Need electrical help with new RetroTek EFI

[65 Fastback]

I have just finished up an engine swap and went with the RetroTek EFI. I could not get it started. But, I think I have identified the problem. I'm getting spark, but not fuel.

The EFI is not firing the fuel injectors while cranking. The RetroTek instructions are very clear that the computer needs 12 volts during cranking. I put my volt meter on and I have 12.3 volts while in the "On" position, but it drops to 10.3 - 10.5 during cranking.

I have tried two different ignition hot leads:
- first from my Painless circuit block (20 amp fuse), clean circuit (nothing else on circuit). The volts are 12.3 in the on position, but went straight to 0.00 during cranking.
- Then I used a jumper lead from the "I" terminal on the solenoid - 12.3 in the "On" position, 10.3 during crank.

Where is the best place to pick up a solid 12V, ignition lead?

Thanks,
Tim

[GetMore]

You may just need a new battery. FWIW, I'm willing to bet that you get a reading of less than 11V at the battery while cranking. As a matter of fact, I think it's within .1V at the computer.

[oestek]

Do you have a battery charger / jump box you throw on there to see if it fires? Like Jason said, it may just be the battery.

[65 Fastback]

Thanks for the quick replys. The battery is fresh, plus I jumped it off of my Explorer while we were cranking it.

Tim

[camcojb]

I always go straight to the battery with the main efi power leads. The ignition circuit on your aftermarket wiring harness should be fine for your "key-on" wire, but you said it shows no volts under cranking............ doesn't sound right, ignition circuit has to be active under cranking. For now, I'd run that wire directly to battery also just to see if it fires, just be prepared as you may have to pull the wire to shut off the engine.

Low voltage during cranking can cause issues, but I'm not sure any of my efi cars show 12 volts during cranking, and they all start and run fine. They're also not down to 10 volts either.

Jody

[65 Fastback]

Thanks Jody, I called RetroTek and the tech said 10.5 should be okay.

He thinks my problem is with the tach signal.

I'm going to load the software and plug it into my laptop and see what it gives me.

Tim

[MonzaRacer]

cranking voltage of 10.5 is normal and if you check it on older vehicles you can tell when a battery/starter is getting bad as the volts will got down but amps go up.
And dont forget all batteries test specs are loading with 1/2 the cold cranking amps and hold it for 15 seconds without dropping below 9.6 volts at 60 degrees.

[MonzaRacer]

tach should come off the negative side of coil, and if you have MSD then you may need a signal conditioner

[65 Fastback]

Thanks for the help guys. The problem ended up being with the wiring order labeled on the distributer cap.

The engine builder dynoed the engine with the distributer in place and a "house" cap and wires. He then marked up the cap with the firing order and gave it to me.


Well, I checked for Top Dead Center and the cap was not marked correctly! TDC ended up pointing to the tower marked #3. I checked the piston position with a straw. I triple checked, convinced myself I has solved the issue, moved the plug wires and turned the key. It started immediately!

Well after I got that resolved, it fired right up, but I had a bad fuel leak at the fuel feed into the throttle body. The threads got stripped out in one of the fuel supply ports.

I finally got it started and found the leak Wednesday night. I'm on the East coast, so I couldn't reach RetroTek until noon on Thursday. I explained what happened and told them I thought the original problem occured with the installation of the fuel feed plugs that were placed in the throttle body. It was very difficult to back out the plugs and I couldn't get the fuel line addapter to finger tighten very far. I told them I would pay for a new "bowl" and gave them my credit card. The Tech sent me a new "bowl", didn't charge my card and told me to send in the damaged piece. If they thought it was do to my neglegance, they would contact me. The new "bowl" showed up today!! So I can replace the damaged part and get my car running this weekend.


I was very impressed with their customer service!

Tim

[qwk406]

How is the retrotek working, I'm on a "waiting list" for purchase.

[65 Fastback]

I should have my car back on the road by the end of August. In the mean time here are some pictures of the fuel system.

https://static1.pt-content.com/images/pt/2009/08/530200925552PM_0003-1.jpg

https://static1.pt-content.com/images/pt/2009/08/63200975822AM_0004-1.jpg

https://static1.pt-content.com/images/pt/2009/08/629200970849PM_0005-1.jpg

https://static1.pt-content.com/images/pt/2009/08/629200970911PM_0007-1.jpg

[65 Fastback]

The signal problem with my fuel pump was a problem with the computer. RetroTek is sending me a new program. I will post back after I get it loaded.

Tim

[70TWO NOVA]

Im going to be doing a Retrotek swap soon and would like to hear what you find out and whether you are happy with it or not.

[65 Fastback]

OK we couldn't get the computer to take the new program. RetroTek sent me a new computer Overnight, got here today and the engine is up and running. I have a couple of small items to sort out and I should be able to drive this week.

I have to give it to the RetroTek tech help, I have been on the phone with them nightly. They wanted me to send my computer back to them to reprogram, but I didn't want to wait to get it back - so they went ahead and sent me a house unit and I shipped mine back to them.

Tim