Starts rough when warm

[Argeo]

I noticed my car (77 911 3.0 ROW) starts great when cold but starts poorly when warm. Took car out for long 30 min. ride (for me) and the car ran great. Stopped at home and I let it sit for like 20 mins. Well, when I started the car it idled very poorly. The revs went up and down but not like it was too rich (revs way up and then down) but more like the gas flow was weak. It would almost die but then get back up to 1,000 rpm's and then drop again. No backfiring or anything. Any thoughts?

[enolam]

You need a set of CIS test guages and a book to figure out these cars. It's probably the best investment you could make before you just start replacing parts.

[yelcab1]

Yes, CIS tester will tell you 90% of the information you need. It would be better than replacing $400 WUR.

[jwmc1]

I had the same problem...changed my fuel accumulator and now it works great. Sounds like vapor lock...very common with these engines. Not a real expensive part to replace and it and the fuel filter are easy to replace.

[Paulporsche]

Malone and Yelcab1 have good advice.

Why do you say the fluctuating is not like being too rich? It certainly sounds like it is.

Usually the fuel accumulator or fuel pump check valve are the culprits for poor warm starting.

Paul