Ok my car is running like crap lately. The tach doesnt move at idle, pretty smooth maybe a tiny but more rough than normal. When Im driving and I push the gas down good at all or WOT the car hesitates a sec then kinda stumbles then when it gets the power kinda shakes and putters a bit. Revs up good but it feels like its only getting half the power, acceleration is very poor. I replaced plugs, 8.8 wires and supercoil a couple months ago so spark should be good. I am throwing a code 32 occasionally for EGR. I wouldnt think EGR would have this extreme an affect at all rpms though, would it? I checked it on the weekend and there was carbon buildups pretty bad on the valve and the holes on the engine. I tested the valve by sucking the end and couldnt get a vaccum, pretty sure the valve is bad but not 100%. Im not throwing any other codes. Feels to me like the air/fuel mix must be majorly off or something. What else could do this? Failing fuel pump? I would think pump would only be at WOT.. I only have basic tools so cant check anything extravigant. Any help would be appreciated. 91' RS 305 TBI

 

If the EGR valve is stuck open that could definitely explain some of your problems.

 

could be fuel filter.

 

It revs perfect in neutral but has problems in gear and under load? That's a characteristic of ignition. If it was just a bad fuel filter or something, the engine's fuel requirements dont really change enough that it would be fine out of gear but die under load.

 

I dont think that is true -- I have had fuel filters get cloged on all kinds of cars and when the engine is subject to load they impede flow enough to cause a stumble. The engine requires LOTS more fuel when it is subject to load. revving in neutral/park requires very little fuel compared to part throttle acceleration.

but you are also correct -- ignition could also be your problem, I was just offereing a suggestion that costs like 10 bucks to test and is never a bad idea to change anyway.

 

WHen I said it revs ok, I meant while Im driving, not in neutral. It revs up with gas or WOT, its just not getting any power. Example, normally you goto WOT and rpms kick up high and go from 60-70 in a second or so. Now rpms kick up and from just 60-65 takes several seconds. Also the rev is rough and the hesitation and stumble before is crappy. It is generally running rougher all around, its much more severely noticed when you try to give it any go at all though.

 

Also, though it would run bad and hesitate when it was cold for a little bit before *which is why I was checking and cleaning EGR*, it was nowhere near as severe, especially all the time, as it is now. Happened almost exactly after I played with the EGR, thats why I figured it must be something with that, just wanted to make sure it could cause these kind of problems before I fork over 50 bucks.

 

Update changed EGR, still the same. Changing the fuel filter tuesday...Wondering what else could do it. Its very hesitant now and loses tons of power with any time of good throttle. If I go WOT it revs up then the RPMs stay the same and so does speed until I let it downshift then it will gradually increase again. Keeping in mind the ignition system is all new accept for the distributor what else could my problem be? It sucks having it this weak and sputtering. Thought EGR would help but no go. What about dirty/dying injectors? Fuel pump? donno....any info appreciated

 

Sure the trans isnt slipping??

That wouldnt explain the roughness though. Definitely sounds like something is wrong with either the air/fuel mixture, or the ignition. Of course there's other possibilities as well...like a clogged cat converter....

If you have an ignition spark tester, try testing it off of one of the spark plug wires. Should be white. Blue is acceptable. Orange is weak.

And test your fuel pressure if you can.. At idle, with vacuum on the pressure regulator, you should get around 40 psi. Unfortunately, you wont be able to observe the pressure when you get on the gas. But you can still rev it up a little and see what happens. Pressure should climb up when the engine revs and fall as the rpms fall. Generally it'll increase by about 5 psi.

And 88305tpiT/A, yeah you're right about the fuel thing. I just remember my friend's Lincoln with a 302 that has an 'instant gas mileage' thing.....and I remember how cruising under load he gets like 16 mpg and with the same rpms in neutral it gets almost 30 mpg, sometimes more.

 

I did forget to mention, haven't changed the cap and rotor or anything to do with the distributor yet. Gonna take a look at that also as soon as I can. Very sure its not tranny, the whole engine shakes, hesitates and stumbles. Something not right. Push the gas and you can feel it putter and hesitate horribly even it idle in park. Dont have a spark tester :/

 

So you said you replaced all ignition stuff besides the distributor & the cap and rotor....so I assume that means the plugwires, the plugs, and the ignition coil...

Pull the cap and see what it looks like. Make sure it isnt cracked, and make sure the contact points are all good and arent eaten up, corroded, etc. They're only like $15 or so together so considering you've replaced most everything else, the cap and rotor wouldn't be a bad idea too.

 

Yep, exactly right. I have 8.8 wires a supercoil and bosch plugs. Im in the middle of a blizzard right now in NY, but going to change the fuel filter and probably cap and rotor on Tuesday, will update after that. Thanks.

 

Whats going on with this, my car started doing the same thing yesterday after an intake manifold swap?

 

Sounds like ya put it back on with the gasket a little skewered, or it was too old. Check your vacuum and check around the gasket...you probably have a vacuum leak.

 

What year and induction type is this happening on?

 

Its 91 305 TBI...Changed the cap and rotor, no go. Still getting no power moderate-wot, very boggy. Going to do fuel filter next. Spark system now completely new besides distributor and theres no play in that. I think I did a good job on EGR, cleaned out intake where I could and all new gasket, dont see anywhere for vacuum leak. Im leaning towards a fuel system problem...bad filter, dying pump maybe.

 

On a V8 powered car the EGR could be wide open and you'd hardly notice it (been there done that one).

Try replacing your coolant temp sensor and inlet air temp sensor. If the fueling on the TBI is controlled like the S/D TPI, those 2 sensors play a very important role in the fuel/air mixture.

 

Well if the CTS is the one that controls the gauge also I know that's bad. SHouldnt I get some codes thrown if sensors are going bad? Maybe it'd be easier in this case just to pay for an hour dealers diagnosis fee than me keep trying to guess...

 

No the CTS isn't the same as the sender that feeds the guage. The CTS costs about $7 and generally won't set a code. What it can do is throw the feuling out of wack enough to set a code for running too rich or lean and can cause all sorts of driveability problems.