Sunday night the car ran fine. Ran it kinda hard and put it away for the night. Monday morning it ran in warm up fine but then right after that, it felt down on power and then it would buck like a horse and then it was way down on power. A minute later the 5-8 light came on and a smell of raw fuel. I let it sit for a couple of hours and it when into warmup mode @ 1,000 rpm and it still did not sound right. I pulled the coil to dist wires and the rear bank (trunkside) was perfect and clean. The firewall side was green and corroded on the coil side of the wire. I also pulled the coils and it was green and corroded on the firwall side coil. I replaced both coils with new OEM coils and the car is still in low power mode with the smell of fuel. I am planning on replacing the coil to dist wires today to see if that is the other issue. If that does not solve the issue, could it be... 1. plugs are now fowled with fuel and then need replacing? after that, I have no idea..... Any idea's?
My car has acted similar in the past. Remove and clean your plugs. Remove and clean all of the plug wires. Before you reseat the plug wires, apply a dab of dielectric grease to each end. Remove and clean the main distributor wire to the coil, use the dielectric grease here as well on both ends. I'll bet this fixes the problem.
Thanks Greg! I will give it a go. I replaced the coil wires and it still acted the same. I unplugged the front bank coil wire and the car would not fire so the new coils are working fine. I also checked the spring in the dist cap and that was fine. I removed the carbon from the rotor and the cap points. The extenders are new so that pretty much leaves the plug wires and plugs. Too bad the front bank are such a pain to get out. Back to the autoparts store for new plugs and grease.
Just a thought though. Could the WUR or the OEM ignition boxes be an/the issue? If the new plugs and clean wires don't do it. Then off to Eugenio's it goes.
I think the flywheel sensors are a common problem too. Mine just had dirty contacts and the car wouldn't start for the PO.
First find out if the other bank coil is firing properly. You can get a spark gap tester fairly cheaply from almost any auto parts store. Possible causes of one bank not firing are: - Coil (replaced, so not likely) - Coils miss-wired (easy to do if you're changing coils) - Flywheel sensors or their connectors- ECU ground strap fix not installed & ground is corroded - ECU (switch ALL wires from one ECU to the other to see if the problem changes banks. If it stays with the bank then check for a broken wire or bad connection between the ECUs & coils, or power to the coils...)
Coils are firing and ok. I double checked that and the "+" and "-" are wired correct. I will check the Flywheel sensoers. I don't have a ECU ground strap. I suspect it is something else unless they would just stop working because of not having a ground strap. I replaced all the plugs. Bank 5-8 had white build up on plugs 1-3. The rest looked fine. After I replaced the plugs, Car fired but still has the same issue. Low idle on Warmup, missing power. I have replaced the coils, Coil wires, Sparkplugs and I checked and cleaned the dist cap and checked that the spring is still there and the rotor looked fine. I will clean the ECU connectors and try switching them now.
Still doing the samething. idle @ 1000k during warmup, Smell of gas, low power. I have cleaned, checked and swaped the ECU's with the same result with the car I have replaced all the plugs, both coils and coil wires I have cleaned and checked the distributors I have doublechecked the coil wiring. I give up. I'd check the flywheel sensors but I don't care anymore. I am going to send it to the shop i guess.
I just talked to Eugenio, He said I should replace the rotor and see if that is an issue. Nothing much left to change. He said the Flywheel sensors are a bigger deal to deal with if they are an issue. Off to call Daniel....
Hmm, Maybe you're not loosing a full bank then, only a cylinder or so In which case you have an extender or 2 arcing thru, common failure, should have thought of that up front. Look at the extenders, if one's arcing thru, usually there's a black sooty spot on the inside & a tiny black pinhole on the outside. May have a carbon track on in or outside as well. A common arc-thru point is inline with the long point of the hairpin spring that clips to the top of the sparkplug. Another common cause of arc-thru is the extender socket not being on the plug tip, but rathar the tip being between the side of the socket & the extender wall.
