LT1 died!

[69camarokid]

I have a cammed LT1/t56 in my 69 camaro. The fuel pump is a MSD ignition 2225 electric unit. it has less then 1500 miles on it.

yesterday i was driving and the car RPM flucuated and started to died, i gassed it and nothing really happened and then it died. After many attempts of restarting it finally did and made it 15 feet jumping like a first time driver behind a stick shift. it then wouldnt start. after a 10 minute wait it started right up and then idled fine, i made it 3 more blocks before the same thing happended and it died again.

I believe it had somehting to do with the fuel pump, something stopping the fuel from getting to the engine. any ideas?

[Jim Nilsen]

Check the wiring to the fuel pump. It could be a ground gone bad. With enough tries anything can arc across for a little running and then go bad again. Also could be a coil going bad and have nothing to do with the fuel. Check the igniton for fire when it won't start next time you try.

[1badchevelle]

check your ground/power cable for the pump, check the filter, and see what pressure you have at the rail. Take it from their.

[69camarokid]

check your ground/power cable for the pump, check the filter, and see what pressure you have at the rail. Take it from their.

when i started going through the system i realized that i dont think i have a fuel filter. Im going to put one in. should it go before the pump or after it?

[Rybar]

Check the Opti spark distrubutor, they are notorious for going bad on LT1's

[monteboy84]

when i started going through the system i realized that i dont think i have a fuel filter. Im going to put one in. should it go before the pump or after it?

After. You definitely need one, but make sure you use high pressure fittings when you install it.

[paul67]

I've got 1 before and after, the 1 before came with the bosch pump I had 1 without a filter before the pump and the crap ground the gears down.

[paul67]

Looking at the advert for the pump I think the pump is not powerful enough for the engine,I would check with MSD though to see if it is.

[Jim Nilsen]

Is this a fuel injected engine of some type still or is it carbed?

With no filter you may have injector problems with the crud passing thru?

With a carb you will have jets to clean.

Either way if you have no filter you will have problems now or problems to come even if it is spark related.

Goodluck you are going to need it.

[Satatic]

A fuel pressure gauge is a must. The problem I run into a lot with diagnosing fuel pressure though is "good pressure". What is good pressure? I dont know. Never will. I look at a number on the gauge. Haynes must use a gauge that says good and bad. Its rare to find a number that its supposed to be.

Also try unplugging your front 02 sensors. If the car is fine while they are unplugged then they are jacked. Replace with AC Delco. The bosch ones are crap.

[vintageracer]

The fact that you waited 10 mintes and the car started up again and ran for 3 blocks indicates to me that you may have an electric issue of a bare wire or bad connection causing high resistance. If you can start the car cold and runs good for awhile until it gets some temperature and then quits look at the wiring. If the car can cool off after running as you described for 10-15 minutes and then starts again but quits rather quickly (within 3-5 minutes) again I would say you have an electrical problem.

I fought the same problem years ago thinking fuel problems, ignition etc. The problem was a wire to the distributor that had a bare spot with no insulaton about 1 inch long. The temperature of the engine caused the bare part of the wire to build resistance (Voltage=Current x Resistance). Cut and properly splice the wire to remove the bare section of wire and problem solved. It took a month, 3 mechanic shops, fuel pump, filters, clean gas tank, ignition boxes and all to figure this SIMPLE problem out by myself. I thought the problem was fuel related. I was wrong.



This may or may not be your problem but is certainly something to consider!

[Jim Nilsen]

The fact that you waited 10 mintes and the car started up again and ran for 3 blocks indicates to me that you may have an electric issue of a bare wire or bad connection causing high resistance. If you can start the car cold and runs good for awhile until it gets some temperature and then quits look at the wiring. If the car can cool off after running as you described for 10-15 minutes and then starts again but quits rather quickly (within 3-5 minutes) again I would say you have an electrical problem.

