2G Car died will not start

[christiane]

Background info: I recently installed a built 7 bolt in my car and the first 200 miles of break in went fine aside fromt he typical leaks here and there. (The build consisted of wiseco 9:1 pistons, eagle H beam rods, bored 20 over 7 bolt, SBR stage II head with titanium retainers, dual spring valve springs, 1g turbo cams, stainless steel valve springs, etc) I had my rev limiter set @ 4000 rpms via DSMlink and set the external wastegate to 5 psi.
On my way to renew the tags on my car I was coming off the interstate and downshifted when the car backfired and lost all power. My immediate thought was that something had happend witht he valve timing so I pulled the upper timing belt cover to examine the timing marks. Everything lined up but the tension of the belts did not feel correct. I had to pull the transmission anyway to replace the mainseal (installed incorrectly from the machine shop where I purchased the short block) I decided to pull the motor as it wasnt much more work to pull the motor and transmission. I turned the motor over with a ratched and the compression numbers were low (between 60 and 80 psi) I attributed this to a combination of the rings not seeding yet and the the fact that I was turning the motor by had.
After this did not fix the car I was informed by a member of another site that the engine would not run with bent valves. Despite the fact that I have had small block V8s that would start and run, poorly but run I took his advice. Took the car to a mechanic and had the head pulled and took it to the machine shop that does all of our machine work for our race cars. They informed me that the head had NO bent valves.
Little things I noticed: the timing belt appeared to have "walked" out towards the timing belt cover and rubbed the outer cover. What would have caused that? Is it a major deal? There was an oil leak under the timing belt cover and the timing belt and components were exposed to oil. Could oil on the crank position sensor have caused it (the sensor) to die?
I have varified that the car is getting spark. I believe it is getting fuel based on 'feeling' the injectors. I have narrowed it down to two possible problems: 1) bad crank position sensor. (Would it still be getting spark if it was not getting signal from the TPS?) 2) Similiar problem as I had before with my DSMLink ECU. I dont really suspect this as the last time the track on the ECU cooked as a result of an electrical short.
Does anyone know of any other possible solutions to this problem? Wisemen please help me out. I apologize for the length of this post but I wanted to provide all the information that would be relevent. Thanks for the space!

 

[Old Mitsu Tech]

Wow. Ok, this may take a while. First of all. If you bend valves you will have zero compression. I've not seen a DSM yet that has thrown the belt and just barely bent valves. Not touched at all. Lucky bums. Or absolutely trashed. Usually ruining the valve guides too.

Do me a favor. Take some cheap Gumout carb spray and spray into the intake. Does it try to start? If not, first thing check plugs to make sure you didn't gas foul them.

If they are ok and it doesn't try to start it's spark/air/compression.

If it tries to start, then it's fuel or the pcm not sending a signal to the injectors.

Do this and let us know. Pm me to let me know when you post.

 

[christiane]

Thanks for your reply tech.
I will be dropping the cylinder head off tomorrow to the mechanic. (I would be doing the work myself but with both dirt cars in the garage there is no room for the DSM )
Are the compression numbers I mentioned on par for a freshly built motor w/ the rings not seaded?
Also, is it possible that the problem could be related to a faulty crank position sensor?

 

[christiane]

[update]I stopped by the mechanic today to drop off the head and gaskets and I asked him about the crank angle sensor as I had planned on replacing it (still under warranty from advance) when he told me that the sensor looked ruffed up.
When I went over to look at it I noticed that the timing belt had been rubbing the lower timing belt cover.
I wont know anything until he gets it back together but I am beginning to think I was sold a walked motor by a fairly well known member here and on the 1gina2g list. [/update]

 

[Doug99RS]

[update]I stopped by the mechanic today to drop off the head and gaskets and I asked him about the crank angle sensor as I had planned on replacing it (still under warranty from advance) when he told me that the sensor looked ruffed up.
When I went over to look at it I noticed that the timing belt had been rubbing the lower timing belt cover.
I wont know anything until he gets it back together but I am beginning to think I was sold a walked motor by a fairly well known member here and on the 1gina2g list. [/update]

Compression numbers are taken using an engine that is being driven by the starter motor. Spinning it over by hand and recording the readings really isn't reliable as no one else measures compression in this manor and there's no standard. You could have used compressed air in each cylind and checked for air coming out the intake or exhaust to check for bent valves. OR you could have used a vacuum gauge and expect to see about 19 inches of vacuum on a good engine with stock cams. Fluttering of the gauge could indicate bent valves, wrong mechanical timing or aggressive cams.

