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jimmers | Car Won't Accelerate! | ||
Senior Guru
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I took my car for a drive tonight on the highway and about half way home the car would barely accelerate. I would have it floored and the car would be shaking and slowly accelerating. At idle the car is fine, doesn't surge or anything. The weird thing is that when the car was running I touched one of the spark plug wires and got shcoked. I looked at my spark plug wires and they all seem fine. The engine was rebuilt just last year so everything is new. I can't really look at to much at the moment because the engine is still really hot. Any way I can test the wires? All I know to do is pull one wire off at a time and see if I notice a difference in the engine idle.
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Posted on: 2008/6/6 0:22
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TommyT-Bone | Re: Car Won't Accelerate! | ||
Chair-man of the bored
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Look at the engine bay in the pitch black darkness and see if you see a light show. I had three wires fried on the right hand side. They were tucked under the valve covers and roasted against the block. How new are the cats.?
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Posted on: 2008/6/6 0:26
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jimmers | Re: Car Won't Accelerate! | ||
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Thats a good idea! I don't have any cats, and the whole exhaust is only 2 years old. |
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Posted on: 2008/6/6 0:48
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Qack | Re: Car Won't Accelerate! | ||
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The fuel filter and fuel pump are possibilities.
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Posted on: 2008/6/6 1:00
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Qack | Re: Car Won't Accelerate! | ||
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I would've been surprised if you hadn't received a shock! |
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Posted on: 2008/6/6 1:02
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jimmers | Re: Car Won't Accelerate! | ||
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What do you mean? I shouldn't get a shock thouching a wire?? |
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Posted on: 2008/6/6 1:12
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Qack | Re: Car Won't Accelerate! | ||
Senior Guru
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Quote:
You said the "weird thing" was that you "touched one of the spark plug wires and got shocked". I didn't find that weird at all. If you touch a spark plug wire when the car was running, you are going to get shocked -- no question about it. Nothing weird about that. I didn't -- and still don't -- understand why you thought that was weird. |
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Posted on: 2008/6/6 2:17
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jimmers | Re: Car Won't Accelerate! | ||
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Thats never happened to me before, on any car I've worked on. |
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Posted on: 2008/6/6 2:18
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TommyT-Bone | Re: Car Won't Accelerate! | ||
Chair-man of the bored
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I thought you were playing trivia.....
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Posted on: 2008/6/6 2:21
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I still am! |
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Posted on: 2008/6/6 2:28
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bogus | Re: Car Won't Accelerate! | ||
Grand Imperial Pooh-Bah
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hm... no acceloration...
fuel or spark. Any codes? |
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Posted on: 2008/6/6 4:52
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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jimmers | Re: Car Won't Accelerate! | ||
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Is there any other way to test the plug wires?
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Posted on: 2008/6/6 12:02
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Klaus | Re: Car Won't Accelerate! | ||
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A plugged catalytic converter might be a possibility.
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Posted on: 2008/6/6 12:36
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jimmers | Re: Car Won't Accelerate! | ||
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I dont have the catalytic converters anymore. |
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Posted on: 2008/6/6 13:00
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bogus | Re: Car Won't Accelerate! | ||
Grand Imperial Pooh-Bah
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Check fuel pressure.
When was the last tune up and what brand components were used? A weak coil will cause this too. Again, any codes? |
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Posted on: 2008/6/6 14:32
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The single biggest problem with communication is the illusion that it has taken place. - George Bernard Shaw Education is the best tool to overcome irrational fear. - me |
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jimmers | Re: Car Won't Accelerate! | ||
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I still have to check for codes. The engine was built last year so everything is brand new. The plug wires are MSD and the plugs are AC Delco. |
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Posted on: 2008/6/6 15:15
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BillH | Re: Car Won't Accelerate! | ||
The Stig Moderator
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Plug wires can be checked with an ohm meter. There's a spec in the FSM for the stock ones I think. When I changed the old worn out stock wires to Taylors, the old wires had 6 times the resistance of the new ones. How old are the MSD's? MSDs and Taylors will last many years before degrading. |
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Posted on: 2008/6/7 14:36
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jimmers | Re: Car Won't Accelerate! | ||
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The MSD wires are not even a year old. I also checked for codes, but there aren't any. |
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Posted on: 2008/6/7 17:22
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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Well I tried another set of wires and the car did the same thing. At idle the car is fine. I can give it gas and it doesnt miss a beat. Once you start driving and give it some gas it starts to choke and barely accelerate. If it were the spark plugs or wires, would it not be noticeable at idle?
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Posted on: 2008/6/7 20:02
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jimmers | Re: Car Won't Accelerate! | ||
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I have a fuel pressure guage under the hood. Right now it reads nothing when the cars running. If I unplug the vacuum line it will only go up to 5psi. I dont have another gauge to go by. |
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Posted on: 2008/6/7 20:18
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I just took every spark plug out and had a look at them. They all look fine. I had an extra set kicking around so I changed them all. The problem is still there. Now I'm stuck!
