Hi I have a 92 RS w/ 305tbi Engine I've been having one heck of a problem with it lately. When you start it it acts like it's starving for fuel rough dies restart and you have to play with the acceletaor to get it going at a constant 1000RPM. When it starts to heat up it kinda goes away but then again it doesn't. Very rough idle and then when driving I have to give it a little gas while cruising along at say 30-40MPH. When I stop I have to give it gas to keep it going. All these problems come and go.

At the suggestion of others in a previous post I just changed and put in brand new "Wells" IAC Sensor, TPS and a Coolant Temp Sensor. After replacing runs a slight bit better but still has that hesitation and acts like it's choking on something.

IN my previous post/s I also mentioned that my Injectors are this discolored brownish color both on the plastic clips and around the injectors themselves. I'm at a loss of what to look at next and where to find that part that you may or may not mention in upcoming posts.

The Engine is the LO3 305 with TBI with 90,100 miles on it. Someone mentioned Fuel Filter. I'm mechanically inclined but not too sure on dealing with Fuel under pressure and how to change that DIY.

The main problem seems to be at Startup when its cold or half way cooled down. When it heats up the problem is still there but I can give it enough gas to get it going but it still hesitates and dies. What's the best way of troubleshooting this without replacing everything under the hood. And would a MAP Sensor or O2 sensor cause this problem? Or could it be something in the ECM? I have no SES light coming on and recently about 2-3 weeks ago replaced the EG R valve but the problem just appeared out of nowhere Wednesday night and has been driving me blinking nuts ever since.

HELP BEFORE I GO CRAZY trying to figure this out. I'm half way certain it's not a Fuel Pump or maybe it is I don't know that's why I'm asking for ANYONES help with experience with a similar problem.

 

I was going to say replace the fuel filter. If that doesn' do it, maybe you fuel pump is dying.

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Mark I was thinking the same thing. But when I have the air cleaner off and looking at the injectors pulsing ( well if you can call it that ) it's not a pulse at all it's like dribbles of gas coming out.

We did a test kinda weird but I have remote start on my alarm system. The first time it cranks for like about 2 seconds then doesn't start. The next time within about 10 seconds I hit remote start again and it fires right up.

What's a Good injector cleaning stuff to put in and will carb cleaner work in it? I put in some of that Outlaw Injector Cleaner about 2 tanks back and I was thinking maybe it dislodged some buildup and it's now clogging the injectors. It just doesn't have a spray like you would expect from a Injector the fan type spray it's like a dribble coming out at a fast idle. I wouldn't think that's normal. But I don't know if that's something I can replace myself and where do I get the injector or assembly to fit that particular TB?

Thanks for your help so far.

 

If the fuel filter's never been replaced, it's past due by this point anyways. It's very simple to do, really -- take out the fuse to the fuel pump, run the car until it runs out of gas, take off the old filter, put on the new one. (It's held on by two bolts on either side of the filter.) It'll take a few minutes to do. Just remember to plug the fuel filter fuse back in. heh. (And remember that it'll take a little longer to start, since the pump has to build up pressure again.)

 

When I got my '87 Z28 it did that. It turned out to be there was crap in the gas tank that would choke it. Had the tank removed and cleaned and problem solved. Something like hundred or so bucks.

 

Check your connections to your sensors (esp. CTS)

 

Hey Guys thanks for the quick response. I think I'm going to get a Fuel Filter. If memory serves me correctly when it was on the rack it looked like a new one in place. But then again the guy said that he had the EGR replaced 3 times in a year and a half. When I put a new one on Code 32 Problem hehe. That thing was plugged up with all sorts of sout and junk.

Ok when you say Take out the Fuel Pump Fuse I know where the fuse panel is but clueless which one is the Fuel Pump Fuse. Is it the standard colored one or is like one of those silver things? Is Deutch or whatever the heck AUtozone sells a Good Brand or can you guys recommend another brand that's better for a Fuel Filter?

So when I disconnect the fuse ( minding that I actually find it ) I run the car till it runs out of gas and then take the Fuel Filter off and install the new one put the fuse back in and then start it right? Should I cycle the key a couple times to prime up the Fuel Pump?

And what is a good way of telling when your Fuel Pump is going? I mean every GM I've had when they go they just go. No advance warning nothing. Just boom it's done.

Also on the same topic in the above post. The Fuel Injectors spray. Shouldn't they put out a Fan like spray constant even at idle or high idle? these are just dribbling like I described. I was thinking maybe that's whats causing my engine to act like it's starving for fuel. Any comments on that would be appreciated. Thanks a bunch.

 

Ok I checked the Injectors at a rate faster than a 500RPM Idle and they are diffently just drizzling out not a spray. I checked the CTS and it's tight and connected as well as the newly replaced IAC and TPS. When me and my fiance were sitting in the car and had it revved up to 2000RPM in Park it was making this weird sound and the Tach was jumping up and down by 100-200RPM either way. And the sound of missing or something. I had a Tune Up Place do the plugs maybe those B$%^&@! put the plugs back on and one is arcing against the headers or something.

It's just really really weird not all the time does it do it. Plus I noticed with the AC Off when I get on it and then go to slow down or stop when I put my foot on the brake I hear a Pssss from the Dash. Vacuum??? Where?

Please excuse the ignorance guys/gals just trying to get to the bottom of this rather strange problem. I'm going to get a Fuel Filter and Install it and see what happens. But I think something is up with those Injectors. And when she punchs the throttle and I'm looking down the throat ( not her's ) =) the butterflys aren't opening up. but when I grab the linkage and punch it they open. Weird. The Injectors are making a pretty destinct ticking noise. What does that say?

Man talk about a Brain teaser day after thanksgiving. I wish someone lived close by, case of beer and pizza or I'm about to offer some Cash to the first person that comes up with a solution!!

 

how u doing?
Im new to the board so i think I should blend in slowly, Ill only metion a couple of things that way I wont go over my head and get stopped dead in my tracks .
First check your fuel pressure
(2) replace the fuel filter ( cheap insuracne)
(3) check fuel pressure again
(4)at idle or any other rpm the fuel should be atomized no matter what. Especially when the engine is cold.
(5)Before changing expensive injectors clean them first properly.
(6)even though they replaced the plugs it may be very possible that one or more plugs are bad, same goes for the wires especially if there cheapies, cap and rotor.
(7)check your charging system and battery fuelie cars need full voltage to operate properly
(8)the coil may be going bad ? never know.
Anyways hope this helps, and if anyone wants to correct me please do so always willing to learn.