I need engine help

trucker677 · 03-27-2010, 03:49 PM

Hi guys, I am new to the site and I am hoping I can get help with my problem, I will explain it as best as I can and what facts I do know about the car, I do appreciate any help I get. I have a 1982 porsche 928s.
My VIN is WPOJAO929CS820074,
I just bought the car from a guy that simply gave up on the car. He said it was running in Sept 2009 but rough, he thought it needed a tune up so he went and purchased it. brought it home on a flatbed trailer. he put fuel stabalizer in it and left it running and ran the tank dry. he put new gas in it and it started and then shut off a few seconds later. I brought it home and tinkered around with it and decided to look at the plug wires, the only one that was right was number 1. I changed the plug wires around and still nothing, next I checked for spark, I am getting spark. I can smell fuel but I took out the number one spark plug and noticed that there was fuel in the piston. I took out the fuel pump relay and cranked the engine over to try and get rid of the fuel in there. I put the fuel pump relay back in there and still nothing. Next I checked the timing marks on the crankshaft, I brought it up to TDC, I looked at the timing marks on the camshafts, can someone correct me if I am wrong but I think the timings marks are a little triangular slot in between two teeth and the line up with a timing tab on the top of the casing. I had to readjust it because it was out 180 degrees. The guy who had the car before the last owner said it was done by himself. But what I dont understand is how the car ran with the plug wires all wrong and the timing out 180 degrees. I pulled the cap off the dist and the rotor button points to number 1 so I can assume everything is set up correctly now. I hope. I tried rolling it over and still no kick or sputter, I am still getting spark and I can still smell fuel. I am at a loss for this now but I am not giving up, it is a nice looking car. just needs TLC.

dr bob · 03-27-2010, 04:56 PM

The crank turns at twice the speed of the cams, so rotating the crank another 360º would have made the cam timing appear correct. You were checking at TDC on number one, but it was on the exhaust stroke.

I hope you kept notes and pictures about which wires you moved, in case you need to move them back.

The '82 car has a cold-start injector that stays on for a few seconds to get the engine going, then drops out. I'm guessing that it ran on that then stopped. There's a very good troubleshooting list for the injection in the factory WSM. Those are no longer in print, but there are CD sets of the manuals and a lot of factory tech publications available in the grey market. The WSM's alone are online at a UK site-- do a search here on WSM and get the URL. Or buy the better complete set from ************.

Probably the premier 928 support website is at Rennlist.com There's a huge pool of available knowledge, and more important a searchable archive of past posts on just about everything 928. You may need to pop for a membership to use the search function, but it is well worth the few dollars. IMHO.

trucker677 · 03-27-2010, 05:52 PM

I rotated the crank until the timing tab was at zero, I pulled the number 1 spark plug and the piston was at TDC, If I rotated the crank another 360 degrees wouldn't the piston be at BDC or does it come up again after one complete revolution and then come up again after one more. If I take the timing belt off and rotate the crank one turn where should the pointer be on the dist. When I did it before the timing mark was on zero on the crank and the timing tabs were on the mark on the camshafts and the button was on #1. If it is on the exhaust stroke would it still point to #1 on the rotor.

MPDano · MPDano's Garage

Take pics of those marks your using. I think you may be using the wrong ones. Ask me how I know. Harmonic, Cams and Distrib.

Mrmerlin · 03-27-2010, 07:23 PM

welcome to the board now a basic primer in engine timing.... The timing marks should all line up remove the top cam cover for the right cylinder bank then turn the crank till the cam timing lines up and verify the crank timing .
Note the crank damper can be put on backwards..
While facing the engine you should be able to read the numbers on the damper.
Note the #1 cylinder is on the right front of the engine and #4 is at the rear of the right cylinder head,
#5 is on the left front and #8 is at the left rear, this is while seated in the car.
I would remove the plugs and make sure they are not fouled. Also inspect the firing order
Note the distributor rotor should also line up to a small nick in the dist housing when the cam and crank are at TDC.

From your post you are checking the cams with the engine 180 degrees away from TDC for #1 simple turn the crank another revolution and the cams should then line up. If the cams line up and the rotor lines up and the crank doesnt then the damper is most likely on backwards or it is out of time with the cams

MPDano · MPDano's Garage

Here's where I am talking about. He may or may not be using the right marks.

Quote:

I brought it up to TDC, I looked at the timing marks on the camshafts, can someone correct me if I am wrong but I think the timings marks are a little triangular slot in between two teeth and the line up with a timing tab on the top of the casing. I had to readjust it because it was out 180 degrees.

A pic is worth a thousand words

76FJ55 · 03-27-2010, 10:40 PM

First, do you have a copy of the service manuals? If not you really should get some either in electronic form or paper. Paper is only available on the used market and typically sells in the $200+ range though can occasionally be found for less. Roger at ************ sells a CD set that includes a search-able pdf of the service manuals as well as a LOT of addition information, don't know the price on them but have heard they are well worth the investment. There is also a UK based website where a copy down loadable copy is hosed. A Google search can probably find them.

the cylinder number convention on the 928 is different than most v8 as mentioned earlier, so you may need to recheck you spark plug wire routing. The cylinder numbering on the 928 is passenger bank from radiator back to fire wall 1-2-3-4, and driver side from radiator to fire wall 5-6-7-8, and firing order is 1-3-7-2-6-5-4-8.

