Occasional Hesitation while driving 1.9l

[beachinwesty]

1.9l 85 weekender automatic. Finding out that I'm having severe acceleration problems about half the time I drive my van. On side streets acceleration feels like a very mild shuddering as if the fuel was not being fed correctly. At highway speeds I can't get it over 45mph and as I drive I can feel the acceleration suddenly "catch" and then the van accelerates and drives ok. Until it doesn't and then I have the problem again as I drive along. It does not seem to be a problem associated with a cold or warm engine and the auto trans is fine, with correct fluid levels.

The other half of the time, it drives fine.

Van starts and idles as well as it ever has (not very well. working on that. Aux air reg I do believe) and I can rev the engine fine when it's in park.

My thoughts run to

1) bad fuel pump/filter
2) bad ground somewhere
3) slightly broken wire somewhere in the FI system
4) ecu socket not seated correctly creating a bad connection (pulled it off the other week to check some connections with the mulitmeter)

I will be running these possibilities down as I find time. Anything else to add to the list?

[stubear334]

I went thru a similar ordeal that had me pulling my hair out for over a month!

First, it is a loose wire somewhere. Period. Find the 2 ground clusters on the left. Cut off all the old eyelets & solder on new ones. Clean the connection point on the body. Next, get rid of that crappy braided ground strap between the engine & body. Replace it with a nice new sealed ground strap from Autozone. Next, find the O2 sensor ground wire connection near the distributor. Put a new eyelet on it & solder it. Next, put a new connector on the O2 green wire. Also, replace the ground strap at the transmission & battery. Oh, check the ground at the ECU as well.

Clean the connections at the fuel pump, coil. Buy some electronics cleaner & disassemble every connection & clean it. VERY IMPORTANT: check the condition of all those Bosch f.i. female connections for tightness. They open up over time && get loose.

You could have a bad wire going to the distributor. Pull the distributor & check the wires going to the hall sensor. If the wires are broken, buy a rebuilt distributor.

Now, I assume you've replaced the plug wires, cap, rotor, & plugs before starting this journey. Also, it doesn't hurt to put the dry gas in the fuel tank. This will burn out any water left in the fuel.

I replaced my throttle switch w/ a new GoWesty vacuum switch. It fixed a myriad of running problems. Check your throttle switch operation. Luckily, you have the better type.

That's all I can think of. Let me know if I can help. Send me a p.m.

Stu

[Halifaxwesty]

[beachinwesty]

Thanks for the reply. I agree that it's a gremlin in the electrical system somewhere. I'll go through the steps you suggest and report back.

John

[morymob]

After all of the above don't forget the ign switch, do have a bunch of keys hanging there.

[t3 kopf]

all of that plus check the timing. if its too retarded, it'll cause those symptoms.
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'90 Carat w/ '95 phase 1 EJ22 OBD2 conversion

[geo_tonz]

You should still look at item #1 - Fuel, although I agree it could be electrical. Blow some air into the tank through the fuel outlet to dislodge any possible debris clogging the screen and replace the filter. Blow out the old filter backwards and see how much crap comes out...will give you an idea what the inside of your tank looks like. Also try cleaning out the inlet of the pump for grit/rust accumulated on the internal screen. If no change you're still further ahead and it took 10 minutes. If it fixes, then sucks again later try blowing out the inlet again. if it fixes again you've got too much crap in your tank and it periodically obstructs fuel flow. Remove tank and clean it or replace it.
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"Ron Burgundy": 1991 Vanagon Multivan (Weekender) 2.1L Auto - Driver/Camper

[beachinwesty]

Found that one of the plugs to the idle stabilizer was not seated completely. Seated it properly and drove 120 miles today and it ran like a champ.

Thanks everyone for your replies and suggestions.

John
Beachinwesty
85 Weekender