1988 Engine Missing Under Load.
Thread Starter
Melting Slicks
Joined: Jul 2002
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From: Upstate Driving a sweet 89 Iroc
1988 Engine Missing Under Load.
Fist off, I did the search and have not come up with the excact problem I seem to now have.
Took the car out for the first time a couple of weeks ago and it works great.
I drive in to work last night for the week ( I work away from home during the week) and the car starts to misfire under load. Runs a little ruff on idle, and when cruising, but under load really shudders and seems to be missing.
I did put fuel stabilizer in last year, filled up with 92 octane this year so don't think it is the fuel.
Had the MAS changed 1 1/2 years ago, along with the ECM, so don’t' think it is this.
Spark plug wires were changed 2 years ago with the plugs changed about 3 years ago (30,000 miles ago).
So, Going to do a complete tune up tonight as well as some Octane boost for incase it is the gas.
I did read on an earlier post that the torque converter might be acting up. How would you diagnose a torque converter?
Thanks guys.
Kyle
Took the car out for the first time a couple of weeks ago and it works great.
I drive in to work last night for the week ( I work away from home during the week) and the car starts to misfire under load. Runs a little ruff on idle, and when cruising, but under load really shudders and seems to be missing.
I did put fuel stabilizer in last year, filled up with 92 octane this year so don't think it is the fuel.
Had the MAS changed 1 1/2 years ago, along with the ECM, so don’t' think it is this.
Spark plug wires were changed 2 years ago with the plugs changed about 3 years ago (30,000 miles ago).
So, Going to do a complete tune up tonight as well as some Octane boost for incase it is the gas.
I did read on an earlier post that the torque converter might be acting up. How would you diagnose a torque converter?
Thanks guys.
Kyle
Race Director
Joined: Mar 2003
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From: Eustis ( Area 51 Bat Cave ) Fl
Re: 1988 Engine Missing Under Load. (88BigGuy)
My ex girlfriends car did that, I changed the plug wires and it fixed it, with these new computer cars it's harder to pin down or is it I'm new to the c4 thing but can't you get the codes from it and it will tell you what's wrong.... Could be ignition or fuel system in the old days....a plugged fuel filter did that once to a VW kitcar I had....
Best of luck,
:thumbs:
PS, I forgot in my 78 camaro did something like that it was the module in the dizzy....
[Modified by The13Bats, 9:05 AM 5/5/2003]
Best of luck,
:thumbs:
PS, I forgot in my 78 camaro did something like that it was the module in the dizzy....
[Modified by The13Bats, 9:05 AM 5/5/2003]
Thread Starter
Melting Slicks
Joined: Jul 2002
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (The13Bats)
OK, changed the Dist, Cap, Plugs, and wires, but still have the same problem.:mad
I did notice that one of the MAS relays that were "suposed" to have been changed when I got the MAS relaced looks really old. I did not check this when I got it back two years ago.
Could this be my problem?
Also, I have an apointment to change the gas filter on thursday, along with the O2 sensors(sp). I have not changed the filter or sensors since just after I bought the car, 4+ years ago.:bb
Thanks.
I did notice that one of the MAS relays that were "suposed" to have been changed when I got the MAS relaced looks really old. I did not check this when I got it back two years ago.
Could this be my problem?
Also, I have an apointment to change the gas filter on thursday, along with the O2 sensors(sp). I have not changed the filter or sensors since just after I bought the car, 4+ years ago.:bb
Thanks.
Race Director
Joined: Mar 2003
Posts: 11,608
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From: Eustis ( Area 51 Bat Cave ) Fl
Re: 1988 Engine Missing Under Load. (88BigGuy)
The fuel filter could do what you have going on, 4 years is kind of long for the same fuel filter...I bet it's full of funk either way....I will have to leave the opinions on the O2 sensor and MAS to new school people I'm still kind of jarassic when it comes to the computer stuff, but I'm learning. don't know if you have Auto Zone parts stores where you live but here in Orlando they will check the computer codes for you and tell you what's going on for free to sell you the part you need, everytime I'm in the parts stores I see signs talking about how important it is to change the O2 sensor for a good running car I thought it was a selling tactic but maybe it has some truth behind it...
