Well, I put the stock ECU back in the car (I'd been trying to do the 7747 swap and chip burning) and a custom chip. It didn't fix the car, so I put the stock chip in it...did the same thing as the custom chip. It idles like a total turd. It's getting gas (you can see the injectors spraying), maybe a little on the rich side but nothing real serious. The #1 cylinder is getting spark when its supposed to (didn't have time to check the others it was getting late). My scanner only scans every now and again. The SES light is on when you turn the key to "on" and then goes off when the engine starts (I've been told this was normal). When the scanner scans there's no codes. It's got a serious miss that's causing the pooey idle (it misses through the whole RPM range). It'll only idle for about 15 seconds before it dies. I need to a list of things to check over the weekend...I'm gonna see if every cylinder is getting spark, what else do you recommend I check?

-Mark W.
'88 SC Camaro w/ 305 TBI

 

firing order?????

 

I'm having a similar problem to yours. My car idles pretty bad and dies after 20 secs. I pulled the whole tbi off, did the tbi mods with all gaskets and orings hoping that this will fix the problem. In our case, i think its a good idea to get a fuel pressure gauge and check the fuel pressure. Also check the fuel lines for cracks or dents as well as the fuel filter.

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88 305TBI
Mods:Hooker Aerochamber 3" exhaust, gutted kitty, March pullies, no smog, 180 thermo,
14x4 K&N, 3.42 gears,
Eibach springs with KYB's all around,
Harwood cowl hood, Z-28 wing, fresh paint(black)
120,000 miles, 5spd, T-tops
Run a best of 16.7 @85mph before gears

92 RS, 305TBI, auto, 3.08 gears, 180 thermo, glasspack (no muffler)

 

Try and get your hands on a digital graphing multimeter and make sure that you are geting a good signal from the pick up in the dist. with no signal drop put and that your tps is working properly with no drop out. Both of those will scew up you idle. Also is it a dead miss or just a miss? You need to read the o2 voltage and make sure your not going lean right off idle, that will make it miss. Check your timing again, see if it runs better with the brown connecter in the harness disconnected. How's your vacum at idle? If you have a vacum leak it will idle bad, make sure there is no leak in the hose to the map and make sure it is not hooked to a ported vacum sorce. Check those things your problem is either your ecm geting the wrong info(from sensors), or not being able to prosses the info which is were a custom chip comes in. Good luck.

Zac Spalding

 

It sounds like a firing order problem to me. I'd double check it, then make sure the distrib is advancing correctly. You said it misses in through all rpm though. As for the ses light. It always comes on and goes off after starting. I wish I could give you help but I don't see the problem from what you've described so I'm thinking it's something else that you haven't checked into.

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, Jon (91 RS too many mods to list), getting new engine in summer

 

I've seen cars with intake valley leaks into intake ports act the same way. Any oil coming out of your intake bolts and/or are they loose at all??? Any/all of the plugs wet with oil (from the valley?)

 

When i took off my tbi there was oil coming out of it but i couldn't tell where from. It dripped down into my throttle body after i flipped it upside down. There was also oil on one of the bolts holding the tbi down into the manifold. What does it mean and what is a valley leak?

 

Sounds like your intake manifold gaskets did not seal correctly OR you are sucking oil into your PCV system.

Intake gaskets:\

The engine can "suck" air/oil from under the manifold, ie the lifter valley. The vacuum generated by the engine sucks the air-oil from underneath the gasket and swirls the crap out of it inside the intake manifold runners. It gets into a cylinder or two and if bad enough can swirl up into your TBI/carb... You'd see wet spark plugs and/or plug threads on the suspect cylinders. Probable oil leaks on the intake mounting bolts as well and you'll really see it when you remove the intake. Hard to exactly diagnose without closing all intake valves and running a vacuum pump to the blocked-off intake (no carb/TBI unit) and listening for leaks while watching a vacuum gage.

PCV:

Blowby from bad rings may be causing high crankase pressures which can cause high oil vapor content which will, as it should, get sucked into your PCV system. Check the PCV hose/lines/valve for oil and go from there. A cylinder leakdown test will help diagnose bad rings. Or you have WAAAAY too much oil in your car...


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