1986 Fiero V6 GT. As I start the car, the engine cranks, the engine runs rough, and the rpm is bouncing. This problem occurs even when you accelerate. The car feels like it is lacking power and you get this unpleasant jittery feel under acceleration. I followed the instructions in the chiltons and haynes manual and it sugguested me to check the PCV valve and air filter. I checked the PCV valve and the hose to make sure they are operating and they are operating like they should. I also inspected the air filter and it's clean. What else could cause this concern? Here's a video of the RPM gauge that I recorded if it helps.
Do you have original ignition parts? Does the car sit a lot, or is it a Daily Driver? How many miles on it? Is the condition worse in wet weather?
It currently has 65k miles so most likely it has the original ignition parts. It gets driven occasionally. The condition seems to be the same rain or shine.
I circled the fuses that I checked, are these the correct ones?
Yes, that's correct.
I figured I should mention the injector fuses just in case. I've read here more than once over the years about a 2.8 not quite running right... and it was one of the two injector fuses which had failed.
EGR stuck open slightly??? at idle EGR should be off, if there is ANY leaking of exhaust into intake system at idle, engine will run horribly, only time EGR is opened is at cruise/steady RPM's, I believe above 35 mph give or take.
Sorry, it's was raining lately so I haven't looked at everything yet. I still need to check plugs, wires, and egr valve. I'll keep you guys updated when the weather gets better.
I have two questions:
If I test spark plug wires using the multi-meter method, do I follow the resistance per foot followed by the length of the cable? If so, how much resistance/foot should I be getting?
For the EGR valve do I use a vacuum hand pump tester and apply vacuum pressure to the EGR and see if it holds pressure and makes a popping noise when I disconnect the tester?
[This message has been edited by LiftHatch (edited 02-07-2015).]
I suppose it does, but I never trust those digital MMs.....
Yes. The way to confirm this for yourself is if you put it down to the 2000 setting then it should go out of range indicating that in the 20K setting you are reading in thousands of ohms. (i.e. 4.98 = 4.98K ohm = 4980 ohm)
[This message has been edited by Neils88 (edited 02-12-2015).]
My 1986 V-6 has been sitting for a long time. I purchased it from someone who purchased and sold it to someone who purchased it from some....you get the point. I have replaced lots of parts, based on responses on this site. Today, I took the fuel out and have two photos. One photo is new fuel (clear). The other photo is of the fuel that came out of the tank:
Two things observed:
1) without the engine running, I was able to hear the fuel pump performance. When I first started removing the fuel by jumping the pump, it started fine, then slowed as though it was going to stop. I thought that this was my problem. However, after removing more gallons of fuel with the pump jumped, the pump started running more quietly and consistently. 2) the fuel in the tank is a brown color. And, the fuel does not smell like fuel (gasoline) It has a kind of chemical scent, like turpentine. I compared the fresh fuel to what was in the tank. Gas has a strong and lasting scent. The brown fuel does not have a gasoline scent.
I will put about five gallons of fresh fuel in on Wednesday (February 5) and see if I can have a smooth running engine.
Car run rarely can have several problems like... Gas sitting in gas tank can get water in thru any opening including EVAP can. This is a problem when have up to 10% Ethanol. Gas sitting can get "Stale" as light parts escape thru any opening. Even thru an iffy EVAP can and lines. Battery low/dead then "jumped" etc. can make ECM to loose memory and need to learn idle again that happens > ~ 35mph/57kph Rust inside dist and other places can cause ignition and other problems. Rust etc. are still active even when parked in a garage w/ AC/Heat. Low battery, iffy alt, or anything cause low volt read by ECM can cause hunting idle. Iffy Grounds and/or power lines can do this. Injectors can have fuel evaporate making varnish etc. w/o having new gas to wash them. Many parked injector leak a little then fuel evaporates w/o making obvious leaking problems. Or injectors stick some to a lot and have problems until have enough gas flow to wash them.
STA-BIL® and other may help but if tank or anything else leak air/fumes even w/o leaking liquid then can still have problems. Note that must add enough Stabilizer to work. STA-BIL® says "1-ounce (30-milliliter) treats up to 2½ gallons (9.5-liters) of fuel." Fiero needs 4-5oz minimum to a full tank. (Later Fiero have larger tanks.)
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
