efi conversion barely runs...need help

66fastback · 01-05-2001, 11:49 PM

I've had most of the parts laying on the shelf for years now, and finally decided to put them on my 66 GT Fastback. Made all the electrical connections and fuel line mods and cranked it up tonight.

The first problem I ran into was the computer did not signal the fuel pump relay when I turned the key on. I bypassed the computer to run the pump and cranked it. It stumbled and finally started, but it BARELY runs. It sounds like it is very lean and has a solid miss--or two--on each side of the engine. I would not be suprised to find out I'm only running on 4 or 5 cylinders.

I have to keep my foot on the pedal to keep it running. I've checked each plug wire with the timing light, and each is firing nice and evenly. The TPS is set at about .9 and the pump is running great. Timing is set to about 10 degrees.

Could there be a problem with the injectors sticking after sitting for about 7 years? Is there any way I can tell? I had some concerns about the eecIV when it didn't trigger the fuel pump, is this a sign of a possible bad computer?

Sorry so long, but I could use some fresh ideas at this point.

------------------
66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

mikew88gt · 01-06-2001, 08:22 AM

It's odd that your EECIV won't turn on your fuel pump relay. I'd double check wiring especially your grounds.

If you can keep it running for a couple of minutes until your exhaust heats up you'll know if you have a bad injector(s). Check for cold header tubes.

Just a long shot but could you have possibly put your injector harness on upside down? (Left harness on right side and vice versa).
I'm not even sure if that's possible.

The fact that your car is running at all and you can check timing suggests your computer may be ok.

66fastback · 01-06-2001, 10:08 AM

thanks, I would have never thought of checking the header tubes. All of my grounds are tied to a wire going directly to the battery, so I don't suspect them, but I will double check all my connections today in the daylight.

The more I think about it, the more convinced I am that it is an injector problem. Will run trouble codes this morning. I wish it would run good enough to do a balance test.....oh well. I do have a few injectors laying around that are a lot newer, if I can find which ones to swap.....

Thanks, Doc.

------------------
66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

01-06-2001, 11:02 AM

I think that there shoul be some chassis grounds in there. I would check to see if the injector harness is upside-down. I think chassis grounds are more efficient grounds than the battery grounds.

QuantumMotorsports · 01-06-2001, 01:28 PM

This is kinda a weird question, but after doing a swap between non HO and HO it has made me think of these things more than I used to. What firing order is the cam you are running? Is it an HO cam? if you are not running the HO firing order (which is the old 351 firing order, 1-3-7-2-6-5-4-8) the HO computer fires the injectors in that order, I'm not sure how much of a difference that would make, but I'm sure it's not good. Just an idea. Good luck with the conversion. A little more info about the parts you are using might help to get more responses. Good luck.

------------------
Michael Black
Quantum Motorsports
Norman, Oklahoma

1988 Merc Cougar 5.0 HO, P&Ped heads, 2.25" custom mandrel bent dual pipes, T5 five speed tranny
15.43 @ 91.08mph (not shabby for a 3600 pound car)
60' 2.453 Street tires suck!!!

Beef · 01-06-2001, 06:10 PM

I would also recomend checking your firing order. I dont believe that it will matter to the computer what firing order you have. I had a non HO cam in my 88 with the "older" firing order and didnt have any issues.

If you want to try and issolate the injectors, have the car running and remove one inj. plug at a time to see if it effects how the motor runs.

66fastback · 01-06-2001, 08:10 PM

Thanks for the help guys....it is the injectors. I pulled them out and tried moving the pintals with my thumbnail. At least four of the eight would not budge. I replaced those with some that I had on the shelf and got it running. Idles at about 800 and is pulling a steady 16 1/2" of vacuum.

I'm going to try a little more timing in the morning and see how she likes that. Sure revs and sounds good.

Thanks guys. Fuel-Injected-Doc.

------------------
66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

red82gt · 01-06-2001, 08:18 PM

Glad to hear you got it going! I'm probably gonna do the fuel injection swap one day so I'll know who to turn to for advice

------------------
GT-40 heads (ported, polished, + milled), B303 cam, 1.7rr's, JE pistons, Offy intake, Carter AFB 625cfm carb, Flowtech 1 5/8" shortys, Flowtech X-pipe, MAC Flowpath exhaust, MAC pulleys, 373's, subframes, Eibachs+Tokicos, B+M ripper, FMS Clutch, Zoom Quadrant+cable, 17" CSA Ultra rims, 235/45ZR17 Yokohama AVS S4's, MSD 6A ignition+coil, FMS 9mm wires, Carbed, Naturally Aspirated, and Nasty!

