i think i have a hunch what it is... i dont want to say cause i wanna hear it from the experts first...



im driving normal and all of a sudden at idle my car starts going a little choppy...like... the RPMS would go up... then down... then up... then down...

well i just apply the gas a lil bit more and it goes away... about an hour later its doign it while i drive... i can have the peddle floored and it just wont go... then it will go.... then it will stop...


so then... it stalls... i start it up... 5ft it stalls again...


2 hours later....

i start it up and find out that it idles... very poorly... but when i apply any gas it stalls...

help guys... i really hope this isnt what i think it is..


89 Iroc-z TPI 305 stock everything...

 

Hey Hamspiced,

How are you doing? What was the final outcome with your brakes, I never did see what your final corrective action was there. In regards to your new problem, I had a similar incident about 8 months ago, mine turned out to be a bad MAF sensor. Try disconnecting it and see if the idle and RPM's smooth out and then check the relays. I know you don't want to hear the dreaded "Fuel pump" diagnosis. When was the last time you changed the fuel filter? Good luck!!!!!!!!!

 

I dunno, a little TS'ing would be in order here...got spark?...Got fuel???...go from there.

Could be a dozen things, but check the basics first....simple fuel filter cuold do what you describe.

Why all the worry?

 

Yeah try the easy first...unhook MAF...then fuel filter..than look at your IAC valve...if the IAC starts sticking the car will start ..but run poorly or stall...any codes? A maf will usually throw one..a faulty fuel filter/IAC won't...

 

whats an IAC?



Fuel Filter was replaced last summer (i forgot to relieve the pressure in the line and i became very flammable very fast...)

maf is brand new from a 350 TPI (works good for me)

what relays do i check and where do i check them?


yea... the fuel pump is exactly what i think the problem is and i really dont want to spend the next 2 days changing that...




Trickster...The problem that was causing my brakes to make me swerve to the right was a Defective Banjo bolt, or Brake Line bolt that connects the line to the calipers. It wasnt properly drilled all the way through. That bolt cost me over 300$ in new parts including Brand new brakelines, steel braided rubber replacements, banjo bolts, proportioning valve, master Cylinder, and Brake Booster. everything even remotely considered relevant to brakes on thsi car is brand new right now.......Thanks for asking... ive been working alot and havent had as much time to post here as I used to.. I am currently playing phone tag with Motormite(manufacturer of defective banjo bolt) and their claims department to see if i can be reimbursed for my losses... including time off work.

 

ttt

 

The relays they are talking about is the MAF power relay and the MAF burn-off relay. You could also check the fuel pump relay. They are all three mounted together on the dirivers side firewall. The two maf relays are the same part number and are interchangeable. Hopefully it won't be the fuel pump that you have to change. There only a few people I would wish that on and you aren't one of them. The IAC is the IDLE AIR CONTROL and is mounted in the right side of the throttle body and has a four pin connector. It should be removed and cleaned every so often along with the passage way it mounts in.

 

well maybe this might help...

when i put my key in the On position...


i dont hear the FP prime up..

 

****... nvm... i guess...


i started it up and went to check the fuel pressure and it was spewing fuel... now im confused as all hell...

i turned the car on and it ran fine... this isnt making any sense to me...


i thought a failed fuel pump means it wont work.. or does it go in spurts?

 

Just spent this weekend dropping my tank and changing the pump. Let's just say that if your suspension has never been taken apart before, it will be a fun experience for you

Check the 3 relays that are on the firewall on the driver's side, right behind the brake booster. Not sure of the order, but they are the fuel pump relay, MAF burn off and MAF power relay.

Does "Check Engine" light come on, and car throw any codes? If you have fuel, and you have spark, then maybe it would be your IAC.

-Dustin

 

If the fuel pump relay fails, there is a back-up in the system thatwill operate the fuel pump. It is the fuel pump/oil pressure switch located above the oil filter. If the fuel pump relay fails, the fuel pump/oil pressure switch will kick in once the oil pressure reaches 4 PSI and will operate the fuel pump.

 

how exactly do i check a relay? i can look at it all day.. but then what?

 

What I did was to switch the 3 relays around with each other. I know for a fact the MAF power and burn-off relays are exactly the same, and the fuel pump relay looked the same to me. Chances are not all 3 go bad at the same time, so if you switch them around, hopefully one of the 3 works and once connected to the fuel pump wiring, it should temporarily solve the problem.

I know there are exact ways to check the relays, but that's what Trickster and his GM service manuals are for

-Dustin

 

well.. then im gonna wait for trickster and his service manuals before i go hobswapping relays around...

 

Sounds to me like the module on your distributor is going bad. I had this exact same problem. I would check the module.

 

I have the same opinion as ant. I had a control module junk out on me and it did the EXACT same thing you are saying. no codes either. have it tested before you get into that horrible project.

 

lol... its a brand new MSD module... i doubt its going out... lol

 

you'd be surprised how easily they go out. Im not even kidding, i've bought brand new ones that were bad before. they are strange things, sometimes they'll last 15 years and sometimes they don't work from the start. And I hope you used plenty of the supplied grease when you put it on.

 

are we talking about the same module? Im talking about the one under the distributor cap.

 

thatd be the one im talkin bout.

 

im not sure its the same one that hambone or whatever was talking about.

 

the name is Hamspiced... and no, i am talking about the msd ignition module, i dont have one under my cap...

cap and rotor were replaced a few months ago.

 

Cap and rotor have nothing to do with the module unless you have an HEI distributor where the module is built into the cap, otherwise the module is built into the distributor.

 

Actually, Ant87IROC, you are mistaken about the location of the ignition module on a HEI distributor with the ignition coil in the cap. It also is located on the base of the distributor beneath the pick-up coil the same as a distributor with the remote ignition coil. HamSpiced, what type of ignition system are you running in your car? Is it all MSd and if so, what components do you have.

 

Regardless of where it is, i still think its worth checking before moving on to other things.

 

i just have the MSD Coil and plugs...

doesnt matter now... the new fuel pump is in... check the new thread....