Engine rebuild complete , now wont start !!
Engine rebuild complete , now wont start !!
Author
Discussion

philbrooker

Original Poster:

91 posts

202 months

Wednesday 23rd February 2011
quotequote all
Good afternoon guys,

2.8 Engine

After rebuilding the engine and refitting it I have had enough !

The engine is timed correctly, has excellent compression, new plugs, coil, roter etc. Engine has a good spark and fuel is getting though, pump working. No visible air leaks either.

The engine will fire up on the key but will not "catch" I can even rev as long as thge starter is still engaged (naughty i know)

Any ideas, I wasted my whole day off messing around with this!

Thanks,
Phil

hallsie

2,185 posts

250 months

Wednesday 23rd February 2011
quotequote all
Have you tried some engine start spray down the air inlet?

Its a high octane type thing that might give you the edge you need to get it started properly and may help blow out anything thats causing either a blockage or minor timing problem!

Stu

Wedg1e

27,041 posts

295 months

Wednesday 23rd February 2011
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If you disconnect the cold start injector does it still try to catch? If not there's perhaps a fuelling problem with the main distribution system.

keatsie

326 posts

194 months

Wednesday 23rd February 2011
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Don't shot me but.... have you double checked the valve timing?

philbrooker

Original Poster:

91 posts

202 months

Wednesday 23rd February 2011
quotequote all
Ill try disconnecting the cold start sensor , what will that do ?

Thanks,
Phil

Druid

1,312 posts

211 months

Wednesday 23rd February 2011
quotequote all
This any help??


keatsie

326 posts

194 months

Wednesday 23rd February 2011
quotequote all
Works for me......

chedder

1,329 posts

237 months

Wednesday 23rd February 2011
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keatsie said:
Works for me......
Me too!......either of em!!!!

D1 MAD

383 posts

262 months

Wednesday 23rd February 2011
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Does your ignition light come on before you engage the starter? Sounds like you only have power to the system when the starter motor is running. Check the supply to the coil before and during cranking.

SplatSpeed

7,491 posts

281 months

Wednesday 23rd February 2011
quotequote all
neat fuel in the inlet manifold

good for a laugh

mrzigazaga

18,816 posts

195 months

Wednesday 23rd February 2011
quotequote all
As the poster says.."Avoids down-time of equipment"...Ill have a can and two of those young wenches please..

adam quantrill

11,679 posts

272 months

Wednesday 23rd February 2011
quotequote all
D1 MAD said:
Does your ignition light come on before you engage the starter? Sounds like you only have power to the system when the starter motor is running. Check the supply to the coil before and during cranking.
Yeah - clip a bulb (or a meter) across it - I bet it goes out as soon as you stop cranking.

E Ponym

1,233 posts

297 months

Wednesday 23rd February 2011
quotequote all
Do you have a 6V coil with a ballast resistor.

If you do then check the 12v feed to the resistor.

The 6V coil is designed to provide a decent spark when the engine is cranking on the starter motor so one side of the resistor is connected to a feed that is only live when cranking.

Under normal running a 12 volt feed to the other side of the resistor is dropped by the resistor to 6V, otherwise the points, plugs and leads would crap out early because of over-voltage.

Russ

Wedg1e

27,041 posts

295 months

Thursday 24th February 2011
quotequote all
philbrooker said:
Ill try disconnecting the cold start sensor , what will that do ?

Thanks,
Phil
Well as others have said it's actually more likely to be a problem with the ignition system, I forgot about the ballast banghead

When you're cranking, the thermo-time switch at the front of the engine causes the cold start injector (CSI) to throw petrol straight into the plenum, as if you had, say, an SU carb with the choke on. Thus the engine gets extra fuel to help it fire. Once the engine fires on its main injectors and you let go of the key the CSI shuts off.
So it can happen that the engine is trying to start using just the fuel from the CSI but the main injectors aren't squirting. The K-Jetronic injection's pretty simple and it relies above all on decent pressure from the fuel pump - the injectors need the pressure to help them open, whereas the CSI is opened electrically so will fire even if the fuel pressure is too low for the main injectors to work.
If the car's been stood a while it's not impossible for there to be crud causing a blockage, fuel pump to have siezed etc etc - all, hopefully, worst case scenarios.

If you disconnect the CSI and the spluttering stops, the engine's possibly not getting fuel from the main injectors.

adam quantrill

11,679 posts

272 months

Thursday 24th February 2011
quotequote all
E Ponym said:
Do you have a 6V coil with a ballast resistor.
Good spot - sometime the "ballast resistor" is just a resistance wire hidden in the loom.

Check that the points get +6 to +12V when the engine is NOT cranking. This checks the resistor, too.

taz turbo

685 posts

280 months

Thursday 24th February 2011
quotequote all
adam quantrill said:
E Ponym said:
Do you have a 6V coil with a ballast resistor.
Good spot - sometime the "ballast resistor" is just a resistance wire hidden in the loom.
Iv'e had 2 V6 wedges, for a ballast resistor both had a thickish (about 4mm O.D.) near or next to the air metering unit/air filter.

Chris.

HOTTY

669 posts

204 months

Thursday 24th February 2011
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philbrooker said:

The engine is timed correctly, Engine has a good spark and fuel is getting though, pump working. No visible air leaks either.

The engine will fire up on the key but will not "catch"

Thanks,
Phil
Daft question, are you sure, as my 350 had a long lay up, I thought that i had set up the dissy correct but i took a more experience wedger (wedg1e) to identify that it was not quiet right.

Get somebody to turn it over, whilst you turn the dissy complete. See if that has any effect, it did for me.

Hopefully you find the problem soon

jeff m

4,066 posts

288 months

Friday 25th February 2011
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Assume you've already checked the 8v on run position.

Crack the pressure reg to check the fuel pressure. If none or just a dribble.
You should have residual pressure.
Check for 12v on WUR or Thermotime thingy as thats the same 12v as the fuel pump. Whilst cranking and stallingsmile
Swap the safety module for a regular relay, it if runs then Safty module is not operating and your fuel pump is loosing it's 12v.
(safety mod ops from HT Coil)

How long did the car sit?

Edit to add logic.
If there IS residual fuel pressure then car failed to continue running due to no spark.
If there is NO res pressure then pump stopped before the inginition gave up.


Edited by jeff m on Friday 25th February 05:18

heightswitch

6,322 posts

280 months

Friday 25th February 2011
quotequote all
are you sure it is timed corectly??

One of the most common mistakes is to get the engine timed correctly but find it is 180 degrees out??

First principles. make sure the piston is rising to TDC (use a pencil in the bore to feel it coming up. then make sure the timing marks line up and your distributor is coming up to number 1 HT.

N.

GV

2,366 posts

254 months

Friday 25th February 2011
quotequote all
Try lifting out the dizzy and rotating it 180 degrees, you may have set it up on the exhaust stroke instead of compression.