The timing belt walking is definitely something to be concerned with and if you hit the crank sensor you will definitely have poor/no/mis-timed spark since this sensor is very tempermental. You can put the crank pulley on the crank and check for walk by prying between the block and pulley even without the rest of the timing assembly being in place.

Finally, feel free to use the trader points system in place to keep your thread from being locked for a potential flame war. Sorry you're having problems with the car.
Doug

 

[christiane]

Doug, thanks for the information regarding the compression numbers. I didn't put much faith in the numbers with turning the engine by hand.
Is there anything, other than CW, that would cause the belt to rub the lower timing belt cover around the idler puller and damage the sensor?

 

[Doug99RS]

Perhaps a pulley out of alignment, worn tensioner pulley (has a bearing in it if I'm not mistaken), there's also another pulley that has a bearing I think. Then there's the balance shaft pulley as well if it's got worn bearings it may walk. Obviously an oil and coolant free timing belt area is very much preferred but I've seen tons of leaking cam/crank seals and they never walked a belt off.

You could move the pistons down until all of them are half-way through the stroke and then rotate each cam individually and verify that the cam gears aren't warped and the cams aren't walking. Of the two I would lean towards warped gear before walking cam (never heard of it, just seized ones).

What about the timing belt tensioner? Is it new or used? Slack in the belt can surely caused some erratic movement of the belt and like everything else on the car once something starts doing something it will continue doing it. Walking leads to running, tire wear never stops, just slows and leaks don't fix themselves.
D

 

[christiane]

Ok, sorry about the delay in posting a reply (working 14 hr shifts on midnights is about to kill me). I doNOT believe the car has CW, after talking to the person I purchased the motor from there car was an auto, then I went to the garage to look at the car and noticed that the crank trigger plate does have an offset, I had the mechanic flip it over to see if that would eleviate the position sensor contact. And I replaced the CPS sensor itsself.
However, I got a voicemail from the mechanic today tell me that the car will not start. I am sure that he did not try spraying carb cleaner or something of that nature directly into the TB. SO I am going to assume, since I was previously getting spark that it is a fuel problem. I am getting fuel to the rail. But apparently the injectors are not firing. What is the trouble shooting procedure from here?
This may be an unrelated issue but here is some additional information ona problem I had believe to be seperate from the starting problem: I had been having some odd electrical problems. The problems were similiar to an alternator dieing. Car wanted to die at low RPMs, started cutting out if the heater and radio were on, lights would dim when depressing the brake pedal. Maybe some type of grounding issue? Could this have fried ECU's ground circuit on my DSMLink ECU again?
Thanks for the help guys.

 

[christiane]

update:
I picked the car up from the mechanic on Friday and it was running terribly. I thought it was due to the configuration on the ECU and the fact that my fuel pressure was not exactly set. So I went ahead and drove the car 20 miles to get back to my house where I could reload the ECU config from my laptop. About a mile away from the house the car started missing, and sputtering terribly and finally died. Before the car died I looked down at the EGT and A/F gauges and noticed that the tach. was bouncing like mad, despite the fact that the RPMs sounded constant. I am going to assume at this point that it is the cam position sensor again. I do not see how I could have walked on a motor that only has 220 miles on it. But, I am at the point now where I do not see any other option.
Can the crank trigger be put on backwards? It has an offset to it, but it is offset outward away from the engine. Any insight would be greatly appreciated.