I'm about to push my car off a cliff! - Third Generation F-Body Message Boards

Svelte_SS · 07-03-2003, 03:32 PM

After two months, my TPI is still running like A$$.
I've replaced just about every sensor, and upgraded the entire ignition system but I still have no idea what's wrong.

It starts and runs but very choppy. It sounds like half the cylinders are missing. The whole engine shakes back and forth in the engine compartment, and huge puffs of black/grey smoke come out of my exhaust.

I'm at my wits end

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chevyboy07 91 · 07-03-2003, 03:55 PM

my first thought is that you have a nasty vaccum leak. I sure as heck did and my car was running like hell.

Second would be timing and thirdly fuel. You may be running pig rich if you have fuel system upgrades like injectors, pump, etc

i need some history/detail/background on what went wrong and when ie( during mods, particularly after a mod????)

Ace · 07-03-2003, 04:41 PM

have you set the valve lash, or was it ever change? i found that made it night and day in my engine.. also check the vaccum...

and what fuel pressure are you runnig at?

and make sure you got the plugs on the right cyls... sounds like you could have one crossed too

92 zzz28 · 07-03-2003, 06:19 PM

You mentioned it sounds/feels like half the cylinders aren't firing. You also stated that there are puffs of black smoke. Have you checked to see if the distributor is installed correctly? Very easy to install it 180* out. Just a thought...

Hope you figure it out.

wyclefsirocz · 07-03-2003, 07:22 PM

my car has the same f*ckin thing with it right now, i took the car off the road for about 7 weeks. swapped rears, did some suspeion wor and rebiult the whole front end. I went away for about the 1st 4 weeks and then came back to start her up and she was doing this choppy thing, at an idle. i have an 89 iroc 305tpi/auto.
car still shifts fine and runs smooth at highway speeds. but at a light the car must be netruel. the car sounds like she has a big *** cam, like too big and tha vacum is an issue. it does sound like 1/2 the cylinders are firing.i replaced the cap and rotor. never removed the distbuter and she is still running like crap at an idle. she is also running a 17.2 on the g tech. (i usally run about a 14.5)my car will hestate under heavy trottle and WOT. then will stat to pump some power. i'm really fed up with thi car,

Svelte_SS · 07-03-2003, 08:26 PM

Quote:

Originally posted by chevyboy07 91
my first thought is that you have a nasty vaccum leak. I sure as heck did and my car was running like hell.

Second would be timing and thirdly fuel. You may be running pig rich if you have fuel system upgrades like injectors, pump, etc

i need some history/detail/background on what went wrong and when ie( during mods, particularly after a mod????)

I don't think it's a vaccum leak because I've deleted my entire smog/AIR setup. I have all the fittings on the plenum capped off and an EGR blockoff plate on the manifold.

I don't have a timing light, but I last had it checked less than a year ago and it's at 12 degrees advanced.

It most definitely could be running way too rich. I have an aftermarket Bosch external fuel pump, TPIS AFPR set @ 42 PSI, and stock injectors.

I haven't really modded it lately, except for removing some of the wiring that went to the deleted A/C, heater, smog, AIR components to try to clean up the engine bay a little...

Svelte_SS · 07-03-2003, 08:28 PM

Quote:

Originally posted by Ace
have you set the valve lash, or was it ever change? i found that made it night and day in my engine.. also check the vaccum...

and what fuel pressure are you runnig at?

and make sure you got the plugs on the right cyls... sounds like you could have one crossed too

I've never messed with the valves since I've owned the car.

I checked and double checked the wires today to make sure the firing order is right because last time I had two wires crossed it did resemble this condition but they are all ok.

Svelte_SS · 07-03-2003, 08:30 PM

Quote:

Originally posted by 92 zzz28
Have you checked to see if the distributor is installed correctly? Very easy to install it 180* out.

The distributor is actually stock, I've never pulled it out. I've replaced everything I could without removing it with Accell parts...

Svelte_SS · 07-03-2003, 08:32 PM

sorry, double post.

Thanks for the help so far guys....

Cruzin Kaz · 07-03-2003, 08:50 PM

Well it may be a couple of things, if your running really rich by any chance, it my have gas fouled some plugs. Or worse, you have some injectors not firing, maybe clogged. Do you have headers, or just OEM Manifolds? If headers, spray a bit of water on each pipe, just a little!.. does it steam off in a instant, or bubble a bit?? If it doesnt' burn off immediately, a injector may be clogged or acting up. It's a thought anyway. My car did the dame things, everything was good, and it ran like crap! It turned out one of my injectors went bad. But try looking at your plugs first.

Ragtop89 · 07-03-2003, 09:04 PM

My car acted similarly once.

Turned out to be a mixture of poor valve lash and crappy plug wires.

Car ran 110% better after an afternoon resetting valve lash and a new set of wires.

jamr0d · 07-03-2003, 09:48 PM

off the cliff thing doesn't sound too bad.. i didn't figure aerodynamics in but it would get you a 9.03 1/4 mile.... i'd think about pulling your distributor.. this may just be a freak innocedent, but my stock distributor had my car running like crap and left me sitting one day.. it wasn't untill i got it towed and pulled the distributor that i found out that was the problem..

Ace · 07-03-2003, 10:36 PM

12 advanced is double what the stock specs are 6 advanced with car in drive.. i know i set mine wrong first.. i didnt pull the right connector..had it running at 30 retarded?! pulled the right plug and set it to 6 and it pulled good vaccum and ran way better...

also check the injectors.. if you have a multimeter measure the resistance.. it should be around 20.. if its low you might have a problem with that one..

chevyboy07 91 · 07-03-2003, 11:16 PM

man...weird. Anyway, pull all the wires off that damn distributor and do it all over again....yes..RE CEHCK your plug wires. I had an a -hole neighbor do a switcheroo on me to fugg me up and let me tell you he had me stumped for days!! Just check them again, b/c maybee one or more got swapped.

Svelte_SS · 07-04-2003, 07:12 AM

Quote:

Originally posted by Ace

also check the injectors.. if you have a multimeter measure the resistance.. it should be around 20.. if its low you might have a problem with that one..

All the resistances were 17-19 ohms. Also I bought an injector and harness tester, and they all seemed to be firing ok.

Ragtop89 · 07-04-2003, 10:01 AM

How many miles on car?

Has the distirbutor been rebuilt recently?

Did you install a new pick-up coil?

Svelte_SS · 07-04-2003, 02:13 PM

Quote:

Originally posted by Ragtop89
How many miles on car?

Has the distirbutor been rebuilt recently?

Did you install a new pick-up coil?

There's probably 20'000 miles on the engine.
Distributor is stock except for the Accell cap/rotor/coil.

What exactly is the pickup coil? I've taken my ignition module to Autozone and it tested ok on their machine.

Svelte_SS · 07-05-2003, 01:43 PM

Just to let everyone know I pulled my plugs today and they were all fouled to hell so I'm thinking that's my problem and have started another thread...

wyclefsirocz · 07-05-2003, 06:22 PM

they could be, my problem was in my burnt wire and that i had my coil installed a lilo wrong. but its all fixed. only thing is now pulleys, and a new alternator.

Slo86TA · 07-25-2003, 09:31 AM

Did you ever think about swapping out the computer? That cured my cars issues. Any SES lights coming on? What are the codes?