I know it's not a 350 or anything like that, but I'm having problems with my 2nd car. It's an 84 Sport Coupe with a 2.8, Auto. A few months ago it started acting up. When going up hills trying to accelerate, the car bucks and almost cuts out at times. I replaced plugs, wires, coil. Everything else looks ok on it. It's not a problem that happens all the time, it's very intermittant. Sometimes it will run fine, but most of the time it does this. I'm really only down to a few different options, I'm thinking it's either the carb needs rebuilt, a new fuel pump, or something is messed up in the distributor.

Anyone got any ideas? Thanks

 

hey this is 3rd gen not 2nd gen so keep it else where

 

WTF? An 84 is a 3rd gen... what are you smoking?

 

Indeed it is a third gen...everybody play nice, now.
In high school I had a 84 Firefird w/2.8 that had a bad mixture control solenoid. It displayed similar symptoms. Don't let it go too long, mine eventually fried the computer.
Whatever it turns out to be, those carbs used to cost a mint to rebuild. Yank the whole works and put an Edelbrock manifold and Holley carb on there (unless you need to pass emissions)
Oh, did you try asking on the V6 board?
Best of luck to ya!!

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88 IROC with cobbled together (not by me)drivetrain, 86 (?) TPI unit on an '83 305,CE subframe connectors, Edelbrock strut tower brace, polygraphite bushings all around...it handles like a dream, but man is it hard to push!!

 

looks like some beat me to it. an 84' is a thirdgen. you might wanna try cleaning up the carb with some carb cleaner if you haven't already done so. when it cuts out can you fire it right up? or does it take some cranking to get it started? yes you might try the v-6 board. the know more about 6's than me.

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88' IROC-Z, 350 TPI, 700-R4

[This message has been edited by mystikkal_69 (edited September 03, 2001).]

 

Chappy,

Welcome Aboard!

Never mind 89 Iroc - he must be having a long weekend. We've all done it - some days I'm the King of DOH!.

The intermittent problems can be difficult to diagnose. I would presume that you could eliminate the ignition system since you've replaced most of the components. As a suggestion, however, you might want to inspect the cap and rotor for signs of carbon streaking and moisture contamination. And while you're in there, check the pickup coil and reluctor and the associated wiring to make sure everything is at 100%. The pickup coil resistance should be between 500 and 1,500 ohms, and there should be infinite resistance to ground (no reading). The reluctor should be relatively clean and rust free, with no signs of visible damage or cracks. Make sure the distributor shaft does not have excessive play side-to-side.

A clean fuel filter certainly couldn't hurt, and if it hasn't been replaced in 30,000 miles, it's due anyway. Fuel pumps usually don't get intermittent unless there is a lot of sediment in the fuel tank. Typically, they either pump or start losing pressure and don't recover.

Aside from that, you might want to reset the TPS voltage and the mixture control solenoid control range. As part of that whole system, you should check the oxygen sensor, since it's input along with the TPS is what controls the M/C solenoid function. The oxygen sensor is a 30,000 mile service item as well.

Another possibility is that the PCV valve is sticking open under heavy acceleration, allowing a lean mixture. You can clean or replace the valve to eliminate the potential problem.

The EGR valve should also be checked for carbon buildup that might be holding it open. If the EGR is sticking open, you'll have almost no power on acceleration, along with the stumbling and bucking.

Report back with results and further questions. We'll be waiting.

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Later,
Vader
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"Click - Click - BOOM!"
Adobe Acrobat Reader

 

Bjase - WHere is the mixture control solenoid located? Is there a way to check it out? I'm not wanting to spend a whole lot of money on this thing, it's my beater car that I bought for $350. It's not something I want to put an aftermarket intake on.

I've already cleaned out the carb with cleaner. Didn't really seem to do anything. It will start up sometiems, other times it will take a few cranks to get it running. I drove it yesterday, and it ran like crap when I first started it, but then ran good for a little while, then crap again. It's not like it's something that it does when it's only cold or only hot.

I forgot to mention that it had a new cap and rotor on it, and a new fuel filter. The inside to the distributor looks good, I haven't checked any resistances or anything like that, but everything looks to be in good shape. One thing to consider is that this is a carb car with a mechanical fuel pump. Not a whole lot of electronics on this car... no TPS or anything like that. It does have an O2, although I'm scared to try to take it out. It looks extremely rusty = might break. The PCV looks like it is ok, it rattles like it is supposed to, but I guess it would be something cheap to try. I haven't checked the EGR, how would I go about checking that?

Thanks for all the help here guys... keep the info coming.

 

one way to check ifthe EGR is working is to use a vacuum pump and apply vacuum to it. look for movement at the diaphram. if space is limited one sure way to check it is when the engine starts and is idling apply vacuum to the egr. then engine should stumble and want to die out. then release the vacuum and the engine should begin to idle normally again(if it didn't die out).

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88' IROC-Z, 350 TPI, 700-R4

[This message has been edited by mystikkal_69 (edited September 04, 2001).]

 

Whoah! Go with what Vader said. He is apparently some sort of Camaro demi-*** ! "The Man", at the very least.

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88 IROC with cobbled together (not by me)drivetrain, 86 (?) TPI unit on an '83 305,CE subframe connectors, Edelbrock strut tower brace, polygraphite bushings all around...it handles like a dream, but man is it hard to push!!