01-05-2001, 11:49 PM	#1
66fastback Registered Member Join Date: Mar 1999 Location: Dallas, TX Posts: 208	efi conversion barely runs...need help I've had most of the parts laying on the shelf for years now, and finally decided to put them on my 66 GT Fastback. Made all the electrical connections and fuel line mods and cranked it up tonight. The first problem I ran into was the computer did not signal the fuel pump relay when I turned the key on. I bypassed the computer to run the pump and cranked it. It stumbled and finally started, but it BARELY runs. It sounds like it is very lean and has a solid miss--or two--on each side of the engine. I would not be suprised to find out I'm only running on 4 or 5 cylinders. I have to keep my foot on the pedal to keep it running. I've checked each plug wire with the timing light, and each is firing nice and evenly. The TPS is set at about .9 and the pump is running great. Timing is set to about 10 degrees. Could there be a problem with the injectors sticking after sitting for about 7 years? Is there any way I can tell? I had some concerns about the eecIV when it didn't trigger the fuel pump, is this a sign of a possible bad computer? Sorry so long, but I could use some fresh ideas at this point. ------------------ 66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

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01-06-2001, 08:22 AM	#2
mikew88gt Registered Member Join Date: Jul 1999 Location: New York State Posts: 242	It's odd that your EECIV won't turn on your fuel pump relay. I'd double check wiring especially your grounds. If you can keep it running for a couple of minutes until your exhaust heats up you'll know if you have a bad injector(s). Check for cold header tubes. Just a long shot but could you have possibly put your injector harness on upside down? (Left harness on right side and vice versa). I'm not even sure if that's possible. The fact that your car is running at all and you can check timing suggests your computer may be ok.

01-06-2001, 10:08 AM	#3
66fastback Registered Member Join Date: Mar 1999 Location: Dallas, TX Posts: 208	thanks, I would have never thought of checking the header tubes. All of my grounds are tied to a wire going directly to the battery, so I don't suspect them, but I will double check all my connections today in the daylight. The more I think about it, the more convinced I am that it is an injector problem. Will run trouble codes this morning. I wish it would run good enough to do a balance test.....oh well. I do have a few injectors laying around that are a lot newer, if I can find which ones to swap..... Thanks, Doc. ------------------ 66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

01-06-2001, 11:02 AM	#4
88GT5.013.02 Guest Posts: n/a	I think that there shoul be some chassis grounds in there. I would check to see if the injector harness is upside-down. I think chassis grounds are more efficient grounds than the battery grounds.

01-06-2001, 01:28 PM	#5
QuantumMotorsports Registered Member Join Date: Jul 2000 Location: Norman, Oklahoma, USA Posts: 597	This is kinda a weird question, but after doing a swap between non HO and HO it has made me think of these things more than I used to. What firing order is the cam you are running? Is it an HO cam? if you are not running the HO firing order (which is the old 351 firing order, 1-3-7-2-6-5-4-8) the HO computer fires the injectors in that order, I'm not sure how much of a difference that would make, but I'm sure it's not good. Just an idea. Good luck with the conversion. A little more info about the parts you are using might help to get more responses. Good luck. ------------------ Michael Black Quantum Motorsports Norman, Oklahoma 1988 Merc Cougar 5.0 HO, P&Ped heads, 2.25" custom mandrel bent dual pipes, T5 five speed tranny 15.43 @ 91.08mph (not shabby for a 3600 pound car) 60' 2.453 Street tires suck!!!

01-06-2001, 06:10 PM	#6
Beef Registered Member Join Date: May 2000 Location: Redford MI Posts: 81	I would also recomend checking your firing order. I dont believe that it will matter to the computer what firing order you have. I had a non HO cam in my 88 with the "older" firing order and didnt have any issues. If you want to try and issolate the injectors, have the car running and remove one inj. plug at a time to see if it effects how the motor runs.

01-06-2001, 08:10 PM	#7
66fastback Registered Member Join Date: Mar 1999 Location: Dallas, TX Posts: 208	Thanks for the help guys....it is the injectors. I pulled them out and tried moving the pintals with my thumbnail. At least four of the eight would not budge. I replaced those with some that I had on the shelf and got it running. Idles at about 800 and is pulling a steady 16 1/2" of vacuum. I'm going to try a little more timing in the morning and see how she likes that. Sure revs and sounds good. Thanks guys. Fuel-Injected-Doc. ------------------ 66 GT Fastback 5.0, 5-speed, cable clutch, JBA's, 3.40 gears, EFI coming soon?

01-06-2001, 08:18 PM	#8
red82gt Sober voice of Reason Join Date: Nov 1998 Location: Kelowna, B.C., Canada Posts: 1,514	Glad to hear you got it going! I'm probably gonna do the fuel injection swap one day so I'll know who to turn to for advice ------------------ GT-40 heads (ported, polished, + milled), B303 cam, 1.7rr's, JE pistons, Offy intake, Carter AFB 625cfm carb, Flowtech 1 5/8" shortys, Flowtech X-pipe, MAC Flowpath exhaust, MAC pulleys, 373's, subframes, Eibachs+Tokicos, B+M ripper, FMS Clutch, Zoom Quadrant+cable, 17" CSA Ultra rims, 235/45ZR17 Yokohama AVS S4's, MSD 6A ignition+coil, FMS 9mm wires, Carbed, Naturally Aspirated, and Nasty!