I thought arching was a hit or miss kinda thing. Not a all at once. Would that keep the warmup @ 1k RPM? Extenders are pretty new. About 14 months old. I will check them again. I pulled the rotor and there was a lot of carbon scaring on it as well as the points in the cap. I cleaned the points and I will replace rotor tomorrow. There was something sure wrong with the front bank though. With the greenish buildup on the coil and rotted, greenish coil wire and then 3 white tipped plugs and the carbon scaring, I am glad I replaced almost everything. Extenders will get a good once over and the rotors will be replaced tomorrow.
Considering all that you have already checked I think a crank sensor is at the top of the hit parade. On a 3.0 there are 3. One is for RPM for both banks. The other 2 are position 1-4 and 5-8. The can come and go with temp because the windings in them open and close thermally sometimes. If you have a VOM and can reach the connectors they should read about 750 ohms or so. Best test is to have them in your hand and gently knock them on something hard while reading the resistance value.
Went back & reread. One possible scenario is that you got some condensation inside your distributor that was just enough to get arcing started. Once the carbon tracks formed, they were enough to sustain the problem. Green corrosion on the coil-dist. wire is consistent with repeated moisture exposure. BTW, get some dielectric grease & give the wires a good coating before plugging them into the coil, dist, & plug extenders again. It'll help keep moisture out & is non-conductive. Just wipe off any excess that squeezes out.
Brian, Not sure where they are at or what they look like. Is this best to leave for others more skilled like you or Verell? I am a great part replacer if it's an easy part.
I used sandpaper to clean the points and I used the grease on all the connectors. I am hoping all that with the new rotors will fix the issue. I now have a pretty much all new ignition system so I have a new base to monitor things. The moisture cover coil was cracked so I am glad I replaced it. I hope it not the thing Brian was talking about. That sounds expensive.
The sensor leads are either green plastic or white silicone and are on the flywheel side. The sensors themselves are no fun to take out with the car on the ground but if you look from about the area of the removable plate on the bell housing below the oil filter forward to the water pipe area where it is very close to the bell housing you will find the leads and their plugs. Pull the plugs apart and measure the resistance going to the sensor. If you have an owners manual have a look at the wiring diagram. IIRC those sensors are also connected to the round diagnostic plug on the left side of the engine comp on the inner side of the sail panel just above the ign coils. If so it will be a lot easier to ck them there.
I would bet The ground wire for the ignition boxes is the problem..do this fix 1st as it will save you alot of headaches (now or later) Run a new ground wire from the trunk where the Marelli Boxes ground to the bolt where the coils mount. The ground in the trunk is trouble and I have done this update on 6 308's to date + 1 user on FC did it 2 weeks ago and solved his problem. Takes 10 minutes and about 25 cents in wire and connector.
Any recommendation on size wire? Also, Brian, Verell, Sloan, spiderseeker and Owens84QV, Thank you all for your help. As much grief as those 5-8 plugs gave me, This has been a blast, for the most part
Happens out of the blue and will eventually happen on all 308's, the ground in the trunk because a floater and I warn people that even if you find the ground lose do the update. One give away of a problem on the 5-8 bank is the tach acting up as the tach runs off the 5-8 marelli ignition box only. 12 guage is fine
You can do it. You'll want to jack the car up and remove the drivers-side rear wheel well. Then, at the 2PM and 10PM positions, you should see thick white cables plugged into the flywheel area on the gearbox. Those are your front and rear bank flywheel sensors. The one for the tach is under the gearbox, also mounted at the flywheel. The rear-bank and tach sensors are easy to replace. The front is a PITA simply because it is all by feel, you'll see what I mean...but you can do it. - Greg
For grounding anything on a 308, I like the grounding straps sold at Autozone. It's a flat braided flexable wire about 12"-14" long I think, with round eyelets at each end, for a bolt or screw. They are easy to work with and are designed for grounding electronics. Just a few dollars I think. Good luck and DON'T give up, it's all a part of bonding and learning about how these great cars work. We all learn from these little problems.
