Secondaries fixed...but new problem

[Mahogaraunch]

I recently had all 16 injectors replaced with the rebuilt injectors from FIC. The car is awesome and powerful. The only problem is after about 10 to 15 km's of driving, the car suddenly has difficulty with acceleration. so much so that I had troubles climbing a hill. The car would lurch and when I accelerate slightly, the car feels like it is bogged down. The engine sounds like there is a lack of fuel getting to it. I pulled over, turned it off, and restarted it. After that, the car would drive perfectly again, that is until 10 or 15 km's down the road when the same thing would consistently occur.

I am thinking its a fuel pump issue, but I have no clue. This happens on both normal and full mode.

Thoughts?

[tomtom72]

You are not seeing the SES light wink at you are you?

If no SES light then it could be fuel pressure/fuel volume issue related to pumps and or filter. A KOEO fuel pump test could be a good thing to do and check up on when the fuel filter was last replaced.

Then there is this. Please do not take this the wrong way as I'm not trying to slander any one. Did you buy the new or rebuilt injectors? I ask because my first thought was this sounds like a couple of primaries crapping out on you. It is not a frequent thing, but with the FIC rebuilt injectors some have had failures with them randomly.

I would do a f/p test, check the spark and check the f/filter and if all that is okay it really only leaves the injectors & their wiring as likely suspects in the absence of no SES light either being set or winking at you.
JMHO

Tom

[tccrab]

Originally Posted by Mahogaraunch

<snip>
The only problem is after about 10 to 15 km's of driving, the car suddenly has difficulty with acceleration. so much so that I had troubles climbing a hill. The car would lurch and when I accelerate slightly, the car feels like it is bogged down.
Thoughts?
<snip>

Boy does this sound familiar.
Runs OK for a while, then when the motor gets to operating temperature it starts cutting out.
Shut it down and cool it off for a little while and problem goes away, only to come back a little while later.
Yup.
Sounds all too familiar.....................
Read here:
http://www.zr1.net/forum/showpost.ph...11&postcount=1

TomC
'Crabs

[Mahogaraunch]

Well, I should have mentioned but there were no warning lights on the dash. The fuel filter was replaced a few weeks ago and the plugs were replaced in '06, which was less than 1000 miles ago. The injectors I replaced were the rebuilt ones. If there was a problem with the replacement injectors then would the issue not be constant other than every 15 or 20kms? Its like clock work when the car would sputter.

I can't imagine it is a heat related issue because when the car was bogged down, i pulled over, turned it off, and literally 10 seconds later started the car and had full acceleration again, that is until the next 15 or 20 km passed.

I can also hear in the rear of the car a slight whining noise which is similar but not as loud as a Tahoe that I once drove for work that had fuel pump issues.

thanks for the advice.

[tomtom72]

well okay here is what I have observed with the people that have used the rebuilt FIC injectors and have had trouble out of the box. That's not many I might add as I'm not throwing rocks here.

It usually turned out to be the coils shorting out. The reason for the coil shorting out is usually fuel penetration, however I have never seen any analysis on what the cause actually happened to be from FIC. I doubt that they do any exams & just send out replacements.

My reasoning for saying injectors are my chief suspect is that when the coils start to short out it usually takes some heat to produce the symptoms of a miss fire. The heat builds over time, and I figure that is why the FSM says to ohm out the injectors when hot. I figure when they cool enough they behave normally until the temperature gets too high and they start to short out again. This kind of matches your symptoms if only a bit. Usually once the coils short they will start to get less tolerant to heat and the miss starts sooner.

I have a 90 so when my OEM injectors failed it was the coils and the symptoms were almost the same. The period of missing and then cool down was not as pronounced as yours is, but the rest of the driveability symptoms match fairly well when my primary injectors started to fail. You could wait for the symptom to appear & ohm them out, or you could go for a ride with a scanner connected and observe the fuel numbers, when they start to drop out if they do the O2 cross counts and the integrator numbers should be the tell tale. Or when it starts to miss, get out and smell the exhaust. If it makes your eyes water she's dead lean.


Tom

[ZR1@gmx.com]

Sounds like the primary fuel pump may be bad... When the car starts it runs on both for 10 minutes i believe then the secondary shuts off.

[Aurora40]

Originally Posted by ZR1@gmx.com

Sounds like the primary fuel pump may be bad... When the car starts it runs on both for 10 minutes i believe then the secondary shuts off.

I don't have my manuals anymore to confirm, but I *believe* that is only on a cold start, and the secondary turns off at a certain coolant temp. He's only turning his car off for 10-15 minutes.

Definitely putting a fuel pressure gauge on there, then driving it until the symptoms occur would be good.

Tom's pin issue is also interesting, did you ohm test the injectors prior to replacement through the wiring harness?

[Mahogaraunch]

I did not test them as I had a garage install the injectors. They probably didnt test them themselves. I have driven the car with bad injectors and they way it drives now is nothing like it drove when the bad injectors were in. I'm sure we have all ran out of gas at one point or another, and know the feeling of the car as fuel is not getting to the engine. It feels just like that, as if the tank is empty. But, I turn it off, and after 10 seconds I start it and it has absolutely no issues until another 10 or 15 kilometers down the road.

[Jagdpanzer]

On my 94 both fuel pumps run after initial strart up until 173-175 degree F coolant temp is reached then the 2nd fuel pump is cut off. After that the 2nd fuel pump comes on again in conjuntion with the secondary fuel injector operation or for a few seconds after the engine is restarted with coolant at running temp.

[Mahogaraunch]

Booya... garage replaced one of the fuel pumps and apparently the car works like a dream. It was about to rain today when I picked it up so I couldnt take it for a real drive. A bird **** right on my hood which pissed me off, however the poop is gone and its safe once again under a cover in my garage.

Thanks for the tips.