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Discussion Starter · #1 · (Edited)
Welcome to my nightmare.

I got an Edelbrock Pro Flo system for my 355 Chevy in early-mid September of last year.

I called Edelbrock first before buying the system because I have an old race motor with a cam that makes almost no vacuum at idle and 12.5:1 compression. They told me there'd be no problem, they could make me a chip that would work fine. So I bought the system from Summit on September 7 of last year along with the Mallory EFI distributor that Edelbrock recommended.

I got it installed and the car started right up. It ran a couple minutes and I shut it off and called Edelbrock to get some tune up help. I made the adjustments to the car with an Edelbrock tech guy on the phone. We got done. I shut the car off. I started it the next day, it ran no more than five minutes and died.

That was the beginning of replacing every single part that Edelbrock tech could think of -- some parts multiple times. For instance, 5 coils, 2 starters, 3 batteries, 3 ignition modules and so on.

I called American Autowire during all of this and they went through my entire wiring job checking for any possible problems with my installation of their kit and we found nothing wrong.

After replacing pretty much everything else on the car except the main computer/chip, we finally got to the point where I replaced the brand new Mallory EFI distributor that I'd purchased at Edelbrock's recommendation at the same time I got the EFI system, and bought a $100 Summit HEI. While installing the HEI, the larger diameter distributor snapped off the oil pressure gauge fitting in the top of the block. It was old and probably corroded. This was about early December, late November.

That was it for me. I'd had 6 or 7 weeks of nonsense and $900 more down the drain trying to make my car run and so I took the car to a shop.

I had 2 ignition modules in the car. The original that came with the kit and a second one that Edelbrock had sent me. They checked both of the Edelbrock supplied ignition modules (Edelbrock calls them "Ignition Amplifiers") and both were bad. One was dead, one was nearly dead.

The shop installed an AC-Delco brand part and installed the HEI, fixed the oil pressure fitting and the car ran fine....until today.

It's got no more than 50 minutes of running time - in the garage, no driving - since it came back from the shop. Today I ran it maybe 5 minutes while I took a video of it and it just shut off. It just stopped as if I'd turned the key off. No warning signs.

I took the ignition module out and brought it over to the shop to be tested. They can't do that until tomorrow. But if that's the problem, I don't know what could be killing ignition modules. I'd be happier if there were something else wrong this time.

Here's some specs: 355 Chevy, 12.5:1 compression, unknown cam (it gets about 8" vacuum at 1200 RPMs, American Autowire Highway 15 wiring kit, Optima battery, Summit HEI, Edelbrock Pro-Flo 3500 with 1000 CFM throttle body (It's Summit part number EDL-3500), new Accel plug wires, new AC Delco plugs - provided by me, but installed at the shop.

If it's the module, does anyone know what would burn them out so fast?

I've got over $4,000 (more than I paid for the car), in this thing now and I can't keep doing this. It's going on eBay soon if it doesn't start working right. (The EFI, not the car. I'm keeping the car. :D )
 

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Race it, Don't rice it!
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Throwing part's at it gettin expensive huh? Try this systematically,

1, Verify the car will crank but not start, If it cranks go to No 2, IF... it won't crank then measure the battery for twelve volts.

2 Cranks with no start, Plug a plug wire and ground it with a plug tester bought at your local part's house for about 5 bucks. It looks like a plug with a alligator clip. Attach wire and attach tester to something grounded like the engine block, crank and look for spark, If you have Don't have spark then go to No 3, if you do have spark then go to 4.

3, Verify spark at the coil by using the same tester above....verify twelve Volt's at the dist while cranking...

IF... you can't find spark there and you have twelve volts at the connector then something is wrong with the dist. Could be the module, and or the mag poles.

If you have spark, I would verify fuel pressure, and start looking in that system for fault's.


As far as the modules go, are you applying conductive grease on the bottoms and buying good ones.? NOT the dime store part's, but real GM part's.
 

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Discussion Starter · #3 ·
Throwing part's at it gettin expensive huh?
Talk to Edelbrock about that. I was following their tech support instructions, not throwing parts at the car myself. In the process of doing that, they certainly made it sound like they were doing things systematically, but.....here we are.

Step 1? Yes, the car cranks. All 2 starters cranked just fine. One got replaced anyway.

Step 2? There was little to no spark all the time. I told Edelbrock that constantly. That's why we went through 2 ignition modules, and 5 coils.

Step 3? Same answer, I guess. That's why we went through 2 modules and 5 coils. And 3 batteries. And 2 distributors.

I've also only got 9.6 volts when I crank the engine. One guy at Edelbrock kept telling me I needed at least 10v, the other one said it was at least 11v. The car has been starting with 9.6. It's always 9.6, regardless of which battery is in the car. Once the car is running, the voltage is over 14v.

