It's a repeatable condition... here's what's happening and what I think's wrong.

Anytime I get on it and the engine revs up past 4000RPM it'll sputter, my tach will go haywire and then the engine will just die. If I stick the clutch to the floor immediately after the engine quits, sometimes it'll catch itself and return to idle. This also happens sometimes when I put load on the engine at lower RPMs.

It spits out a code when this happens as well, however I didn't have a paper clip on hand to check it, as it just started happening today and I don't want to try it again for fear of messing something up if my assumption about what's wrong is incorrect.

Crate 350 from D&J machine, bored TBI intake, headers/cat-back and all smog equipment. The coil is old but the plugs/wires like the rest of the engine have about 15k miles on them.

I think that the coil may be to blame or I have a fouled plug (I had some oil consumption problems in the past that were related to the intake gaskets), any opinions?

 

Doesn't sound like ignition.

It's fuel delivery.

Check your fuel pressure, WHILE IT'S DOING IT (as opposed to, say, sitting in the driveway iding).

 

Thanks for the reply.

Checked the code on the way to the parts house and got #42, EST system. Since I'm not getting a code for Lean Mixture (even after it's in closed loop) I'm not sure if it's fuel related.

Haven't gotten around to checking fuel pressure though, but I'll look.

 

Sounds either fuel or ignition related.

Since its throwing the EST code i would suspect ignition. Possibly a dead module in the dizzy...

 

I'd like to think it's not the module, because I just replaced that, and the last time it died the engine wouldn't even start, but it was messing with the tach signal...

Weird stuff today, the problem went away after driving warm for about 20 minutes.

 

it might not be the module...

But dont think for one second that just because its new its working fine, you wouldnt be the first guy to get a bum module. same goes with pretty much any electrical parts, seen many new starters and alternators that were dead!

 

Yeah I got a bum module before, but the engine isn't behaving the same way now that it was when I got the bad module... Might be a different failure within the module though...

Also, I think I've ruled out the possibility of my problem being fuel related: I took it out for a test, cruised around and let it warm up, then stuck it in 4th (going 30mph) and stuck my foot to the floor for a few seconds (up to 70mph or so) and it didn't die.. If it were a fuel problem I would think that it would manifest itself in that kind of test.

 

In cap HEI or external coil?

In cap coils are prone to fail form the heat.
If its old.............
As they are expoxy filled and closed in the cap.
Expoxy holds in heat, the oil filled coils are better.

but also why they mount them in the open anymore.
So they can get ride of some heat.
----------
Im having my dizzy pro built and switching to external coil on my V8.
I got the accell incap HEI coil n cap, plus two good ign moduals id sell cheap.
one Wells and one brand new Sorensen.

Turned out to be my pickup was bad so if it was coming that far apart....
best to get it done right.

 

No, its an external unit. I'd just like to get to the bottom of what might be wrong instead of throwing money at it for parts I dont need.

 

Sounds like your ready for a new dizzy. How many miles do you have one the one you have? If you had a fuel problem you would notice the power loss across the board. Might check the ext. coil wires. I caught mine shorting out with my finger while moving them around in the dark once, hurt like hell! DON'T DO IT!
It caused mine to miss bad above 3K and just killed the tach. After I seperated them the problem went away.

 

New distributor? Hoboy. I know my dizzy shaft wiggles a little but it isn't THAT sloppy (about a degree and a half by my timing light), how about just a new cap, rotor, wires and plugs? Think that would solve it? I'll fiddle with my voltmeter and the module inside the diz tomorrow, and if I replace that then I'm getting a new cap/rotor/wires/plugs anyway, but the less work the better, the cap and rotor probably have about 25k and the plugs/wires have about 15k...

 

Probably not. Especially not if it's a fuel delivery issue (which is what it sounds like...)

 

Assuming that it is fuel delivery, where should I look first?

I'm not sure how old the fuel filter is, but this problem came on rather suddenly and I'm not sure how likely it is that the filter would get gummed up so quickly when it was running just fine a day before. I hear my fuel pump pressurize the lines in KOEO... And I keep getting code 42, no fuel/exhaust related codes...

 

my quad did this, and when i took the carb out, it was the floats in the carb. i just re-built it. dont know how the tbi system works, but it could be that. i dont think it would be the cap and roter because the car would run like garbage all the time. when mine went on my winter beater, the car ran like garbage all the time at all rpm missing and stuff. it could have been an extream case, but i still dont think its that. im almost 90% sure its fuel. it could be a filter. they are 10 bucks for a filter anywhere, so try cheepest first.

they these:
-fuel filter
-check air filter
-coil-if you have one
-fuel pressure-once you got above 4000 rpm, your pump might not be strong enough to suply the car
-not sure about tbi systems, but it could be in there. check this alst becuase it could be the most expensive

have you noticed bad gas milage?

 

well, i checked my code book for my 92, and the 42 code is says "electric spark Timing" and "Poor electricle connection, open or short in circit; defective ignition module; defective ECM"

so its the computer, wires, anywhere involving the ignition, coil.

check those other things as well,

 

Thanks Dave.

I doubt that it's the TBI itself because I just put it on there and up until a few days ago the car would rev to 6k easy with no stumbling. Fuel filter first, ok. Then if that doesn't help, check the Ignition system. Lovely.

Looks like a combination of problems. Yippee.

 

yea man, try coil first. its really easy to do, and you can get a msd one anywhere. i picked one up for 40 bucks canadian, so you can find them. and they will get more spark energy, meaning better throttle responce

 

DIY PROM BURNING!

 

Yeah, I want to. :-D

More ideas for what could be wrong. I talked with my father in law who has 20 years experience with vettes and f-body cars, he said that it may be the "sock" around the fuel pump. Occasionally they'll get gummed up and under high flow requirements will get sucked up into the pump itself, choking off fuel at high RPM only. The code 42 is likely being triggered by the engine's inability to burn exhaust gases.

To do list:
Check fuel filter
Check fuel line pressure
Check ignition system

Thanks for the help everyone! I'll let y'all know how it turns out.

 

Father in law called me again this morning, said he forgot to mention that it could possibly be my MAP sensor, but it's not throwing a code for that...

Cheap part, and it's the original unit, so I should probably replace it anyway.

 

Sounds a lot like an ignition problem to me. Could be module or distributor, not likely to be coil but could be. Inability to burn the fuel mixture will not set a Code 42.

There have been reports on the Board of corroded distributor works under the cap. I'd look there to see if that's what you have, if so, a replacement distributor may be the quickest and least expensive solution.

I can't imagine a MAP sensor causing this. But, since you put in a 350 and did other mods, did you modify the PROM tuning? You could be driving the computer bonkers trying to figure out what it's supposed to do. But, it shouldn't die out like that, nor set a Code 42.

 

Roger, will check the distributor. As for the PROM, I've been meaning to DIY it but I ran out of money. It's next on my to-do list for the car once I get it running again, but the point is that this engine was running fine until a few days ago. It has been wet and miserable around here for the past few days, but humidity hasn't caused this problem before. Maybe the distributor finally let go.

Thanks for the input.