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Engine Specific Info and Questions => IDI Engine => Topic started by: Duster 5.9 on September 04, 2008, 08:07:13 am

Title: inj pump runaway
Post by: Duster 5.9 on September 04, 2008, 08:07:13 am
got a question on an injection pump. awhile back i got a rebuilt pump from a guy. i won't say where yet. anyway after alot of tuning, this thing does not like to come down in rpm when reved up sometimes. or very slowly. i took it out, but when i would drive it i would have to wait a bit with clutch in for rpm drop to engage clutch again. also had to shut it down a few times also.  i know its the pump for sure, but what? how can i fix it.
Title: inj pump runaway
Post by: zukgod1 on September 04, 2008, 08:10:09 am
Have you attempted any adjustments?

Throttle stop on the idle side?

Max fuel screw?
Title: inj pump runaway
Post by: Duster 5.9 on September 04, 2008, 08:15:49 am
yes it is like what ever is inside is not coming back, but with engine off you can rev on throttle and it feels fine.
Title: inj pump runaway
Post by: zukgod1 on September 04, 2008, 09:08:30 am
Have you attempted to reindex the throttle shaft?
Title: inj pump runaway
Post by: burn_your_money on September 04, 2008, 09:43:58 am
Make sure that the throttle shaft is not binding, but I would suspect that the max quantity adjuster is turned in a bit too far.

It could also be bad injectors, have those been tested?
Title: inj pump runaway
Post by: Duster 5.9 on September 04, 2008, 10:03:18 am
i decided to send it back to where i got it from. it is for my father.
the car is driven every day with a different pump although it is majorly underpowered. meaning it is hard to keep it going 60 mph. it does smoke. i'm thinking it may need rings.
Title: inj pump runaway
Post by: gigaz2 on September 04, 2008, 10:28:48 am
bad rings and injectors(probably) and you're blaming the pump??

I also agree with the above, shaft reindexing and max fuel screw.

VW says in the manual:

try the following list before diagnosing a bad pump:
HUGE list, basically everything else  :wink:

EDIT: basically VW says that if the engine runs, pump is good, it may require some love, but its good.
Title: inj pump runaway
Post by: burn_your_money on September 04, 2008, 02:29:59 pm
My car as 250 psi across the board, it NEEDS rings. I can still easily do 75 mph on the highway, and get there pretty quickly (relativly of course)

I'd suspect pump issues, timing or injectors.

You should send the pump to Giles for a super pump
Title: inj pump runaway
Post by: Smokey Eddy on September 04, 2008, 03:09:26 pm
If you don't have $1,000 like many to send it to giles,
i'd get a timing dial on the pump and make sure the timing is set right, or even play with the timing a little bit and take it for a rip with each minor adjustment
Title: inj pump runaway
Post by: Duster 5.9 on September 04, 2008, 06:16:00 pm
i know that pump was not set up correctly as it made funny noises also. i even put the pump from my daily drive on this car and it ran the same. i have set the timeing many times on this car and many others. i even turned up the original pump on it to give it lots more fuel and it made 0 and i mean 0 difference.
Title: inj pump runaway
Post by: 4KTD on September 04, 2008, 06:46:13 pm
I just resealed my 1.9 pump and when I put it back on my car it does the samething.  When I rev it up it creeks up to 3000 rpm and VERY slowly comes back down and won't idle. If I index the throttle shaft to the next notch it idles at 4700 rpm... a bit high.  It does not smoke at all, I adjust the max fuel and doesn't make much difference.  I messed around with it long enough and couldn't fix it so I just bought another pump and will try it soon.  

PS: the original pump was working perfectly before I resealed it, except it leaked of course.
Title: inj pump runaway
Post by: gigaz2 on September 04, 2008, 06:46:40 pm
so definitely not the pump :(

have you done a compression test?
bad injectors could also be the culprit as these little engines seem to work with very little compression (mines arounf 300PSI and still pulling strong)
Title: inj pump runaway
Post by: Duster 5.9 on September 04, 2008, 06:51:24 pm
Quote from: "gigaz2"
so definitely not the pump :(

have you done a compression test?
bad injectors could also be the culprit as these little engines seem to work with very little compression (mines arounf 300PSI and still pulling strong)

 no ,i have a very nice mac compression set, but i don't have that adaptor, I NEED IT! yes.
 i also would like to make that homemade pop tester when i find the time  :)  :)  :roll:
Title: inj pump runaway
Post by: zukgod1 on September 04, 2008, 08:57:11 pm
I tell ya what injectors will cause some weird crap to happen as well. I'm not saying that's your problem just backing up what gigaz2 said.

I just got done re ringing my engine (new pistons also) and I had this weird miss. It sounded like a Subaru with a after market exhaust system till 2000 or so where it would smooth out.

I swapped in my HUGE injectors just to see and idles smooth and runs perfect now.

Weird I say weird...
Title: inj pump runaway
Post by: Duster 5.9 on September 05, 2008, 01:53:54 am
Quote from: "zukgod1"
I tell ya what injectors will cause some weird crap to happen as well. I'm not saying that's your problem just backing up what gigaz2 said.

I just got done re ringing my engine (new pistons also) and I had this weird miss. It sounded like a Subaru with a after market exhaust system till 2000 or so where it would smooth out.

I swapped in my HUGE injectors just to see and idles smooth and runs perfect now.

Weird I say weird...

subaru thats funny, i went to see my step son in tn this summer he drives one, what a wierd setup  :lol:
Title: inj pump runaway
Post by: Duster 5.9 on September 05, 2008, 01:59:10 am
this is my thread so i can keep changing ( jacking) subject right LOL anyway if you do a pop test and you get the correct psi or bar what else has to be looked at on the injectors? i've taken some apart on a parts car to get running and put back together (no test) just to clean, was easy job just tryed it. didn't see advantage on that set.
Title: inj pump runaway
Post by: smutts on September 05, 2008, 10:46:24 am
Quote
what a wierd setup


You never had a Renault 16 then? :D
Title: inj pump runaway
Post by: Vincent Waldon on September 05, 2008, 11:27:53 am
Quote from: "Duster 5.9"
if you do a pop test and you get the correct psi or bar what else has to be looked at on the injectors?


- do they have a uniform and consistent spray pattern ?
- do they snap open and closed cleanly ?
- do they dribble after they close ?
- do they hold pressure ?



Pretty good injector:

http://www.youtube.com/watch?v=7jXX_rGqgGo&NR=1


Pretty bad injector:

http://www.youtube.com/watch?v=JQ3uR99SPfA&NR=1
Title: inj pump runaway
Post by: Tintin on September 06, 2008, 08:00:24 am
Just by curiosity, where you get this rebuilt pump?
Title: inj pump runaway
Post by: Duster 5.9 on September 06, 2008, 08:21:08 am
emiata, not saying there no good, just this pump is not working for me and right now i don't need it or the headache of it.
Title: inj pump runaway
Post by: 4KTD on September 06, 2008, 10:24:50 am
Quote from: "Duster 5.9"
emiata, not saying there no good, just this pump is not working for me and right now i don't need it or the headache of it.


Funny... I got my reseal kit from them, some of the o-rings (made in China of course) weren't the exact size.  Some weren't even close and my pump leaked and I had to take it out and put back some old o-rings.
We sure got what we paid for.