I fought the same problem years ago thinking fuel problems, ignition etc. The problem was a wire to the distributor that had a bare spot with no insulaton about 1 inch long. The temperature of the engine caused the bare part of the wire to build resistance (Voltage=Current x Resistance). Cut and properly splice the wire to remove the bare section of wire and problem solved. It took a month, 3 mechanic shops, fuel pump, filters, clean gas tank, ignition boxes and all to figure this SIMPLE problem out by myself. I thought the problem was fuel related. I was wrong.

This may or may not be your problem but is certainly something to consider!

On my 89 Camaro RS I had an intermitant problem like this too and it was the B4 wire in the distributor connection where it plugged in. the B4 terminal got pushed back far enough to barely touch and with vibration would go out. I would get under the hood and play with the wires and it would work for a few days or wouldn't start at all. I finally took it to a shop with an analyzer and if I had understood the code I was getting it was actually telling it was the B4 connection. I just didn't know from the book I had where it was. The tech had seen this before and in 20 minutes decided to just wire tie the damn connector up tight and call it good instead of charging me for more time on something he knew I could fix easily. It cost me $60 and was well woth it. To this day it is still like he left it and has never caused me anymore problem. Now the car sits waiting for the Cormaro to be finished.

I too believe he just has an electrical problem but no filters is trouble waiting to happen if it already hasn't, Good thing the tank has one?

[megaladon6]

first, keep it simple, make sure you have fuel volume and pressure. next make sure you have strong, properly timed spark.

[69camarokid]

so took out the exit end of the fuel pump to see if i had flow when the car was turned on. The pump flowed with no problems and the car started right up and idled just fine. Need to test it running though.

[megaladon6]

most likely something is overheating, or can move and ground out.

[TA219]

Check the Opti spark distrubutor, they are notorious for going bad on LT1's

I second this,back in the day my LT1 TA did this when it was on its way out. It died and took a while to get re-started, I made it to my apartment and then went out again and it happened again, only that time it wouldnt re-start and I had to have it towed.

[130fe]

For a filter consider the GF-481 (can be had at any parts store). Meant for LT1's and you just have to add 16mm o-ring/AN6 adapters to install it. Mine has worked well for years.

I used to run that particular MSD unit before I got a tank with an in-tank pump. What was your fuel tank level when you encountered the problems? Is your tank sumped? I ran into starvation issues when the tank was low (during hard acceleration or cornering). Just something else to think about. Post up what you happen to find out with it.

[69camarokid]

For a filter consider the GF-481 (can be had at any parts store). Meant for LT1's and you just have to add 16mm o-ring/AN6 adapters to install it. Mine has worked well for years.

I used to run that particular MSD unit before I got a tank with an in-tank pump. What was your fuel tank level when you encountered the problems? Is your tank sumped? I ran into starvation issues when the tank was low (during hard acceleration or cornering). Just something else to think about. Post up what you happen to find out with it.

my fuel tank is the stock style for 1969, so pretty sure its not sumped.

Myfuel tank was low, about 2 gallons left when i had the problem. but after removing nad checking the fuel puimp yesterday and then reinstalling it i was able todrive it a few miles with no problem!?!?! then today i put in some gas and drove 15 miles with no issues at all. very confusing

[130fe]

Yeah, I was also using a 68 factory style tank that I had put some pipe fittings in the bottom of it so gravity would get the fuel there (these style pumps push fuel alot better than sucking it). In my situation, it was a temp fix that I always was careful about (not to starve the pump out). Just be careful and keep an eye on your fuel level especially when you are under 1/4 tank. I usually tried keeping it above 1/2 if possible.

Is another tank (sumped) in your future (ie Rick's or Rock Valley)? If not you might consider it because even those MSD pumps aren't cheap when you burn one up (from fuel starvation).

[Jim Nilsen]

Glad you got it running good so far.

2 gallons is not a lot of gas in a stock tank, they will run out with about a gallon in them with out fuel injection adding to the need for fuel.

You may have checked the ground wire and made the connection better just by wiggling it so if you haven't pulled it and really checked the connections on the hot and the ground you should.

Wiring problems disappear just like that.