Classic Audi - View Single Post - cold start problem

andya · 14-01-18, 08:39 AM

Update on this one:

The cold start issue has gone on till now, when my new years resolution was to get it sorted! Well it's now fixed!

There was a combination of factors that I reckon somebody may find useful if it ever happens to them. Checked every hose for leaks, replaced every vacuum pipe with brand new silicone hoses. There were leaks, bit it wasn't the main problem. The warm up regulator that I had refurbished - faulty!!! I pressure tested it, and it was at 10 bar under pressure. Replaced it with an old spare oily reg, perfect! So it's stayed on, and now wondering whether I can contact the firm where I had it refurbished and get it sorted - it's just a pain in the arse!!

Last weekend I also set about replacing the throttle body, as the switch on the body itself is broken. That's all sorted. In my quest for air leaks, I found that the fuel injectors were quite loose where they sat in the cylinders - you could wiggle them around, and having no idea when they had been last done, thought this should be my next port of call. So during the last working week I ordered new seals, o rings and inserts from Quattro Corner, and the bits he didn't have from VW Heritage. Yesterday I did the job, including cleaning the injectors in an ultrasonic bath. The spray was so much better afterwards!! All back together again, start from cold, hallelujah!!!!!

Real test is this morning, from cold!

However there is a sting in the tail. All put back together again in the dark last night, I could adjust the mixture, but turning the idle screw made no difference. This reared its head last week. It would indicate an air leak, but I've now covered everything!

Any ideas, got another day today to try and sort

14-01-18, 08:39 AM	#8
andya Senior Member Classic Audi Club Member Join Date: Aug 2010 Location: Hampshire Posts: 1,149	Update on this one: The cold start issue has gone on till now, when my new years resolution was to get it sorted! Well it's now fixed! There was a combination of factors that I reckon somebody may find useful if it ever happens to them. Checked every hose for leaks, replaced every vacuum pipe with brand new silicone hoses. There were leaks, bit it wasn't the main problem. The warm up regulator that I had refurbished - faulty!!! I pressure tested it, and it was at 10 bar under pressure. Replaced it with an old spare oily reg, perfect! So it's stayed on, and now wondering whether I can contact the firm where I had it refurbished and get it sorted - it's just a pain in the arse!! Last weekend I also set about replacing the throttle body, as the switch on the body itself is broken. That's all sorted. In my quest for air leaks, I found that the fuel injectors were quite loose where they sat in the cylinders - you could wiggle them around, and having no idea when they had been last done, thought this should be my next port of call. So during the last working week I ordered new seals, o rings and inserts from Quattro Corner, and the bits he didn't have from VW Heritage. Yesterday I did the job, including cleaning the injectors in an ultrasonic bath. The spray was so much better afterwards!! All back together again, start from cold, hallelujah!!!!! Real test is this morning, from cold! However there is a sting in the tail. All put back together again in the dark last night, I could adjust the mixture, but turning the idle screw made no difference. This reared its head last week. It would indicate an air leak, but I've now covered everything! Any ideas, got another day today to try and sort __________________ 1985 Coupe Quattro 1986 Coupe 1.8 weber carb 1987 Coupe 2.2 GT Last edited by andya; 14-01-18 at 08:48 AM.