Starting Problem - 1988 Toyota MR2

toyota
mr2

#1

I have a twenty year old 1988 Toyota MR2 that I am trying to keep going. My rust warranty is still active, but it will expire in two months if I can?t get it into the shop for its annual rust-proofing. And there?s the rub. The car won?t start.



A few days after I had a new muffler installed, the car started to start funny. It would turn over and briefly fire but within a second it would stop. Eventually, when I tried again, it would start and continue running. Once it ran for a while, it seemed to restart okay. After a few days of this balky starting it finally refused to start at all.



The mechanic at the garage said the injectors were not getting a signal to send the fuel on its way. He also said the distributor was not sending a signal to the injectors. After replacing the distributor, the car still didn?t start even though the distributor was now emitting a signal, according to the mechanic.



Next the mechanic said he was 90% sure the computer needed to be replaced. But installing a different computer didn?t work either. When I later spoke to the garage owner, he also didn?t know what was wrong. He refused to give me an estimate. Instead he essentially offered me the opportunity to continue to buy a pig in a poke. I said he should put in a little more time, but now two more weeks have passed and he still hasn?t fixed the problem nor told me what is going on.



What is causing the starting problem? Is it possible that something went awry when the new muffler was installed, or is it just a coincidence that the starting problem happened so soon thereafter? If you have any ideas as to what needs to be done to fix this, I would really appreciate it.


#2

On a car this age it could be anything. Since it ran for a few days after getting the muffler installed, I suspect the timing of the failure is just a coincidence.

You need a new shop. This guy is throwing parts at it at your cost. Simply put, any credible shop would check to see if you’re getting spark, a simple test, and if you are the shop would look next at the fuel supply, also a simple check.

If you were not getting spark, a shop will look for the 12VDC signal at the coil primary (preferably with a scope, because it’s a square wave) and work back from there. If there’s no 12V, keep backing up the system. If there’s 12 VDC constant, start looking at the distributor (that turns the 12VDC on and off).

Now, if he’s done that, if the description he gave you is accurate, and the injectors are getting a signal and activating, then he should be looking at the fuel supply…the fuel pump and regulator.

If I’m right about this engine, the injectors aren’t controlled by the distributor. They’re controlled by the ECU based on signals from the MAF, the MAP, the temp sensor, the CPS, the CSS, the O2 sensor, and the throttle position sensor. The spark is the only thing controlled by the distributor.

Any competant shop should be able to solve this.