The timing is based on crank position (degrees) with TDC (top dead center)= 0 =360, and BDC (bottom dead center) = 180. if you roatate the crank 360 degrees the pistons will all return to their previous positions. ie TDC to TDC. However, the cams are geared at a 2:1 ratio. 2 revs of the crank = 1 rev of the cam. So even though the piston position is the same the stroke position changes. If you start with the #1 piston at TDC at the beginning of the power stroke and rotate the crank 360 the #1 piston again at TDC but this time it will be at the regaining of the intake stroke (the cams will be 180 degrees from the starting position). Two revs of the crank will take the engine to an identical position ie TDC power to TDC power (pistons and cam will be back at their original position).

trucker677 · 03-28-2010, 08:02 AM

I was working on the car this morning and I was looking thru the WSM and I did a screw up. I had number 1 correct, but I am used to working on small block chevys where all numbers are on one side and even numbers are on the other, so I got the firing order correct, #1 is on the passenger side followed by 2, 3,4 and on the drivers side is 5,6,7,8. I did the firing order as stated above and still I have no start. I have fuel, you can smell it, I have spark, you can feel it. I looked at the rank when it was at TDC and looked in the book for the timing marks to double check that I was in the right location, I was. Took off the dist cap to see where the button, I have a question regarding that, if the crank was at TDC on the exhaust stroke where would the button be, would it be in the same location as if it was on the TDC on the compression stroke. I just want to make sure I am doing this correctly before I start doing other stuff.

If I have a vacuum leak will that prevent it from starting or will it start and run rough.

Is there a good way to clean out the injectors without buying new ones. Can I soak them in a cleaner or something.

does anyone know the sizes of rubber hoses I will need to replace all vacuum lines in my car.

Once again I thank everyone for the help, It is very much appreciated.

MPDano · MPDano's Garage

trucker677 · 03-28-2010, 09:08 AM

trucker677 · 03-28-2010, 09:12 AM

sorry, I forgot to add the words to the pic, the top pic is the timing mark for the drivers side and the middle pic is the timing mark for the passengers side and the bottom pic is for tdc. The pic in this one is the triangular notch that has to line up with the timing mark,

Landseer · 09:36 AM

Can you shoot a picture of each cam backing plate, and get the whole plate. I don't think you are using the right marks on them. I need to see them, though.

Edit, never mind, I see it now. Sorry.

76FJ55 · 03-28-2010, 09:34 AM

Cylinder 1 and 6 are at TDC at the same time. one will be at the beginning of the power stroke and the other will be at the beginning of the intake stroke. so at TDC marked on the crank pulley both 1 and 6 will be at TDC. depending on which one is at the beginning of the power stroke will determine which location the distributor rotor should be pointing at. I believe that if the cam timing marks are lined up with their respective marks on the head the dist. rotor should be pointed at cyl. 1 on the distributor, and if the marks are on the opposite side of the cam gears than the rotor should be pointed at 6.

Landseer · 09:44 AM

Go to this site, where sharkskin has done a Timing Belt job and look down about 5 or six pictures in his treatise. It will illustrate the back cam cover marks for 1-4 and 5-8 banks. I think yours should be like his. (And in retrospect, I think they are.)

SharkSkin - Shark Attack Round Twenty-Seven - Timing Belt/Water Pump

Crank should be dead-on the mark at the same time.

You are right, those notches need to match the sharp triangular pointer marks on the covers.
I got sideways thinking you were actually matching the notches with the red-colored dot. Sorry, just trying to help.

Restring the belt inf necessary so it all lines-up. But you've got that it seems.

There should also be a notch low on the distributor consistent with TDC. I'll go look at one, put it at TDC, and give you an answer on approx. rotor location.

76FJ55 · 03-28-2010, 09:46 AM

I'm more familiar with the 32v motors which have different marks but he page from the WSM may be beneficial for you. At first glance it looks to me like your cams are timed incorrectly.

76FJ55 · 03-28-2010, 09:56 AM

here are some pics from a thread on rennlist with regard to cam and distributor timing. Hope the original poster doesn't mind. the thread can be found here in full

Landseer · 10:45 AM

Basically speaking, the rotor points forward approximately toward the radiator at TDC.

This should help. Got me and 76FJ55 tag-teaming today. (76, I can't see the rennlist pictures unless the computer recognizes me as being logged-into rennlist / )
Here's 84 5 spd USA at TDC.

Rotor shown at position when system is in this TDC state

The main timing mark on crank

Here's the right bank 1-4 (by Porsche naming convention its right with respect to driver facing forward, AKA passenger side)

Here's your #1 sparkplug wire

Here's your rotor in TDC position (hmm, needs some 400 paper polishing).
Note the little mark on the edge of the distributor, normally covered by the plastic shield, at base of cap.

Finally, another shot of the rotor at TDC. Looks like it has just passed the tic mark, in the picture above, when at TDC. The rotor moves Clockwise, just like the crank does, when viewed from standing position in front of the motor and facing the motor.

MPDano · MPDano's Garage

The marks with your pen is correct on the engine side. Your cam marks will be on the engine side of the cam gear (notch). Do NOT use that round circle and triangle as a guide. Remove the paint from it so not to confuse you later. You look like your also off a tooth since the 0|T is not aligned. Pics of Cam Notch to Pen Marks, 0|T and Distributor Rotor pointing to 1. Once you can get good pics of that, then you will be on time.

trucker677 · 03-28-2010, 02:50 PM

I put the crank at TDC on zero, I looked at the cam gears and they are both on the timing marks, I took off the cap and the rotor is at #1

Landseer · 03-28-2010, 03:10 PM

OK that all is good, then.

We can run you through a bunch of empirical stuff that may help.

Jumping some relays; checking green wire and so on.

Fuel injector relay gets a three way jumper, 30 to 87 to 87a.

Fuel pump relay gets a jumper, 30 to 87.

Grounds (there are a series of them to check) and little positive cable need to be clean. Battery charged. You have lots of reading to do here and on rennlist.