SndOfProgress

so, I'm going to try to be as detailed as possible.

1988 manual s4 non-turbo

the engine has been in the car since wednesday and i cant figure out what i've done wrong. There is spark, gas, and compression.

the omp was a big reason for my having to rebuild this engine due to it being faulty, so i have disabled it. and i am premixing 1ounce oil :1 gallon of gas.

here goes:

when cranking it initially i found that i did not adjust the crank angle sensor correctly (was looking at wrong mark on pulley) so i adjusted that, and since then the timing sounds ok. after it still wouldnt start i figured it was flooding (which it was) so i pulled the plugs, cranked it for 10-20 seconds w/out the egi fuse, added some seafoam and reinstalled the plugs.

when i pulled the plugs they were definately wet. but the strange thing is that the liquid was dark. like grey-black. also, the trailing plugs were worse than the leading.

anyways, i reinstalled the plugs and it got closer to starting than it has yet, (to about 800 rpms, then died again.)

I repeated that process more times than i can remember, and still no luck.

i am not sure what caused the plugs to look so 'dirty' is that normal? maybe its just cruddy gas from sitting. (i did, however drain the gas tank and add fresh gas/oil before i tried to start it).

so what do you think guys? could i have missed a connection on the engine harness??

a vacuum leak is not probable right? wouldnt it at least start if i had a vacuum leak.

it definately sounds like it wants to start. some people have suggested push/tow starting it. is this a good idea? im a little wary.

any help is definately appreciated, thanks alot

HAILERS

Make a fuel cut switch or pull the plug on the fuel pump. Forget the EGI pulling bs. Spray starter fluid into the air filter for two seconds and no more. Try starting the engine. After a couple of tries I expect it to rev and die a couple of times. Then spray in the filter as described but this time have someone at the ready to put the fuel pump plug back on the harness in a nano second. Start the car and as soon as it revs the other fellow couples the fuel pump plug and the engine stays running with your right foot.

Just one way, not the only way. A rebuild will have low compression initially in most cases imho.

Hmm. I re-read your post and you have it rev to 800 give or take, several times? Happens almost every time? But won't keep running? AFM elect plug on????? SURE??????? The AFM isn't used until the rpms get over 500rpm, THEN it's the item that determines fuel amount.

HAILERS

Or something else to ponder. Two things normally keep the fuel pump running. First is the key being HELD to START turns the pump on, and it keeps running , IF the key is HELD to Start.

Secondly, once the key is relaxed from start to ON, if the engine is running then the fuel switch inside the afm is MADE, and the pump keeps on running. IF the switch in the afm is not MADE, then the pump stops once the key is not HELD to START anymore.

Simply jumpering the yellow, two socket fuel pump check connector overcomes the switch inside the afm and the pumps keeps running anytime the key is to ON or better.

SndOfProgress

yeah, i was wondering about that.
ill try that this time around... i will need to de-flood it again. on the s4 is the fuel cut when you hold the pedal to the floor??

if i do bridge the yellow connector that keeps the pump on, but if the afm is bad will it be injected into the engine?

polito Racing

iTrader: (1)

nope thats on the S5

SndOfProgress

so apparently the afm works. when i push the flap open the % increases on the monitor on my safc2.

due to my blocking off the omp i also put a cap on the vaccum nipple that would run to the 4 oil injectors. should this be capped? or left open?

UPDATE:: in my first post i couldnt get it to start at all. now it will start and die as soon as it gets to ~800 rpms.

is this vacuum related or electrical? theres a small green wire coupling (on the engine harness) that i couldnt find a appropriate connection for. I believe it was for the "water thermo switch" which is for auto trans only right? should i leave this wire loose? are there any other engine grounds other than the one that bolts to the housing/vacuum bracket?

polito Racing

iTrader: (1)

that is probably your problem you are probably unmetered air into the engine causing the car to die. take the oil injectors out and block holes. there are actualy aftermarket plugs for this.

HAILERS

Full pedal with a series five will cut the fuel coming from the injectors. NOT on a series four though. Some people make/buy a fuel cut switch on series four cars, to keep the fuel pump from running. NZCONVERTIBLE wrote a thead or wrote on a thread on how to wire it. The idea is to cut the fuel pump off only when trying to start the engine instead of pulling EGI fuses etc. Once the flood clears the engine will start and at that same time you flip the switch you made to ON. Engine then keeps running.

Ehhhhhhhh....the jumping the yellow connector will bypass the fuel switch in the afm. That switch in the afm is just that. IF the vane/flap moves aft just a eighth inch or more, the switch gets *made* and puts a gnd on the circuit opening relays coil. Jumpering the yellow connector does the same. Puts a gnd on the circuit opening relay. I"d assume the rest of the afm is working IF its electrical plug is still on it.

That yellow two socket connector has two wires (who'd a thought). One wire goes directly to gnd. The other to the circuit opening relays coil. That OTHER wire is also spliced to the wire going to the afm. So you more or less can see how jumpering the yellow connector is the equiv of the afm fuel switch *making*.

I'd assume the rest of the wires/functions of your afm are probably good. Who knows.

HAILERS

Ah. YOU fixed your problem. The water thermo sensor is a large player in the starting and running of the engine. Put the green plug on the sensor now. The one on the back of the water pump HOUSING is the one I mean.

Oil injectors.................capping it should have worked. The nipple right on top of them. The suction is FROM the rotors so they should stay on. I'd have put just a dab of RTV on the *caps* you make/installed. The nipple on the injectors where the oil lines were should also be capped or a dab of RTV put on them. Not so much where you can't go back and use the injectors again someday.

PUT THE GREEN PLUG ON THE SENSOR AND TRY AGAIN.

EDIT: Ah, dog poop, You said a green wire, not PLUG. MY bad. A green/black wire would be the wire to the aux fan water temp switch, not the water thermo sensor. Again.........to lazy to erase the above.

A LARGE air leak could be the problem, I agree. Where? Got me. The one inch hose on the bottom of the black intake duct could be one. IT in turn connects to a metal tube on the back of the throttle body and leads to the air bypass valve and BAC feeds on the left rear side of the engine. One of those hose could be off. Intakes been off. Maybe a wire caught under the upper intake manifold is causing a leak. Kinda hard to say where. Talking series four non turbo car.

SndOfProgress

yes, all the omp injector holes have been blocked. i was referring to the vacuum nipple on the dynamic chamber (top in series of 3). should that be capped or left open?...

yeah, the wire was for the water thermo 'switch' according to this pic in my haynes manual. which should then be left alone right?

ill double check all the air lines and such. thanks for all the help!

HAILERS

Capped if not in use. If that's the large nipple it's an unmetered air leak. Cap.

HAILERS

What is the color of this green wire???? Green with a black stripe? Green with a white stripe?

SndOfProgress

alrighty heres the final update::

ITS WORKING!!! WOOOO!! turns out im just lame, and didnt have the timing set right... :/ but, guess thats just a learning curve. also the rear primary injector was bad. (took it to the shop and had the pros set timing and stuff" but man does it run smooooth.

cant believe i actually built an engine!! but anyways. now i just have an overheating problem to tackle.. that might be material for another thread.. thanks for all the help guys!