Help no one can fix my 88 4Runner

1988 4Runner sr5 3.0 3vze. I have taken this vehicle to 5 mechanics. No one can figure out what’s wrong.
Here are my symptoms
1.Starter works most of the time (it’s new) but when parked on a decline I notice I have to tap on it to get it started
2. Sometimes out of nowhere I wil start my car and it will start but it’s starts stuttering and I have to give it gas to keep it going. Makes popping and gasping sounds.other times starts right up .
3. Sometimes out of nowhere I’ll start it it wil run for a second and then stall like it can’t hold the idle at 800 rpm . Other times it’s perfect
4. Sometimes it stalls in reverse and when idling at traffic lights.
5. Sometimes when going up a steep hill I can’t get it up to 4000 rpm (55 mph)
Oh and this was happening with original engine and now happening with brand new engine

My guess is a faulty fuel pump maybe? Like sometimes it’s working and sometimes it is not

Anyone have an idea? Thank you in advance

 

I’m sure someone will be along shortly with more info, but I’ll toss a few ideas out that may help narrow it down from dealing with other vehicles over the years.

Starter, is it correctly shimmed if this model uses shims? Also it could just be defective, as its mechanical, even new they can be bad.

the stalling and struggling to run, could be the fuel pump, fuel rail, or injectors, again all mechanical in nature.

the other side of the coin, how are the vacuum line and fuel lines, you said new engine, are they all in good shape, not pinched or collapsed, no air or pressure will shut it down as quickly as no fuel.

 

Sounds like bad ground connection somewhere. Electrical gremlins are very hard to find when intermittent. Fuel pump would have nothing to do with tapping on starter. You may have SEVERAL PROBLEMS.

 

Injectors and fuel rail are good I’ve been told . Fuel pump I’m not sure. I’m not a mechanic but this vehicle is actually teaching me a lot. As for electrical I have no idea where to start. Thank you

 

Tough problem. Start with all engine, chassis ground connections you can find. Also computer grounds. It may have a break [bad crimp/corrosion] right where wire end goes into eyelet. Sometimes hard to see problem hidden under wire sleeve.

 

Thank you so much

 

The running troubles could also be the airflow meter. I had symptoms with a 1988 22R-E which uses a similar meter. The ‘butterfly’ had slight binding, which went away after I sprayed WD40 on the pivot points, too and bottom. It’s a quick thing to try.

 

Did you open up the airflow meter to spray it . Because the plate on top seems to be glued on shut?

 

Careful what you spray on airflow meter, they can get ruined pretty easy with some substances. Most I have ever done is sprayed brake cleaner on rag and wiped down where I could see and only used compressed air. If it is to gummed up I would of thought, it would of set code. Your described symptoms still to me sound like ground issues.

 

Thank you all for your info you have given me a good place to start

 

Another member had similar issues in regards to how it runs and they replaced the Main EFI relay and it solved their issues.

That of course will not help solve your starter issue.

 

I pulled the intake hose off, looked inside and manually moved the butterfly back and forth to get an idea where the pivot points were, and sprayed sparingly. I agree with jeepster09 to be careful. I had no codes to work with, and my diagnosis and research had me at the point where I was ready to replace the airflow meter. Those were around $500 at the time, so I had reached a what-do-I-have-to-lose standpoint. In my case, that resolved the problem.

 

Have seen an errant magnolia leaf on the filtered side of the air intake blocking the sensor and caused all types of odd issues.

 

Thank you I will check all this out

 

a car needs 2 things to fire up. Gas and spark. Id go right to those and troubleshoot/replace. You could also ahve a clogged fuel filter at the pump or inline if yours has one of those.

 

When ever it doesn't make sense and you can't find the issue. It's a bad ground.