1981 308 GTSi rich condition | FerrariChat

1981 308 GTSi rich condition

Discussion in '308/328' started by Sickly308GTSi, Oct 13, 2018.

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  1. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Hello everyone,

    My father-in-law just pick up this GTSi. When he test drove it, it ran great. Between the purchase in California and the delivery in New Jersey, it has developed an insatiable desire for fuel. He drove it a few miles to work and the performance stated to wane. On the way home, it became too sick to drive. It was towed home, where it may or may not start. He flew me in from Houston as an expert (his words, not mine) to assist. After a bit of chasing, we found where the air/fuel mixture screw was missing, and replaced that. The warm up regulator also needed to be adjusted, we're thinking that is because the air/fuel mixture screw was missing, so someone made the necessary adjustments in the WUR.

    Now what we have is a car that finally starts immediately and idles well, but has absolutely not power. It revs ok, but seems to be a little burdened to do so. To me, it sounds and feels a lot like retarded timing. The intake is very loud when rev-ing (which may be normal?) and has no power. Being that its electronic, we cannot adjust it, and being that it ran well before, it's not as though the timing belt jumped teeth or anything. It doesn't always smoke, but it still smells rich.

    The fuel system and control pressures are very good. We hooked the pressure gauge to each line going out to the cylinders to monitor their behavior. We made it to 5 of them (before calling it a night) and have found 2 injectors that seem to be stuck open. Once we got the gauge hooked up, we started the car. We expect some lag time for the pressure to build, but we noticed where one injector never built pressure at all. We noticed another that was very slow to build pressure, only came up to 42 PSI (approximately 50 PSI is required for injection) and did not hold pressure when we turned off the engine.

    In the morning we are going to pull the injector that never build pressure at all, but I wanted to run this by everyone to get some feedback. Do we seem to be on the right track? Are we going off in the wrong direction? While there is some literature about some of these issues individually, there isn't anything that resembles a combination of our symptoms. Any feedback would be greatly appreciated, as I'd prefer to stay on the favorable side of my in-laws. Please help me stay married!
     
  2. ferrariowner

    ferrariowner Formula 3

    Feb 21, 2014
    1,109
    Mansfield, TX
    Full Name:
    Ron
    Mark,
    The injectors on these cars are not electronic and flow continuously. Is fuel flowing to each injector? Is it a US car or a Euro? The adjustment hole in the Bosch fuel distributor must be plugged as you have found or it will run rich at idle.
    Good luck.
     
    Albert-LP likes this.
  3. topcarbon

    topcarbon F1 Rookie
    Silver Subscribed

    Nov 3, 2006
    2,580
    I would check your spark plugs
     
  4. johnk...

    johnk... F1 World Champ
    Owner

    Jun 11, 2004
    10,627
    CT
    Full Name:
    John Kreskovsky
    Are you sure it's running on all 8? These flat crank engines will run smoothly on one bank but will be slow to rev and have no power.
     
    308 milano likes this.
  5. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Hey Ron - Honestly, I didn't check to ensure each injector has fuel on it initially since it's extremely obvious that it's rich. What we were doing last night was checking the pressure between the distributor to each injector, so I know that 5/8 do. This is a Euro car that was adapted. Once we got the mixture as good as we could, we did plug the hole for the adjustment, which seemed to have very little or no effect.
     
  6. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    The first thing I did was check the plugs and that were all fuel-fouled. They were all gapped appropriately. I cleaned them and put them back, with no change in performance. Since doing that, we have gotten it to start, idle and rev just fine, so its my humble opinion that they're not a culprit. But then again, this isn't a car that I'm experienced with. It's been my experience that plugs will not grant you the drastic change needed to put us in the performance arena we need to be in. For example, we cannot even pull it into the garage without rev-ing it to 3,000 RPMs.
     
  7. topcarbon

    topcarbon F1 Rookie
    Silver Subscribed

    Nov 3, 2006
    2,580
    Compression check?
    I had a similar problem.
    Compression on the back four was very
    Low and the car ran really rich(but I have a 1977 carbed car). Problem was the timing belt jumped two or three teeth.
     
  8. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    We can confirm that all 8 cylinders have fire.
     
  9. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    The timing belt was done recently, but the car ran great since. I know that timing belt jumps happen, but I ruled it out as an extreme scenario since you would need other problems (failed tensioner, pulley, etc) for the environment to facilitate an otherwise unlikely event. However I has felt like timing to me, but I quit pursuing that since no adjustment was possible for me to try.
     
  10. topcarbon

    topcarbon F1 Rookie
    Silver Subscribed

    Nov 3, 2006
    2,580
    So, my engine was rebuilt, everything was done and everything tested fine. Something so small, like putting the car in gear, at a stop, and then setting the ebrake(and the car rocks forward) can s cause the time
    Belt to jump. From there problems start multiplying. Check compression to see if there is a difference.
     
  11. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Jason - We just ran a compression test and the results are as follows...

    1-195
    2-200
    3-195
    4-190
    5-185
    6-180
    7-175
    8-180

    The forward bank is consistently high, while the rear bank is consistently low(er). I'm going to do some research now and see where the compression should be on a 75,000 mile motor.
     
  12. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    I would start by checking the cam timing. Belt may have skipped. Replace all injectors and spark plugs. What are your system and control pressures ? Check your WUR input screen for any varnish. Is this a vacuum WUR ? A vacuum WUR should drop 10 PSI (control pressure) when revved with the throttle fully open. This is what gives you acceleration power.

    Unburned fuel smell could also be an ignition problem. One or more cylinders is not firing, and the fuel goes straight out the exhaust. Check plug, extender, wires, cap, rotor. Wires with increased resistance is a common problem. Should be around 10K Ohms. Bad wires will measure open circuit.
     
  13. johnk...

    johnk... F1 World Champ
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    Jun 11, 2004
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    John Kreskovsky
    Those numbers seem awfully high for a 308.
     
    Jbrauer and waymar like this.
  14. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    They were cranking numbers, with all the plugs removed. We were going to do dynamic numbers, but we can see enough consistency to rule out compression as an issue, in my opinion.
     
  15. ferrariowner

    ferrariowner Formula 3

    Feb 21, 2014
    1,109
    Mansfield, TX
    Full Name:
    Ron
    I think your numbers look about right for a Euro. They have higher compression (9-1). Also, You may want to check the timing by removing the timing cover under the oil filter. I can post the timing chart if needed. Idle is 2 degree (6 with vacuum port disconnected). 1800 rpm 12-25 degrees. 32 degrees at 2700 rpm.
     
  16. johnk...

    johnk... F1 World Champ
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    Jun 11, 2004
    10,627
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    Full Name:
    John Kreskovsky
    I'm going to go out on a limb here and simply state that this doesn't sound like a rich condition. I know you said you have spark in all cylinders, but smelling rich with no power and labored reving sounds a exactly like running on one bank, or at least a few cylinders not firing. You just don't lose power because it's rich unless it's so rich plugs are fouled and cylinders aren't firing.
     
    ferrariowner likes this.
  17. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    I would imagine that the numbers will go down if we were to run the static compression test again with all the plugs in it, which I will be doing just to ensure I'm correct.
     
  18. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    So we never finished checking the injectors. After finding (2) bad ones, we decided that it didn't matter how many more were bad, but that we needed to go ahead and replace them all. I just got back from the parts run and I'm about to install them now. Will update soonest...
     
  19. GordonC

    GordonC F1 Rookie
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    Aug 28, 2005
    4,119
    Calgary, AB, Canada
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    Gordon
    #19 GordonC, Oct 15, 2018
    Last edited: Oct 15, 2018
    Those compression numbers look fine, but for reference: #1 - #4 are the rear bank, #5 - #8 are the front bank. Here's the factory diagram, note 'volano' is the flywheel, "direction of march" points to the front of the car.

    Image Unavailable, Please Login

    PS - I'd also suggest double/triple-checking that all cylinders are firing on front bank and rear bank - your symptoms, rich smell, sluggish acceleration, match exactly what happens when one of the three crankshaft sensors on the flywheel is not working, and result of a failed crankshaft sensor is that none of the cylinders on the associated bank will fire.
     