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Posted on: 2008/6/7 21:55
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Calm | Re: Car Won't Accelerate! | ||
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You need at least 40+ psi for fuel pressure.
Seems that's your problem. I'd guess either clogged fuel filter but probably fuel pump. (ex-Peger here ) |
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Posted on: 2008/6/8 0:02
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jimmers | Re: Car Won't Accelerate! | ||
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Thats what I figured. Or my fuel pressure guage could maybe not be working. Is there any way to test the fuel pump or fuel pressure guage? Where did you use to live in Winnipeg? |
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Posted on: 2008/6/8 5:30
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Calm | Re: Car Won't Accelerate! | ||
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I'd rent or buy a fuel pressure tester. I use mine alot on other vehicles. It takes the guesswork out of a fuel problem.
Birds Hill -> N. Kildonen -> Elmwood -> Charleswood -> -> -> God's Country Vancouver. You? |
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Posted on: 2008/6/8 5:52
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1995 Forged 385 ZF6 227/234 1.6 FIC30# MSD BBK SS SLP Bullets X-Pipe DynoMax |
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I live in the Maples. You prefer Vancouver I take it! I managed to dig up an old fuel pressure tester that my dad used to use, but it only has one vacuum line. Where exactly do I plug this into or will this even work? |
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Posted on: 2008/6/8 15:22
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CasetheCorvetteman | Re: Car Won't Accelerate! | ||
Elite Guru
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The fuel pressure gauge goes on the shrader valve, not on any vacuum lines.
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Which vacuum line? Quote:
My new leads must be shot then, ive never had that happen with any plug leads that were not on their way out. Pull the sensor unit out and check the strainer sock in the tank, its on the base of the pump. |
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Posted on: 2008/6/8 15:38
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I didn't think it would work with just a vacuum line. I think the fuel pressure tester I have is really old! Quote:
I was always told that when checking the fuel pressure to remove the vacuum line that goes to the regulator.[/quote] Quote:
What exactly am I looking for? In the FSM it says the strainer life is usually the same as the pump itself. DO I just look for a dirty/clogged filter. I'm leaning more towards a fuel pressure problem, but I still don't understand why I got shocked under the hood. |
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Posted on: 2008/6/8 15:50
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CasetheCorvetteman | Re: Car Won't Accelerate! | ||
Elite Guru
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Sorry mate that should say SENDER unit. The strainer sock is on the pickup. Pull it out and have a look, if its no good, youll know exactly what youre looking at. The factory service manual might say that, but that doesnt mean its a fact, and ive seen a few strainers that were sucked flat (which can reduce flow) as well as a few that were clogged with shit. Only way to know for sure what it looks like and what the condition of it is, is to pull the sender unit out and have a good look. Its not hard, 4 torx screws, 3 hoses, one power plug, then about 10 or 12 hex head bolts hold it in the top of the tank.
You shouldnt have been shocked under the bonnet, that has never happened to me with good leads EVER. Id have to see it to know, but ive had leads that you could see the spark while bending over and blocking the sunlight, and the car still ran ok, certainly not great (quite far from it), but it would accelerate, just bucked and missed abit. While youre looking around, check to make sure the knock sensor line doesnt get real close to a leaking plug lead, cause this can cause false knock (which i dont think is your problem here) No, you dont need to pull off the vac line to the regulator, all that will do is stop the regulator from lessening the fuel pressure when vac levels are higher and less pressure is required to flow the same about of fuel. |
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Posted on: 2008/6/8 16:01
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jimmers | Re: Car Won't Accelerate! | ||
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To relieve the fuel pressure to check the filter, can I just remove the filler cap? I shouldn't need to drain the lines for this, right? I hate working with gas!
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Posted on: 2008/6/8 16:17
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CasetheCorvetteman | Re: Car Won't Accelerate! | ||
Elite Guru
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No mate, pull the fuel pump fuse, start the engine and then while it runs take the cap off. I dont think itll run for long, if it does at all, but sometimes they could run for a long time.
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Posted on: 2008/6/9 3:07
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jimmers | Re: Car Won't Accelerate! | ||
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Thanks, I'll check it out after work! |
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Posted on: 2008/6/9 12:04
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BillH | Re: Car Won't Accelerate! | ||
The Stig Moderator
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Jammers, stop right here, yep, the gauge you have is really old. I have one in the shop somewhere, it's a vacuum/pressure gauge that was used to check manual fuelpumps on carb motors. If won't work on a FI motor. You can get a pressure gauge at any auto parts store or even Sears. |
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Posted on: 2008/6/9 15:08
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CasetheCorvetteman | Re: Car Won't Accelerate! | ||
Elite Guru
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Thought it may have been Bill, but i dont go back that far mate, never even seen one.
