can Not start, please help

[tr928]

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

[Mrmerlin]

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 ?

[jim ross]

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.....

[tr928]

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

[vdubr928]

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.

[tr928]

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

[Fredfox]

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.

[jim ross]

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.

[JK McDonald]

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

[tr928]

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

[tr928]

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

[tr928]

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

[jim ross]

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.

[rjm65]

Originally Posted by tr928

and since i did the throttle body, plenum, and runners clean it has run fine. Theres all brand new fluids as well.

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.

[jim ross]

Originally Posted by rjm65

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!

[tr928]

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

[jim ross]

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.

[tr928]

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

Thanks

[rjm65]

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.

[tr928]

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