can Not start, please help
 

I picked up a '79 928 in october in some what of a running condition (misfiring on 2 cylinders). Since i have had it i pulled apart the intake runners, plenum, throttle body, injectors, and intake to clean it all up and then reassembled. I replaced the plugs, cap, rotor, wires, air filter, and several vacuum lines. After this was done it ran better but still misfire on cylinder # 8 (previously #'s 1 & 8). Then the car sat from middle of november till a weeks ago since i changed all the belts, blew clean all the fuel lines, new fuel filter, and checked and cleaned fuel distributer. The battery died during this time so it was just replaced but now the car will not run. I had it run for about an hour a weeks ago perfectly smooth but went out the next day to start it and ever since it will not turn over. Seemed like fuel so pulled everything apart but fuel was fine all the way to injectors. The it kicked over for a few seconds and then popped and white smoked poured out the intake body, and once again would not kick over again. I was wondering what i should try and do, or if it is just that the car has sat for such a long time that it may be doing this, any help would be greatly appreciated as i am a newbie. Thank you

do you have a hot post cover??
was the car wet or has it been sitting with snow on it??
Is the CE panel or the floor wet ?

it hasent turned over since new battery? if so its your battery connection. also sound like could be loose or bad starter? dead alternator draining power? the white smoke was probably condensation. Also injectors can seem OK until put under a load then fail...****** sells rebuilts for a good price. Check for spark from distributor..if you have strong spark has to fe fuel related....928's dont like to sit for a long time...could be waterleakage around fuse box as well.....

thanks for the reply. The car did turn over for a few seconds since the new battery and i checked the starter everything is properly placed and tight. The car is not wet on the inside, but it did sit in snow for about 2 days since we had a blizzard in the end of Dec. but it was under a cover and i cleared all the snow by the second day that was on it. Like i said i had it up and running about a week ago for a good hour and it was smooth and since then i did not touch anything and it would not kick over again so then thats when i went ahead and changed the battery and check all the fuel lines again. I will check the fuses as well and try again, i appreciate all the help and thanks again

You have alot of testing to do. Start by hot jumping the starter post. This will tell you if your starter is bad. Let us know.

ok i will try that and post back soon, thank you

Hey tr928, I am in Tuckerton. Just picked up an 86.5 after tbelt failure. Maybe we can learn stuff together. I have pulled my engine and am ready to reassemble.

Did you check for consistent spark yet? Do you smell fuel when trying to start? heres a tip...check fuel pump relay #XVII and starter relay#XV and fuses 22 and 13...my 928 wouldnt start once and it was just a loose #13 fuse! these fuses supply power to the fuel pump relay.charts may say 13 isnt used..but it is!..an inline fuse.. the relays can be "jumped" to check its working right.

No Start - Cylinder Miss
 

Hey TR928 - Perhaps your "No Start" issue is something as simple as an intermittent (Park/Neutral) switch if you have an automatic transmission or your clutch peddle switch if you have a 5 speed.

The cylinder miss sounds like it may be a partially blocked fuel injector. To run a static test on your injectors - Remove the fuel pump relay and jumper power to the fuel pump. Point each injectors down into 8 plastic milk jugs then manually move your CIS air monitoring throttle plate. After approximately 10 - 15 seconds of injector flow you can check for any deviation in the cone shaped spray patterns and if there is any deviation between the quantity of fuel accumulated inside each milk jug.

The operation and cleaning of a CIS injector is fairly basic. I have had good luck using a spray can of carburetor cleaner to free up and correct many flow problems. 1st spray carburetor cleaner down through each injector using the attached red plastic nozzle hose and following up with several blasts of compressed air. I have found that a perfect spray pattern isn’t as important as a reasonably matched or well balanced quantity between injectors.

Good Luck - Michael

hey fredfox that sounds great. I do smell fuel when starting it, and when i pulled apart the lines i tried kicking it over to see if there was a blocked fuel line, but fuel came pouring out of all the lines and the distributer when the lines where disconnected. The starter seems to be fine as well, and all the plugs are pretty new but where pulled and cleaned just to make sure. It seems to me as if it where either the fuel, air, or spark that is causing the issue. Since i check and insured that all the fuel lines and injectors are good i assume i can eliminate that, and the plugs look good, so now i feel it may have something to do with the air. All the fuses checked out and battery components seem good as well, but i am only a newbie so my theory is only so good. I appreciate all the input, thank you. I am going to see it i can come up with some more information and try to eliminate more possibility and will post back soon

hey fredfox that sounds great. I do smell fuel when trying to start it. I checked out the starter, fuses, and battery related things and they all seem to check out good. I assumed it was what seemed air, fuel, or spark related. As i stated though i pulled apart the fuel system and they all where clean, i even tried kicking it over to see and the fuel came pouring out of all the lines and the distributer when lines where disconnected insuring me that the fuel could not be the issue as well as all injectors where removed and cleaned placed back and all pulled and where all wet with fuel. So i assumed that i could eliminate fuel, next the plugs are all good but where pulled and cleaned just to make sure, so i would be left with air as a potential problem as well, but the filter is brand new, and all the intake parts where cleaned. My theory can only be so right though as i am a newbie and do not know much about the car but i assumed it had to do with one of theses. I am going to go back and try to test and eliminate other possibilities and will post back soon. I appreciate all the help and thank you

