88 vw jetta GLI 16v, the same ol hesitation under load stuff again!!!!

alright guys, im new to this group, im a regular in the vw vortex, gratefuldude11.

i do mainly scirocco fun stuff.

i am having a problem with my GLI 16v though, tonight. taking a friend somewhere, i started to lose power, starving for fuel kind of. had a 88 scirocco 16v did the same thing, never figured it out. when at idle, she idles great. when under load, hesitates like hell, not your usual no performance from low end on a 16v, it hesitates badly.

if i slam on the gas, car will roughly make its way to speed, then run good after about 4000rpm, if i keep it that high. no vacuum leaks. no ripped intake boots. like i said, ive had no warnings this was going to happen. usually when a dub breaks, it tells you before hand....my jetta isnt so nice.

exhaust is fine, doesnt smell bad, not pissin coolant out of it, nothing bad.

this all happened after my 300lb friend was riding in the front.....thinking i may have caused damage somewhere.....no clue.

my AIM is gratefuldude1981 if anybody can help me out. my email is snipped-for-privacy@yahoo.com. or simply reply to my post, im sure i can figure out how to get back here to read it. thank you for helping me.

Reply to
hippy steve
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Improper Spark (BAD distributor cap, rotor, wires, plugs or coil) Improper Fuel Delivery (BAD injectors, fuel distributor, fuel pressure regulator, etc.)

Clogged fuel filter, broken fuel distributor boot, defective 02 sensor or knock sensor(s)

I guess I would start with the ign system like plugs, rotor, cap and wires then go from there. AND then filters like air, fuel and oil. NOW troubleshoot. ;-)

later, dave (One out of many daves)

Reply to
dave AKA vwdoc1

i have checked all of those. this just happened out of nowhere.

no leaks, no unsealed vacuum lines, new rotor/distributor cap, perfect timing, im meticulous with my cars. this is something that has me stumped big time.

something that im thinking, is the in-tank pump/sending unit assembly. could that somehow not be functioning properly and causing this?

i have not checked my 02 sensor though, although i have run without one on an 87 scirocco 16v and nothing like this ever happened.

is there anyway the load weight of my 300+lb friend had anything to do with starting the problem, as he was in it when it happened.

Reply to
hippy steve

Maybe the air flow sensor just inside the intake, next to the air filter box. Dirty and/or out of alignment.

Additional engine load will magnify such a problem.

Reply to
Jonny

replies within............

ARE YOU SURE THAT LARGE BOOT IS NOT CRACKED? When cracked the engine may idle/cruise smoothly but under acceleration the engine twists, the crack widens/opens causing a vacuum leak and the engine starts to buck. A heavy person in the vehicle might even cause the crack to lengthen more and open more since the vehicle is under more load. CHECK THAT BOOT THOROUGHLY and off the vehicle. Don't ASSuME please! ;-)

I have seen some mufflers and cat. conv. that would clog up. On my Passat I had a muffler with a loose inside baffle. When I pressed on the gas pedal the baffle would shift and restrict the flow of exhaust = NO POWER. I did hear the problem though when accelerating.

You checked the knock sensor with the timing light? Your engine is getting full advance? I think that there might be some grounds that need to be attached to the cylinder head or intake manifold for the knock sensor system. I don't remember how yours is set up again but doesn't it have a seperate module?

Usually the main pump will start complaining by whining/buzzing louder. Very noticeable. Did you check the current at the fuel pump regulator? I have seen wiring to those bad also. I am not sure where the 16V has it's ground wire, but on the 8V it is at the cold start valve. Check the fuses too.

The 02 sensor, and I think yours is heated, might have a wiring problem causing the wiring to short and the engine to either run rich at times or lean at times. You could try unplugging it and see what happens.

Probably not, but may cause you to find a problem that existed without your knowledge. Thank him when you do find the problem. ;-)

JMHO later, dave (One out of many daves)

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Reply to
dave AKA vwdoc1
92 Jetta 8v had the same problem the fix was a new voltage regulator because the brushes were worn down, 145K miles without changing, and low voltage was causing the fuel injection/ignition system to not function properly. It's worth checking with a DVM while the engine is running.
Reply to
Larry Gardner

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