92 Plimouth Colt Vista

rlp in Co. · Jan 28, 2022

Well, I think maybe the computer went bad. The problem is when you floor the gas pedal, the engine goes full power and then nothing over and over. I first thought it was starving for gas but I checked and it pumps a couple of cups in only seconds. The pressure is at 45 pounds even when the motor cuts out. The voltage to the coil is good even when it cuts out. The signal from the distributor is good even when it cuts out. The voltage on an injector goes to zero when it cuts out! So I think it's the computer right? I unhooked the knock sensor and the oxygen sensor and it made no difference.There are three vacume lines going to the intake plenum that I don't know what they do. Any suggestions?

rustytractors · Jan 28, 2022

If you are doing this with no load as not in gear it is called a rev limiter. Just my guess!

Janicholson · Jan 28, 2022

It has OBD-1 type CPU readout. The link explains how to read the CPU fault codes. Jim
COLT codes no reader needed

Steve@Advance · Jan 28, 2022

Check the air duct between the throttle body and the air cleaner box.

I've seen them rip open down in the bellows ribs, when the engine torques against the (possibly broken) motor mounts, it opens the rip and allows unmetered air to enter, leaning the mixture.

Also try pulling on the wiring harness, the same as the engine would when the mounts flex. Could be a broken or shorting wire.

RWT · Jan 28, 2022

On a 85 Dodge turbo Omni I think it would idle and would cut out at high idle. It would start to die and come back before it did.

I own a good scanner but it was the MAP (manifold absolute pressure) sensor. When the vacuum got too high it would cut out until it dropped lower.

You really need to scan it. I actually have the old cables and that's what is needed on something that age.

Since that is a old mopar if you turn the key on and off 3 times ending with the key on it will flash the check engine light to give you the codes. Like 1 flash, hesitate and then 2 flashes is 12 and I think it might flash that. I think that one is the power has been unhooked. A 55 is end of message.

That's also old enough it will erase the codes if you unhook the battery. This is just a thought.

RT

rlp in Co. · Jan 29, 2022

Thanks very much for that link. I will try to read the codes tomorrow.

rlp in Co. · Jan 29, 2022

It does seem like a bad wire or connection. Thanks for the suggestion.

rlp in Co. · Jan 29, 2022

I didn't know that it would blink the codes. Thanks! I ordered a manual but it will be a while before it gets here.

rlp in Co. · Jan 29, 2022

Well, I checked the codes today. I found out that they are close to impossible to read with a digital meter, but very easty to read with an analogy meter. The code was one long and two shorts, which is air flow sensor. I will try to figure out what's wrong later.
I'm glad I don't have a new car that you have to take in to read the codes!

Hobo,NC · Jan 29, 2022

Nuttin to lose unplug the sensor and see how it runs.

92 Plimouth Colt Vista

rlp in Co.

Well-known Member

rustytractors

Member

Janicholson

Well-known Member

Steve@Advance

Well-known Member

RWT

Member

rlp in Co.

Well-known Member

rlp in Co.

Well-known Member

rlp in Co.

Well-known Member

rlp in Co.

Well-known Member

Hobo,NC

Well-known Member

Similar threads