New 1.7 won't start Options

[silverteener]

Hey guys,

We put my rebuilt 1.7 in my 72 but when I went to start it the thing won't fire. (IMG:style_emoticons/default/confused24.gif) Is it the timing? The guy that rebuilt it supposedly set it before we put it in but that doesn't mean its right. Can I check the timing if it won't start? Any tips on how to get it running would be greatly appreciated. Its starting to get warm again and I should be driving this instead of my truck. Any suggestions?

thanks

Scott

[johnnie5]

Before you assume the timing is off, check that you are getting spark and fuel....

[silverteener]

how should I check for spark?. I will also pull the injectors and make sure they are spraying. Since its a brand new engine my Dad is worried about me turning it over too much. he's worried it will hurt the engine.

[SLITS]

Pull a high tension lead (spark plug wire), stick a screwdriver in the end, hold the shaft of the screwdriver about 1/4" from a metal surface on the engine, have someone crank the engine over ... if you see a spark jump or get knocked on your ass ... you have spark.

[Spoke]

You can always check spark with a timing light.

[McMark]

(IMG:style_emoticons/default/agree.gif) I like the timing light technique. You're not looking for timing marks. If you see the light flash, then that spark plug is firing.

Carbs or FI?

[Cupomeat]

Sorry to state the obvious, if I am, but is the fuel pump running while cranking?

This is a good start.

[silverteener]

I'll try the timing light. I'd rather not get shocked! It's fuel injected and I can hear the pump when I try to start it. I know there was fuel to the injectors but I haven't checked to see if they sprayed. They are all rebuilt so I just assumed they would.

Thanks!

[r_towle]

If you have points, and once you establish that you have spark...you can static time the car.
Look up "static timing" to establish a base line of timing that is damn close...close enough to start most cars.

Rich

[silverteener]

I pulled the injectors on the drivers side to see if they spray and they don't. I can hear the pump run for a second when I try to start it but the injectors are not working. This would be something electrical right? Maybe something on the relay board?? Please help!!

[McMark]

Check to see if the center two relays on the relay board click on when you turn the key. Just turn the key on and pull the relays one at a time. As you reinstall the relay you should feel it click. If that technique doesn't work, you can put a finger or two on the relay and have someone else turn the key on and off to feel for the click. If that doesn't work for you, it's multimeter time.

[swl]

I pulled the injectors on the drivers side to see if they spray and they don't. I can hear the pump run for a second when I try to start it but the injectors are not working. This would be something electrical right? Maybe something on the relay board?? Please help!!

So you have the fuel pump spinning. That's good. Next step is to determine if it is actually delivering fuel. If you don't mind getting a little gas on your engine try this. There is a little cap screw on the drivers side fuel rail. Try taking it off and turning on the ignition. You should get a little squirt when the pump does it's initial presurization. I guess you could hook it up to a hose to avoid getting gas in the engine compartment - might be safer too ;-) .

Best way, of course is to hook up a fuel pressure meter but I'm assuming you don't have one of those.

If there is pressurized fuel then most likely you are looking at electrical. Either the trigger contacts on the distributor or the wiring harness to the mps.

[silverteener]

I do have a fuel pressure meter but don't really know how it works. I hook it up on the drivers side fuel rail but then do I just try to start it and see what it reads? What should it read?

thanks

[swl]

That tit on the drivers side rail was intended (it think) to attach your fuel pressure guage. My guage doesn't fit so I tee it in between the rail and the fuel pressure regulator. 28-29 psi is the target pressure.

You can get a good indication that the pump is working without having to crank it - just key on and off a couple of times. Right now you are just seeing if fuel is being delivered. Really a lot easier just to run a hose off the tit and see what the pump is putting out. This is troubleshooting not tuning.

[silverteener]

I pulled the screw out of the tit and turn the key a fuel times and fuel does come out, but still nothing out of the injectors. I still need to check the relays.

[silverteener]

The guy that rebuilt it finally called my Dad back today and they might be working on it this afternoon. Other than checking the relays is there any else I can point them to.

Thanks

Scott

[swl]

grounds, trigger points, wiring harness to mps - the relays will not be a problem since your pump works

[silverteener]

Well,

the guy never showed up so I'm on my own again. I will check the grounds after a little while. how do I check the harness to the mps? Not sure how to check the trigger points either? what is it that makes the injectors work.

[swl]

lol - everything makes the injectors work!

Here is a link to the the best damned D-Jet guru who ever graced the internet - Brad Anders. Before you poke around anymore take an hour and read his site. Then you will understand. Pay particular attention to the section labeled Porsche 914 D-Jet Fuel Injection Harness Data - para 10. His method of testing by removing the wiring harness from the ECU is the best thing a guy/gal can do when confronted with a contancerous D-Jet. Well - that and replacing the vacuum hoses. Don't just read the page I'm pointing you at. Look at all his d-jet stuff.

http://members.rennlist.com/pbanders/DJetParts.htm

[silverteener]

I found one of the wires going to the MPS was broken. Hopefully I can get it fixed tomorrow. Thanks for the info on Brad Anders site. I forgot I actually had all that printed off already. Hopefully this broken wire is my problem.