Cols Starting Problems, 190E 2.6
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From: N. Alabama
Cols Starting Problems, 190E 2.6
I'm having cold starting problems with my 1993 190E 2.6. If the car sits overnight or is parked for about two hours, it turns and turns for about 15-20 seconds before firing. After it's warm, a quick flick of the key starts it right up. Seems to run normally. Have changed the fuel filter and the plugs, and checked all I could for vacuum leaks. Previous posts indicate the OVP relay could be the culprit, but I can not find the OVP relay on this car. Have also pulled the rubber vacuum hose from the top of the EGR valve with no detrimental effect on the idle. Any suggestions besides bringing it to the (gasp!) dealer?
Thanks; Don
93 190E 2.6
Thanks; Don
93 190E 2.6
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
Did you check the function of the duo-temperature switch on top of the block? (driver side far end of the block). These control the cold start phase and the motor management.
Another the cols start valve which enriches the mixture during cold start. It sits on the on intake manifold between 3rd and 4th cylinder, and has an electric cable attached. It sprays extra fuel for a few seconds into the manifold to help starting at lower temperatures. The OVP has nothing to do with this. If the OVP is bad there is more than hesitating cold starts.
Another the cols start valve which enriches the mixture during cold start. It sits on the on intake manifold between 3rd and 4th cylinder, and has an electric cable attached. It sprays extra fuel for a few seconds into the manifold to help starting at lower temperatures. The OVP has nothing to do with this. If the OVP is bad there is more than hesitating cold starts.
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Have not checked but I'll look for them. I guess the only to check the cold start valve and duo-temperature switch is with a multimeter? It sounds like the fuel pump runs a lot longer than it used to when I turn the ignition on. Is there a check valve somewhere in the fuel line which is suppossed to prevent fuel from draining back to the tank?
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
Originally posted by hornbrod
Have not checked but I'll look for them. I guess the only to check the cold start valve and duo-temperature switch is with a multimeter? It sounds like the fuel pump runs a lot longer than it used to when I turn the ignition on. Is there a check valve somewhere in the fuel line which is suppossed to prevent fuel from draining back to the tank?
Have not checked but I'll look for them. I guess the only to check the cold start valve and duo-temperature switch is with a multimeter? It sounds like the fuel pump runs a lot longer than it used to when I turn the ignition on. Is there a check valve somewhere in the fuel line which is suppossed to prevent fuel from draining back to the tank?
To check the temp switches you need a multimeter, for checking the cold start valve you need to take it out and apply 12V to open it. Before you need to apply system pressure to the fuel lines by either bridging pin 8 and 7 in the fuel supply relay socket or simpler just turn the key 2-4 time w/o starting the engine. When you apply 12V the valve shall spray fuel, as soon you disconnect the voltage the valve close and NOT leak.
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Thanks Bamberger_1. Tried starting with the key on the third time as you recommended after sitting all night; didn't start the first time whem I bumped it, but the second time I bumped it it started instantly. Normally it cranks for about 10-15 seconds. Will try a few more cold starts like this to be sure, but it looks like the check valve might be leaking back. Looked under at the fuel pump/filter assembly and saw what looked like an inline fitting screwed into the discharge line of the fuel pumps. Is this it? Might it just need cleaning (hope, hope)?. Also, one of the fuel pumps looked like it might be leaking or leaked at one time; it had a thick varnish-like sticky substance on it. Not bad, wasn't even wet, and looked to be like that for a long time. My 190E has been in storage for quite awhile (only has 35K miles) so while under there I changed out the fuel pump; it still had the original! Will check with the dealer and see if I can purchase the check valve. Anyone know if this is doable? Also, should I replace the fuel pump too?
Tanks for all your help - Don
Tanks for all your help - Don
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From: N. Alabama
Fuel pump check valve. Found this pic on the web from a MB part house. Text says Bosch E3030-27620, two required per vehicle, so I'm assuming the check valve is an integral part of the fuel pump? Or is it seperately installed inline on the fuel line?
Thanks, Don
Thanks, Don
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Thread Starter
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From: N. Alabama
Well, I knew the cold starting problem wouldn't be that easy to fix. It's back to long cranking times when cold starting. Still runs fine when warmed up. But because of the sticky varnish-like substance on one of the fuel pumps which I described on an earlier post, I'm going to replace it and hope this cures the problem. Will replace with a Bosch pump (0 580 254 950) - does the backflow/check valve come with this pump or do I have to purchase separately?
Thanks for all your help - Don
Thanks for all your help - Don
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From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
The back flow valve comes with the pump. I still have the drawing but I cant attach it to the thread. If you want it, send me your E-mail address.
