Opti Spark? Fuel Pump? HELP!
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Opti Spark? Fuel Pump? HELP!
I was driving along yesterday afternoon when my '94 suddenly lost power and started to backfire from the exhaust. The backfiring wasn't loud, just like popping from the rear of the car. I pushed in the clutch and tryed to rev it up but it would only go to about 3k. There were no warning lights (check engine/guages, etc.). It idled for a little bit but finally stalled completely and I pulled to the side of the road. I called a friend and when he got there we tested for spark by pulling a plug wire and it threw a spark to something metal, so I think the coil is still good. The engine will actually crank and continue to run/stumble at what seems to be 75 (yes, 75) rpm if I keep pumping the gas. I was going to buy/borrow a fuel pressure guage and check the pressure at the rail to see if its the fuel pump. Very strange. Any help is appreciated!
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
Oh boy, sounds like the symtoms of an opti-spark going south. How many miles on your current opti-spark and coolant pump?
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
Oh boy, sounds like the symtoms of an opti-spark going south. How many miles on your current opti-spark and coolant pump?
I just bought the car about 2 months ago and have put about 1000 miles on it. The car has 120k on it and the guy I bought it from told me that as far as he knew everything was original. I was waiting for this happen, so I'm not to upset about it. Just sucks that it did it so soon after I got it. Keep the suggestions coming. Thanks!
I just bought the car about 2 months ago and have put about 1000 miles on it. The car has 120k on it and the guy I bought it from told me that as far as he knew everything was original. I was waiting for this happen, so I'm not to upset about it. Just sucks that it did it so soon after I got it. Keep the suggestions coming. Thanks!
If you do tackle it yourself, I'd be glad to help you through it as I just did it myself.
SEE YA
Strick :flag :flag :flag
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
Well of course I want to fix the problem! :yesnod: All repairs will be done by me. I'd say I've got the basic knowledge of working on cars down. I rebuilt the motor in my '85 Vette, removed/replaced transmissions, rearends, gears, etc. etc. Not bragging of course. :D My father would be very disappointed if any of my vehicles were to go in a shop...hehe. He has been a great help. I'm still a newbie when it comes to LT1s however. I owned a '95 Firehawk for a short while but never really got into the motor. I took the intake off to replace the gaskets, but that's about it.
So your guess is the definitely the Opti, Strick?
So your guess is the definitely the Opti, Strick?
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
Yes, If you read all the opti-spark posts in the past, it seem to be more than just a rare occurence in the LT-1. You said that you had no engine codes, sometimes a faulty opti-spark won't give an engine code. Besides, after looking inside my opti-spark (44k on my Vette) I found dirt, water and rust everywhere. I was a heartbeat away from being stranded on the road.
Oh, I didn't mean to imply that you know little about car mechanics. I was just trying to get a feel of whether I would advise you to tackle this job yourself, but with your background, I know you can do this project. Between using the Service Manual and all the knowledgable guys on this forum, you'll get this done in no time. Vettes----a way of life.
Strick :flag :flag :flag
Oh, I didn't mean to imply that you know little about car mechanics. I was just trying to get a feel of whether I would advise you to tackle this job yourself, but with your background, I know you can do this project. Between using the Service Manual and all the knowledgable guys on this forum, you'll get this done in no time. Vettes----a way of life.
Strick :flag :flag :flag
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
I was a heartbeat away from being stranded on the road.
Oh, I didn't mean to imply that you know little about car mechanics.
:cheers:
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Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
Hey Scott,
Your profile shows an 85 vette. :confused:
Your profile shows an 85 vette. :confused:
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
Okay, When are you going to start on the problem? Also, there are two places I recommend to buy the opti-spark: 1. Go to http://www.corvetteclinicinc.com and look under C-4 solutions and read about the opti-spark venting and what Chris has to offer, and 2. Dyno-Tech Engineering (ad on the left column) they have a newly engineered opti-spark that solves allot of the problems. Also, if you feel you want to solve all your problems, buy an electric coolant pump. Most of the forum members have been using Meziere HD found in all the catalogs. These pumps do a better job especially during idle with the A/C pumping, and you gain a couple of ponies.
Let us know how it goes.
:flag :flag :flag
Let us know how it goes.
:flag :flag :flag
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
Thanks for the recommendations! I read the ad for the Dyno-Tech unit and it looks very promising. I signed up for the mailing list, too. I received an e-mail containing this:
I wonder when they will have the final product finished?
I've heard good things about the Meziere HD. Did you do this, Strick?
The Billet Aluminum Gen I Dynaspark Distributor is currently not
available for sale as of 4-10-03. We had slated the Gen I unit to be
released for sale in mid-April, however we have identified a potential
problem area that we feel we must correct before the final iteration is
released to the public.
Changes in the design like this require our selected machinist to
re-program the CNC program file to reflect the improvements that we want
implemented in the final version and that of course, causes delays.
Bringing something entirely new such as this to the aftermarket is very
challenging and sometimes there are unexpected snags along the way.
The Gen II unit was much easier to develop and perfect than the Gen I,
primarily due to the unique splined drive mechanism that is inherent to the
Gen I distributor, therefore further refinement is needed to perfect the
proprietary design.
We apologize for the increased delay time, but we will not release a
rushed, poorly designed product to the public just to make a quick sale. We
WILL have it right the first time and you deserve nothing less.
available for sale as of 4-10-03. We had slated the Gen I unit to be
released for sale in mid-April, however we have identified a potential
problem area that we feel we must correct before the final iteration is
released to the public.