C. :thumbs:
C. :thumbs:
Team Owner
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: 1988 Engine Missing Under Load. (88BigGuy)
Are you getting any SES lights? Check your fuel pressure also, did you change the rotor in the distributor?
Thread Starter
Melting Slicks
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (vader86)
Thanks so far guys,
We do not have an autozone around here (Canada sucks for stuff like that).
Yes, did change the rotor, sorry forgot to mention that as well. No SES lights on the dash.
7 of the plugs were a nice chocolate brown, so running clean, I think it is the MAS screwing with me again.
1 plug was just a slight shade darker than the rest, maybe a fuel injector? THis would mean that one cylinder is running just a little rich right? Can a Electronic Fuel Injector get stuck open?
There is lots of good hints on the forum for how to test the injectors, maybe do that on the off colored plug tonight.
We do not have an autozone around here (Canada sucks for stuff like that).
Yes, did change the rotor, sorry forgot to mention that as well. No SES lights on the dash.
7 of the plugs were a nice chocolate brown, so running clean, I think it is the MAS screwing with me again.
1 plug was just a slight shade darker than the rest, maybe a fuel injector? THis would mean that one cylinder is running just a little rich right? Can a Electronic Fuel Injector get stuck open?
There is lots of good hints on the forum for how to test the injectors, maybe do that on the off colored plug tonight.
Team Owner
Joined: Sep 2001
Posts: 62,127
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 1988 Engine Missing Under Load. (88BigGuy)
Unplug the MAF sensor, and see if it runs any better.
Yes, if one plug looks a little different, it can indicate that the injector above it is going out. You can have them all cleaned by CruzinPerformance or buy some Ford SVO injectors.
Yes, if one plug looks a little different, it can indicate that the injector above it is going out. You can have them all cleaned by CruzinPerformance or buy some Ford SVO injectors.
Thread Starter
Melting Slicks
Joined: Jul 2002
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (vader86)
I did the unplug on the MAS and it ran the same, except seemed to smell like it was running rich. So maybe not the MAS, but the injectors.
OK, Ford SVO injectors, but I just had mine changed less than 4 years ago. :sad:
I did get a new butt out of the last injector change, charged me $150CND/Injector, plus labour. I now see you can get a whole set for under $300 USD and I can install them myself :mad
One last question, does anyone have a part number for the Ford SVO injectors. I have a friend who works for a Ford Dealership who might be able to get me a deal on the injectors. :yesnod:
Thanks guys.
[Modified by 88BigGuy, 2:47 PM 5/6/2003]
OK, Ford SVO injectors, but I just had mine changed less than 4 years ago. :sad:
I did get a new butt out of the last injector change, charged me $150CND/Injector, plus labour. I now see you can get a whole set for under $300 USD and I can install them myself :mad
One last question, does anyone have a part number for the Ford SVO injectors. I have a friend who works for a Ford Dealership who might be able to get me a deal on the injectors. :yesnod:
Thanks guys.
[Modified by 88BigGuy, 2:47 PM 5/6/2003]
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Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: 1988 Engine Missing Under Load. (89vette)
Hmmm, only other thing i can think of that wouldnt set a code are TB problems (TPS, IAC valve) or maybe a clogged cat.
Racer
Joined: Nov 2002
Posts: 471
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From: Queens NY
Re: 1988 Engine Missing Under Load. (vader86)
i have the same problem with my vette.. an 86. i was told the module in the distributor might cause the same problem otherwise i'd also guess fuel pressure, let me know if it runs any better with a new filter
Thread Starter
Melting Slicks
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (CarAteMyMoney)
:lolg: CarAteMyMoney :lolg: Your screen name kills me!
You actualy got me to thinking about my work on the vette last night.
When I change the rotor, the old one and new one seemed to be loose on the shaft, like there was some play in it. I checked the old one and the bolts were tight, but I was able to jiggle it on the shaft.
I just assumed this was for timing advancement, is this true, or is there a possible issue with my distributer shaft?? :skep:
You actualy got me to thinking about my work on the vette last night.
When I change the rotor, the old one and new one seemed to be loose on the shaft, like there was some play in it. I checked the old one and the bolts were tight, but I was able to jiggle it on the shaft.