carboned plugs
 

hi, i was able to run through the car again, checked the fuses and electrical related things and all seemed to check out. The car was sitting is the snow for two day back in the end of Dec.. It seemed to me as if it may have been a fuel, air, or spark issue. So i went through the fuel system and it all checked out clear, then air has all been cleaned out and brand new filter, and the plugs where brand new as well, but i pulled them anyways. Sure enough the plugs where fouled, they were all carboned up, so i cleaned them and put it all back together and it turned right over, ran for about 5min but then turned off. So i pulled the plugs again and there are all carboned up again. So what could be causing this to happen? I did not tough the motor these past 2 months except for doing all the belts and cleaning it up a bit, and since i did the throttle body, plenum, and runners clean it has run fine. Theres all brand new fluids as well.

Thanks

either your rings are shot and its oil fouling the plugs..or valves leaking oil in..or its running really rich fuel / air mix..caused by bad o2 sensor or airflow meter.

Lots of crud/sludge can build up in the runners, how well did you clean them? Might be some loose stuff still left in them breaking free and fouling your plugs.

79 doesn't have O2 sensor, and airflow meter is mechanical so easy enough to check to make sure it's operating freely and not binding. Pedal switch on clutch is not a starter safety switch, only disengages cruise control when shifting.

thats another possibility...perhaps intake runners are sending junk into cylinders?...so hard to tell without being there!:confused:

i would say that i cleaned the runners and plenum pretty well. I pulled them completely apart and one by one cleaned them down with tons of brake cleaner and a wire brush. Scrub them inside and out till they where back to bare aluminum. The throttle body was cleaned just as well, with out scrubbing the inside to prevent from damaging it at all. Thanks for the tips on the O2 sensor and airflow meter, where exactly is the airflow meter located? Could the plugs possibly be the wrong gap and be causing this to happen as well? i had NGK BPR5ES

Thanks

plug gap wouldnt cause carbon..thats the clue!..somethings off....the airflow meter is located under the airbox, and is shaped like a box with a blk connector. But if you dont know what your doing dont try to take it apart..its sealed. you can dip it in parts cleaner and clean it up too.

o yea, ok well i will try and clean that up.

Thanks

78-79's have a slightly different setup on the air meter than 80 forward, see image below. Airbox sits over #9. #12 through #15 are one assembly that sit inside of #9, airflow pushes down on #14 which in turn moves the piston inside the fuel distributor upwards and that's the old fashioned air flow meter.

Cutting edge technology back when 8-tracks ruled the world.
http://www.pelicanparts.com/PartsLoo...ATALOG-038.jpg

ahh yes the cutting edge technology, that diagram and explanation helps a ton, thanks you, i will try and clean that up tomorrow.

could the plugs im using cause it to be running rich and therefore causing the plugs to carbon up? i have NGK BPR5ES, if so would you recommend i switch to the Bosch plugs, WR7DC or WR8DC, the motor is stock.

Thanks

try it! i believe the higher the number the hotter the plug..porsche recommends the bosch wr's. a hotter plug may help burn off more oil or gas without foulling -J

hey i just picked up the Bosch WR7DC+ plugs and am going to try to put them in tomorrow, i was wondering if adjusting the fuel/air ratio would help me out as well, since it appears that it is running rich.

You shouldve gotten the WR8DC--hotter plug. but it shouldnt be that much difference. the problem lies elswhere and the plugs will just help counteract that rich tendency. DO you have a manual? im not totally sure about your 79' but most airflowmeter box's have an adjustment screw on the top corner to tune in air-fuel mix. i think its hex head. I would remove the A.F.M. first and totally clean it and check that the "flapper" valve is moving freely. this device tells the ECU how much fuel to add according to amount of air flowing thru the "flapper" valve. so if its malfunctioning that would throw everything off. the flapper valve controls an internal rheostat switch that could be faulty as well. it could also be as simple as corroded or wet connectors to the AFM! give it a good looking over and get a manual..theyre avaliable on disc now for cheap..highly recommended! ;)

Watch my Video I made when I changed my injectors. It's CIS like your car. I also changed my plugs. Towards the end of the video, it shows where and how to adjust your A/F. You'll need a very long 3mm allen. Push down and clock to richen and counter to lean.

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The carbon on the plugs is probably due to the extra fuel provided during cold starts. If they are carboned after warming up to operating temps, you should check your A/F mixture, check for worn valve guides or check for excessive blowby into the intake.

ok yea i was going to pull it apart and clean it first then put it together with the new plugs and try possible adjusting the air/fuel to see if this would make a difference. I do not have a manual and have hear that i can get one on cd for cheap but just dont know where to get it from. The video is a great help. I will check the other stuff as well.