Changes in the design like this require our selected machinist to
re-program the CNC program file to reflect the improvements that we want
implemented in the final version and that of course, causes delays.
Bringing something entirely new such as this to the aftermarket is very
challenging and sometimes there are unexpected snags along the way.
The Gen II unit was much easier to develop and perfect than the Gen I,
primarily due to the unique splined drive mechanism that is inherent to the
Gen I distributor, therefore further refinement is needed to perfect the
proprietary design.
We apologize for the increased delay time, but we will not release a
rushed, poorly designed product to the public just to make a quick sale. We
WILL have it right the first time and you deserve nothing less.
I've heard good things about the Meziere HD. Did you do this, Strick?
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
Interesting note on the Dyno-tech. I didn't know they had a problem. As far as the coolant pump goes, If I knew about them before I bought my AC Delco replacement, I'd have gone that route because it just makes sence. So, 40 or 50k from now, I'll make the change. Did you try corvette clinic? I had my opti-spark vented by him and it is complete and well done. Again, I bought a new opti-spark through my son who works at the Chevy dealer and the price was right, but the total opti-spark package Chris offers is resonable.
The hardest part of the job for me was getting the dampner hub off, other than that it's just time consuming labor. I call it bonding with my Vette. :lol: :rofl: :lolg:
SEE YA :seeya
The hardest part of the job for me was getting the dampner hub off, other than that it's just time consuming labor. I call it bonding with my Vette. :lol: :rofl: :lolg:
SEE YA :seeya
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (Strick)
$599 for the modified unit from Corvette Clinic. Thats the same price as the one from Dyno-tech, which is supposed to eliminate ALL of the problems with optispark design. I wish the Dyno-Tech unit was available, as it looks like the way to go. Do you mind me asking how much you paid for the opti your son got you? I have a "hook-up" at a local Chevy dealer parts department, too. Guess I need to give him a call. :D
What's the going price for the electric pumps these days? Reliability? Expected life? Thanks again, Strick. BTW, do you ever leave the computer?!? :jester
What's the going price for the electric pumps these days? Reliability? Expected life? Thanks again, Strick. BTW, do you ever leave the computer?!? :jester
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
$599 for the modified unit from Corvette Clinic. Thats the same price as the one from Dyno-tech, which is supposed to eliminate ALL of the problems with optispark design. I wish the Dyno-Tech unit was available, as it looks like the way to go. Do you mind me asking how much you paid for the opti your son got you? I have a "hook-up" at a local Chevy dealer parts department, too. Guess I need to give him a call. :D
What's the going price for the electric pumps these days? Reliability? Expected life? Thanks again, Strick. BTW, do you ever leave the computer?!? :jester
What's the going price for the electric pumps these days? Reliability? Expected life? Thanks again, Strick. BTW, do you ever leave the computer?!? :jester
As far as do I sit at the computer all day, I'm waiting for a sripper-crimping tool from MSD so I can finish my project. I hate being a perfectionist, thinks take too long. :sleep:
:flag :flag :flag
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP!
Did some troubleshooting tonight. Tested for spark on a couple of the plug wires, all good. Tested for spark straight off of the coil, good. Bought a fuel pressure guage hoping it was the fuel pump or filter, but it tested at @ 43 psi with just the key on and while cranking. Unplugged the MAP, MAF, and TPS one at a time, none of which made any difference. I still can't convince myself it's the opti, since good spark was delivered on two of the wires. And like I've said before, the engine will actually "run" but it seems almost as if off of one cylinder. It "ran" like this when I had a plug wire off, too.
I didn't have any of the opti symptoms, either. It went from running great, to backfiring, to nothing. Am I just in opti-denial?
Thanks again everybody.
:cheers:
I didn't have any of the opti symptoms, either. It went from running great, to backfiring, to nothing. Am I just in opti-denial?
Thanks again everybody.
:cheers:
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
You might want to check the ignition control module as well. Mine died and I did the opti thing to find out it wasn't the opti. The ICM is located adjacent to the coil on the passenger head. But, most likely it is the Opti. If you do replace the Opti, then take it apart just for the knowledge of them.
Pro
Joined: Aug 2001
Posts: 571
Likes: 0
From: Redmond WA
Re: Opti Spark? Fuel Pump? HELP! (Goody)
Check for spark on one of the wires while gassing the motor, not just idle. If the opti is arcing it might only be doing so under load. My problem turned out to be the opti too, but you might just want to replace the plugs first and check the wires just to make sure that something didn't go screwy on you.
Sam
Sam
Thread Starter
Racer
Joined: May 1999
Posts: 290
Likes: 0
From: Nashville TN
Re: Opti Spark? Fuel Pump? HELP! (LT4Sam)
Check for spark on one of the wires while gassing the motor, not just idle. If the opti is arcing it might only be doing so under load.
...replace the plugs first and check the wires just to make sure that something didn't go screwy on you.
Race Director
Joined: Feb 2003
Posts: 11,672
Likes: 20
From: Lake Wylie SC
Re: Opti Spark? Fuel Pump? HELP! (85z51vette)
When the opti-spark goes, it has a number of symtoms and all may not show up at one time. I would take the water pump off and remove the opti's cap. If you find rust, moisture, and dirt, it is definitely in need of replacement. If it is clean as a whistle, put a new seal/gasket around the cap to base and re assemble. This way you'll know for sure. Good luck
:flag :flag :flag
:flag :flag :flag
