Having mid rpm hesitation/missing 1.7 jetta

[Fusor2]

As is said in the title, I am having mid rpm missing and im baffled... The car will idle all day long and will full throttle all day long but hesitates when your giving it throttle. I replace the original distributor and pigtail with one from my good running gti With new plugs and wires. Also replaced the timing belt and had it timed to the bentley specs. The fuel pump has also been replaced because it was noisy along with the fuel filter. The injectors have been checked for pattern and volume new o-rings and all is good....No vacuum leaks and STILL it has the midrange miss and seems to chug going down the road when not at full throttle. any input would be greatly appreciated..... pics for clicks

[Llcoolchris]

Check the o2 sensor. By chug I guess you mean sputtering?

[Fusor2]

By chug it will pull for a second then feels like its misfiring and is jumpy... the o2 sensor I believe is unhooked but ill see about replacing it today

[Fusor2]

well, hooked back up the o2 sensor and seems like no change. im not saying the sensor is good in the first place so i ordered a new one... anyone else have any more ideas...

[diive4sho]

Timing, control pressure (warm), fuel mixture too rich, fuel pump relay, fuel filter, fuel pump, ground wires, distributor cap and rotor, plug wires, injectors.

[Fusor2]

i have not checked the control pressure... still waiting on some parts to assemble my gauge. i have almost everything on the list new including pump and filter and the injectors were tested and look good... im not a noob to these cars just getting frustrated quick...

[rabbitnothopper]

hmmm..........im sure your floorpan hates you by now

you put jackstands basically STRAIGHT THROUGH the floors........stupid



why not use the correct jack points?

[8v-of-fury]

Car is a pos. who cares lol.

Also that is not a 1.7 motor.

[Fusor2]

hmmm..........im sure your floorpan hates you by now

you put jackstands basically STRAIGHT THROUGH the floors........stupid

why not use the correct jack points?

Holy Fuk who called the jackstand police.... At least im using a jackstand.... and i have a 2x6 under the contact patch, at least im using a jackstand...
Still better than these guys i would think



And as far as i know it is a 1.7 ... or at least its what it says on the side of the block... but then again i could be wrong. its a german built jetta and i thought all came with 1.7s

[8v-of-fury]

And as far as i know it is a 1.7 ... or at least its what it says on the side of the block... but then again i could be wrong. its a german built jetta and i thought all came with 1.7s

The 1.7's have the water neck coming out between cylinders 1&2, whereas the 1.8's have the water neck coming out between 3&4 like yours does. However, it could just be a 1.8 head on a 1.7 block..?

The German built GLI Jetta's came with the 1.8L motor. Also, FYI all A1 Jetta's were built in Germany.

Also, why not put the jack stands on the reinforced pinch welds like was designed??

[Fusor2]

my jetta is not a GLI... you could be right about it not being a 1.7 and when i jacked it up i used the jacking point with my jack and placed the jackstand where i could. as you can see im working on this car in my back yard as i am moving and have alot of junk in my garage in boxes. Any ideas as to why my car is stumbling at off idle? And yes i realize the jetta may look like a piece of crap but if i dont save it somebody else would have sent it to the scrap pile.

[8v-of-fury]

Timing, control pressure (warm), fuel mixture too rich, fuel pump relay, fuel filter, fuel pump, ground wires, distributor cap and rotor, plug wires, injectors.

All of this.

[rabbitnothopper]

The 1.7's have the water neck coming out between cylinders 1&2, whereas the 1.8's have the water neck coming out between 3&4 like yours does. However, it could just be a 1.8 head on a 1.7 block..?

The German built GLI Jetta's came with the 1.8L motor. Also, FYI all A1 Jetta's were built in Germany.

Also, why not put the jack stands on the reinforced pinch welds like was designed??

truth


the reason both of my cars have rotted floors is because some asshats didnt use the correct jack points
instead they opted to use the floorboard
what happened? bent frame rails on the floor structural supports

meaning most likely the weakest points in the car are now the "floor structural supports"

[rabbitnothopper]

my jetta is not a GLI... you could be right about it not being a 1.7 and when i jacked it up i used the jacking point with my jack and placed the jackstand where i could. as you can see im working on this car in my back yard as i am moving and have alot of junk in my garage in boxes. Any ideas as to why my car is stumbling at off idle? And yes i realize the jetta may look like a piece of crap but if i dont save it somebody else would have sent it to the scrap pile.

check your fuel pressure
what is the system pressure reading,
what is the control (wur) pressure cold/warm?

that will give you ideas what to check next

most likely your valves arent closing fully, timing, bent valve, or carboned valve



car is a car, whatever it looks like or drives like
just as long as it gets you places safely and reliably

im giving you a hard time about the floorboards because its stupid how you did it

if you were going to use jackstands (on dirt...)
lift the front of the car up by the control arm near the frame
put the jackstand on the jack spot
lower the control arm
watch the car sink into the mud....

did you ever wonder why you cant open your front doors when you lift the car up?
thats why

[Fusor2]

it just so happens that the asshat who owned it before me used the pinchweld to jack it up and folded it over... and now is a bit rotten, thats why i opted for the floor support with the 2x6. Im in the middle of a GTI resto to get rid of some rust... and i take on some serious projects...