Thanks

check EBAY for cd manual....or 928 m ot or spo rts...or 928 intl. your on the right track...probably a faulty AFM....or as i said before..could even be a bad connection! Many problems ive had were just simple electrical connections! It cant hurt to clean that AFM anyway after 30 yrs of service! may have never been serviced before! good luck, keep us posted!-J ;)

Roger sells Jim Morrisons CD collection this is the one you want Roger@************

ok thanks you i will try and get my hands on a manual asap...as an update, i didn't have much time yesterday since the cars outside and the sun was going down in bout 40min and i had to try and move the car anyways, so i didn't get to pull apart and clean the air flow meter, or mess with the air/fuel ratio. I put the plugs in to see where i was and i started it, it turned on and i ran it for about 30-40 min, and drove it around the block a few times. The idle was extremely low, on the virge of dieing out, but wen i gave it gas it responded well after it warmed up, just wouldn't idle more than 100rpm's. When i was driving it 1st gear would almost shut off even when i gave it 2500rpms and slowly released into it, then it would go after a few seconds of what seemed like chocking for fuel. I pulled the plugs after it ran for a while but the sun was down so couldn't do much, but they where no where as nearly carboned up as the previous plugs, but where slightly carboned up. I know i should still take the other steps and clean the air flow meter and prob adjust the ratio, but is there anything else i should try as well?

Thanks

stay on track and work with the AFM..and idle adjustment on throttle body....go to autozone and get a air fuel mix meter...that will help you see what happening in real time..but i heard the 79 dosent have an O2 sensor? maybe someone else knows how to hook one up to your 79? good luck.

79 does not have an O2. Buy a Innovate Wideband O2 with Gauge and you will be loving life with your CIS and knowing exactly what it's doing in realtime from "Inside" your car. The kit comes with an O2 Bung that you can have your local Muffler shop weld in. If you you look at the video i posted, you can see the gauge working and that's how I adjust my A/F Ratio.

Here's also a link to my thread on how I installed mine with pics:

Porsche 928 Forums dot com - View topic - Pics of my First 928 and Current Project

Since it accelerates alright, don't mess with the A/F mixture just yet. Clean the air sensor plate and look for any vacuum leaks. After that, adjust the idle and give it another test drive. Then, if it still carbons the plugs, adjust the A/F mixture. The slight carboning can be caused by the crud on the air sensor plate which could also adversely affect the idle.

ok thanks ill try those tips and try to get one of those meters, i just realized that the one vacuum advance that comes off the distributer is not connected, and i can't seems to remember or find where it goes.

Thanks

that disconnect on distributor can cause HUGE idle and surging problems! take a pix and post it.... your talking about the spark plug distributor? or air distribuor? if its the distributor cap for ignition it should connect to the closest vacuum outlet on throttle body. If off the air distibutor it connects to either the brake booster( on drivers side between 2 air tubes) or a switch that connects to smog control and carbon canister...( this ones in the very front of air distributor) you could plug either up with a cap and see how she runs..good luck ;)

i will try and post a pic tomorrow, but the one from the spark plug distributer cap is the one that is disconnected. I thought it went to the throttle body, but didn't see any openings but im sure there is so ill look and post pics, may be a few days though since the temp dropped pretty low here. If im looking from the front of the car that would mean its on the drivers side? and will it be on the back side of the throttle body closest to the drivers side? sorry if that confusing i know pics would be most helpful.

Thanks

P.S. i ordered the cd manual

drivers side is drivers side no matter which way your looking.....there will be a vacuum port on the front next to idle screw...now im going by mid 80's model car..but i believe it should be the same. if just one vacuum port is open that will cause your engine to not start or start and surge w/ rough idle. :)

Finally
 

Hi, sorry for the long time lapse, just had alot of snow here and no time with school. Finally got out today to work on the car, i was able to connect the vacuum advance from the distributor, clean the AFM, all plugs cleaned as well, then adjusted the A/F slightly and the idle. It starts up & runs, throttle responds great after it warms up, doesnt seems to be misfiring either. So i let it run for bout 15-20 min and checked over everything and off i went. When i went to drive it tho, same problem occurred in bottom of 1st gear, it wants to dies out (not as bad as before), but after a few seconds it slowly picks up then goes and through the rest of the gears it fine, but then once i go back to first at low speed it wants to die out. It occurs only when i engage 1st gear and start to take my foot of the clutch, otherwise if its stopped its fine, but when i ease of the clutch to start goin thats when it occurs. I don't know wut to check now, im thinking air/fuel still possibly but dnt see how. Any help would be greatly appreciated. BTW have an exhaust leak in two spots if this is any contributor to the problem, before muffler and where the cat would connect to the rest of the system back to the muffler, and it appears that there has been a cat delete.

Thanks

Have you checked the ignition timing on this car?

N