| Author |
Message |
Ric Rainbolt (Ricrain)
Member
Username: Ricrain
Post Number: 489
Registered: 2-2002
| | Posted on Thursday, February 20, 2003 - 10:33 pm: | |
I'd bet 100 lira that it's a fuel pressure problem. The check valve at the outlet of the fuel pump and leaky injectors are the most likely culprits.
BTDTGTTS |
Bill White (Nc_newbie)
New member
Username: Nc_newbie
Post Number: 19
Registered: 2-2003
| | Posted on Thursday, February 20, 2003 - 5:03 pm: | |
I had a problem like this on a Porsche 911 once. It was caused by leaking injectors. That caused a double problem - mild flooding of the engine due to the dripping and vacuum in the fuel lines. Try starting with the pedal all the way down to give you some insight. The only way to be sure though is a 3-way pressure gauge that I was able to build with brass fittings for about $100. |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1386
Registered: 1-2001
| | Posted on Monday, February 03, 2003 - 4:38 pm: | |
Collin -- When cold, the thermo-time switch will open the cold start valve for the first second or two during cranking so this may be dumping enough fuel to give a brief "cough" at the initial start attempt, but the injectors won't actually squirt fuel until the system pressure gets up to ~3.3 bar (~50 psi) IIRC. If the car is running OKish both cold and warm (and the delayed start is the only problem), I doubt you have a serious problem elsewhere (but these system are so complex that it's difficult to say anything with certainty). If you're not a DIYer, I think any Volkswagen/Audi/Mercedes shop should be able to check your K-Jetronic supply fuel pressure behavior for a minimal fee.
As Greg said, the easy/safe way to check spark presence is to put a timing light on the coil wire or a spark plug wire during cranking and see if it's flashing. If you're desperate you can take a spark plug wire off and see if it arcs over a say ~.050" gap to ground when cranking -- but this can be a "shocking" experience so I prefer to use the timing light too.
PS Please add year/model/version to your Profile |
Greg Rodgers (Joechristmas)
Member
Username: Joechristmas
Post Number: 658
Registered: 3-2001
| | Posted on Monday, February 03, 2003 - 1:48 pm: | |
Use a timing light to verify spark. |
Collin Hays (Chaysintexas)
New member
Username: Chaysintexas
Post Number: 33
Registered: 4-2002
| | Posted on Monday, February 03, 2003 - 1:39 pm: | |
Steve, when cold, the car "tries" to crank immediately, then settles back down with the starter just turning, then all of the sudden, it fires up. How do I verify that a spark is present immediately when cranking? |
Mark (Markg)
Member
Username: Markg
Post Number: 372
Registered: 2-2001
| | Posted on Monday, February 03, 2003 - 10:05 am: | |
My '82 GTSi starts almost instantly, hot or cold. Sounds like cold start valve, warmup regulator or thermo-time switch may be defective. Fuse box may also be culprit, it was on mine (too much resistance causing down-line system componant failure). My thermo-time switch was defective also which led to incorrect data input to warm-up regulator and cold start valve, resulting in intermittant backfire and cylinder dropping issues.
Do a WEB search on K-jetronic, thermo-time switch and cold start as 'keywords', it will bring up a wealth of tech info as well as input form others with similar issues. Add that info to response you get here and you will pretty much be able to narrow it down! |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1384
Registered: 1-2001
| | Posted on Monday, February 03, 2003 - 9:54 am: | |
Collin -- Excessive cranking on the K (or KE) cars can be caused the supply fuel pressure not behaving properly (12-13 sec warm is still an eternity). If it's wacky you'd be looking at things like fuel accumulator, fuel pump check valve, fuel pump. Have you verified that spark is present immediately when cranking? |
Collin Hays (Chaysintexas)
New member
Username: Chaysintexas
Post Number: 32
Registered: 4-2002
| | Posted on Monday, February 03, 2003 - 9:23 am: | |
From the time I turn the key, it can take up to 20 seconds for my car to fire up. That's probably not good on my starter. Anyone else have this problem? If so, how did you fix? After the car is warmed up and I re-start it, it's more like a 12-13 second delay. Thanks for your imput. |