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Discussion Starter · #1 ·
ok, here's the deal:
a few months ago my VW started doing this but now it's gotten pretty bad. when the car is being cold started, i have to press the gas and crank the car for about 10 seconds before it starts. if i press the gas pedal 3 or 4 times before turning the key, that helps.
i have:
- replaced the fuel filter
- checked the timing
- replaced the cap and rotor
- checked the spark plugs (but not for spark)
- checked the air sensor plate for adjustment and freedom
- checked the fuel distributor plunger, cleaned it and replaced it
- checked for vacuum leaks, and loose wires
here's another thing i noticed:
my Halmeter AF30 air-fuel ratio gauge is going nuts. the car is running LEAN! the gauge is pegged in the red (running too lean) but then when i hit the gas the gauge pegs to the green (running full rich) for a second then zips back down to full lean. also on start-up the car struggles to stay running so i have to nail the gas just to keep it from stalling. almost like the ignition or pressure is insufficient.
i haven't touched or adjusted anything before this happened. it was sort of overnight. i'm wondering if there is a fuiel pressure problem (something clogged or leaking like the cold start injector maybe), or if the distributor has gone bad.
any help would be greatly appreciated! if this was a Porsche i could fix it no problem but when it comes to VWs, i'm almost lost.
thanks!
obin
 

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Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Obin Robinson)

For sure , test the fuel pressure, you may have a weak fuel pump.
 

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Discussion Starter · #3 ·
Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Coupe_88)

thanks!
offhand, i just thought... this is CIS, so i'm wondering if it could be the fuel accumulator or check valve. i had those problems in our old Porsche and it proved to be the accumulator.
where is the best place to order a nice rebuilt pump if that is indeed the problem?
thanks!
obin
 

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Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Obin Robinson)

Could be a few things....
I'd check these in this order
-Bad Fuel Pump Relay
-Leaky fuel lines
-clogged fuel filter
-in-tank fuel pump filter could be cloged or just weak...
-weak fuel pump
Check those first and let us know whats up
G'luck
 

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Discussion Starter · #5 ·
Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Scirocco_Clan_Man)

could this be at all a bad DME (computer) or ignition or should i be focusing on fuel supply?
thanks!
obin
 

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Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Obin Robinson)

Quote, originally posted by Obin Robinson »
could this be at all a bad DME (computer) or ignition or should i be focusing on fuel supply?
thanks!
obin

it could be, but I rarely hear of the ignition computer going bad and I've never heard of a bad ECU. It could be clogged injectors also. I don't think the fuel accumulator affects fuel pressure when the engine is running, it just maintains pressure when it's off so I would look elsewhere. If you have a dwell meter check the duty cycle, and adjust the A/F ratio accordingly. You adjust it via a 3mm allen bolt hidden under a cap between the fuel distributor and airflow plate. However this would likely just be compensation for another problem, I'm guessing clogging somewhere. What kind/year of VW is this? CIS had a few changes over the years, it may be helpful to state your model and year. G'luck,
-Rob
 

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Discussion Starter · #7 ·
Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (robw_z)

Quote, originally posted by robw_z »

What kind/year of VW is this? CIS had a few changes over the years, it may be helpful to state your model and year. G'luck,
-Rob

whoops!
1986 Golf GTI 8V SOHC 1.8 litre with the CIS-E.
i'm wondering if it is a clog also, that's why i did the fuel filter (that didn't help it so i'm wondering if the pump or check valve is bad?).
it does seem like a fuel pressure problem though. after all i have to mash the gas pedal when starting out and the car feels sluggish. then when the pressure is up the car runs like a rocket.
thanks!
obin
 

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my guess would be a fuel pump or check valve. while yoru at it. come and test my 2 pumps and figure out which ones is bad lol i think its the main but need to test both before i go spend 200 bucks on a new one...
 

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Re: car running LEAN! bad ignition, DME, or bad fuel supply? ... (Obin Robinson)

Quote, originally posted by Obin Robinson »

1986 Golf GTI 8V SOHC 1.8 litre with the CIS-E.
obin

Check your wiring to your fuel distributor! Most importantly, the wiring and plug to the control pressure actuator (the plug on the right side, look for the grey-ish plastic box on the side of the fuel distro that says "Bosch")
The actuator itself may be defective, and have to be replaced.
You can diagnose that circuit with an ammeter (one that reads low current, 0-25 mA) according to instructions by Bentley. I don't remember what the correct figures are off the top of my head.
Once, I had problems exactly as you describe with an 85 GTI, and found that plug to be the culprit!
Oh yeah, there's a little P.O.S. filter inside of the fitting that connects your fuel supply line to your fuel distributor. It might also need attention.


Modified by der_panzer at 9:30 PM 7-2-2003
 
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