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Posted on: 2008/6/9 15:14
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Matatk | Re: Car Won't Accelerate! | ||
Webmaster
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I just worked on this problem yesterday. You need to get a fuel injection pump tester. I bought one at harbor freight for $10. They sell them at autozone for $45. Same thing basically. It screws onto the schrader valve at the rear of the fuel rail. http://www.harborfreight.com/cpi/ctaf ... item.taf?itemnumber=92699 When the pump primes the system, you should have btw 40.5-47 psi and hold steady. At idle/normal temp, it should drop 3-10 psi. If it is not within range, there are several culprits that the FSM outlines. Several have been mentioned here. Weak fuel pump, dirty pickup, clogged filter, leaking injectors, bad fuel pressure regulator are several. I'm not saying this is your problem, but make sure you have all the info when trying to track down a problem. Good luck, Matthew |
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Posted on: 2008/6/9 16:12
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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It was my dads when he was younger. He didn't think it would work either. |
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Posted on: 2008/6/9 22:42
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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Thanks, I'll go pick one of those up tomorrow. Is it easy to attach to the schrader valve? I don't even know what that is, I'll have to check in my FSM. |
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Posted on: 2008/6/9 22:44
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Matatk | Re: Car Won't Accelerate! | ||
Webmaster
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Yes. The schrader valve is inside of a threaded piece. You just screw the appropriate sized threaded end onto the schrader valve and the other end to the gauge - it's that simple.
Matthew |
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Posted on: 2008/6/10 1:20
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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Matatk | Re: Car Won't Accelerate! | ||
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Posted on: 2008/6/10 1:34
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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Thanks Matatk, especially for the pictures! Thats where my fuel pressure guage is currently attached. I'll pick a guage up tomorrow and see what I find. I'll post my findings afterwards. Thanks for everyones help!
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Posted on: 2008/6/10 4:09
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CasetheCorvetteman | Re: Car Won't Accelerate! | ||
Elite Guru
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Matak, all is well there, but the temp of the engine should have little or no bearing at all on the pressure. Its all related to vacuum
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Posted on: 2008/6/10 6:59
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Matatk | Re: Car Won't Accelerate! | ||
Webmaster
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If you say so - what I wrote is a quote directly out of the FSM. I'm not gonna argue with you about it. Matthew |
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Posted on: 2008/6/10 14:15
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I called around to every parts store that I know of and no one has a cheap one. They are all about $100! I can't even find one to rent. I'd hate to buy one from the internet and wait a week before I can troubleshoot my problem.
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Posted on: 2008/6/10 19:00
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jimmers | Re: Car Won't Accelerate! | ||
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My buddy said he has one that is 3/8 thread. Will this work? I'm not at home to measure.
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Posted on: 2008/6/10 20:50
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jimmers | Re: Car Won't Accelerate! | ||
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I managed to get a FP guage from a mechanic I know. He let me borrow it for a few days. I'll let everyone know how it turns out tomorrow.
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Posted on: 2008/6/11 3:14
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Matatk | Re: Car Won't Accelerate! | ||
Webmaster
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Sounds good - do you have a FSM for the testing sequence? Matthew |
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Posted on: 2008/6/11 3:26
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2002 EBM convertible, Magnusson supercharger, cam, headers, etc. 1989 Corvette...RIP |
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jimmers | Re: Car Won't Accelerate! | ||
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Yes I have a FSM. |
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Posted on: 2008/6/11 12:04
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BillH | Re: Car Won't Accelerate! | ||
The Stig Moderator
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Ha, yea, the gauge has a needle that points straight up. The left side reads vacuum, the right reads pressure. I go back so far, I don't remember most of it. |
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Posted on: 2008/6/11 14:30
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I tried my test FP guage and I get 40psi at idle that holds steady. I found out that whenever I touch the plug wire for cylinder 2 at the distributor, I get a shock. I tried a whole other set of plug wires earlier and the car still had the stumble. Bogus mentioned earlier that it could be a weak coil. Is there anyway to test this other then the ohm test? Would this cause me to get a shock?
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Posted on: 2008/6/11 23:02
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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Forgive me if I'm asking dumb questions but when it comes to electronics in cars I'm really green. I'm more of a wrench guy! Here is a picture of my coil. It looks like the edges have been burned.
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Posted on: 2008/6/11 23:59
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jimmers | Re: Car Won't Accelerate! | ||
Senior Guru
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I replaced the coil today but it's still doing the same thing. Any ideas?
Also the instructions that came with the coil said to install a secondary ground. It says if I don't install them it will lead to voltage punch and destroying both the coil and dist. cap. I didn't have on on the original coil. Do I need one? In my FSM it talks about 2 grounds, but I don't see where it goes. |
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Posted on: 2008/6/12 22:25
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