Wont start settings problem?

chenz · Post by **chenz** » Sun Jul 15, 2007 9:14 am

When I crank my engine it sounds like it wants to start but doesn't. It has good spark and fires but sounds like it's not getting enough fuel but when I raise the cranking pulse widths it doesn't get any better The longest Ive been able to get it to run for is about 3 seconds. The timming is set to 10BTD, been tested with a timing light. and I get good spark at all the plugs. it has a purchased relay board and has a hall sensor direct coil control and it's setup for a knock sensor. I have had a reset problem so everything is now fine on the wiring side of things. (fixing everything possible)

I have megasquirt 2 installed on a volvo 740 turbo with the latest code.

Also the RPM signal drops out sometimes, it's mostly seen after setting the warm up enrichments. resetting megasquirt fixes the problem.

I sure it's something in the settings as Ive been over the board and the wiring many times as Ive been having hiccups for about a month now. It works fine on the stim.

I have 300cc injectors and am planning to run 10 pounds boost. the fuel presure is 45psi and the engine cranks at about 200rpm. engine sise is 2316cc

I downloaded some tables and have modified the spark table (I know it's not supposed to look like that) just for a start. The reason it has such long cranking pulse widths because Ive just kept rising trying to get a start.

I can't download the datalog off the floppy. I will post it tommorow

chenz · Post by **chenz** » Sun Jul 15, 2007 6:22 pm

ok so here's the datalog and it desn't look right. It's only a portion of it as it was long.

Another thing is I have simultanious injection only operating from one injector output. I hope to run duel rails down the track.

I have also reloaded the code a few times which seems to have fixed my intermediate spark but has not helped otherwise.

oughtsix · Post by **oughtsix** » Mon Jul 16, 2007 12:54 pm

Does the fuel pressure stay around 45psi while you are trying to start it?

chenz · Post by **chenz** » Mon Jul 16, 2007 3:38 pm

yes, whenever the fuel pump is on the pressure quickly spikes to the set pressure and holds until the pump is turned off. Although it is a $40 from ebay. Would it be worth swapping back with a stock one just in case? Is there anyway to test them, feed the inlet with the compressed air and seeing what it does maybe?

chenz · Post by **chenz** » Tue Jul 17, 2007 4:38 am

the only thing I can think of is it may be in flood clear mode. How can I tell.

Another point which I didn't think was important is my TPS max calibration is about 460 from memory. whether it's contributing to the problem I don't know.

chenz · Post by **chenz** » Wed Jul 18, 2007 2:20 am

Lance, Did you have a look at my msq?

Ok just reading the link you gave me, which Ive read about 10 times but just then noticed

The after start enrichment starts out at a user-defined percentage enrichment value (typically around 20%), and ramps down to 0% after so many ignition trigger events

as I raised the afterstart enrichmets I would decrece the ignition events, I though it was an enrichment % for certain amount of ignition events, and that's it. I didn't absorb the bit about ramping down. I have been adjusting it wrong

thinking the less ignition cycles the more fuel as the more recycles.

I hope you've just sorted my problem lance, I will try raising the ignition events and see what happens.

chenz · Post by **chenz** » Thu Jul 19, 2007 2:48 am

Problem sorted, well sort of. According to what Ive read I have low impedance injectors, so I used the resistor pack from the donor car. I bypassed the resistor pack and she fired right up. so the car runs, sounds fine, but now I have to find out why they are acting like High impedance. Maybe they are, Ill leave that up to research.

Thanks for the help