Post Reply
Bruce
Gold
Gold
Posts: 187
Joined: Tue Mar 22, 2005 10:09 am
Location: Four Ashes, UK

Difficult hot engine restart

Post by Bruce »

Hello all,

Every 75 (3.0 litre) I have had, all suffer(ed) from the same problem; difficult / jerky / misfire after restart. This occures with a hot engine.
I have checked the carbon canister, valves, filter etc with no fault found.
I have noticed that during the cranking period there is a hissing or drone from the petrol tank; sometimes releasing the vapour pressure by opening the petrol cap elevates some of the problem.
Any idea what the problem is?
User avatar
ar4me
Verde
Verde
Posts: 645
Joined: Fri Dec 03, 2004 9:55 am
Location: Southern California

Post by ar4me »

Assuming this is an L-Jet car (and not a later Motronic) I would check the cold start thermo time switch and cold start injector (at back of plenum). The hissing at re-start (kinda sounds like a jet passing?) is pretty normal, I think. I have it and have had it on a number of 3 liter milanos/75.
Jes
87 Milano Verde - daily driver - Juliet
87 Milano 3.0 Motronic - budget race car - Roxanne
87 Milano 3.7 24v - race car
(Repeat or do as I say at your own risk - be critical)
Bruce
Gold
Gold
Posts: 187
Joined: Tue Mar 22, 2005 10:09 am
Location: Four Ashes, UK

Post by Bruce »

...it is motronic, the last 3 I had where L-jet..
User avatar
ar4me
Verde
Verde
Posts: 645
Joined: Fri Dec 03, 2004 9:55 am
Location: Southern California

Post by ar4me »

If it is a Motronic then the 164-guys are probably a better source as no gtv6s and relatively few 75s were Motronic. I'm not sure if it is the same Motronic version as on the 12v 164s, but you could try the 164 forum or the 164 section on the Alfa BB.
Jes
87 Milano Verde - daily driver - Juliet
87 Milano 3.0 Motronic - budget race car - Roxanne
87 Milano 3.7 24v - race car
(Repeat or do as I say at your own risk - be critical)
User avatar
Zamani
Site Admin
Site Admin
Posts: 1774
Joined: Sun Nov 28, 2004 8:20 pm
Location: Cameroon

Post by Zamani »

Motronic just changes the pulse width of the injectors instead of a cold start injector.

Sounds like vapor lock? But vapor lock should be almost non-existant in an EFI car. Something tells me that there's something wrong with the "breathing" of the fuel tank. I'm not very good with these types of problem.

Try opening the fuel cap and starting your car, does it start without problems?
User avatar
Mats
Verde
Verde
Posts: 4059
Joined: Mon Nov 29, 2004 12:26 am
Location: Gothenburg, Sweden
Contact:

Post by Mats »

Whan did you change the plugs? Often overlooked and can make a HUGE differance.
Mats Strandberg
-Scuderia Rosso- Now burned to the ground...
-onemanracing.com-
-Strandberg.photography-

GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
Bruce
Gold
Gold
Posts: 187
Joined: Tue Mar 22, 2005 10:09 am
Location: Four Ashes, UK

Post by Bruce »

I think it is a vapour lock or percolation / heat soak issue.
I always thought the fuel tank was a pressured closed loop system with any vapour or excess pressure released into the manifold on start up.

Plugs are OK.
Post Reply