Another 308 Warm Start Problem

I have looked at numerous previous threads discussing this problem and I have gathered quite a bit of information about how I should go about trouble shooting this problem. I do however,have a question that I have not seen previously addressed.

My '81 Euro GTBi starts, and runs fine from cold. When attempting to restart with a warm motor the fuel pump appears to be running when the key is in Pos II. It does not do this when cold and I was under the impression that the fuel pump only operated in Pos III and when the motor was running. I have pulled the fuel pump fuse to confim that the noise I was hearing was in fact the fuel pump running. Every prior thread I have seen on this topic suggests that I would need to disconnect the plug on the fuel distibutor in order to activate the pump at this ignition setting. Any ideas on what is normal for my car or what might be going on here would be greatly appreciated!

 

Thanks for the replies guys.This info you have provided is extremely helpful and I really appreciate the comments.
The previous owner let this car sit up too long and I suspect I will need to go through and check all the FI components. After just completing the belts/tensioners and changing the fluids I am now actually getting to drive the car some ( YeeeHa!) and also figure out what is going to be needed to be fixed next.

Thanks to Steve's post about air possibly entering the system, I recalled thinking when I previously looked at the air defletor plate that it didn't look completely closed on one side so I went back and carefully depressed the deflector plate and cleaned the seat....there was considerable soot buildup there which may have kept the plate from closing properly and thus allowing the safety switch to operate the fuel pump. I ran the car pretty good today and then shut it off. I could restart the car right away with minimal trouble with the accelerator half way depressed. I then let it sit for about an hour. Upon returning,I was not able to replicate having the fuel pump run with the ignition in Pos II, and the car again would not start when warm. I suspect the fuel system is losing residual pressure.

Thanks to a tip I picked up in a previous post I was able to get it started when warm after disconnecting the cold start solenoid and depressing (both slightly and briefly) the air deflector plate with the ignition in Pos II. I assume that this procedure bleeds the system of errant air while repressuring the system.

From what I read in similiar threads, I think I need to look at my check valve as a possible culprit for losing system pressure.

Anyone want to comment as to whether the WUR is a component that can/should be disassembled and cleaned? Is the WUR a likely culprit in the failure to start warm?

 

well..after inspecting my FI components I have discovered that I appear to be missing the air mixture adjustment screw located on top of the fuel distributor. I have an open threaded hole just in front of the safety switch which according to my OW is where the mixture screw should be located...this cannot be good....

 

If the adjusment screw is located right in front of the safety switch between the fuel distributor and the air plate and the threaded hole has a about an 1/8 rim around it..then I am missing the adjusment screw and the cover cap if there is one....there is nothing there but a threaded hole..no hex headed adjustment screw to be found..am I looking in the right place for this screw?

 

Thanks to your ( and Steve's) post I was finally able to locate the head of the adjustment screw. The screw is tiny and hidden from sight.

I have installed a replacement screw at the opening. This, in itself should change my A/F mixture although I do wonder how much air could be drawn through this small access hole. I will try and see if during a warm/hot restart I can replicate having my fuel pump run again prior to starting in Pos II again. The air plate might be out of adjustment, as was the case for Gilligan's 308.

 

OK..I drove it today and got it nice and warm....recranked it right after I shut it off and it would crank with hardley a problem...came back and tried to re-crank after about an hour and it would not start...even with some gentle pushing on the air plate with the ignition on. I was trying to be careful not to flood the motor. Three hours later I was finally able to get it started and drove it home. When I got it home I left it running with the engine lid open. When I shut off the ignition I detected a faint hollow thumping sound coming from the area of the fuel pump. Probably made about 5 or 6 thumps...Is this possibly the check valve or the accumulator making this noise? I have no fuel coming out of the accumulator overflow pipe. I'm thinking about replacing both of these parts. Seems like I am losing residual pressure to quickly

 

I decided to replace the fuel pump since my original fuel pump had the internal check valve which I suspected to be contributing to my residual fuel pressure loss. I ordered a new replacement fuel pump from Autohaus AZ for a 450 SL ($45,which included a new external check valve). Larry Fletcher at CIS Flow Tech in LA ( Lower Alabama) is THE man for CIS issues and was extremely gracious with his time ,knowledge, and resources in helping me make the new parts work for my application. In updating the fuel pump it is necessary to replace the factory steel lines connecting the pump with the accumulator with new lines and fittings. I could not have done the upgrade with out Larry's assistance.

I have driven the car hard and gotten it warmed up to varying operating temps and let it sit for varying lengths of time before attempting to restart it. It has restarted on all occassions effortlessly. It appears as though the replacement of the check valve has solved my 308's warm starting problem. Many thanks to everyone who helped me trouble-shoot this problem, especially Steve and Larry!