Help please - no power!!

[FriscoSteve]

'93 5.0 GT EFI motor transplanted in my '66.

I almost had this swap all buttoned up until a new problem has come along.

I took it out for a test drive and it ran really good after putting in a new MSD distributor as the other one was defective. At WOT, it pulled real hard.

Next time out, serious power/acceleration issues. I can get the car up to any speed, that is not the question. You just have to give it very little gas to get there. If you give it a lot of pedal, it feels like it's missing horribly or slipping or just nothing!!! I took it to a local shop to see if it was a transmission issue (AOD). Nope. All was good with good pressure, etc, so no issues there. They said it must be something else.

I checked timing, was about 8 deg. so I bumped it up to about 10-11 deg. Same issue. Sucks horribly.

What the heck could it be? Dirty MAF all of a sudden? What would cause this lack of power issue?

Thanks for the thoughts and support here guys. Car show time and mine is soooo close!!!

 

[FriscoSteve]

Anyone?

 

[killer5.0]

does it accelerate smoothly...bad fuel/filter?

 

[FriscoSteve]

I am LOST.

I cleaned the MAF.
I adjusted the TPS.
Tested fuel pressure - checks out ok.

The car will drive good and will get to a high speed, but you can only barely touch the gas pedal to slowly get up to speed. I mean a LITTLE pedal. If I give it more than just a 'tad', it does not want to go. Sounds like small (very small) little backfires out of the exhaust. At least I think that's what it sounds like.

I have no idea....HELP!

 

[885.0conv]

I am dealing with kinda the same problem but mine will go when it hits 3k, thinking its a vacuum leak issue.

 

[ID89GT]

Maybe a fuel pump, sounds like how mine did when my pump was going out. If I barely accelerated it would go just fine but if you got into it just a little bit it would bog down and not do anything.

 

[FriscoSteve]

I was thinking the fuel pump as well, but I was watching the pressure guage as I drove it, and the fuel pressure stayed within 38-40 psi, so I am thinking the pump is ok?

 

[ID89GT]

How high were you going in RPM's? Mine would go down pretty fast after about 2500 rpm's

 

[v8only]

set your timing at 15-16 degrees initial

 

[FriscoSteve]

set your timing at 15-16 degrees initial

Do you think that being at 10-12 degrees initial is such a difference that it would cause this problem? I thought the rule of thumb was 10-13 degrees without the spout connected and then let the computer do its advance?

I'm willing to try anything!

 

[v8only]

it's likely not your entire problem, but you WILL notice a BIG difference between 10 and 16 degrees. The computer does control total advance, but initial is still set by you, and the more the better so long that it doesn't ping.

My timing was f'd up, at 8 degrees at the track. I put it at 16 degrees between runs and literally picked up an entire second in the 1/4

 

[FriscoSteve]

Nope, timing didn't make a difference. It sputters when putting any throttle down.

 

[ID89GT]

When you are testing fuel pressure, are you just sitting there parked or are you actually driving around?

 

[FriscoSteve]

Both. I taped it to the hood so I could watch it. The fuel pressure stayed pretty constant between 38 and 40 psi.

I smell fuel, real strong odor.

O2 sensors have been replaced as well. I have no clue!!

This is in a '66.

 

[ID89GT]

I just read through this all again, when you installed the MSD distributor did you make sure you put in it right? If you have backfire out the exhaust that is usually timing related, I wonder if you have the distributor in maybe 180 out or something.

 

[FriscoSteve]

Well, the car starts great. Idles good. Revs good. It will drive fine with just a tad of throttle. I have timing set back to 14 degrees.

If timing was 180 degrees off, would it still start good, rev good and still accelerate to speed (under little pedal)?

 

[sychomustang87]

it does sound like its your timing if u ruled everything else out. When you step on the petal when driving does the motor just rev without speeding up.

 

[jgarrard]

Could you have another bad distributor? I sold parts many years and have seen NEW parts be bad right out of the box. It wasnt often but it did happen sometimes. On another note I think putting a newer 5.0 in a classic is simply awesome. I helped a friend put a 92 5.0 T-5 combo in a 65 back in 1999 and he now has a pro charger and a host of new go fast goodies and drives it everyday. Sorry to carry on. I hope you the best of luck.

 

[FriscoSteve]

Thanks everyone for the help. Its SO frustrating.

The issue is when I am driving the car and accelerate, it just doesn't want to go and it sounds like small popping or kicking, it's very hard to describe. Maybe sputtering?

When I put in the distributor, it seem to drive great. No issues. The next day, it wouldn't go. ODD.

I am two steps away from pulling the intake and going carb. But then again, my luck its the motor.

 

[y0ukantride]

When you installed distributor did you have number 1 cylinder top dead stroke?