  20. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Hey Gordon - That's an interesting diagram because the original manual that came with the car shows that the forward bank is (left to right) 1-4 and the rear bank is 8-5. But in keeping with the information that we find, nothing is consistent. We checked fire and it is strong and consistent. The only way we might lose fire is if the sensor is breaking down above idle. It's been my experience that you didn't have sensor failures like that until they went to a 5V reference or frequency-based sensors. we have actually (I believe) cured the rich smell today when we replaced some injectors that we hanging up. We do still have the sluggish acceleration and a disdain for anything above 2500 RPMs. Have you ever seen crank sensors provide erratic readings?
     
  21. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    We've got a good 75-80 PSI system pressure and 50 PSI control. Our cold pressure is still giving us fits, but we're moving on with the bigger (power) problem and will get back to the cold start pressure issue later. We did replace all injectors, to no avail. We're have the WUR off and open approximately 10 times trying to adjust the cold pressure, and there is no debris in the diaphragm or screen. I have cleared it backwards with solvent just to be sure, and still nothing showing up in the screen.
     
  22. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Ok guys, update from today...

    I started out by driving down to AW Italian Auto in Eatontown, NJ. i wouldn't consider them extremely competitive, but if you need parts in NJ and you're under the gun, they're absolutely worth it. Stacey Giglio is a wealth of knowledge and is extremely familiar with Ferraris. They have a lot of parts in stock. In fact the only thing they DIDN'T have today was the driver's door window. Please don't ask why I need it, I'm not ready to talk about that yet.

    I came home and started replacing the injectors and seals. I was feeling really good about this, since we found at least 2 injectors that were stuck open. We started it up and after adjusting the mixture to the new injectors, we have the same @%$&*$# problem. We have a good idle, but it won't rev over 3000 RPMs. Its quite the struggle to get it over 2500 actually. We're going to check the timing, because that's the only thing we haven't checked and that's the only thing that we cannot control. My thinking is that the computer is working against us here, but I don't know why. We aren't yet read to start throwing parts at it, but we are getting close to replacing the crank sensors to see if we're having a fire issue under a load. Does anyone know if that's a problem?
     
  23. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    For cold control adjustment disconnect the electrical connector, then adjust while the motor is running. Once you get into range, the pin position is very sensitive, so you have to be patient and tap lightly.

    To identify a single cylinder misfire, run the motor for 2 minutes from cold. Then shut it off and touch the exhaust manifold pipes close to the head. For a misfiring cylinder, you will be able to hold your finger there with no discomfort.
     
  24. Sickly308GTSi

    Sickly308GTSi Rookie

    Oct 10, 2018
    16
    Full Name:
    Mark Collins
    Ok so we verified that the timing is acting as it should on both banks, both at idle and above. We used an adjustable light so we were able to bring it off idle and monitor the advancement in accordance with a chart we found and the vacuum advance seems to be ooerating correctly. We still cannot get it over 3,000 RPMs. We doubled-checked the system pressure and it’s 78-80 PSI. Control is 50. I wanted to see if we had a coil breaking down under power, so I looked at the coil fire at idle and above, and we have a healthy blue arc. While not a technically robust diagnostic procedure, I feel satisfied that we have adequate spark through the small range that the engine operates in right now. The only thing that we can not verify is that the cams are in time, because we’re trying to avoid removing the covers. My thinking is that we would have (at best) erratic timing light results if our teeth were off.

    With a myriad of information at our fingertips, all of it seeming to be within spec, we still cannot get it to behave. Last night we weren’t yet at a place to start arbitrarily changing parts, as for today, I’m not sure we still have that tenacity. If anyone has any other ideas, I’d gladly hear them out.
     
  25. spicedriver

    spicedriver F1 Rookie

    Feb 1, 2011
    3,859
    More tests for misfiring cylinders - remove the wire and extender for each cylinder at a time. Connect your old plugs and make sure the body of the plug is grounded. Start the motor, you are looking for a good spark on the plug, and also if shutting down this cylinder has a negative effect on the running condition.

    Test for fuel flow to all cylinders, FD slit clogs - remove the injector hats and place the pipes in graduated cylinders, or baby bottles, something with a measurement on it. Turn the ignition key to run, then press down on the air vane. Try different positions of the air vane. You should get an equal amount of fuel in each bottle.

    Test for a lean running condition - rev the engine to 2500, then press down slightly on the air vane. If the RPM increases that would indicate a lean condition. (e.g. vacuum leak) Your fuel pressures do look okay.

    If there is a possibility that the cams are off, I would check that first.
     

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