The 9.6 volt reading was another reason the starter and battery got replaced. Edelbrock kept insisting there was a drain, the high compression, the starter needed to be shimmed (I did that), the battery is just bad, etc.... But the car starts with 9.6 volts. And there is no pre-existing drain. There's 12v when the key is on, it drops to 9.6v while cranking and goes up over 14v once the car is running.

The fact is that throughout all of this, I didn't have spark and the modules were bad.

That's why after the car died today, I took the module to be tested. Hopefully, they'll be able to test it tomorrow and let me know.

If that's not the problem, I'm wondering if Edelbrock's Hall Sensor has failed, rather than the module. If so, it lasted maybe 2 hours. The hour or so that I ran the car after it got back from the shop and the hour or so the shop ran the car before I got it back here.

Conductive grease on the modules? Yes.

Dime store parts? Again, talk to Edelbrock about the parts in their kit. It's funny you brought that up because the first thing the guy at the shop told me after he told me that both of Edelbrock's modules were bad was that they were "foriegn *****" and that he'd used an AC Delco part.

As for my buying dime store parts, it's an Edelbrock system. The distributors were a Mallory distributor and now it's a Summit part. The first and last of the 5 coils were MSD, the others were from Auto Zone, they were Kem brand. The new starter is a high torque Summit starter, the old one was a high torque starter that was built by a local shop (that started the car every time when it was carbureted). Accel wires, AC Delco plugs. The first battery was a Duralast that came with the car, that I'd buy again. That thing took an enormous amount of abuse. The second one was the AC Delco from my other car. The one in the car now is an Optima.

So, there are no dime store parts on the car that I'm responsible for. I can't speak for the quality of the various components of the Edelbrock system. Other than that I've been told the modules are "foriegn *****".

Fuel system? You mentioned that last, Edelbrock had me check that first. I had to buy a gauge. Fuel pressure was/is fine. The needle on the gauge was at 40lbs when the car shut off this afternoon. I checked thinking I might have run out of gas, even though there was no stuttering or roughness. The car just shut off as if I'd switched the key off.

Thanks for the help, I appreciate it.

I also just realized as I read through my post, that I should be able to test the distributor myself. If there's no RPM reading from it when I crank the engine, the hall sensor is either dead or disconnected. I'll have to go check on that now.
 

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I didn't see this anywhere but how is your fuel pressure?? Kinda sucks installing a HEI there goes the sequential injection along with the fuel savings. I thought the pro flo system required a hall effect pickup to identify number 1 cylinder. How does it run without it?? Is there an option to control fuel only??
 

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Discussion Starter · #5 ·
The fuel pressure was 40lbs when I checked. That was a few minutes after the engine died.

The system requires you to install Edelbrock's "upgrade" kit (or whatever they call it), inside the HEI. There's not much left of the original guts of the HEI, besides the shaft, once you're done. Matter of fact, if I remember right, that's all there is left, the shaft and the housing. and the gear on the bottom of the shaft.

I checked the Hall Sensor too, as I said I would in my last post. As I understand it, if you get an RPM reading on the ECU, the sensor is working. I get a reading. So, it must not be the Hall Sensor.

So, I'm still waiting on the module test.
 

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Discussion Starter · #8 ·
A wire pulled loose. I guess from engine vibration. I found it a little while ago. That's why the car sounded like someone had shut it off with the key. The wire popped off, the car shut off. I'm as sure as I can be that that's what wrong without having the module to try to start the car. But I think it was just a loose wire.

Let's hope so.

Thanks for the replies.
 

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Yes, I was going to say that the 9.6 volts when cranking IS a problem.. :nono:

It has to be either a bad wire, or a bad battery.
Cranking shouldn't drop you below 11.5.
Since it is shutting off, then an intermittent wire or bad ignition switch, etc.

I have heard of intermittent current popping the Unilites, not sure about yours.
 

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how is working now

i have the EFI on my 351w motor. just got it fire up and i'm in the process of tuning it. i had a few glitches along the way, but the all turn out to be install errors. like it would start and not turn off. i have a idle surge when cold. i still haven't adjusted the transmission pressure. AOD. so i haven't driven it yet. but it sounds good.
 

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Hopefully you found your problem with the wire that came off. I was going to say check you voltage going to the computer. Even though your gauge reads 14 volts, that might not be what your CPU is seeing. The computers can be sensitive to low voltage too. Make sure you have good grounds to EVERYTHING. That will kill an EFI system quicker than anything.
 

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Edelbrocks ignition stuff is a joke. The distributor you bought is money well spent and will time much better than the junk edelbrock conversion for HEI. You need to remove that ignition module and put an MSD or similar box on it.
All that edelbrock module has in it is a GM HEI ignition module in a hokey read box.
 
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