[diive4sho]

Since you say that you have replaced most of what was on the list I'm willing to bet your pressures are all out of whack. Low system and control pressures will cause a rich running condition and the car will buck down the road as you describe. Measure and adjust the system pressure, then the cold control pressure, then warm and also check the residual pressure after being shut off for 1 min.
System 75 psi
Cold 25
Warm 55
Residual at least 15 after 1 min.

Don't quote me...these numbers are from memory.

Also you may want to look into adjusting the valves.

[rabbitnothopper]

Since you say that you have replaced most of what was on the list I'm willing to bet your pressures are all out of whack. Low system and control pressures will cause a rich running condition and the car will buck down the road as you describe. Measure and adjust the system pressure, then the cold control pressure, then warm and also check the residual pressure after being shut off for 1 min.
System 75 psi
Cold 25
Warm 55
Residual at least 15 after 1 min.

Don't quote me...these numbers are from memory.

Also you may want to look into adjusting the valves.

hope this information everyone has repeated helps you solve your hesitation issues

[Fusor2]

System pressure 68psi
Cold 22 psi
Warm 52 psi
Residual after a few min 25 psi

Where do i go from here? the pressure across the board seems a bit low...

[Fusor2]

well, im stumped... i changed out the fuel distributor and still the same running issues. same pressure numbers as well... on a side note... i found the engine is a 1.8 FN code motor from a fox. Maybe this could be the source of my problem... it has started raining and couldnt change out the WUR in time...

[diive4sho]

You're going to want to shim the fuel distributor to bump that system pressure up to 75. something like a .5mm thick washer should get you close.
If you Google how to adjust system pressure you'll find some DIYs.

[diive4sho]

Also did you check the dwell?

[Fusor2]

No I didn't check the dwell. What do I need to check? I will shim the pin tomorrow and let you know how it goes. I will also be checking for a callapsed lifer if shimming it does nothing.

[Fusor2]

So i added a shim and brought the pressure up to 74 psi... cold pressure is up a bit and warm also.. It will idle all day long and sounds good but the second i try to give it throttle it coughs thru the intake and wants to stall... im so lost... is it time to take it to a shop?

[rabbitnothopper]

just a thought...
are you running good spark plugs, are the gapped to .028 inch,
is the spark blue (correct) or is it yellow (bad) ?

[Fusor2]

yeah im running good plugs, ngks and ill pull them and doublecheck the gap

[bpetry]

Just went through this with my 84 gti turned out my ecu went bad. If you have a spare swap it out and see if it starts running better. If not you can test it using the procedure here. http://www.cabby-info.com/cis.htm. If things are working correctly you should also hear your frequency valve buzzing.

[Fusor2]

i pulled the plugs and they were showing about .032 on the gap... the spark looks pretty good being blue/purple... so i tightened up the gap on them. I reinstalled them and started it up. it honestly sounded like it was running on two cylinders and when you applied the throttle it would cough and stall out. i pulled a plug and looked at it, it was wet, put it back in and now it wont fire. i think i might have fuel fowled the plugs so ill stop and grab some more tomorrow night. ill be swapping out the computer tomorrow to see if there is any difference.

[rabbitnothopper]

hmm...so explain to me your vacuum advance


most have 2 vacuum ports (some do have one)

one is on the rear goes to the air intake outlet
you have two, one goes to brake booster, that one looks ok
the one to the left..looks bad....and has nothing? connected to it

second is on the check valve (that white thingy under the letter "EED")

vacuum advance? anyone?...

[Fusor2]

not sure what part your talking about but the vacumm advance for the distributor is t'd one goes to the back of the throttle body and the other to the white vacuum bulb under the "eed"... not sure where your going with this...

[RabbitJockey]

I don't think I have ever seen a mki that someone didn't jack up in the middle of the floors people are mis led by those ribs that go down the center of each pan. Atleast 3 times ive had this problem when getting my cars inspected even after specifically telling them do not jack in the middle of the floor

[rabbitnothopper]

I don't think I have ever seen a mki that someone didn't jack up in the middle of the floors people are mis led by those ribs that go down the center of each pan. Atleast 3 times ive had this problem when getting my cars inspected even after specifically telling them do not jack in the middle of the floor

there should be no reason to jack up the car for an inspection...

and you should stand there with a video camera on them while they do it
complain to the company and get free replacement floorpans.......dropped off at your door.......

[rabbitnothopper]

not sure what part your talking about but the vacumm advance for the distributor is t'd one goes to the back of the throttle body and the other to the white vacuum bulb under the "eed"... not sure where your going with this...

well..
you are saying



i am asking if this is what yours Should be



do you see the extra white line on the rear of the distributor?
....

[Fusor2]

There is no other lines that come off of the distributor. The distributor is from my 84 gti if that matters... I redid the vac line to the distributor in case there was a leak or clog maybe and there is not any change

[Fusor2]

Just to give an update... i had a really good mechanic buddy look at my car several weeks ago, he suspected the throttle body was leaking so we replaced it with a known good one and ran a little bit better. Then he suspected that the distributor was out of wack so we replaced it also and now it runs WAY better. It still has a bit of a hot start issue where i have to press the gas down to get it to fire and then it will miss for like 10 seconds but runs great after, i suspect i have a fowled plug or something. but here she is now.

[tangerine_coupe]

Looks good man. I need to get some rabbit bumpers on mine, not to stoked on the stock ones.