the hot wire was slightly loose. After replacing the nut and making sure it was tight I never had another problem.
I talked to a friend about it afterward and he said he has seen that same issue a few times at the dealership service dept. he works in.
My problem was the main hot that went to the fuse/relay block behind the LH head light. The nut was not completely tight and was siezed from the heat/resistance/arcing but the hot wire was slightly loose. After replacing the nut and making sure it was tight I never had another problem.
I talked to a friend about it afterward and he said he has seen that same issue a few times at the dealership service dept. he works in.
08-25-2007, 06:22 PM
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na it's fuel related cause of my fuel pressure. I just took it out for a test drive and the hotter it gets and the faster i go the more it does it. New regulator and my injectors are fine, no leaks anywhere so it has to be fuel pump i assume.
08-25-2007, 07:45 PM
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i guess cause all of a sudden it has no fuel so my computer picks that up and everything is trying to compensate and then it gets fuel and changes and i am loosing power so my rms and speedo will go up and down due to my speed and fuel supply. So my rpm and speedo go nuts this is my theory.
09-01-2007, 06:41 PM
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Heelllppp Mmeeeee!!!!!!!!! I am loosing my mind!! Ok so here is the deal the car is hesitating like retardedly bad. I can't even drive it. So this is what i have tried in order: coil, msd opti, plugs, fuel filter, MAP, TPS, fuel pressure regulator, walbro fuel pump. My car is still hesitating like frickin ccrazy seems worse after all of it. SES light comes on when it hesitates and goes away when it stops. It isn't throwing any codes. Please help me I am almost in tears already it has been like 6 weeks already or more. My fuel pressure is good now though. When i took my injectors off i forgot to label the wires. Does it matter which wires go to which injectors?
Last edited by roadhog_113; 09-01-2007 at 06:49 PM.
09-03-2007, 01:10 PM
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the car already had a brand new walbro in it when you bought it. it went in with the heads. it also had new 38lb injectors id say its electrical not fuel. everything is covered there
09-04-2007, 11:13 PM
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Originally Posted by roadhog_113
I am loosing my mind!! Ok so here is the deal the car is hesitating like retardedly bad. I can't even drive it. So this is what i have tried in order: coil, msd opti, plugs, fuel filter, MAP, TPS, fuel pressure regulator, walbro fuel pump. My car is still hesitating like frickin ccrazy seems worse after all of it. SES light comes on when it hesitates and goes away when it stops. It isn't throwing any codes. Please help me I am almost in tears already it has been like 6 weeks already or more. My fuel pressure is good now though. When i took my injectors off i forgot to label the wires. Does it matter which wires go to which injectors?
I think that's how it works neway, I'm still learning this stuff myself, lol.
09-04-2007, 11:35 PM
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Originally Posted by chasejulia
Mos def man. It's an SFI system, so the injector only pulses when its cylinder is on the intake stroke, crossing the wires would cause them to pulse at the wrong time. How that would affect the drivability I dunno tho. I know that the gas would just kinda sit there until the intake stroke of the cylinder, and that would defeat the purpose of the system, as the fuel would no longer be atomized. I have no idea if it would run at all, but I think it might, just far less efficiently.
I think that's how it works neway, I'm still learning this stuff myself, lol.
I think that's how it works neway, I'm still learning this stuff myself, lol.
oh and welcome to the site, btw
Last edited by infinitebird; 09-04-2007 at 11:48 PM.
09-05-2007, 09:17 PM
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I can't believe somebody actually has the same problem I have.
93 Z28 A4, I changed my opti to the MSD model and had the same exact problems. I was convinced the opti was bad removed it and sent it to MSD for warranty repair...I did this three times. I could never get the MSD to work. I bought an no name opti from a local parts store and the car runs fine for about a half hour before it dies and won't start for a few hours. I still have a fully functional MSD opti with an extra pick-up that I'd love to install, but I'd like to know what the real problem is first. I have replaced coil, ignition module, and checked all the wires.
Roadhog, may I suggest pulling the codes from the OBD ? It may not be lighting anything on the dash, but it still may have a code.
93 Z28 A4, I changed my opti to the MSD model and had the same exact problems. I was convinced the opti was bad removed it and sent it to MSD for warranty repair...I did this three times. I could never get the MSD to work. I bought an no name opti from a local parts store and the car runs fine for about a half hour before it dies and won't start for a few hours. I still have a fully functional MSD opti with an extra pick-up that I'd love to install, but I'd like to know what the real problem is first. I have replaced coil, ignition module, and checked all the wires.
Roadhog, may I suggest pulling the codes from the OBD ? It may not be lighting anything on the dash, but it still may have a code.
09-05-2007, 10:53 PM
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I know this sounds kinda stupid but my gauges were going crazy on my car and it was acting similar to yours and my problem was the ignition switch. You might give it a shot?
09-05-2007, 11:16 PM
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Same problem with my buddy's old 95 t/a. A plug wire melted to the driver side exhaust manifold and every time the wire made contact to the manifold the gauges would go crazy and the car wouldn't run for anything. Just a thought. Check it out and I hope it helps.