Hard to Start when cold - Benzworld.org

Evo2lvr · 05-09-2008, 07:35 PM

I own a 1989 190-E 2.6. Here's the problem, the car is hard to start when cold.

When I pump the accelerator 5 to ten times and continue to crank the engine the car eventually starts. I know compression fuel spark ignition.

I checked the battery and had a load test done on it, it is ok. Checked all the fuses ok too.

When the car starts and is warmed up a little it seems to start fine.

Pulled and checked all the spark plugs to see if any were fouled, all ok too.
Pulled off the air assembly and cleaned the carb. and surrounding area all ok.

I had the compression done about year and half ago most cylinders 150 140 one cylinder 120 ok for a car with over 200,000 miles I think 160 is real good.

I did change the fuel filter maybe 2 years ago and checked the fuel pumps. One was replaced by a mech. The other one is the original.
Just ordered two new AIRTEX pumps and bosch filter, and some other brake parts,

What else could be causing the hard start when cold ie initial turn on. Could it have something to do with the choke mechanism on the carb.

shingleback · 05-09-2008, 07:40 PM

Cold start valve; do a search on this forum, there is lots of information.

MTI · 05-09-2008, 07:42 PM

Putting "Hard Start Cold" in the search feature . . wow, looks like a FAQ.

Wild Child · 05-11-2008, 05:29 AM

Could be any of numerous things, i changed the ovp,cold start,plugs,wires,fuses were good, end result my ecu was shot , slappped another one in, no more problems. Your best bet is to get it up on a diagnostic to isolate the issue rather then troubleshoot it yourself.

WC

GPost · 05-11-2008, 06:17 AM

I am going to vote for the OVP. Correct me if I am wrong, but there is a certain temperature at which the cold start valve comes into play. Seems like it was in the 30-40 degree range. I also believe the ovp supplies current to the cold start valve when needed. You can add 12 volts to the cold-start valve and get someone to crank it and see if that works. If it does, then it is either the valve or the OVP. It could be an ECU, but that is a rare problem in any car.

Wild Child · 05-11-2008, 09:42 AM

I was saying his problem was the ecu...was just giving referrence to what I did when mine had the issue and saying it would be cheaper on his wallet to get it up on a diagnostic computer then to try to troubleshoot it blind. I did that and it got costly.Original from the dealer the OVP runs $109 and change.

WC

Quote:

Originally Posted by GPost

I am going to vote for the OVP. Correct me if I am wrong, but there is a certain temperature at which the cold start valve comes into play. Seems like it was in the 30-40 degree range. I also believe the ovp supplies current to the cold start valve when needed. You can add 12 volts to the cold-start valve and get someone to crank it and see if that works. If it does, then it is either the valve or the OVP. It could be an ECU, but that is a rare problem in any car.

Evo2lvr · 05-16-2008, 02:58 PM

Ok have been working on the car for about two days now when I get off work.

Cleaned every thing around fule line areas. Had a hard time getting the cold start valve off stripped 5 mm hex bolt finally got it off. Anyways here goes.

Found a small hose that was cracked on the exhaust manifild connected to a very small clear air line i think. Mercedes junk yard/ dismanteler is near my apartment and I got a new hose for free. It looks like a 180 degree rubber elbow size of a quarter don't know yet if this will fix starting problem probably not.

Bought a digital multimeter, cheap one 9 dollars, to check the 12 volts to the cold start valve. Hooked up valve externally and hooked all fuel lines back up and cranked the engine no 12 volts to valve.

Could this be the OVP relay that is shorted. ?? If I take apart the relay OVP what should I see inside to tell that this has gone bad ?

By the the GP sorenson does not make the right cold start valve for this vehicle.

If I hook up 12 volts to the cold start valve and the car starts right away doesn't this meen that it is definately the OVP.

Evo2lvr · 05-16-2008, 03:10 PM

Where is the idle air control valve on 190E 2.6 pictures would help or else when I find it will up load pictures to this thread.

Evo2lvr · 05-16-2008, 03:25 PM

What is the MAS mass airflow sensor or what? I would like to meter the 11.5 volts from OVP with ignition on pin 21 but where is MAS?

shingleback · 05-16-2008, 06:17 PM

If you want to take a look at the OVP, it is pretty easy; remove the fuse (or 2), straighten the tabs on the bottom and slide the unit out. Inspect the solder joints on the board; they are prone to cold solder joints and cracking. I resoldered all the joints on mine and reinstalled. Cost = 0.