I just assumed this was for timing advancement, is this true, or is there a possible issue with my distributer shaft?? :skep:
Burning Brakes
Joined: Mar 2003
Posts: 1,174
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From: NW MN
Re: 1988 Engine Missing Under Load. (88BigGuy)
Did you replace your coil when you did your tune-up? My 86 had the same symptoms you describe and I replaced everything like you did and still had a misfire. I replaced the coil and all was good. :thumbs:
Good luck!
Good luck!
Drifting
Joined: Jul 2001
Posts: 1,751
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From: Miami, FL, USA
Re: 1988 Engine Missing Under Load. (86Pacecar)
I would check the coil, ignition module, timing, and the wires at night (look for sparks). The fuel filter, fuel pump, and fuel pressure would be next. Its strange that it doesnt throw a code though....have you checked you catalytic converter?
After the tune-up, you should have reset your ECM to re-learn the car, did you do that?
After the tune-up, you should have reset your ECM to re-learn the car, did you do that?
Thread Starter
Melting Slicks
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (GusBustamanteJr)
Went back and reviewed the removed spark plugs, and noticed one was not the same color as the rest :nonod: ,is the damn injector stuck open :confused:
So, got the car into a mechanic today, he called back and said that the injector is fine, he can hear it clicking open and closed with a stethascope(sp). He is confident that it is working fine.
He said he noticed that there was engine coolant on the back of the motor. He seems to think one of the gaskets has let go, and also thinks this might be my missfire problem, as the cylinder might be sucking in coolant or oil.
He explained it better than me, but it sounded logical, so for $550+tax (canadian) he is going to change the gasket. Even if it does not fix the misfire, it will fix the coolant leak.
I have heard nothing but good from people about this mechanic, but what do you think of what he told me.
So, got the car into a mechanic today, he called back and said that the injector is fine, he can hear it clicking open and closed with a stethascope(sp). He is confident that it is working fine.
He said he noticed that there was engine coolant on the back of the motor. He seems to think one of the gaskets has let go, and also thinks this might be my missfire problem, as the cylinder might be sucking in coolant or oil.
He explained it better than me, but it sounded logical, so for $550+tax (canadian) he is going to change the gasket. Even if it does not fix the misfire, it will fix the coolant leak.
I have heard nothing but good from people about this mechanic, but what do you think of what he told me.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
Re: 1988 Engine Missing Under Load. (88BigGuy)
A visible coolant leak would be from the intake manifold; not the head. A leaking head gasket can showup as rust on the spark plug or (if it's really bad), a clean plug. If the head gasket is completely shot it'll do more than miss under load - idle will be horrible, engine will backfire & a host of other problems will be evident too, but a small leak can cause the symptoms you describe and with the different color in plugs, appears you have something more than a manifold leak. $550 for a manifold & head gasket job is a good deal.
Thread Starter
Melting Slicks
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From: Upstate Driving a sweet 89 Iroc
Re: 1988 Engine Missing Under Load. (SunCr)
So, the price is right, I will let you guys know what is the result after the mech is finished.
PS, I forgot to mention one of the workers at the garage drives a beautiful C3, chrome bumpers front and back so at most a 1971?? :cool:
PS, I forgot to mention one of the workers at the garage drives a beautiful C3, chrome bumpers front and back so at most a 1971?? :cool:
Race Director
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From: Eustis ( Area 51 Bat Cave ) Fl
Re: 1988 Engine Missing Under Load. (88BigGuy)
The intake bolts run into galleries, in the case on my 86 the front to intake boltsdrivers side were leaking the front one coolant the second one oil, this is caused when the person who assembled it didn't put sealer on the bolt threads, I fixed mine in 30 minutes driveway style by putting the two bolts cleaning them, putting good silicone sealer on them and putting them back and retorquing them, like I said this is a driveway fix, 550 to do the whole intake which doesn't look like a fun task is a bargain for the piece of mind it will give you if it is leaking coolant.... :yesnod:
Safety Car
Joined: Feb 2002
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From: Sun City West Az
Re: 1988 Engine Missing Under Load. (88BigGuy)
So, the price is right, I will let you guys know what is the result after the mech is finished.
PS, I forgot to mention one of the workers at the garage drives a beautiful C3, chrome bumpers front and back so at most a 1971?? :cool:
PS, I forgot to mention one of the workers at the garage drives a beautiful C3, chrome bumpers front and back so at most a 1971?? :cool: