My 87 NA is still having trouble with bucking at cruise and stuttering hard on acceleration.

It's definitely running lean, as the engine heats up alot, haven't overheated it yet, but it goes from a lil less than a quarter to almost a half when accelerating and hesitation. Sometimes it works fine, others it doesn't.

I've replaced:
Fuel Pump
Fuel Filter
Pressure Regulator

I've checked the harness to see if it's grounding out anywhere. So far I've found nothing. Will the ECU throw a code even if the Check Engine light doesn't come on?

Sticky Injectors? I thought maybe clogged cat, because the car came with a cat, but no air pump to give it fresh air. But it's not like the thing is glowing or anything after driving forever.

Anyone have any more ideas?

 

Oh also, if the OMP is not working, will that give me trouble? Could I be losing compression with no seal if the oil isn't getting in there?

Of those 4 little lines coming off the front of the engine, then kind of dissapearing around the manifolds, 3 of them have oil in them and one of them is bone dry.

 

TPS out of adjustment?
Typical3800 hesitation?

I had a similar problem and got rid of it by going standalone (microtech).

 

This isn't a typical 3800 problem... and I don't think it would be a TPS adjustment, maybe a replacement? It's cutting out at all RPM ranges, all the way to red line (yea I had to check it ) It sputters and kicks, jerks and hard hesitation. Like no fuel or no spark, or no nothing.

I'd love to go standalone on all my vehicles but right now, driving 10 miles without this problem would be nice.

Also, it only seems to do it after car has reached running temp. Water Thermo sensor is broken off. But it has been for the entire time I've had the car, this problem just started after I had already put 5-600 miles on it.

 

Update....

I tried hooking up some LEDs to see if the ECU is shittin any codes. I followed the instructions on http://fc3spro.com/TECH/HOWTO/ERRORC...KI/zerror.html and neither of the LEDS would light when I turned the key into the ON position. They work on the battery, but not in the check connector.

The LED's were 12V 60mA Red LED's. Could my CPU be trashed?

 

Sounds like the problem i was having...
Unplug your o2 sensor and see if it goes away.
If so, replace.

 

might wanna look into gettin an injector flush- sounds similar to my problem
could possibly be sticky injectors

 

Tried this, didn't work. Even made sure to unplug battery and crap first to make sure it would "clear" any memory that it doesn't have.

 

injector flush?? can i put injector cleaner into my gas? I thought I read somewhere on here that fuel injection cleaner is bad for our cars?

I was planning to try switching the primaries and secondaries and see if that solves the problem short term....

 

sure sounds like a fuel problem, have you checked the fuel line pressure? You just need a piece of hose, a t-fitting and a 20 dollar gauge from autozone or what have you. I know you replaced the regulator, pump and filter, but there could be some kinda blockage somewhere in the line that isn't obvious.

I would check your ignition system too, you could be having some kinda ignition breakup.

I think the guy talking about cleaning ur injectors meant to send them to a shop to get em cleaned. I used www.cruzinperformance.com for mine when I did my rebuild. if you don't want to wait a little over a week you could prolly find a local shop that will give similar service.

 

How long will the fuel stay pressurized in the system? When I popped the regulator off(4.5 hours after I had last driven it), there was little to 0 pressure inside the fuel rail.

 

Any updates?--I have the exact problem have yet to gigure it out.

 

Yea. I did the grounding. Worked like a charm as far as the fuel problem went. Put a new water thermo sensor in and the cold start problem went away.

Other than some exhaust work that needs to be done, she's running great.

 

man, i know how you feel i have problems with my 87 N/A as well....my clutch master isent keeping pressure (think its the steel line leaking) idle pulses, shutters sometimes at take off, too much play in the clutch & gas pedal, its alot of work, but i think that once you get her done its so much joy to know that you did it yourself....it also sucks that i get out of work at 6:00pm and theres no time to work on her, bacause its already dark when i get home...i wish i had a garage....everytime i see her just sitting there it makes me sad....anyway, good luck with getting it running and problem free....

 

Bump

I have the same problem...not sure on the amperage of my LED's but they are 12v and look exactly like the ones pictured in the walkthrough. I got them at RadioShack. Pupil, do yours work now that you fixed your grounds? That's on my list of to-do's.

 

Mine worked even before grounding, but only at night lol. I was getting the water thermo code (figures, i already knew that was a problem) and the first blip was so faint it was impossible to see... the next 2 shined brightly.

I would recommend lower amperage LED's. The ones I got are pretty el cheapo. They just need way too much power.

If you really want to check it, connect it to a multimeter. Not a permanent connection, but it'll work.

 

Just FYI, but if the water thermo sensor is busted/disconnected, the ECU sees a default of 176*F.

The ECU has a fuel map for the start cycle. It's dependent on three things. The output of the water thermo sensor, rpm less than 500rpm and seeing 12vdc when the key is to START.

When it sees a temp of 176* degrees F the fuel injectors will stay open approx 6-10 milliseconds. If it sees a temp of say 40-50*F, the injectors will stay open 45 milliseconds give or take.

So, you can see what happen to you. There was not enough fuel being injected when the engine was cold. After you got the engine up and running and hot, then you didn't have the problem because the water thermo was defaulting to 176* which is close to running temperature so there was no problem when the injectors stayed open only 6-10 ms each time they injected during START.

 

I had this same problem with my V-8 van a couple months back and it got progressively worse. At first I thought it was my overdrive solenoid shorting out cause it only happened in the shift to overdrive and especially in rainy weather. It would buck very violently until I either backed off the throttle or the van got up to speed; I thought the van was intermittently disengaging from final gear causing the bucking. But then it started happening in lower gears and at lower speeds...

Solution? Spark plug wires were bad and some were arcing to ground causing "misses" under load; The rain helped increase condutivity. Swapped out wires and problem went away - fuel economy and power improved too. ~rich

 

One thing you mentioned. Your OMP is broken!!!

I hope you are premixing. If not you are going to need a rebuild soon. Without the lubrication you'll start losing compression.

 

Whose OMP?? mine?? because of that empty tube?

 

Well you said it's not working......

So if it's not working then you engine isn't getting lubrication.

If one is dry I bet the others aren't doing very well either.

 

I put quite a bit in during one of my last fill-ups.. i guess i should make this a regular thing... i guess you can't have TOO much oil? just not enough?

 

Well,I got the prblem fixed at least on mine and don't tell me how it fixed it.
I wired the ports open a while back hoping that did nothing.Well today after changing the ecu,the injector solenoid and the main relay--that did nothing,I was trying to figure out what we changed or took off of the last 2 motors we put in.I have had this problem forever.
We added a rb header but I had no backpressure line--hince why I have ports wired.
We capped off the place where that hose goes to the motor.I took it off today --the idel changed and went up a couple hundred rpms.I screwed around with the idel,and got it where it should be.Took it out and damn if she doesn't run perfect now.The the small hesitation at 3600(normal)no more stalling,hesitating.
Unbelievable that that line that I had capped would cause all these problems.
So check your line.


>edit: signature removed for size violation

 

Mine doesn't have an idle problem anymore, that was 100% due to the thermo sensor... Think I'm down to exhaust leak, 5/6 ports, and OMP....